TREATISE 
 
 O N 
 
 BUILDING in WATER: 
 
 IN TWO PARTS. 
 
 PART I. 
 Particularly relative to the Repair and Re- 
 building of Essex-Bridge, Dublin, and 
 Bridge - Building in general ; with Plans 
 properly fuited to the Re-building of Or- 
 mond-Bridge. 
 
 PART II. 
 Concerning an Attempt to contrive and intro- 
 duce quick and cheap Methods for erecting 
 
 TO WHICH 
 
 P A R T III. 
 feTiBERNiA's Free Trade ; or, A Plan for 
 the general Improvement of Ireland: pecu- 
 liarly adapted for Improving the Commercial 
 
 fubfiantial Stone Buildings and other Works, 
 in Frefli and Salt Water, Quaking Bogs or 
 Morafles, for Various Purpofes ; fully laid 
 down, and clearly demonft rated, by Twelve 
 Practical Propositions, but not in any 
 Cafe exceeding Ten Fathom deep: Together 
 with a Plan for a fpacious and commodious 
 Harbour for the Downs in England, pro- 
 jecting to Twenty Feet deep at low Water. 
 
 EDITION. 
 
 IS ADDED 
 
 and Landed Intereft of Ireland ; and briefly 
 demonftrating, that not only Great Britaini 
 but the whole Britim Empire, may gain 
 proportionable Advantages thereby. 
 
 THE SECOND 
 
 Uluftrated with Sixty-four Copper-Plates* 
 
 By GEORGE S E M P L E> 
 
 Bid Harbours open, Public Roads extend, 
 
 And Temples (worthier of the God) afcend; 
 
 Bid the Broad Arch the dangerous Flood contain* 
 
 The Mole, projected, break the roaring Main ; 
 
 Back to his Bounds their Subject Sea command, 
 
 And roll obedient Rivers thro' the Land : 
 
 Thefe Honours Peace to happy Britain brings $ 
 
 Thefe are Imperial Works, and worthy Kings. Pope's Epift. 
 
 LONDON: 
 Printed for the Author : and Sold by T. Longman, No. 39, Paternofter-j-ow ; J. Almon, 
 No. 178, Piccadilly ; and I. Taylor, No. 56, oppofite Great Turnftile, Holborn. 
 
 M,DCC,LXXX ( 
 
T O 
 
 THE KING. 
 
 S I R, 
 
 YOUR Majefty has been conftantly confidered 
 as the Friend and Patron of the Sciences and the 
 Arts. The eminent Virtues that beam from Britain* § 
 Throne, would have rendered a private Station illuf- 
 trious, and dignified the Scholar and the Man. To 
 whom then can I, with fuch Propriety, infcribe thefe 
 Sheets, as to a Monarch, who is peculiarly interefted 
 in the Subjeft of the moft important Part of them, 
 that of a " Plan for the general Improvement of 
 "your Majefty's Kingdom of Ireland?" I lay them, 
 with the utmoft Deference and Humility, at your 
 Majefty's Feet. They are the Fruits of a clofe 
 and unremitted Application of twenty-feven Years. 
 Should they be thought deferving the flighteft At- 
 tention of your Majefty, or induce any of your Ma- 
 jefty's Servants to think the Plan \ have defigned 
 may be conducive to your Majefty's Service, I fhall 
 think thofe Years the beft employed in my Life ; 
 and, in the Evening of my Days, refled, with a pe- 
 culiar Degree of Satisfaction, I have not lived in 
 vain. 
 
 I am, with the moft dutiful and profound Refped^ 
 
 Your Majesty's 
 Moft loyal and faithful SubjeB and Servant , 
 
 GEORGE SEMPLEe 
 
 b 
 
THE 
 
 V T H O R 
 
 TO THE 
 
 R E A D E R. 
 
 BEFORE I attempt to engage your Attention, I think I 
 ought to apologize for prefuming to treat on Subjeds of 
 fuch great Importance, and far above my Capacity ; I fliall there- 
 fore affign the Caufe of my engaging in them. They were oc- 
 cafioned by a particular Incident that occurred in my conquering 
 all Difficulties in building EJfex-Bridge. 
 
 In the Year 1755, having made a convenient Carriage Road 
 over it, many Gentlemen were pleafed to congratulate me on my 
 good Succefs, amongft whom were feveral of the Right Honour- 
 able and Honourable Commiflioners of the Inland Navigations ; 
 who informed me, that if I chofe to be concerned, they would 
 get me nominated as Controuler of thofe Works, and that my 
 Department fliould be to infpecl into the Works of all the Canals 
 in the Kingdom, to make my Reports to their Board, and to 
 take Care that all the Locks, Bridges, Aqueduds, & € . were ef- 
 fectually executed, &c. I fliall not trouble you any further with 
 this Affair, but only obferve* that after I had been at great Ex- 
 pence, I was fharnefully circumvented. 
 
 In the Winter of that Year, fome very warm Debates happen- 
 ed in Parliament, concerning the Navigation from the Liffey to 
 the Shannon, fome were for the North, and fome for the South 
 Lines. My private Opinion was afked by thofe on both Sides of 
 die Queftion ; but not having applied my Thoughts to any 
 Thing of that Nature, and not choofing to give a raft Opinion, 
 I fct off s and took a curfory View of all the Rivers worth my 
 Notice, between Dublin and Gorki thence to LbmricK and 
 
 traced 
 
( vi 1 
 
 traced the Courfe of the Shannon on thfc ^^/? Side, croffed at 
 Eyrecourtj and came Home by Tullamore and Philipjlown : And 
 on my Return, having compared the Opinions of feveral Gen- 
 tlemen that were employed and had wrote on it ; upon the 
 Whole I was not able to determine which of thofe Lines ought 
 to obtain the Preference ; nor do I to this Day believe, that 
 either of them has been fully confidered ; but I am determined 
 not to depreciate that moft ufeful Improvement. 
 
 Through the Whole of this little Tour, you may depend upon 
 it, that my Imagination did not get much Sleep ; I had Variety 
 of Objects to entertain it, many of them exhibiting rude and 
 doleful Profpe&s through Poverty and Neglecl:, which I hoped 
 would be at fome Time or other taken into public Consideration : 
 And thefe, and the like Thoughts, fpirited me up to give them 
 free Entertainment, and induced me to collect all Kinds of Ma- 
 terials for this Purpofe ; and to that End I frequently revifed my 
 Diary of the Work I then had in Hands, well knowing that ma- 
 ny of the Methods might prove extremely ufeful in future ; 
 and as they had never been publifhed in Englijh, I thought it in- 
 cumbent upon me to depofit them in the Hands of the Public, 
 which led me at leifure Hours, after that Work was accomplifh- 
 ed, to form Schemes and Plans for a general Improvement of 
 the Kingdom, with which I was very well acquainted. But 
 thofe Defigns were foon interrupted ; for the excelFive Colds, 
 and extreme Application to that moft arduous Talk, fell fo 
 heavy upon me, that my whole Frame was, as it were, dillo- 
 cated, and I was difabled from doing any Kind of Bufinefs, and 
 obliged to retire to the Country in a deplorable Condition, and 
 was often fo ill, that I could fcarcely go acrofs my Room, but 
 was particularly afflided with the Gravel and Rheumatifm ; yet 
 I carefully preferved my Notes and Sketches during, the. Space 
 of ten Years, and at length having, in a great Meafure, got the 
 better of fome of my Diforders, I returned to Town, and ac- 
 cording as I found myfelf able, proceeded with Alacrity, and 
 to the utmoft of my poor Ability, engaged in the Firft and 
 Second Parts which now lie before you, as they contained the 
 
 moft 
 
( vii ) 
 
 mod neceffary Matters I could devife, for thofe or the like Pur- 
 pofes, either in this or any other Country. But I muft beg Leave 
 to acquaint you, that from my earlieft Days, I was employed to 
 do Things, and not to write upon them ; for, in Truth, the 
 Whole of my Scholarfhip, except what little I got whilft I was 
 a meer Child, was acquired within the Compafs of fix Winter 
 Weeks, in the thirteenth Year of my Age. Having therefore 
 made this ingenuous Confeffion, I muft hope that your Genero- 
 fity will proted: my humble Work from the Cenfure of ill-natur- 
 ed Critics. However, in order to fhelter myfelf, I was driven 
 to the Neceffity of contriving to delineate my Ideas, rather than 
 to convey them or my Sentiments by Words ; and that is the 
 Reafon of my having gone to the Expence of engraving fo large 
 a Number of Plates for fo fmall a Book : In the Firft and Second 
 Parts of which, the bare looking at fome of thofe Plates will 
 be abundantly fufficient for fome People, as it was for me, when 
 I had the good Fortune of meeting with Colonel Belidores Hy- 
 draulic Architecture, as you will find mentioned in Chapter IV. 
 from which, within the Space of only one Minute, I clearly 
 comprehended the very Thing that I had travelled England in 
 Queft of, to no Manner of Effeft. 
 
 It is generally admitted, that in all the Arts and Sciences, we 
 are at leaft one hundred Years behind the French. Is it not won- 
 derful then, that the Art of working in Coffer-dams fhould be, 
 through the Supinenefs of our learned Gentlemen, totally neglect- 
 ed ? I have related the wretched Situation I was in for want of 
 that Knowledge, which I acquired in fo fhort a Time, by- bare- 
 ly looking at Plate 8, in my Book: And had not Providence 
 thrown that in my Way, I mod certainly fhould have mifcarri- 
 ed in my Attempt, which probably might have coft the City five 
 or fix thoufand Pounds, befides the infinite Difficulties that 
 might attend their ever getting a Bridge efFe&ually built in that 
 Place afterwards. 
 
 Having with fome Difficulties accomplifned thefe two Parts, I 
 found it advifable to poftpone my general Plan for the Improve- 
 ment and commercial Intereft of the Kingdom, well knowings 
 
 c that 
 
( m ) 
 
 that all the Expectations we formerly entertained, of our getting a 
 Free Trade, had dwindled and died away for many Years paft. 
 To what Purpofe then fliould I be at the Trouble and Expence of 
 publifliing a Scheme that did not feem to be fo much as inEmbryo ? 
 But, in the Beginning of the prefent Seflions of Parliament, 3. Free 
 Trade, which certainly we had a Right to derived from Heaven, 
 and which no Kingdom on Earth could legally withhold from 
 us, being granted, I thought it high Time to proceed in that 
 Work ; but as I could not explain the Remainder of my Plans by 
 Delineation, and knowing that it was abfolutely neceffary to offer 
 fome Arguments in the Support of the Rectitude thereof, with 
 Refpect to the Manufacturers and Artifans of Great-Britain, I 
 ufed my Endeavours to throw the beft Things I could devife into 
 the public Scale ; but that Affair went on with fuch Rapidity, 
 and paffed fo fuddenly, that I was not by any Means able to keep 
 Pace with them ; but now, as the Act has paffed, the greateft 
 Part of the Arguments and Allegations I had prepared are ren- 
 dered unneceffary ; yet I ftill think, that as my Plans are of a 
 peculiar Nature, I ought to offer fome Reafons in Support of 
 them, fo that nothing may be omitted that might conduce to- 
 ward the reconciling and uniting both the Affections and Intereft 
 of all his Majcfty's Subjects ; as it is to be ardently wiflied, that 
 fuch a happy Reconciliation may be permanently fettled between 
 them : And with that Intent, I have endeavoured to order my 
 Plan in fuch Manner, as to leave no Room for Complaints, in 
 any Cafe where Reafon fliall be attended to, and followed. 
 But, pleafe to obferve, that I have not ftudied to contrive an 
 Amufement for you, as I thought it would be more ufeful to offer 
 fomething inftructive. 
 
 But, 1 am aware that perhaps I may be fufpected of forming 
 this Scheme, to involve the Nation in an immenfe Expence, to 
 anfwer fome pecuniary Purpofe. Now, to what I have offered 
 above, I think it is neceffary that I fliould declare my true Senti- 
 ments on thefe Affairs, and- that I am entirely difinterefted in all 
 Refpects. I fliall therefore apprize you of the true Principles on 
 which I have formed my commercial Plan, u e. on a well grounded 
 
 Hope, 
 
( i* ) 
 
 Hope, that by our being cftabliflied in a Free Trade, we may 
 give immediate Employment to our Poor, make our Country 
 flouriffi, and exalt the Britijh Empire, and thereby fecure her 
 Colonics and Settlements in future : And that if ever thefe falutary 
 Purpofes are effected, I apprehend it muft be by bringing Eng- 
 land, Scotland, and Ireland, to be considered as one Nation in 
 Trade and Commerce. Woeful Experience has taught us that we 
 ought to be fo ; for if we crofs one another's Intereft, and put 
 Bars and Impediments in one another's Trade and Commerce, 
 we do not only become as it were Foreigners, but even as Ene- 
 mies to one another. The Source from whence thefe Difagree- 
 ments muft flow, may be eafily difcovered by any Perfon who 
 can folve this wonderful Paradox, viz. u That Englijhmen law- 
 €i fully fent over to fupprefs Rebellions in Ireland, fhould, after 
 " having effected the fame, be as it were disfranchifed and lofe 
 " their own Birthright in England, and be obliged to pay Cuf- 
 " toms and Duties as Foreigners for all they fpend in Ireland, 
 " whither they were fent for the Honour and Benefit of 
 " England" — If thefe Matters are not properly considered, how 
 can any Meafures be formed for the Redrefs of the numerous 
 Grievances Ireland has complained of, with Refpect to her Re- 
 strictions in Trade ? I fliall ffiew you in the proper Place, that 
 Ireland alone has more good Ports and Bays, and a larger Coaft 
 than France, our greateft Rival in Trade ; and if it was improved 
 to its full native Capacity, it would be greatly fuperior to her : 
 How then fliall we endeavour to point out the true Intereft of the 
 Britijh Empire, or to fliew how it ought to be purfued ; but by 
 fhewing the ftrong Connection there is between Land and Trade, 
 and putting all the Subjects of thefe Kingdoms on the fame Footing 
 in Traffic and Commerce, and by that Means to cement their 
 true Intereft and Affections together, fo as never to be feparated ; 
 which I propofe to be the principal Bufinefs recommended to 
 your Confideration in the Third Part. And I prefume to entreat 
 you in due Time, to accompany me with pure and unprejudiced 
 Intentions, and to lend your Endeavours to accomplish thefe 
 falutary Purpofes, according as you may think fit. 
 
( * ) 
 
 In my treating on this Subject, I confider it under thefe two 
 principal Heads, the general Improvement, and the commercial 
 Intereft of Ireland ; and each of thefe Heads is alfo to be confi- 
 dered under two other lefs confiderable Heads, which are the interior 
 and the exterior Improvements. All the moft difficult Matters that 
 are to be encountered under thefe two Heads, you will find mi- 
 nutely laid down and explained in the Firft and Second Parts ; 
 and many of the moft important Matters concerning the com- 
 mercial and landed Intereft, you will find briefly ftated in the 
 Third Part ; but to introduce you clearly to the Thread of it, 
 you ought to begin at Seel:. V. page 153, becaufe the Conclufion 
 of that Se&ion leads you into the Third Part ; in which, if the 
 Plan I have therein laid down, is approved of by the Public, I 
 intend (provided my Health permits) to proceed and treat on 
 three other diftin& Matters which may be found neceffary to 
 compleat my Book, either in other Chapters, or as a Fourth 
 Part ; but if my Plan is not approved of or adopted, to what 
 Purpofe Ihould I proceed, as I obferved above ? It is however 
 proper, that I fhould inform you what thofe three other diftincl: 
 Matters are 5 of which 
 
 Firft, To lay down fuch Marks, and other Circumftances, as 
 may guide any intelligent Perfon to choofe proper Sites for either 
 interior or exterior Villages, Towns or Cities. 
 
 Secondly, To treat on effe&ual Methods for colle&ing and 
 managing frefh Water, &c. . 
 
 Thirdly, I propofe to delineate the Plan of a Granary, to con- 
 tain 700 Barrels of Wheat, on the Area of fix teen Feet fquarein 
 the Clear of the Walls, and to keep it perfe&ly fafe for feven 
 Years, if neceffary, by Means of a fimple Engine, and the 
 Work and occafional Attendance of two Boys ; the Expence 
 whereof may be compleated for a very fmall Sum in Companion 
 to other Granaries that have hitherto been built in this Kingdom ; 
 and by the fame Model it may be made to contain more or lefs 
 in Proportion, 
 
CONTENT S, 
 
 P A R T I. 
 
 CHAP. I. 
 
 Concerning the Temporary Repair of Eflex-bridge Page i 
 
 CHAP. II. 
 
 Some Preparatives towards drawing a Defign for a new Bridge, and 
 Obfervations relative to Bridge-Building in general 4 
 SECT. I. Hijiorical Accounts of fome remarkable Stone Bridges in 
 foreign Parts* 6> 
 SECT. II. A Jhort AbfraB from Leon Battista Albert* S 
 SECT. III. ExtraS from the celebrated Andrea Palladio 10 
 SEC T. IV, A fbort Abflrafit from Scammozzi and Sebastian 
 Serlio. 14 
 SECT. V. Brief Accounts of fome of the Stone Bridges in France* 
 and their Methods of building them. %& 
 
 c hap. rn. 
 
 A fuccinB Narrative concerning the re- building of Eftex-bridge. 1 7 
 SECT. I. On the Plan, Soundings and Borings of the former Bridge y 
 
 with Remarks on the Failure thereof ibid. 
 SECT. II. General Remarks on the Bed of the River, &c. and Plans 
 
 defgned for the new Bridge. 24 
 
 CHAP. IV. 
 SECT. I. Concerning Coffer-dams, with a fort mate Incident 
 relative thereto 2 9 
 SECT. II. Concerning the ConJlruBion of Batter deaux, or Coffer-- 
 dams. 30' 
 
 CHAP. V. 
 
 Concerning Pile and Pump Engines 35 
 
 C H A P.* VI. 
 SECT. I. Of demolijhing the old Bridge 38 
 SECT. II. Defcription of the Foundations 33 
 SECT. III. Breajl-work for the North Abutment, Jhewing the 
 Method of keeping up a Bank of loofe made Ground upwards of 
 30 Feet high, on only ten Feet Projeffion 40 
 
 € H A P. 
 
C O N T E N T S. 
 
 CHAP. VII. 
 
 An extraordinary Difcovery at eleven Feet beneath Low-water 
 Mark a 2 
 
 CHAP. VIII. 
 
 A Continuation of the Abftratl of our Diary, and laying the Foun- 
 dations of the North Pier, 2 1 Feet beneath the ufual High-water 
 Mark 46 
 
 CHAP. IX. 
 
 Concerning different Methods of centering, for large Stone Bridges, 
 and a Continuation of the Abfiracl of our Diary. 50 
 
 CHAP. X. 
 
 The proper Method of building ^uay Oralis, and a Continuation of 
 the AbjlraB of our Diary 53 
 
 SECT. I. Concerning other neceffary Matters r dative to the 
 building of Stone-Brtdges. 58 
 
 CHAP. XL 
 
 Concerning Ormond-Bridge, with the Soundings and Borings ad- 
 jacent, and Remarks w the Bed of the River. 62 
 
 C H A P. XII. 
 
 The principal Lines of a Defgn for Ormond-Bridge ? with proper 
 InftruSions for the Execution thereof, &c. 66 
 
 P A R T IL 
 
 C H A P. XIII. 
 
 Concerning jome Methods made ufe of by the Antients, and on par- 
 ticular Qualities of Lime, Mortar and Grout, 7 5 
 
 5 E C T. I. Concerning Coffer or cajedJV alls or Foundations, abridged 
 from L. B. Albert i 77 
 
 SECT. IL Concerning Lime, Mortar and Grout 79 
 
 CHAP. XIV. 
 
 Coffer-work applicable to various domeflic t Purp>ofes, as introduBory 
 to building in deep IVater . 83 
 
 SECT, 
 
CONTENTS. 
 
 SECT. I. Concerning Oak and Fir "Timber 83 
 
 SECT. II. Of the ConflruSlion of Coffers, and the Ufes to which 
 they may be properly applied \ for building in Water 86 
 
 Prop. I. A Gentleman has a Bafon of Water in his Gar 'den , and 
 requires a fure, quick and cheap Foundation to be laid therein, fuf- 
 ficient tofuflain a Statue of Lead, on a Stone, Pedeftal, the Plinth 
 of which is three Feet fquare, the Water fix Feet deep 8 7 
 
 SECT. III. Of fluffing the Coffers and Petrifications, laid down , 
 and to be considered as general Conclufons 8 8 
 
 SECT. IV. Concerning two other more weighty Purpofes to which 
 thefe Methods may be applied in flill Water 94 
 
 Prop. II. Let us fuppofe that a Gentleman has an elegant Viflo, ter- 
 minated by a fpacious Canal, the Water in which is twelve Feet 
 deep, and he requires a Foundation to be laid in ii y whereon he in- 
 tends to ereEl an Obelijk of 36 Feet high ibid. 
 
 Prop. III. To build a Pavilion of cut Stone, in a Lake of frejh Water 
 eighteen Feet deep ; the Platform to be enclofed with a Parapet of 
 the fame> extending 34 Feet fquare 95 
 
 CHAP. XV. 
 
 Concerning another Method for laying of the Foundations for the 
 Piers of Stone Bridges, in large and deep Rivers 96 
 
 SECT. I. Prop. IV. To build the Piers of Stone Bridge, in a 
 frejh Water River of one Fathom deep, &c. -97 
 
 SECT. II. Prop. V. To build the Piers for a Stone Bridge^ in 
 fmooth frejh Water River of fx teen Feet deep, &c 10a 
 
 SECT. III. Concerning the building of Stone Piers, in a deep 
 Ttde-river, on a hard rough Bed 103 
 
 Prop. VI. To lay a fure, quick and cheap Foundation for the Piers 
 of a large Stone Bridge, in a fpacious Tide-river, greatly expofed 
 to the Agitations of the main Ocean, — in 6 Fathom Low-water, 
 and fpring Tides at Times rife 4 Fathom more y &c. ibid. 
 
 SECT. JV. Concerning Bridges principally contrived for the Ufe 
 of Londonderry, Waterford and Wexford* and for fuch other 
 large and deep Rivers no 
 
 SECT. V. On an exceeding cheap, and mo fl fubflantial Method 
 of building a Bridge, in a very deep and fpacious River,, which 
 may be grafted on any of the former Methods j 1 3 
 
 * Prop* 
 
CONTENTS. 
 
 Prop. VII. To lay down fure, quick and cheap Methods for build- 
 ing a fubjlantial temporary Bridge with Stone Piers \ the Arches of 
 Timber , and the River at fpring Tides io Fathom deep, &c* 114 
 
 CHAP. XVI. 
 
 Concerning fome Endeavours to apply Coffer-work to other private and 
 public Purpofes, on "Land or in Frejh Water 1 1 8 
 
 SECT. I. Prop. VIII. To make a cheap temporary Road thro 
 part of a Lough, 9 Feet deep, &c. ibid. 
 
 SECT. II. Prop. IX. The Method of making a fubjlantial T urn- 
 pike Road, through a quaking Bog of 15 Feet deep, and to erecl 
 Forts or other weighty Stone Buildings in the fame 120 
 
 SECT. III. Prop. X. To make a navigable Canal through Part 
 of a /baking Bog of 15 Feet deep, &c. 124 
 
 CHAP. XVII. 
 
 Coffer-work applied to Buildings, that may be thereby effectually 
 executed in the Sea I2 (5 
 
 SECT. I. Prop. XI. To build a fubjlantial Stone and Lime 
 Beacon, or Light Houfe of 20 Feet Diameter in the Sea, the 
 dead low W ater being about eight Feet deep ; and fpring Tides 
 fometimes rife ten Feet more 127 
 
 SECT. II. Prop. XII. To build a Jingle Stone Pier-head in the 
 Sea, the dead Low-water 20 Feet deep, and high Spring-tides 
 rife 20 Feet more 
 
 SECT. III. Obfervations on the feparate Operations and united 
 Powers of Winds and Tides, aEling upon the Heads of ft rait 
 and curved Piers, 8cc. 143 
 
 SECT. IV. Concerning the Conjlrutlion of commodious Harbours 
 of the largeft Magnitude in the Sea ; with Obfervations on the 
 Operations of the Waves on the Pier-head. Fig 4. And alfo, a 
 concife Summary of the Principles on which thefe Propoftions are 
 founded 147 
 
 SECT. V. Concerning the ConftruElion of a Harbour for the Downs, 
 projecting to 20 Feet Low-water, the higheft fpring Tides fuppofed 
 not to exceed 20 Feet more. * 153 
 
 PART 
 
CONTE NTS, 
 
 PART III. 
 
 Concerning a Plan for encreafing the commercial and landed Inter eft 
 0/Treland ; and briefly demonflrating, that not only Great-Britain, 
 hut the whole Britifh Empire, may gain mutual Advantages 
 thereby ! 5 8 
 
 CHAP. XVIII. 
 
 SECT. I. Concerning the Purport or true Meaning of the 
 Words Free Trade, with fome Preparatives thereto 160 
 
 SECT. II. Shewing in what Senfe the Words Free Trade are to 
 be taken, with refpeB to our Exports and Imports, and how they 
 are to be adapted to our prefent Plan 166 
 
 SECT. III. On Roads, Fairs, Markets, &c. 168 
 
 CHAP. XIX. 
 
 On the frugal and effeSlual Management of fever al ufeful Matters 
 and Things relative to our general Plan * 176 
 
 SECT. I. Concerning the great Road from Dublin to Galway by 
 Athlone. 
 
 SECT. II. On reclaiming Ground 183 
 
 CHAP. XX. 
 
 Some brief Propofltions tending to a concife Summary of the Whole, 
 and pointing out eafy Methods for the Accomplijhment , and de- 
 monflrating the public Utility of this Plan 184 
 
 SECT. I. Concerning the Surveyor, or Supervifor of thefe 
 Works ibid. 
 
 SECT. II. On fome pra&icable Methods humbly propofed for the 
 eafy Accomplijhment of the foregoing Plan 185 
 
 SECT. III. On the public Utility of this Plan, and briefly de- 
 monflramtg^ that not only Great-Britain and Ireland, but alfo 
 the whole Britifli Empire, may gain mutual Advantages thereby; 
 illuftrated by feven fhort Conclufeons drawn from the Whole 187 
 
 BUILDING 
 
BUILDING in WATER. 
 
 PART I 
 
 Particularly relative to the Repair and Re-building of E/fex- bridge, 
 Dublin, and Bridge-Building in general, with Plans properly 
 fuited to the Re-building of Ormond-bridge. 
 
 CHAP. I. 
 
 Concerning the Temporary Repair of Eflex-bridge. 
 
 I N the latter end of May, 1751, I accidentally met with Mr. 
 Prior at his Grace the Lord Archbifhop of Dublin s, where 
 I heard him very pathetically lament the Lofs and Inconve- 
 nience the Public fuftained, by being near four Months deprived 
 of the Ufe of EJJ ex -bridge : On which his Grace enquired further 
 into that Matter, and was informed, that there were then two 
 or three Schemes lying before the Corporation of the City; one 
 of which, was to repair it with Timber in five Months for 500 / 
 another with Stone, within fix Months for 800/. &c. &c. 
 
 Mr. Prior then earneftly requefted my Opinion, to which, I 
 replied, That as I had not taken any particular Notice of it, I 
 could not prefume to give my Sentiments; but not being fatisfied 
 with that Anfwer, he prelled me to tell him what I thought of it. 
 On which, I told him, that I did not apprehend there was any 
 Difficulty in making an effeaual temporary Repair with Timber ; 
 and to further Queftions, I inflantly anfwered, that I believed, it 
 might be done within ten Days, for about one hundred Guineas. 
 
 On this, he immediately acquainted Alderman John Cooke, then 
 Lord Mayor, and from that Time Mr. Prior (living contiguous 
 to me) made me frequent Vifits, and at length prevailed on me 
 with fome Reludance to engage in it. Accordingly, I began to 
 
 B examine 
 
( 2 ) 
 
 examine the whole Structure, and to prepare for the temporary 
 Repair. See Plate I. 
 
 EXPLANATION of Plate I. Scale 30 Feet to 1 Inch. 
 
 This Plate reprefents the Plan of the Superstructure, as I found it 
 on the aoth July 1 751. Wherein Note, 
 
 A. Carriage Way, 20 Feet 5 Inches Broad. B. Foot- way, 
 9 Feet 5 Inches, on an Average. C. Pedeftal of the Eque;ftrian 
 Statue of King George I. D. The Pier that fell down, and caufed 
 the Breach in the Carriage-way. See Plate II. 
 
 EXPLANATION of Plate II, per the fame Scale. 
 
 This Plate Fig. 1. reprefents the Eaft Front of the Bridge to the 
 
 Surface of the Pavement. 
 
 E. The Breach that was made by the Failure of the 5th Pier 
 from the South. F F. Low-water Mark. G. Surface of the Pave- 
 ment at the Corner of the Excife-office, 24 Feet 2 Inches above 
 the Low-water Mark. H. Surface of the Pavement at the Corner 
 of Mr. NewtonVShop, 19 Feet 4 Inches above the Low-water 
 Mark. 1. Summit of the Pavement 26 Feet 8 Inches above Low- 
 water Mark. N. B. From this Place the Pavement declines 2 Feet 
 6 Inches to G. and 7 Feet 4 Inches to H. whence it feems as if the 
 Bridge had fettled fomewhat into the North Bed of the River, which 
 put me upon Examining. K. A level Line taken from the Plinth 
 of the 2d Pier, on a Suppofition that all the Arches originally 
 fprang from that level Line: If fo, then the third Pier funk into 
 the Bed of the River (on the Surface of which they were built) 
 
 6 Inches; the fourth, 8 Inches; the fifth, 1 Foot ; the fixth, 1 Foot 
 
 7 Inches. L. Reprefents that this South Pier is rebuilt on the 
 Ruins of a former Arch that had fallen down. The Surface of the 
 higheft Part of the Ruins is about 4 Feet clinches above the 
 Low-water Mark, confequently obftru&ed fo much of the Water- 
 way, and made it incline to the Northward. 
 
( 3 ) 
 
 In the Year 1676, Sir Humphrey Jervis began to build this 
 Bridge (of the Stones of St. Mary s- Abbey ) and in about eleven 
 Years after, viz. On the 4th and 5th of December 1687, there 
 happened a very great Rain, and a violent Storm at E. S. E. 
 (which is the likeliefl Point to caufe high Tides in this River, 
 becaufe both Tide and Land-flood coming together, generally 
 occafions the Tides riling higher in the River than ordinary) and 
 this high Tide meeting with an exceeding high Flood in the River, 
 rofe the Water to fuch a prodigious Height, as quite overflowed 
 the lower Parts of the City : In fome Houfes the Water rofe up 
 to the Parlour Floor, and on fome of the Quays much higher, fo 
 that Boats plied in the Streets. 
 
 At this Time there happened to be a Hackney-coach driving 
 over the Bridge, but providentially there was no Body in the Coach, 
 and as they were juft on the Crown of that Arch, the Bed of the 
 River under that Pier being carried away by the Floods, the Pier 
 fell down, and fo down came the Arch, Coach, Coach-man and two 
 Horfes, and all together were fwept down to the Watering-flip. 
 The Man clung fa ft to the Coach-box, fometimes under and lbme- 
 times above Water, till they came to the Slip, where one of the 
 Horfes broke his Traces and fwam out, but the Man and the other 
 Horfe were drowned. And as this happened in the Midft of Winter, 
 they certainly could not conveniently get the Ruins at that Time 
 removed, therefore, they only juft rough-levelled them, and 
 built the new Pier upon them. 
 
 Fig. 2. by the fame Scale, reprefents the Weft Side of the Bridge 
 inverted : Wherein obferve, that the Plinth of the third Pier from 
 the South, has on this Side funk from the level Line about 1 Foot; 
 the fourth 1 Foot 7 Inches; the fifth 2 Feet 1 Inch, and the fixth 
 Pier 3 Feet 6 Inches; fo comparing thefe with the fame on the 
 Eaft Side refpeclively, the Caufe of this Weft Side finking more 
 than the Eaft Side, is obvious, viz. That the Foot-way being 
 lately built, and the Workmen taking down the Cut-waters to 
 Low-water Mark, in order to join the Piers of the Foot-way clofe 
 to it, built Part of the Piers of the Foot-way on Part of the Foun- 
 dation of the Cut-waters, and the reft of them on the naked Bed 
 
 B 2 of 
 
( 4 3 
 
 of the River. This was the Caufe of the Foot-way being opened, 
 and feparated about eight Inches from the Bridge, and the Ground 
 being much fofter at the North than at the South end, it yielded 
 and funk fo much the more under it. 
 
 EXPLANATION of Plate III. or Temporary Repair, laid 
 down by a Scale of 8 Feet to i Inch, 
 
 All that I found neceflary for this Purpofe, was to clear and 
 fquare the Breach down to the Plinths A. and thereon to bed the 
 Plates B. on which I lodged the Ends of two Brace-beams of 16 
 Inches Square, and in like Manner two more Inwards covered 
 with Joifts, and floored with three Inch Plank, under which I pre- 
 vioufly erected two Frames to fupport them at their joining; and 
 as I was aware that the outward Frame was in great Danger of 
 being fwept away by a Flood, I did not engage them to the Brace 
 Beams, which in Truth flood in no Need of their Support. The 
 eight Joifts marked c. and the Crown Beams d. projected from three 
 to five Feet, to fuftain the Feet of the outward Braces, ee. Is the 
 Top of the Parapet Wall, and I hope that bare Inflection is fum> 
 cient to explain the Reft. On the 30th of the fame Month of 
 July, I had compleated the whole, that is, on the 10th Day I 
 laid it open for Carriages, and the Coft did not exceed the Sum of 
 100 Guineas, as I had unpremeditatedly mentioned to Mr. Prior. 
 
 . CHAP. II. 
 
 Some Preparatives towards drawing a Deftgn for a new Bridge, and 
 Obfervations relative to Bridge-Building in general. 
 
 WHILST I was going on with the Repair, Mr. Prior, feve- 
 ral of the Aldermen, and other principal Gentlemen of 
 the Corporation of the City, often vifited me, and when they 
 found me near the Accomplifhment of it, gave me great Encou- 
 ragement to engage in rebuilding the Bridge, which fomewhat 
 alarmed me, as I was at that Time engaged by Contract: in 
 
 building 
 
( 5 ) 
 
 building St, Patrick's Holpital, two Houfes for the Rev. Dr. 
 Leigh in Capel-ftreet, and one for Arthur Newburgh, Efq; I was alfo 
 engaged in the conduct of the building a new Houfe for his Grace 
 the Lord Archbifliop of Dublin, and another for Colonel Ram, at 
 Gorey, &c. However, I found myfelf extremely inclined to engage 
 in the building the Bridge, though I well knew it would be a. 
 very arduous Talk. 
 
 Thad on many Occasions before felt a great Defire to acquire 
 Knowlege in difficult Matters of Arts and Science ; and whenever 
 they grew eafy and familiar to me, I could no longer perceive in 
 them the Charms which had before captivated me. Intereft alone 
 could never fway me in thefe Refearches and Purfuits; but from 
 my earlieft Days I had entertained a Notion, that the greater the 
 Difficulty, the fweeter the Conqueft. In fhort, that Subject took 
 firm Poffeffion of me; and I applied myfelf to fearch my Books, 
 of which I then had a fine and valuable Collection, and I found in 
 them numerous elegant Defigns; but as touching the laying a 
 Foundation in deep and rapid Rivers, all the Authors were in a 
 Manner filent. 
 
 This Deficiency in fo many excellent Authors, greatly amazed 
 me ; and in Hopes of procuring better Inftructions, I fettled my 
 domeftic Affairs, and went to London, where I procured about 40 /. 
 worth of Books, Plans, &c. which I ordered to be fent after me, 
 and returned Home within the compafs of fourteen Days, full of 
 Hopes that by their Affiftance, I Ihould be able to pick out fome- 
 thing for my Purpofe; but after I had attentively perufed them, I 
 found myfelf in the fame Situation I had been in before. 
 
 I cannot defcribe the Indignation and Sorrow I felt, at finding 
 an Art of fuch public Utility, as that of building Bridges confeffedly 
 is, fo fhamefully neglected : However, thefe Books furnifhed me 
 with many ufeful Hints, and Obfervations, fome few of which, 
 I fliall give for the Improvement of the young Student, and as 
 neceffarily connected with the Subject I am treating. 
 
 SECT. 
 
( 6 ) 
 
 SECTION t 
 
 Hijlorical Accounts of feme remarkable Stone Bridges in foreign Parts. 
 
 IT has been a Rule laid down by the Writers on Science in ge- 
 neral, that Excellence in any particular Branch is only to be ac- 
 quired, by attentively and diligently perufing and digefting the 
 Works and Defigns of the mod eminent Authors and Artifts; but 
 the young Student fhould always be on his Guard, when he is 
 about defigning any Thing, that a too lively or over-heated Ima- 
 gination does not lead him into Chimeras, which fober Judg- 
 ment would not approve. This Error may be in a great Meafure 
 avoided, by paying a proper Deference to the Sentiments of learned 
 Men. For my Part, I think a young Man will gain greater Re- 
 putation by being an humble Copier of an ingenious Artift, than 
 to pretend to excel every one by the Fertility of his own Imagina- 
 tion. But in fuch Matters, where you cannot be furniflied with 
 Precedents, you are under a Neceflity of ftriking out fomething 
 from your own Brain. Yet thefe are not to be abortive, mifliapen 
 Beings, the mere Creatures of a wild Fancy, but the fair, the legi- 
 timate Offspring of a well-regulated Judgment. This Obfervation 
 deferves to be well attended to in all Cafes; but particularly in 
 thofe where a Mifcarriage may be attended with fatal Confequences. 
 
 There are an infinite Number of Bridges over the natural and 
 artificial Rivers in China. We fhall content ourfelves with ob- 
 ferving one of the mo ft famed, which is the Stone Bridge over 
 the River Saffrany, which joins two Mountains together, and is in 
 one fingle Arch, which fpans 600 Feet. From its Foundation to 
 the top of the Parapets is 750 Feet, and from the exceeding great 
 Height of it, Travellers have given it the Name of the flying Bridge. 
 There is another very remarkable Stone Bridge at Oxu, the Capital 
 of Fo-kin, which confifts of 100 Arches, But as we have a long 
 Journey before us, we cannot make any further Remarks on the 
 Bridges in China, and therefore, we mull make large Strides, and 
 ftep over to the Danube* 
 
 The 
 
( 7 ) 
 
 The next enormous Bridge I fhall mention, Is that which the 
 Emperor Trajan had built over the Danule, in order to convey 
 his Troops with the greater Readinefs to fall on the Barbarians; 
 but I find a great Difagreement among the Hiftorians concern- 
 ing it. 
 
 Some fay, this Bridge was one of the moft amazing Works in the 
 World ; but they generally agree, that it was compofed of twenty 
 Arches, nineteen Piers, and two Land Abutments, all of folid 
 Mafonry ; each Arch was 170 Feet Span. The Piers, we are told, 
 were 60 Feet broad, and 150 Feet high; that each of the Land 
 Abutments was 120 Feet (which is twice the Thicknefs of the 
 Piers) that the Arches were all true Semi-circles, and that it was 
 built where the River was narroweft, and confequently the moft 
 rapid, which renders the Fabric ftill more ftupendous and amazing, 
 on Account of the prodigious Difficulties they mud have met with 
 in laying the Foundations. But fome relate that the ten outward 
 Piers were built on an artificial Foundation, made by wheeling in 
 vaft Quantities of large and fmall Stones, and other filling, after 
 the ufual Manner of carrying a Mole into the Sea, but they form 
 not the leaft Conjecture, how the Piers were erected in the middle 
 of the River. 
 
 The Architect employed on this Occafion was one Apollodorus 
 of Damafcus, who it feems, left a Defcription of this great Work, 
 which (the Hiftorian fays) may be feen in Procop. de JEdificiis y 
 Juftin, B IV. c. 6. But when Adrian came to be Emperor, he 
 ordered the Arches to be demolifhed, to prevent the Barbarians 
 making Excurfions into his Territories. But Dion Caffius relates, 
 that the Piers were {landing in his Time, which was 120 Years 
 after the Bridge was built; but when it was entirely demolifhed, 
 the River was fo choaked up with the Ruins, that it was not navi- 
 gable, which obliged them to make a new Channel for it. We fhall 
 treat of this no further at prefent, but proceed in more ufeful 
 Enquiries, and fee what fome of the moft eminent Architects have 
 left us concerning Stone Bridges. 
 
 SECT. 
 
( 8 ) 
 
 SECT. IL 
 
 A Jhort AbJlraB from Leon Battista Albert i, 
 
 r^p HIS Author in his 8th Book, Chap. 6. Page 62. fays, the 
 I Parts of the Bridge are the Piers, the Arches and the Pave- 
 ment, or the Street in the Middle for the PalTage of Cattle, and the 
 raifed Caufey on each Side for the better Sort of Citizens, and the 
 Sides or Rails, and in fome Places Houfes too, as in that moft 
 noble Bridge, called Adrian V Mole, a Work never to be forgotten; 
 the very Skeleton whereof (if I may fo call it) I can never behold 
 without a Sort of Reverence and Awe. It was covered ^ with a 
 Roof fupported by two and forty Columns of Marble, with their 
 Architraves, Freeze and Cornice, the Roof plated with Brafs and 
 richly adorned. 
 
 A Bridge muft be made as broad as the Street which leads to it. 
 The Piers muft be equal to one another both in Number and Size, 
 and be one third of the Aperture in Thicknefs. The Angles, or 
 Heads of the Piers, that lie againft the Stream, muft project in 
 Length half the Breadth of the Bridge, and be built higher than 
 the Water ever rifes. The Heads of the Piers that lie along with 
 the Stream muft have the fame Projeaion ; but then it will not 
 look amifs to have them lefs acute, and as it were blunted. From 
 the Heads of the Piers on both Sides, it will be very proper to 
 raife Buttreftes for the Support of the Bridge, in Thicknefs, not 
 lefs than two thirds of the Pier itfelf. The Crowns of all the 
 Arches muft ftand quite clear above the Water. Their Drefs may 
 be taken from the Ionick, or rather the Dorick Architrave; and 
 in large Bridges, it muft not be lefs in Breadth than the fifteenth 
 Part of the whole Aperture of the Arch. 
 
 To make the Rails, or fide Walls of the Bridge the ftronger, 
 erea Pedeftals at certain Diftances by the Square and Plumb-lines, 
 on which, if you pleafe, you may raife Columns to fupport the 
 Roof or Portico. The height of this fide Wall with the Zocle and 
 Cornice muft be four Feet. The Space between the Pedeftals may 
 
 be 
 
( 9 ) 
 
 be filled up with a flight Breaft-work. The Crown both of 
 the Pedeftals and Breaft-wall, may be an upright Cymatium, or 
 rather a reverfed one, continued the whole length of the Bridge, 
 and the Plinth at the Bottom muft anfwer this Cymatium. 
 
 The Caufey on each Side for Women and Foot-pailengers, 
 muft be raifed a Foot or two higher than the Middle of the Bridge, 
 which is intended chiefly for Beafts and Carriages, and may be 
 paved with Flints. The Height of the Columns, with their En- 
 tablature, muft be equal to the Breadth of the Bridge. — And he 
 has given us the Draft of a very neat little Bridge of three fmall 
 Semi-circular Arches, with a Roof fupported by thirty Iouick 
 Columns, &c. 
 
 In the 6th Chapter of his fourth Book he treats of Wooden 
 Bridges, which is foreign to our Purpofe; but I cannot omit fome 
 
 Things he has therein obferved concerning Stone Bridges. 
 
 " Make," fays he, in Page 72, " the Foundations of your Piers 
 in Autumn, when the Water is loweft, having firft raifed an In- 
 clofure to keep off* the Water, which you may do in this Manner: 
 Drive in a double row of Stakes very clofe and thick fet, with 
 their Heads above the top of the Water like a Trench, then 
 put Hurdles within this double Row of Stakes, clofe to that Side 
 of the Row which is next to the intended Pier, and fill up the 
 Hollow between the two Rows with Ru flies and Mud, ramming 
 them together fo hard that no Water can poflibly get through; then 
 whatever you find within this Inclofure, Water, Mud, Sand and 
 whatever elfe that is a Hindrance to you, throw them out, and 
 dig till you come to a folid Foundation; or if you find it ne- 
 cefiary, make one of Piles burnt at the Ends, and driven in as 
 clofe together as ever they can iiick. And here I have obferved 
 that the beft Architects ufed to make a continued Foundation of 
 the whole length of the Bridge, and not only under each Pier; 
 and this they did,. not by fhutting out the whole River at once 
 by one fingle Inclofure, but by firft making one Part, then another, 
 and fo joining the whole together by Degrees; for it would be 
 impoffibie to withftand and repulfe the whole Force of the Water 
 at once; We muft, therefore, whilft we are at Work at one Part, 
 
 C leave 
 
( io ) 
 
 leave another Part open for a PafTage for the Stream. You 
 may leave thefe PalTages either in the Channel itfelf, or if you think 
 it more convenient, you may frame Wooden Dams or hanging 
 Channels, by which the fuperfluous Water may run off; but if 
 you find the Expence of a continued Foundation for the whole 
 Bridge too great, you may only make a feparate Foundation for 
 every particular Pier, in the form of a Ship, with one Angle in 
 the Stern, and another in the Head, lying directly even with the 
 current of the Water, that the force of the Water may be broken 
 by the Angle. We are to remember, that the Water is much more 
 dangerous to the Stern, than to the Head of the Pier," &c. 
 
 SECT. III. 
 
 "ExtraB from the celehrated Andrea Palladio. 
 
 IN his third Book, Chap. 4. Page 138. He lays down the fol- 
 J[ lowing Rules, and fays, — " Bridges ought to have the felf- 
 fame Qualifications that we judge necelTary in all other Buildings, 
 which are, that they (hould be commodious, beautiful and lafting; 
 they will be commodious, when they will not be raifed above the 
 level of the reft of the Way, or if they are, when they are of eafy 
 Afcent and Defcent; and likewife, when fuch a Place is chofen for 
 building them, as fhall be moft convenient for the whole Province 
 or City.— Bridges will be fine and lafting, if they are made after the 
 Manner and according to the Proportions fpecified in this Book ; 
 but in the Choice of a Situation for erecting them, Care muft be 
 taken to fix on fuch a Place as may give good grounds to expect 
 that the Bridge may be perpetual, and where it may be erected with 
 the leaft Expence. That Place muft be chofen where the River is 
 narroweft, and alfo the moft (hallow, and where its Bed or Bottom 
 is even and uniform, and is either of Stone or of Gravel, becaufe 
 Stone or Gravel are excellent Foundations in Water. Moreover, 
 Swallows or Whirlpools, and that Part of the River's Bed which is 
 fandy, or has much foft Clay in it, ought to be avofded; — but in 
 Cafe the Bed of the River be altogether Gravel or Sand, then the 
 
 Foundations 
 
( II ) 
 
 Foundations mud be made according to the Directions I fhall lay 
 down hereafter." 
 
 Chapter X. Page i 53.—-" In Bridges of Stone four Things are 
 principally to be confidered, viz. The Heads which are made at 
 the Banks; the Piles or Pilafters, which are fixed in the River; 
 the Arches which thefe Pilafters fupport, and the Pavement which 
 is made over the Arches. 
 
 The Heads of thefe Bridges ftiould be made as firm and fubftan- 
 tial as poffible; becaufe, they not only ferve to fupport the Weight 
 of the Arches as other Pilafters do, but they likewife keep the 
 whole Bridge together, and the Arches from cracking or opening : 
 They ought, therefore, to be made where the Banks are the moil: 
 folid. — The Pilafters, which are to be made in Proportion to the 
 Largenefs of the River, ftiould always be even with regard to their 
 Number. — The Foundations of Bridges ought to be made in 
 Autumn, and in Cafe the Bed of the River be Stone or Gravel- 
 Stone, you have the Foundation without any trouble; but in Cafe 
 the Bottom be Quick- fand or Gravel, you muft dig therein till you 
 come to folid Ground; or if that ftiould prove too laborious or im- 
 praaicable, you muft dig moderately deep in the Sand or Gravel, 
 and then you muft thruft in Oak Piles, which will reach the folid or 
 firm Ground, with the Iron by which their Points are to be armed. 
 
 To lay the Foundations of the Pilafters, only one Part of the 
 Bed of the River muft be enclofed from the Water, and then to 
 build there; that the other Part being left open, the Water may 
 have its free Current, and fo go on from Part to Part. 
 
 The Pilafters muft not be lefs in Dimenfions than the fixth Part 
 of the Breadth of the Arch, nor generally fpeaking larger than 
 the fourth ; they ftiould be made of great Stones, which are to be 
 joined together with Cramps and Bars of Iron fattened with Lead, 
 that they may be all as it were of one Piece; the Fronts of the 
 Pilafters, or that Side which faces the Stream, are ordinarily made 
 Angular, i. e. that they end in a right Angle, and fometimes they 
 are made Semi-circular in order to divide or break the Water, and 
 that thofe Things which are impetuoufty brought down the River 
 
 C 2 vv hen 
 
( i* ) 
 
 when they ftrike againft them, may be llioved from the Pilafters 
 and pafs through the middle of the Arch. 
 
 The Arches too ftiould be made very ftrong and fubftantial, 
 and with great Stones well united together, the better to refift the 
 conftant paffing of Carriages, or any other Weight that may hap- 
 pen to come over them. Thofe Arches are the ftrongeft that con- 
 fift of a Semi-circle, becaufe they intirely reft upon the Pilafters 
 and never prefs upon each other; but if by Nature of the Situation 
 and Difpofition of the Pilafters, a perfect Semi-circle fhould not 
 be commodious, as rendering the Afcent and Defcent difficult, a 
 leiTer Se&ion muft then be made ufe of, and fuch Arches made as 
 rife only the third Part of the Diameter, and in this Cafe, the 
 Foundation muft be made extremely ftrong upon the Banks, &c. 
 
 In his Xlth Chapter, Page 155, he begins to treat of particular 
 Bridges, and fays, u Abundance of Bridges were ereded by the 
 Antients in feveral Places, but particularly in Italy, and on the 
 Tyler, whereof fome are at this Day intire, and others h aye fome 
 fmall Remains only left to preferve their Memory."— -And in Page 
 156, he fays, " Extraordinary great and moft deferving of Admi- 
 ration, was that Bridge built over the Danube in Tranfdvania, 
 and on which were infcribed thefe Words, " Providentia Augufti, 
 vere Pontificis, virtus Romana quid no n Domet? Subjugor ecce rapi- 
 dus Danubius" i. e. a This is a memorable Monument of the La- 
 bour and Affiduity of Auguftus, the Roman Pontiff" : What will not 
 Roman Valour enterprife ?" 
 
 But of all the Bridges that I have mentioned, that appears to me 
 to be the moft beautiful and the moft worthy of Qbfervation (not 
 only for its Strength but the Compartment of it) which was ereaed 
 at Ariminum, a City of the Flaminian Tribe, and I believe by 
 Auguftus Ctefar. It is divided into five Arches, the three middle- 
 moft whereof are equal, confifting of % 5 Feet in Breadth, and the 
 two next the Banks are lefs, confifting only of 20 Feet; all thefe 
 Arches confift of a Semi-circle, and the Depth of their Archivolte 
 is a tenth Part of the light or void of the greater, and an eighth 
 Part of the light of the lefTer ones. The Pilafters, as to their 
 Thicknefs, are a little more than the half of the light of the greater 
 
 Arches; 
 
( *3 ) 
 
 Arches; the Angle of the Spurs, which cut the Water is a right 
 Angle. This, as I obferved, the Antients followed in building all 
 their Bridges, as being ftronger than the acute Angle, and for that 
 Reafon, the obtufe Angle is lefs expofed to be thrown down and 
 deftroyed by Trees or any other Matter, that rolls down with 
 the Stream. On the Sides of this Bridge, there are four Ionic 
 Niches, with pitched Pediments over the four Pilafters; there is 
 a Cornice over thefe Niches, the Length of the whole Bridge 
 = i I Foot high, confining of a Semirect and a Semirevers and Tufcan 
 Blocks. The Piers are funk 7 Feet into the Bed of the River, 
 the Water is fix Feet deep, and the Arches fpring 6 Feet above 
 the Surface of the Water. 
 
 His Xllth Chap. P. 158, is concerning the Bridge of Viccnza: 
 a Two Rivers run through Vicenza^ one whereof is called the 
 Bacchigilone, and the other the Ret one : This laft enters into the 
 firft, juft without the City, and fo lofes its Name immediately. 
 There are two antient Bridges built over thefe Rivers, one of 
 which is demolifhed; the other is divided into three Arches, the 
 middlemoft is 33 Feet broad, the other two are 22 \ Feet each. 
 The Pilafters are the 5 th Part of the leiTer Arches, and the 6th of 
 the greater, and the Arches rife 3 of their Diameter ; their Archi- 
 volte has \ of the fmall, and % of the large Arches, which is a 
 common three-faced Architrave; the Piers have a Plinth that pro- 
 jects about a Foot, and a Foot under the fpringing for the fupport 
 of the Centres, and from the level of that Courfe the front of 
 each Pier is hip'd of, and from hence the Architraves fpring. The 
 Bridge is 24 Feet from out to out." 
 
 Chap. XIV. P. 161. defcribes a Bridge, of his own Invention. 
 " The River is 180 Feet. In three Arches, the middle Arch 60 
 Feet, and the fide Arches 48 Feet each; the Pilafters 12 Feet 
 thick, and the Points of the Cutwaters (which are a right Angle) 
 extend 1 2 Feet each beyond the naked of the Bridge; the middle 
 Arch rifes 20 Feet, the fide ones 16 Feet, with a three-faced 
 Architrave the 17th of the middle, and the 14th of the fide 
 Arches. The Piers finifh at the Spring with two leaning Figures, 
 
 over 
 
( *4 ) 
 
 over which there are two Corinthian Niches with Statues and pitched 
 Pediments. This Bridge is 30 Feet from out to out." 
 
 SECT. IV. 
 
 A fijort Abjlratl from Scammozzi and Sebastian Serlio. 
 
 C A M MO Z Z I has alfo treated of Stone-bridges, and the 
 laying their Foundations; for which Purpofe, he generally 
 approves of piling, as the fafeft Way where the Ground is foft. 
 He fays, he laid two Defigns before the Senate of Venice, for the 
 Pont Rialto, one of three Arches, and the other of one Arch, which 
 he propofed to lay over the great Canal, with Piles of Timber drove 
 into the Ground, then with Net-work of Timber upon them, and 
 Planks of Oak upon the Net-work, on which the Stone-work was 
 to be raifed ; and there is not the leaft doubt but he drew and pro- 
 pofed to execute this Plan of the one Arch, but it is generally al- 
 lowed as the Work of Michael An gelo, built by him in 1591. 
 Indeed, it is a moft noble Arch ; 1 have now three feparate Drawings 
 of it by me, but they had not any Difficulties of Water to encoun- 
 ter with. The Arch is the Segment of a Circle, the Span 98 \ Feet. 
 It fprings at high Water Mark, and rifes 23 Feet, &c. But let us 
 come more to our Purpofe. 
 
 Scammozzi propofes four different Methods to lay Foundations 
 in deep Water, viz. 
 
 1 ft. To fhut up the River in Parts on one Side, and then on the 
 other, by driving a double Row of Piles, and filling in between 
 them with good Chalk, or fome clofe Materials, then to pump out 
 the Water from the inclofed Part, and clear out the Mud; after 
 that, to pile the Foundation to the extent of the intended Pier, and 
 then to begin your Foundation of Stone, upon a Platform of 
 Plank. 
 
 2d. Having founded the Water, and levelled the Bed of the 
 River, to prepare a Grillage of Oak, ftrong and well pinned, and 
 bound faft together with iron, and kept upon the Surface of the 
 Water by large Hulks or Gabbards, with Cables and other Ma- 
 chines. 
 
( r S ) 
 
 chines, having a thick Stratum of large Stones laid on this Frame 
 of Timber, the Stones being well cramped together, and the Joints 
 filled with ftrong Puzzoli, Terrafs, or Cement, and then letting 
 them down gently to the Bed of the River by proper Machines 
 and Cables. 
 
 3d. To turn off the River another Way, or to make feveral 
 Channels to fink the Water, then with a Number of Workmen to 
 make a Dam with Piles, above and below where the Bridge is to 
 ftand, quite a-crofs the River, and fo turn the Stream into the 
 new Channel ; then to clear the Earth and Mud away, where the 
 Foundation of the Bridge muft be laid, and to build the Piers above 
 the Water, and after that to let the River return into its proper 
 Channel. 
 
 4th. He feems to think that the Emperor "Trajan muft needs 
 have made ufe of the following Method, in building that wonder- 
 ful Bridge over the Dannie, viz. To take an Elbow or Bend of 
 the River where it makes a Peninfula, to cut out a direct Canal 
 through the Neck of Ground or Ifthmus, then to build the Bridge 
 with eafe and upon dry Ground, and afterwards to open the Paflage 
 through the Ground left at each end of this new Bed or Channel, 
 whilft the Bridge is building, then turn the River through it, mak- 
 ing ftrong Dams on the old Channel to divert the River from its 
 former Courfe. 
 
 Sehaflian Serlio mentions the Proportions of fome of the principal 
 Bridges at Rome, &c. which I think, we do not now ftand in any 
 need of, as our chief Enquiry is after the fureft and moft practicable 
 Method, of laying a Foundation of about feven and twenty Feet 
 under High-water, in an exceeding rough and rapid River; and as 
 I am certain there is not one of all thefe which we now have before 
 us, that will anfwer our Purpofe, let us turn our Faces Homewards, 
 and on our Way take a curfory View of fome of the Bridges in 
 France, and let us refolve to infpect narrowly into the Methods, 
 which we hear, they have practifed with great Succefs, in laying 
 the Foundations of many of their Bridges, 
 
 SECT. 
 
( *6 ) 
 
 SECT, V. 
 
 Brief Accounts of fome of the Stone Bridges in France, and their 
 
 Methods of building them. 
 
 THERE are many magnificent Bridges in France, both 
 antient and modern, and we mall begin with the Pont 
 Royal at Paris, which was built in 1685, by Monf. Manfart : 
 This Bridge is built over the Seine, oppofite to the Grand Pavilion 
 of the Thuilleries, and was executed according to the Plan ordered 
 by the King. The River in this Place is about 403 Feet Englifh, 
 and the Bridge confifts of 4 Piers and 5 Arches; the middle Arch 
 is 77 Feet, the two next 74 Feet each, and the two next the 
 Quays 58 Feet each; the two middle Piers are each 16, and the 
 two other Piers 15 Feet each; the middle Arch is 26 Feet high 
 from the fpringing, and is elliptical, and fo are the reft in Propor- 
 tion ; the Road over it is divided into three Parts, the middle is 
 32 Feet 6 Inches, and the Foot-ways on each Side are 9 Feet 
 9 Inches broad, and feparated by Stone-pofts; the Parapets are 
 3 Feet thick, and 3 Feet 3 Inches high; the River in this Place 
 is about 7 Feet deep, and the Bridge was ere£ted by Means of 
 Batterdeaux. 
 
 The Bridge at Blois, was defigned by the Sieur Gabriel: Breadth 
 of the River 935 Feet Englifli ; it has 10 Piers, 2 Abutments and 
 11 elliptical Arches; the middle Arch is 86 Feet 9 Inches, the 
 two next 80 Feet each, the two next 73 Feet each, the two next 
 66 Feet each, the two next 60 Feet each, and the two next to the 
 Quays are 55 Feet 4 Inches each: Total Water-way 755 Feet 
 5 Inches; the two middle Piers are 22 Feet 6 Inches each, the 
 two next are 17 Feet 2 Inches each, and the other fix are 16 Feet 
 1 Inch each : Total folids =175 Feet 1 o Inches, and the two 
 Abutments = 60 Feet; the Piers project 16 Feet beyond the ex- 
 tent of the Bridge on the upper Side, and 10 Feet below the Bridge, 
 and terminate in right Angles; the Height of the middle Arch is 
 36 Feet 10 Inches, and the reft in Proportion, and all elliptical; 
 
 from 
 
 \ 
 
From the bottom of the Piers to the fpring of the Arches it is 
 1 6 Feet 6 Inches; the Breadth of the Bridge is 45 Feet 6 Inches, 
 between the Parapets, which are 2 Feet 2 Inches each; the Car- 
 riage-way is 30 Feet, and each of the Foot-ways is 7 Feet 7 Inches, 
 and raifed about a Foot above the Carriage-way; the Foundations 
 were laid on Oak Piles, and the Water kept off in the mean Time 
 by Batterdeaux. 
 
 There are a vaft Number of other very excellent Bridges in 
 France, whofe Foundations have been laid after the fame Methods, 
 on which I fhall make fome Remarks very foon ; but as I am not 
 writing a Hiftory of Bridges, I fhall defift; my prefent Pur- 
 pofe being to find out and lay down fome effectual Methods to 
 keep off the Water till we fhould accomplifh our Defigns, which I 
 fhall now begin to prepare for and to confider minutely, not by 
 Way of Precedent, but in order to fhew young Students that there 
 are an infinite Number of Matters and Things to be thoroughly 
 examined and digefted, before one can fit down to draw a proper 
 Defign of this Nature; for in many Cafes, a Plan or Defign, that 
 may appear curious or elegant enough upon Paper, may prove the 
 Inftrument of involving both the Projector, his Employers and 
 the Public in very difagreeable Circumftances, of which there are 
 numerous flagrant Inftances to be met with. — But to proceed. 
 
 C H A P. III. 
 
 A fuccintl Narrative concerning the re-luilding of ElTex-bridge. 
 
 jft£yK *M T. 1 I % \ r' r ' ' 
 
 On the Flan, Soundings and Borings of the former Bridge. 
 
 i 
 
 EXPLANATION / Plate IV. Scale 30 Feet 1 Inch. 
 
 THIS Plate exhibits a Plan of Effex-hidge, as it was in 175 r, 
 and the Bafs of the Effigy, with fome of the Borings or 
 Piercings into the Bed of the River, as alfo the Soundings above 
 
 D and 
 
( »» ) 
 
 and below it: In explaining of which, I fhall demonftrate the Caufe 
 
 of the Failure thereof, wherein note, 
 
 L. The Pier that was rebuilt, and now ftanding on the Ruins 
 of a former Arch, as before-mentioned. M. Part of the Under- 
 work of the fecond Pier of the Foot- way, failed and carried off by 
 the Floods. N. Shews a Diagonal opening quite acrofs the third 
 Arch, caufed by the fecond Pier having funk into the Bed of the 
 River Weftward, and the third Pier Eaftward. O. What now 
 remains of the fifth Pier. P P. The two Piers of the Foot-way 
 that have funk the mo ft into the Bed of the River. Bafs of 
 the Effigy. R. Sh ews how the Current is now directed by the 
 Bafs of the Effigy, the Confequence of which fhall be hereafter 
 explained. S S. Shews the Soundings of the River at High-water, 
 taken in a direct Line, 60 Feet below the Bridge, in every 1 o Feet. 
 T T. Shews the Soundings of the River in every 1 o Feet, taken 
 in a direct Line, 65 Feet above the Bridge. 
 
 I took thefe Soundings in the following Manner : I had a Haw- 
 fer (trained very tight from Quay to Quay, to which we moored our 
 Boat, and over that at a proper Height, we had a tight Rope 
 marked in 10 Feet Divifions, and numbered. I had alfo a found- 
 ing Rod, made of a Piece of Scantling 26 Feet long, 4. by 2 at 
 the lower End, and 2 [ by 1 [ Inches at top; the Butt of it was 
 firmly fixed in a Cut-ftone of 4 Inches thick, and about 20 Inches 
 Diameter. The Rod was marked out in Feet and Inches painted. 
 In the Butt of the Rod there was a Hole, through which a long 
 Piece of Safh-cord was drawn, by which we hove the Rod along, 
 noting the Depth at every Divifion, and notwithftanding the Ra- 
 pidity of the Water, we got this done with tolerable Exactnefs. 
 
 I took the. following Method to bore the Bed of the River; 
 the Rods were in three Pieces of Inch Square Bar of juft nine Feet 
 each, which fcrewed together occafionally ; into the lower one the 
 Chiflell or Augers were fcrewed, the Chiflell or Piercer, was well 
 fteeled, with a drill Point ; we had a handle like that of an Auger, 
 which moved up or down, and by a Screw made tight whenever we 
 pleafed : Practice foon taught us, that we did not know how to 
 perform this trifling Piece of Work in that rapid Water; but we 
 
 foon 
 
PI: 4. . 
 
( 19 ) 
 
 foon found it neceflary to bore through wooden Pipes made of 6 
 Inch Scantling, of different Lengths, with Iron Ferules on the 
 lower End, to drive into the Bed of the River, and an Iron Hoop 
 at the Top, to keep it from fplitting in the driving. 
 
 I ought to have obferved, that I had erected many founding 
 Boards in the moft confpicuous Places; thefe were made of Inch 
 Plank 12 or 14 Inches broad, divided into Feet and Inches, with 
 very large Figures painted, fome upwards and fome downwards, 
 from the Low-water mark. 
 
 We frequently kept feveral Pipes drove down at one Time, of 
 different Lengths, to anfwer the Tide, always obferving to note 
 the exact Spot or Scite of each of them in the Plan, and they were 
 all numbered fo that we could not miftake, as in each of them we 
 were guided by our founding Boards : And here I think it neceflary 
 to give this caution, if you are boring through fharp or quick 
 Sand, do not let your Rods get any reft, for if you do, the Sand 
 will fet upon your Piercer or Augre, and you will hardly get it 
 out again. 
 
 This is all I think neceflary to be mentioned concerning found- 
 ing and boring; but obferve, that the large Dots over the No. 
 fliew the individual Spots into which we bored : As for inftance, 
 at the N. W. corner of the third Pier is No. t, and the S. W. corner 
 of the fame No. 2, &c. N. B. The ordinary neap Tides in Sum- 
 mer generally rife about 6 Feet and a half; but when Land-floods 
 meet with Spring-tides and a S. E. Wind, they often rife to 12 or 
 13 Feet: However, in our Work, we computed our High-water- 
 mark at ten Feet upon an Average, and we took all the Soundings 
 and Borings from the fame. 
 
 Remarks on the caufe of the Failure of the Bridge. 
 
 ALL the Piers were originally built on Frames of Oak, of 
 about 9 or 10 Inches Square, the Clear of which was juft 
 the fize of the Pier from out to out; the Bottoms were made of % 
 Inch Oak-boards dovetailed into the Frame crofs-ways, but done 
 in very coarfe rough Work; thefe Frames were laid on the Bed 
 of the River, on which they built the Piers ; the increafe of the 
 
 D 2 Rapidity 
 
( 2° ) 
 
 Rapidity of the Water between the Piers, funk and carried off that 
 Bed of the River left between the Piers, and continued to fap and 
 gull the Frames every Flood, and the Bafs of the Effigy Q^gave a 
 new Direction to the Current, for that on the South Side was di- 
 rected to the Pier L. where it was obftructed by the Ruins of the 
 former Arch, and as it hurried back to get into the third Arch, it 
 fapped the Foundation of the Foot-way, M. and on the North Side, 
 the Strength of the Current was directed to O. where it did full 
 Execution on that Pier, and then made its Way to R. where meet- 
 ing again with the Currents that ran through the third and fourth 
 Arches, they ftruggled together, and fo wore away the Bed of the 
 River to 23 Feet 8 Inches deep, and fometimes deeper, juft as the 
 Flood and Ebb happened to leave it. Now let us examine the 
 borings of the Bed of the River. 
 
 BORINGS. 
 
 NT. 
 
 Feet. 
 
 Inches. 
 
 
 1 
 
 1 ] 
 
 9 
 
 To the Bed of the River. 
 
 
 3 
 
 5 
 
 Pretty clofe Gravel. 
 
 
 3 
 
 6 
 
 Ditto, fofter and finer. 
 
 
 4 
 
 7 
 
 Ditto, rather clofer. 
 
 
 2 3 
 
 3 
 
 We came to the Rock. 
 
 % 
 
 1 1 
 
 6 
 
 To the Bed. 
 
 
 1 1 
 
 6 
 
 Gravel and Sand. 
 
 
 
 0 
 
 Rock. 
 
 3 
 
 9 
 
 6 
 
 To the Bed. 
 
 6 
 
 0 
 
 Gravel and Sand pretty clofe. 
 
 
 6 
 
 6 
 
 Ditto, but clofer and finer. 
 
 
 22 
 
 0 
 
 Rock. 
 
 4 
 
 10 
 
 2 
 
 To the Bed. 
 
 8 
 
 1 
 
 Gravel and Sand. 
 
 
 5 
 
 9 
 
 Very fharp Sand. 
 
 
 24 
 
 0 
 
 Rock. 
 
 
 
 
 
( ax ) 
 
 N°. 
 
 5 
 
 Feet. 
 
 I O 
 
 8 
 
 Inches. 
 
 2 
 10 
 
 T ft fUp R Pr l 
 
 Gravel and Sand, 
 
 
 B 
 
 O 
 
 Wrv rlofp "Tharn Sarin 
 
 
 24. 
 
 O 
 
 
 6 
 
 r i 
 
 O 
 
 To the Bed. 
 
 
 5 
 
 tz 
 O 
 
 6 
 0 
 
 Coarfe, iliarpJ5and 
 dole, iharp band. 
 
 
 *3 
 
 0 
 
 Rock. 
 
 
 
 
 Note, Between the 4th and 6th boring, by my 
 giving a very fhort refpite to the Men, the Sand 
 fet on the Piercer, which we could not move 
 
 7 
 
 I o 
 7 
 
 9 
 
 9 
 6 
 
 afterwards, and we were obliged to unfcrew the 
 upper Joint, and leave the riercer and the lower 
 
 T/-\inf in flip lirrnnnn 
 JvJllil 111 LUC VJiUUilUt 
 
 To the Red 
 Rough Gravel. 
 Hard fine Sand. 
 
 
 2 2 
 
 0 
 
 Rock 
 
 o 
 
 I 
 
 I \J 
 
 C\ 
 
 y 
 
 T/^ the* D^J 
 1 0 ine oea. 
 
 
 7 
 
 i 
 
 6 
 
 n 
 
 Q 
 O 
 
 j-jooie rougn vjravei. 
 
 v^lsjlv dllvJ. lllaiu OallvJ. 
 
 
 0 I 
 
 Q 
 
 Rnrk 
 
 y 
 
 I 3 
 
 U 
 
 1 0 the Bed. 
 
 
 4 
 
 O 
 
 Coarfe, loofe Sand. 
 
 
 Q 
 
 Q 
 
 V^IUIC ail Li lllal IJ Ocliivi. 
 
 
 26 
 
 Q . 
 
 y 
 
 Rnrlr 
 IXOCJv. 
 
 10 
 
 12 
 
 0 
 
 To the Bed. 
 
 
 7 
 
 r 
 
 0 
 0 
 
 Loofe, coarfe Sand. 
 C^lnfe fine fnarn Sand. 
 
 
 r 
 
 0 
 
 Rock. 
 
 1 1 
 
 5 
 7 
 
 0 
 0 
 0 
 
 To the Bed. 
 Loofe coarfe Sand. 
 Loofe quick fharp Sand, 
 
 
 a6 
 
 0 
 
 Rock. N°,i2 
 

 .Feet. 
 
 Inches. 
 
 12 
 
 1 1 
 
 O 
 
 
 s 
 
 O 
 
 
 5 
 
 O 
 
 
 i 
 
 9 
 
 
 22 
 
 9 
 
 1 2 
 
 ,12 
 
 0 
 
 
 8 
 
 0 
 
 
 6 
 
 0 
 
 
 26 
 
 0 
 
 ii 
 
 1 1 
 
 0 
 
 
 4 
 
 0 
 
 
 15 
 
 0 
 
 1 5 
 
 1 1 
 
 0 
 
 
 0 
 
 10 
 
 
 6 
 
 0 
 
 
 3 
 
 11 
 
 
 3 
 
 6 
 
 
 0 
 
 6 
 
 
 25 
 
 9 
 
 16 
 
 1 1 
 
 6 
 
 
 1 2 
 
 8 
 
 
 2 
 
 0 
 
 
 26 | 
 
 2 
 
 in 
 
 1 1 
 
 0 
 
 
 3 
 
 0 
 
 
 8 
 
 0 
 
 
 5 
 
 0 
 
 
 0 
 
 9 
 
 
 2 7 
 
 9 
 
 
 1 0 
 
 0 
 
 
 7 
 
 / 
 
 0 
 
 
 1 
 
 0 
 
 
 7 
 
 0 
 
 
 1 
 
 0 
 
 1 * 
 
 26 | 
 
 0 
 
 ( 22 ) 
 
 To the Bed. 
 Coarfe, loofe Sand. 
 Dit to, but finer. 
 
 Rouigh and ftubborn like Quarry Rubbifh. 
 Rock. 
 
 To the Bed. 
 
 Loofe, quick and fliarp Sand. 
 Rough and ftubborn. 
 
 Rock. 
 
 To the Bed. 
 Loofe and ftony. 
 
 Here we were forced to defift, it was fo ftony. 
 To the Bed. 
 Very ftony. 
 I Loofe, fharp Sand. 
 Clofer fharp Sand. 
 Something finer ditto. 
 Like Quarry Rubbifli. 
 
 Rock. 
 
 To the Bed. 
 Sharp Sand. 
 Something finer ditto. 
 Rock. 
 
 To the Bed. 
 
 Coarfe loofe Rubbifh. 
 
 Ditto, and gravelly Sand. 
 
 Fine foft Sand, that we could almoft thruft down the 
 Quarry Rubbifh. . [Rod into it. 
 
 Rock. 
 
 To the Bed. 
 
 Soft, loofe, gravelly Sand. 
 Ditto, but much ftiffer. 
 
 C Very foft loofe Sand, feemingly mixed with Mud, 
 C but not quite fo foft as that of N Q . 1 7. 
 Like Quarry Rubbifh. 
 
 Rock. N°. 19 
 
( 23 ) 
 
 
 Feet. 
 
 Inches. 
 
 To the Bed. (South end) 
 
 l 9 
 
 9 
 
 O 
 
 7 
 
 6 
 
 Coarfe Gravel. 
 
 
 16 
 
 6 
 
 Rock. 
 
 2 O 
 
 Q 
 
 'j 
 
 Through the Rubbifh. 
 
 
 7 
 
 0 
 
 Very coarfe and ftony ditto. 
 
 
 16 
 
 3 
 
 Rock. 
 
 2 I 
 
 9 
 
 3 
 
 To the Bed. 
 
 
 y 
 
 3 
 
 9 
 
 Stony Rubbifh. 
 
 
 3 
 
 2 
 
 Finer Rubbifh or Gravel. 
 
 
 16 
 
 2 
 
 Rock. 
 
 22 
 
 ?4 
 
 0 
 
 To the Bed. (near R.) 
 
 
 1 
 
 7 
 
 Loofe Sand, or Mud. 
 
 
 
 7 
 
 Rock. 
 
 2 3 
 
 24 
 
 6 
 
 To the Bed. 
 
 
 1 
 
 3 
 
 Loofe Sand, or Mud. 
 
 
 
 9 
 
 Rock. 
 
 24 
 
 24 
 
 9 
 
 To the Bed. 
 
 0 
 
 1 1 
 
 Loofe Sand, or Mud. 
 
 
 
 8 
 
 KJ 
 
 rvocK. iv. -D. 1 neie lait tnree rsumDers are lateen 
 
 
 
 
 111 LI1C U.CCUC1L lall Ol LI1C YV IllI 1—pOOl, Wlilwl 
 
 
 
 
 nearly coroborate with the Soundings at R. which 
 
 
 
 
 is 2 3 Feet 8 Inches deep.) 
 
 
 9 
 
 3 
 
 To the Bed. (South Arch) 
 
 
 3 
 
 Q 
 
 Rubbifh or Ruins of the former Arch. 
 
 
 3 
 
 3 
 
 Loofe Gravel. 
 
 
 ib 
 
 2 
 0 
 
 Rock. 
 
 26 
 
 7 
 
 6 
 
 To the Bed. (See North Side) 
 
 
 8 
 
 0 
 
 Soft Sand. 
 
 
 2 
 
 0 
 
 Ditto, but much fliffer. 
 
 
 7 
 
 0 
 
 Ditto, ftiffer and finer. 
 
 
 1 
 
 6 
 
 Very ftifF, and fine Sand or Loam. 
 
 
 26 
 
 0 
 
 Rock. 
 
 N°. 27 
 
( 24 ) 
 
 
 Feet. 
 
 Inches. 
 
 
 27 
 
 7 
 
 0 
 
 Ta f-Up P Pr l 
 
 X \J LI1C J_>CU. 
 
 Q 
 0 
 
 4 
 
 JL/OOic lanuy j_ioam. 
 
 
 2 
 
 2 
 
 .L/lllO. DUt mucn lXlrTcr. 
 
 
 ft 
 
 3 
 
 1 Jiffr» lTiTTPr cinri rinpr 
 
 ivillCl all 11 lllld« 
 
 
 2 5 
 
 9 
 
 Rock. 
 
 2d 
 
 7 
 
 4 
 
 1 0 the bed. 
 
 
 8 
 
 0 
 
 Soft Sand, or Loam. 
 
 
 2 
 
 6 
 
 Ditto, but pretty ftiff. 
 
 
 7 
 
 0 
 
 Stiff Sand, or Loam. 
 
 
 1 
 
 6 
 
 Ditto, and Quarry Rubbifh 
 
 
 26 
 
 4 
 
 Rock. 
 
 SECT. II. 
 
 General Remarks on the Bed of the River y &c. and Plans dejignea 
 
 for the new Bridge. 
 
 \^ PvOM thefe borings it appeared, that the Bed of the River 
 \J was chiefly compofed of coarfe Sand, Gravel, Mud, and other 
 loofe fluctuating Matters, brought down by the Land-floods, but 
 chiefly lince the North-quay-walls were built, and fo adding them all 
 together in my own Mind, I found that the Sum total was, that I 
 could not have the leaft hopes of building a fubftantial Bridge in that 
 Place, without removing all that loofe Subftance, and getting down 
 to lay the Foundation on or tolerably near the Rock, which we found 
 quite a-crofs the River; but how, or by what Means to get thatac- 
 complifhed in fuch a rapid River, and particularly in the North Side, 
 where we found the Rock in fome Places upwards of 27 Feet under 
 high Water, was the fole Circumftance that quite confounded me, 
 and threatened to fruftrate my Intentions of building a Bridge that 
 fliould laft as long as the little adjacent Mountain, called Sugar-loaf- 
 9 hill as I had determined, and made fome Declarations to that 
 purpofe. 
 
 To conquer all thefe feemingly infurmountable DifHculties, en- 
 gaged my whole Attention: Many Schemes and Projects crowded, 
 
 and 
 
( 2 5 ) 
 
 and fome of them made deep Impreffions on my Imagination ; but 
 whenever the Apprehenfion of the Danger the Workmen would 
 be in, in Cafe the Inclofure, I thought I had projected, burft in 
 upon them," they all vanifhed. « 
 
 In this diftrefied Situation I had frequent Recourfe to my Books, 
 all of which could not afford me any fort of Encouragement, fav- 
 ing what I have already laid before you : They told me, indeed, 
 to make an Inclofure ; and fo might they tell a Man, that to 
 meafure Time, he mull make a Clock; but what would that avail 
 to a Man that had never made nor feen any kind of Machine for 
 that purpofe? — However, I proceeded to form my Plan of the 
 Bridge, in projecting of which, I found myfelf moft plentifully 
 ftored with Precedents, and yet after all (in Juftice to Mr. Labely) 
 I mult declare that tVeftminfter Bridge deferved the Preference ; 
 therefore (fave only in fome Particulars) I took it for my 
 Precedent. 
 
 EXPLANATION of Plate V. Scale 30 Feet 1 Inch. 
 
 T I ^ HIS Plate reprefents the Plans of the Old-bridge, and the 
 annexed Defign of the New-bridge laid down together; 
 not only to know the exact Parts of the Bed of the River as they 
 then were, but as they were to be occupied by their refpe&ive 
 Piers ; and likewife to confider and compare them together, with 
 regard to their Voids and Solids. 
 
 E Old- 
 
 \ 
 
( 26 ) 
 
 Old Bridge. New Bridge. 
 
 • 
 
 Arc 
 
 hes. 
 
 Piers. 
 
 
 Arches. 
 
 Piers, 
 
 
 Ft. [Inch. 
 
 Ft. 
 
 Inch. 
 
 
 Ft. 
 
 Inch. 
 
 Ft. 
 
 Inch 
 
 i ft or South Arch 
 
 18 
 
 5 
 
 0 
 
 O 
 
 1 ft or South Arch 
 
 
 kJ 
 
 KJ 
 
 KJ 
 
 ift or South Pier 
 
 O 
 
 0 
 
 8 
 
 I O 
 
 r ft or South Pier 
 
 0 
 
 O 
 
 8 
 
 O 
 
 2d Arch - " 
 
 18 
 
 5 
 
 0 
 
 O 
 
 2d Arch - - 
 
 4 1 
 
 O 
 
 0 
 
 O 
 
 2d Pier 
 
 O 
 
 0 
 
 12 
 
 I I 
 
 2d Pier 
 
 0 
 
 O 
 
 9 
 
 O 
 
 3d Arch - 
 
 27 
 
 9* 
 
 0 
 
 O 
 
 3d Arch - 
 
 46 
 
 O 
 
 0 
 
 O 
 
 3d Pier 
 
 C 
 
 0 
 
 
 O 
 
 3d Pier 
 
 0 
 
 O 
 
 9 
 
 O 
 
 ,1 A t 
 
 4th Arch - - 
 
 28 
 
 1 
 
 0 
 
 O 
 
 .1 A 1 
 
 4th Arch - - 
 
 
 O 
 
 0 
 
 0 
 
 4th Pier - - 
 
 O 
 
 0 
 
 9 
 
 1 1 
 
 4th Pier - - 
 
 0 
 
 O 
 
 8 
 
 0 
 
 5th Arch - - 
 
 26 
 
 6 
 
 0 
 
 O 
 
 !5th Arch - - 
 
 36 
 
 O 
 
 0 
 
 0 
 
 5 th Pier - 
 
 O 
 
 0 
 
 10 
 
 I 
 
 
 
 
 
 
 
 
 
 
 
 
 
 6th Arch - - 
 
 25 
 
 5 
 
 0 
 
 O 
 
 
 
 
 
 
 6th Pier - - 
 
 O 
 
 0 1 
 
 10 
 
 3 
 
 
 
 
 
 
 7 th Arch - - 
 
 IS 
 
 10! 
 
 0 
 
 0 
 
 
 
 
 
 
 Total = 
 
 l 7°! 
 
 -r| 
 
 6S 
 
 0 
 
 Total = 
 
 200 
 
 O 
 
 34 
 
 0 
 
 By this Scheme it appears that the Water gains 29 Feet 6 Inches 
 in Breadth, more than it had done in the old Bridge. 
 
 EXPLANATION of Plate VI. Scale 30 Feet 1 Inch. 
 
 ^T^HIS Plate exhibits a Sketch Draft of the new Bridge, 
 I wherein note in Fig. A. Breadth of the Body of the 
 Bridge from out to out. In Fig. 2, B. the Rock. C. Surface of 
 the thorough Foundation. D. Low-water Mark. E. High-water 
 Mark. F. Pavement. 
 
 EXPLANATION*/ Plate VII. Scale 40 Feet x Inch. 
 
 9 I S HIS Plate reprefents the firft general Plan of Operation in 
 r* laying the Foundations ; wherein note, A. the Inclofure, or 
 CofTer-dam. B. Pit for North end. C. Ppol for the Pumps. 
 D. Water Ttunks. 
 
 In 
 
( 27 ) 
 
 In my defigning this Bridge, I conceived that it was abfolutely 
 neceflary to depart from one Rule laid down by L. B, Allerti, viz. 
 a That the Bridge muft be as broad as the Street that leads to it." 
 Now the Street leading to it on the South Side, was 'but twenty 
 feven Feet broad, including the Projection of the Pallifades, and 
 considering the great increafe of the City, I thought that it fhould 
 not be made lefs than fifty one Feet from out to out. fV efltninfter 
 Bridge, indeed, is but forty-four ; but the Pont Royal at Paris is 
 fifty two Feet broad, and this led me to think of forming a Plan, 
 to get a Street opened in a direct Line of fifty one Feet broad 
 from the Bridge to the Caftle, anfwerable to the Breadth of the 
 Bridge, which would then be conformable to Albertis Rule: 
 And fo having got all my Plans adjufted to the utmoft of my Abi- 
 lity, on the 20th of May 1752, 1 fet off again for London, under 
 thefe three ftrong Inducements, ift. To find out the Methods which 
 were at that Time in Agitation, for opening the Streets in London 
 and IVeJtminfter-. 2d, And principally to confult my Friends, and 
 to procure Advice concerning my intended Inclofure for laying the 
 Foundations. And 3dly, to procure feveral Utenfils, which I knew 
 I fhould want. 
 
 On my arrival in London, I foon acquired the Knowledge of their 
 Method of forming Plans, Maps and Schemes, for opening and 
 widening their Streets, and procured the three Acts of Parliament 
 palled there for thofe falutary Purpofes. 
 
 But as to my principal Bufinefs of procuring Information or 
 Advice, concerning my intended Inclofure for laying the Founda- 
 tions, 1 was not fo fortunate as to obtain it ; for after all my molt 
 zealous Endeavours, my Friends gave me no fort of Encouragement, 
 and having laid the Plan, Soundings and Borings before fet down, 
 before Mr. Labely, he freely told me, that he did not by any Means 
 approve of that Method of laying Foundations in Coffer-dams, as 
 he called my Inclofure, and he afTured me that if would not anfwer 
 my Purpofe. I then hurried away to my more intimate Friends, 
 Mr. Et ridge and Mr. Prefton, who were then carrying on the Pier 
 at Rant/gate, as I was extremely defirous of obtaining their Opi- 
 nionSj particularly that of the former, who had been not long .be- 
 
 E % fore 
 
( 28 ) 
 
 fore fent over to project a Bridge for Coleraine, and at that Time 
 was employed by fome of the Gentlemen of the Corporation of the 
 City, to view our ruinous Bridge, which he did. There was then 
 only a little trifling Frefh in the River; he faw the Rapidity with 
 which it fell; examined and informed himfelf about the Rough nefs 
 of the Bed of the River, the Depth of the Water, &c. So I was 
 fure there was no other Gentleman in England, that could be fo 
 good a Judge of my Coffer-dams, as I fhall now call my Enclofure. 
 Thefe two Gentlemen were very courteous and communicative, 
 and told me that as neither of them had feen that Method pradifed, 
 they could not give me any fort of Encouragement to attempt it ; 
 and the former concluded with thefe Words, 4 take Care that you 
 do not find yourfelf miftaken;' and the latter, with this friendly 
 and parting caution, 4 above all Things take Care that you do not 
 ipare Timber.' 
 
 As I have mentioned Ram/gate, I fhall only now obferve, that 
 that Work was then going on with great Spirit: To me it was 
 really wonderful to fee with what Dexterity they handled great 
 Blocks of Portland Stone, and with what Eafe and Deliberation 
 they laid them under Water. Mr. Prefton was fo kind as to favour 
 me with a rough Copy of their Plan, and I then obtained feveral, 
 and afterwards collected many other principal Matters relative to it. 
 
 Seeing the mafterly Proceedings in this great Work, made me 
 look upon my own little Projed in a very diminutive Light. How- 
 ever, after flaying there two Days, and hearing many Remarks 
 concerning the moll commodious Situation for a Harbour in the 
 Downs, I ported away to take a curfory view of that Coaft as far 
 as Dover. 
 
 I have mentioned above, that the fight of the Work at Ram/gate, 
 had given me fome fort of Confidence in the Succefs of my own 
 Project \ but I cannot help relating a very fingular Incident that 
 happened on my going down Dover-hill, which was fo fteep that I 
 was obliged to alight and walk down, and my hopes of Succefs 
 at that Inftant operating ftrongly in my Mind, I chanced to efpy a 
 leaf of a School-boy's copy Book lying on the Road, I took it up 
 and thereon found thefe Words, 44 The more pofriive thou art, the 
 
 more 
 
( 29 ) 
 
 more wilt thou he derided if thou mifcarry? This fhrewd, yet juft 
 Remark was fo a-propos to the Situation of my Mind at that Time, 
 that it made a powerful Impreffion on it ; and if it had no other 
 Effect, it at leaft made me thoughtful and referved. 
 
 I fhall not relate the various Opinions of feveral judicious Per- 
 fons, whom I confulted concerning my Inclofure, or Coffer-dam; 
 but in brief, I purchafed more Books in hopes of meeting with 
 fomething concerning it, as I found I could not acquire any prac- 
 tical Knowledge from profefled Artifts. I purchafed .two Chain- 
 pumps, three Double-fcrews, fix Jacks of different Sizes, two 
 Drudging-engines, and feveral Sorts of Tarrafs, and went to 
 Leigh near Warrington, to procure fome Leigh-lime (which as I 
 was informed, would fet under Water as well as Tarrafs) picked 
 up a few Labourers at Liverpool, and on the a 3d of June returned 
 to Duhlin. 
 
 CHAP. IV. SECT. I. 
 
 Concerning Coffer-dams, with a Jortunate Incident relative 
 
 thereto. 
 
 (f~\ N my return to Duhlin, I immediately fet about to fum up 
 and re-confider all the very little Knowledge I had acquired, 
 concerning Coffer-dams; the Refult of which was, that after all I 
 found myfelf in the fame Predicament I was before. Not one 
 Man had I feen or heard of, that feemed to be in the leaft ac- 
 quainted with the Subject; nor one Book that contained even that 
 Word, or conveyed the leaft Idea of the Conftruction of it, except 
 what I before mentioned; but fortunately for me, I went to en- 
 quire for fome Books at Mr. George Ewing^ and telling him of the 
 dubious Situation I was in, he informed me his Son Alexander y 
 was then on his Travels, and he believed by that Time in Paris. 
 I earneftly requefted he would write to him directly in the rood: 
 preffing Manner, to procure me at any Expence, all the Books, 
 Drafts or Plans, that could afford me any kind of Instructions for 
 
 laying 
 
( 3° ) 
 
 laying the Foundation of a Bridge about 25 Feet under High-water, 
 in a rapid River, and to fend them with all Expedition. 
 
 He moft zealoufly performed his Part, and it happened at that 
 Juncture, Colonel Belidor, had compleated his 4th Volume of 
 Hydraulic Architecture, which was fent me, together with the other 
 three Volumes; and alfo a perfpective View of the Men at Work 
 in a Coffer-dam, at the Bridge at that Time rebuilding at Orleans, 
 — The Language I was a Stranger to ; but on turning over the 
 Plates, I quickly perceived his Construction of Coffer-dams, as we, 
 now call our Inclofure. My drooping Spirits then inftantly re- 
 vived, and I immediately went on with my Work with Vigour, 
 and entertained the moft fanguine Hopes of Succefs. 
 
 SECT. II. 
 
 Concerning the Conftruclion of Batterdeaux, or Coffer-dams. 
 
 "f 17E have already noted the French Method of laying Foun- 
 \ V dations in Batterdeaux, which is their technical Term for 
 damming off the Water; and it is the very fame of that practifed by 
 the Romans, as is before flightly mentioned by Alberti Faladio, and 
 Scammozzi, which is tranflated Inclofure; and 1 think there is no 
 doubt, but that the French have not only retained, but improved 
 and extended this moft ufeful Method, which probably has never 
 been acquired, at leaft not much practifed in any of thefe King- 
 doms, or otherwife, there probably would have been fome men- 
 tion made of it in fome of our Books; but particularly in fuch as 
 were relative to the building of Bridges, or the like Work in 
 Water. They have indeed, of late tranflated the Word Batter- 
 deaux, and rendered it Coffer-dam, which I prefume, is a Word 
 or technical Term not ufed, nor even fo much as known in the En- 
 glijh Tongue before the Year 1734; about which Time it was 
 introduced in iome Proportions concerning Wejlminfler Bridge ; 
 for if the Engli/h (who are fo juftly celebrated for Learning and 
 Ingenuity) had been acquainted with this Word, or with this Me- 
 thod of laying Foundations for Bridges, it is not to be fuppofed, 
 
 that 
 
; f!|f : . W?:^ fi^mr - ^ : : fifl 
 
 that the Authors of the univerfal Dictionary of Arts and Sciences, 
 and innumerable other Books, would have intirely over-looked an 
 Art of fuch public Utility. 
 
 It was in the Year 1737, that the Act paffed for building a 
 Bridge at tVejlminfter, on which many Plans and Schemes were 
 projected; but how to lay effectual Foundations, was the principal 
 Thing that engaged the Attentions of the Commiffioners. Mr. 
 Labely propofed to lay them in Caiffons, but feveral ingenious 
 Gentlemen moft earneftly recommended Coffer-dams: Now pleafe 
 to obferve Mr. Labely s Objection to Coffer-dams, taken from his 
 Defcription of Wejlminfter Bridge, Page 41. 
 
 Proportion 3d, " Why could not the Foundations of the Piers 
 have been laid by the help of Coffer-dams, fuch as are called by 
 the French Batterdeaux ?" To which Mr. Labely gives the follow- 
 ing anfwer. 
 
 u That if thelnclofure is not ftrong enough in the infide, it will 
 not be able to fupport the Preffure of the external Water ; but ad- 
 mitting it was ftrong and {launch, he calculates that the ouzing 
 in of the Water through the Pores and Interftices of the Gravel, 
 loofe Clay or Sand, would amount to a Hole of fix Inches Square, 
 which, he fays, is much under the Truth, and that it would give 
 above 770 Tuns per Hour, which is more than 70 Men could 
 pump out, fuppofing them to Work always with the fame Strength 
 both Night and Day; and more than 150 Men, or 30 Horfes 
 could do, working as they commonly do." And proceeds, u All 
 that I fliall add to this Article is, that forhe of the Perfons who 
 propofed or efpoufed this Method of making an Inclofure round 
 the intended Pier with Dove-tailed Piles, and pretended to drain 
 the Water from within, might remember how fruitlefs was the 
 Attempt, or rather Experiment that was made of it in Hide-park f 
 not many Years ago." 
 
 Note 1 ft, " As to his Aflertion, that the ouzing would give 770 
 Tons per Hour." 2d, " That they might remember how fruitlefs 
 was the Experiment not many Years ago." Pray does not this 
 prove that we are not acquainted with this moft excellent Method 
 
 of 
 
( 3* ) 
 
 of Working ? And how neceffary it is to have it cultivated amongft 
 us, I fhall leave you to judge on what follows. 
 
 Now it is probable that the Story of Columbus's Egg will occur 
 to the Mind of the Reader, when he turns to Plate VIIL where he 
 will fee Colonel Belidor's Conftruction of a Coffer-dam, fo clear' 
 and fo intelligible, that from the bare Glance of an Eye, any com- 
 mon Journeyman Carpenter might readily comprehend it. 
 
 EXPLANATION / Plate VIIL Scale 5 Feet 1 Inch. 
 
 Fig. 1, is the Plan of it with the flieeting nailed on the Piles, 
 juft ready to receive the Clay; that Fig. 2, reprefents the Section 
 of the Dam in the middle of the Bridge; A. low, and B. high 
 Water marks, and it is in this Place 17 Feet broad, but that 
 Breadth diminiflies to 12 Feet up, and to 14 Feet down the River, 
 as you may obferve in the laft Plate ; and alfo, that the extreme 
 Ends of it are let into the Quay Walls, fo as the Clay of the Dam 
 and the Earth of the Banks might unite together. 
 
 The Braces, C. are only to be ufed occafionally, for .all the 
 Stages ought to be kept clear, and in Cafe any part of the Bed of 
 the River fhould prove fofter than another, and the Dam inclines 
 to one Side more than to the other, drive down the Pile e. into 
 the Bed of the River D. and then by the help of a Rope and a Boat- 
 hook, you may guide the point of the Shoe of the Brace-pile f. 
 into a kind ot Mortice, or a Hole made for it in the Pile e. at the 
 Surface of the Bed of the River; and if you find the Preffure is 
 great (which is no Way improbable on fome Ground) then you 
 may Spike on the Slob or Plank g. and if you pleafe alfo Spike it 
 to the Dam at h. and all this you might do on the out Side of the 
 Darn alfo; in Cafe the Water was 8 or 10 Feet deep, but it was 
 Experience that taught me the Ufe of thefe Braces, and they were 
 very ferviceable to us. 
 
 I mu ft alfo obferve, that the Piles of Colonel Belidors Coffer- 
 dam were drawn upright as thefe are, and that as I did not under- 
 ftand French, and could not conveniently get it tranflated, I do 
 not know what he wrote upon it; but this I am certain of, that 
 
 the 
 
Fl 
 
 &. 
 
( 33 ) 
 
 the Caps of the middle Rows, of piles, ought to be morticed 9 or 
 12 Inches narrower, than the Rows are in perpendicular, and in 
 putting them on, to ftrain the Piles together with a twitted Rope,, 
 till they are brought to anfwer the Mortices of the Caps, and then 
 ftrain the other outward Rows till they anfwer the fame Batter; 
 for this equal Batter on each Side, makes the whole Dike fit fteady 
 and firm on the Bed of the River. 
 
 I muft now acquaint you with an exceeding great Misfortune 
 which we had to furmount. You have feen both in our Sound- 
 ings and in our Borings, that within 60 Feet below the Bridge, 
 the Water was about 23 Feet deep^ particularly at Boring N° 24, 
 and that by the Failure of the Pier and in pulling down the re«- 
 mainder of the old Bridge, it was utterly impoflible for us to prevent 
 the Water carrying large Stones down the Declivity, and a very great 
 Part of the coarfe Rubbifh naturally declined into that deep Water- 
 and we found when we were drudging for a clear Seat for our Dam^ 
 that it was in a Manner impoflible for us to get up much of the Stones 
 and Rubbifh: We could, indeed, with our Brakes turn them up, but 
 they tore and totally deftroyed our Drudging-bags, and we could not 
 find out any other Way in fuch deep and rapid Water to get therm 
 taken up, and fo we were under an abfolute Neceflity of leaving 
 them there; and upon the top of them we were forced to make that 
 Part of our Dam, and even that was attended with much trouble^ 
 becaufe when we were driving our Piles, we often happened on 
 fome of the large Stones, that with the ftroke of the Ram they 
 frequently tore and burft the Shoes of our Piles to Pieces; but this 
 was not all ; as the Bridge was built on the Bed of the River,, 
 the Rapidity of the Water between the Piers was continually 
 wafhing away the Bed of the River, efpecially at the Stern of the 
 Piers ; and in order to prevent that, they had frequently from 
 Time to Time, thrown in large Quantities of rough Stones, to 
 fill up what had been fo wafhed away, and afterwards the great 
 Floods tumbled many of them down the great Declivity of the: 
 Bed in that Place, fo that there was, as it were, a Wire or a Stone 
 Dike almoft quite a-crols the River, about 65 or 70 Feet below 
 the Bridge,, which we did not in the leaft perceive,, nor fufpec\ 
 
 F when. 
 
( 34 ) 
 
 when we were boring, as we did not bore any to the Eaftward but 
 N Q . 22, 23, and 24. and by their filling up and raifing the Bed of 
 the River, they alfo concluded, that they had thereby taken off the 
 Rapidity of the Water: In fhort, the force of the Water had car- 
 ried away every Thing it could, and left little behind it but coarfe 
 Rubbifh and Stones, which were juft like a French Drain under 
 our Dike, and the great Wonder is, that we were in any Ways 
 able to conquer it, nor fhould we have been able to do it but by 
 this one Method. We drudged all we could come at away, as 
 clear as we could from the Back of the Dike, and immediately 
 filled up the Vacancy we fo made, by throwing in feve;ral Floats 
 of Clay, which united with the Clay of our Dam. If you ever 
 happen in any fuch diftreffing Circumftances, I advife you to fpare 
 neither Money nor Time, to clear the Seat of your Dam of all fuch 
 loofe Stones and coarfe Rubbifh, before you begin to make your 
 Dam, and then you will not have the leaft Trouble nor Anxiety 
 about it afterwards ; for of all the Methods that have been invent- 
 ed, I believe there are none fo fecure, nor fo pleafant to execute, 
 as that of building and laying your Foundations on Terra Firma : 
 Nor is there any fort of Difficulty in accomplishing it in any rea- 
 fonable Depth of Water, provided you work on frefh maiden 
 Ground, that has not been fouled or incumbered with Stones. 
 
 I muft further advife you if ever you have a Bridge to build in 
 pretty deep Water, do not be difcouraged by Mr. Labelys erro- 
 nious Calculation, of 770 Tons per Hour. — The Circuit or Ex- 
 tremity of our Dam, was much greater than any that he would 
 want for one of his Piers, upon which he made his Calculation; 
 and I affirm that notwithftanding the Roughnefs and Loofenefs of 
 our Ground, after we got our Dam (launched as before mentioned, 
 we wrought with great Eafe and Pleafure at the North end, which 
 was upwards of twenty one Feet under our high Water mark, and 
 for many whole Tides together, not a fmgle Hogffiead of the ex- 
 ternal Water ever annoyed us ; and I am very fure that by the 
 Methods hereafter directed, you may lay a Foundation thirty Feet 
 under high Water mark with great eafe, provided as before-men- 
 tioned, 
 
( 35 ) 
 
 tloned, you have clean frefli maiden Ground to work upon in a 
 moderate River. # 
 
 CHAP. V. 
 
 Concerning Pile and Pump Engines. 
 
 BEFORE I treat of the Pile Engine, it is neceflary to inform 
 you, that in frefli Water Rivers of 5 or 6 Feet or more in 
 Depth of Water, you probably may have very little trouble in 
 making your Dams ; recollea how (lightly Alhrti fpeaks of getting 
 a few Hedge-ftakes and the Branches of Trees, &c. to make them, 
 and even in the upper end of our Dam, neither the Trouble nor 
 the Expence was of any great Value, which we performed after 
 this Manner. We floored one end of a fmall Float, and on that 
 let two Treflels of about 4 Feet high, and in driving the middle 
 Rows, we eredted another Stage of the fame Height over the firft, 
 and drove them with double-handled Mauls, and probably it will 
 not be neceflary to flioe them with Iron, but juft point them or 
 burn the Points of them in a Fire to harden them, obferving to 
 begin at the Head of your Dam, and drive the out-fide or in- 
 fide Piles juft as the Tide anfwers, and always take Care to keep 
 your Float tightly moored up to your Work, for which purpofe it 
 may be neceflary to have a Sea-faring Man to help you : Let your 
 Mauls be well hooped and ftrapped with Iron, otherwife the 
 Hoops may be liable to come off with the driving : According as 
 you drive in your Piles (if the Water be rapid) it may be very 
 proper to nail Pieces of Slabs or the like, to keep them together, 
 left the Current fhould difplace them; and after this Manner you 
 may do very effectual Work without an Engine. However; I (hall 
 give a Draft of ours, which I took partly from V aulous y and partly 
 from Belidor\ Defigns, as follows. 
 
 EXPLA- 
 
( 36 ) 
 
 EXPLANATION / Plate IX. Scale 4 Feet 1 Inch 
 
 This Plate fliews the framing of the Platform of the Pile-engine 
 in Fig. 1, where in the dotted Lines a. {hew, that after it is floored, 
 there mult be Ledges nailed on to give firm hold to the Feet of the 
 Men that work it ; h. is the Block into which a Brafs Socket is to 
 be fixed for the Axes to Hand upon, and this Block muft be Aided 
 over to c. which you will find further defcribed in the nth Plate; 
 d. is the Ladder to bring you to the fecond Floor, viz. Fig. 2, in 
 which note that e. is another Block to be framed in its Place with a 
 Collar of Brafs, left open quite through the Block, over which there 
 muft be a Shutter or Lid to keep it free from Dirt, or to greafe it 
 when neceilary. 
 
 EXPLANATION of Plate X. Fig. 1. fame Scale as 
 
 Plate IX. 
 
 This reprefents the Front of the Engine, with the Ram and 
 Follower retting on the Head of the Pile. Fig. 2. is the Follower 
 playing in its Grooves by a Scale of 1 Inch = 1 Foot. Fig. 3. (by 
 the fame Scale) fliews the Section of the Follower and Ram, feem- 
 ingly juft ready to engage one another, as alfo, how the Tongs 
 are opened by the two inclined Planes, a. a. 
 
 EXPLANATION / Plate XI. Fig. 1. Scale 4 Feet 
 
 1 Inch, 
 
 Reprefents the Section of the Engine from Front to Rear, wherein 
 cote, that the Block k above-mentioned, is occafionally to Hide 
 over to c. and one half of the Block a. muft be firmly bolted down 
 to the Floor, and the other half opens and fhuts with a Hinge 
 about the Axes, with Semi-brais Collars, obferving to leave pro- 
 per Room above your Drum-head, for the Axes to lift fo high as 
 to clear the Socket of the Block b. at any Time, when you have 
 pccafion to repair it ; d. is the Spring that locks the Drum to the 
 
 Shaft. 
 
( 37 ) 
 
 Shaft. Fig. 2. (by an Inch to a Foot) is the Plan of the Ram; 
 and Fig. 3. is the Upright of it with the Staple, that the Tongs 
 take hold of. This Ram is only four hundred and a half, which 
 may be fully fufficient for thefe or the like ordinary Occasions ; and 
 for more weighty Work, you may on the fame Principles propor- 
 tion the Size of the Ram to the Size of the Engine which you 
 think you will want. 
 
 EXPLANATION of Plate XII. Scale 8 Feet 1 Inch. 
 
 Fig. 1. is the Plan of the Timber of the Floor of the Pump- 
 Engine, with the Situation of the 8 Pumps, and Centre or Socket 
 of Brafs, on which the main Body plays. 
 
 Fig. 2. Section of the Engine, wherein note, that a. is the 
 bottom of the Pool; b. Low-water Mark; c. is the Inclofure of 
 Piles and Boards that keep up the Banks of the Pool; d. High- 
 water Mark ; e. open Gutters, that convey the Water from the 
 Pumps over the Dike; f. both in Fig. 1. and Fig. 2. and D. in. 
 Plate VII. are the Trunks that either carry off the interior, or let 
 in the exterior Water occafionally at Low-water Mark, to which 
 there were Sluices fixed in the middle Stage of the Dike, that were 
 wound up and down by a Jack. 
 
 From my fir ft forming an Idea of the Inclofure, my Mind was 
 conftantly op pre fled with the dread of its burfting in upon the 
 Men, when they were at Work in the Pit as before-mentioned; 
 from which intolerable Anxiety, I was relieved by contriving thefe 
 Trunks. I cannot tell whether Colonel Belidor ufed any fuch 
 Thing, becaufe as I before obferved, I was ignorant of the Lan- 
 guage he wrote in; but I am well allured, and you will hereafter 
 find, that they were of infinite Service to us. \ The other Parts ot 
 this Engine are obvious, as indeed, there is karcely any good Mill- 
 wright but what may comprehend and execute the whole Co li- 
 ft ruction of it. 
 
 Having now to the utmoft of my Power fully confidered every 
 •Tiling relative to this Work, I fat down, and by the Affiitance of 
 my Bi other John, made an Eftimate of the Expence, fuppofing the 
 
 Balluft 
 
C 33 ) 
 
 Balluftrade to be made of Fire-ftone ; and we found it amounted 
 to twenty thoufand Pounds, and I promifed that I would not ex-^ 
 ceed twenty thoufand five hundred, for we allowed the five hun- 
 dred for Incidents ; and I computed, that within, or about the Space 
 of two Years, from the Day upon which I fhould flop up the old 
 Bridge, that a fafe new Road might be made over the new Bridge 
 for Carriages ; and upon thefe Calculations and on mature Deliber- 
 ation, I made the following Declaration, not only to the Overfeers 
 with whom I treated, but alfo, promifed to the Lords Juftices, to 
 the Committee of the Houfe of Commons, and to the Public in 
 feveral Papers to this Effect. 1 ft. That I would build them a 
 Bridge that fhould ftand as long as a little adjacent Mountain called 
 Suga; loaf-hill. 2d. That the Expence fhould not exceed 20500 /. 
 3d. That I would have a Road opened for Carriages over it, 
 within or about two Years from the Day of my flopping up the old 
 Bridge as above-mentioned; but I did not any otherways bind 
 myfelf to the Performance of any of thofe three Articles, yet not- 
 withftanding, I looked on myfelf to be as much bound to the 
 Performance of them, as though I had engaged for them under 
 my Hand and Seal, and flaked any little Reputation I had acquired, 
 faithfully and effedually to perform- them to the utmoft of my 
 Power. 
 
 CHAP. VI. SECT. I 
 
 Of demolifhing the old Bridge. 
 
 WE began on January 19th, 1753, to flop up and demolifh 
 the Bridge, and take down the Equeftrian Statue of King 
 George I. which had been put up in 1722. 
 
 February 19th, we drove the firft Pile of the Coffer-dam. 
 In pulling down the Bridge, we began at the South, and took in 
 the largeft half of it in order to open and deepen that Side, to let the 
 whole Current run there. In doing of this, I found it neceffary to 
 make a temporary Dam*, to turn the River to the North, in order 
 to lengthen the Time of Ebb, and clear away the old Ruins, tS c. 
 * After 
 
( 39 ) 
 
 After this Dam was made, we were going on very fuccefsfully till 
 the 28th of April, when there came down a pretty ftrong Land- 
 flood, which obliged me to take the Men off that Part of the 
 Work. I then ftood on the northerly Part of the Bridge, dread- 
 ing the Fate of our poor little Dam, when I efpied the Water 
 within Side of it grow very black, the caufe of which I well knew 
 to be the blue Clay burfring out, and I hurried down to it in order 
 to fee if there was any Poffibility to fave it; but the very Moment 
 I had got on the top of it, I found the whole rife up under me, 
 and had not above a fecond of Time to fave my Life ; for the 
 Floor that was on the top of it turned immediately down, and the 
 Points of the Piles rofe up, and notwithstanding the Adivity of 
 the Men, great Part of it was carried down the River; but this 
 fricrht was of much ufe to me, for as the caufe was the Floods get- 
 tino- in under the Clay, I was ever after on my guard by making 
 our & great Dam in fuch a Manner, as might refill the Force of any 
 Land-flood or Torrent. 
 
 May 3/, the laft of the Piles of the Coffer-dam was drove, and 
 June 4th, we began to fill the Clay into it, and the fame Day 
 having taken up all we could of the Foundations, we began to 
 deepen it by drudging. 
 
 SECT. II. 
 
 Defcription of the Foundations. 
 
 HE Foundations of this Bridge, or rather the Piers of it as 
 before mentioned, were built after this Manner. They 
 made Frames of Oak of 9 or o Inches Scantling, the exad Shape 
 of the Pier, with rough two Inch Planks of Oak Dove-tailed a- 
 crofs it, in every three or four Feet and pinned to the Frame, and 
 on thefe Planks they ftretched other Planks Length-ways but not 
 fo thick. Thefe Frames fo made, they dragged to their Birth, 
 and let them reft upon the natural Surface of the Bed of the River. 
 The Piers being extremely grofs, increafed the Rapidity of the 
 Water between them, and the Bed of the River (as you have al- 
 ready 
 
( 40 } 
 
 ready feen) being ftiarp Gravel, the Floods fwept it down as be- 
 fore-mentioned, and indeed, the only Thing furprizing is, that it 
 flood fo long. 
 
 Now I am come to one particular Circumftance, which I recom- 
 mend to your ferious Attention, as I fhall hereafter endeavour to 
 draw fome ufeful Inferences from it. After we had got fome of 
 thefe Frames taken up, particularly the third, we found under the 
 inner Part of it, a fmooth Floor of clean fharp Gravel, hard and 
 firm under our Feet; but when we thought to go on with filling 
 the Floats with it, to carry it away, as we had done in the Bed of 
 the River between the Piers, we found it very hard, and as the 
 Shovel could not move it we tried the Pick; but when we had got 
 a little further into it, the Pick made little Impreflion upon it, and 
 when we got further into it, we found that we had no other Way 
 to break it, but by undermining it, and then break it off in Pieces 
 with the largeft Sledge we had. The middle of it was an actual 
 Petrification of about a Foot thick, but not fo hard in the bottom 
 as in the top. Some of the Piers were much more petrified than 
 others, and particularly this, as being better guarded by the Bafe 
 of the Effigy, and having imbibed the petrifying Qualities that 
 foaked from it. The Grit or Grain of it greatly refembled that of 
 a Mill-ftone ; but the Colour was juft the fame with the Bed of 
 Gravel it lay upon. Where the Gravel partook of Mud 9 the Pier 
 that lay on it was not near fo hard, and thofe Piers did not petrify 
 at all that lay on Beds that were not gravelly. 
 
 ;s E C T. III. 
 
 Breaff-work for the North Abutment, /hewing the Method of keeping 
 up a Bank of loofe made Ground upwards of 30 Feet high, on 
 only ten Feet Projection. 
 
 WE began June 8th, to fink for the Abutment, which was 
 a Piece of Work I was afraid would be attended with very 
 great danger, becaufe I had a very great Depth to fmk ? and very 
 
 little 
 
little Room to fink upon, without depriving the Public of the ufe 
 of the Carriage Way. 
 
 EXPLANATION of Plate XIII. Scale 5 Feet 1 Inch. 
 
 In this Plate, Fig. r. reprefents the Method I took to keep up 
 the Br e a ft of the Bank, wherein note, A. Pavement. B. High-water 
 Mark, which is 9 Feet 4 Inches from the fame. C. Low-water 
 Mark = 1 o Feet. D. Bottom of the Pit 1 1 Feet, that is == 3 1 Feet 
 4 Inches. E. Is the whole Projection of the Breaft-work, which 
 is 10 Feet, and that I divided into 4 equal Parts, allowing 2[ Feet 
 to each Stage. Having ftrained a Line at right Angles to the in- 
 tended Bridge, and 10 Feet from the back of the Abutment, we 
 funk about three Feet, and then drove in a range of 4 Inch Piles 
 clofe to the Bank; then with paving Hammers we chipped orT fo 
 much more of the Bank as juft barely admitted the fheeting to Aide 
 down between the Bank and the Piles; and when we had funk 8 
 Feet in this Manner, we made our firfl: fet off % \ Feet, and pro- 
 ceeded in the fame Manner as you may perceive by the Draft ; but 
 after we had got down to the third Stage, we always kept Braces 
 againft the Breaft-piles, which we removed down according as we 
 funk ; and notwithstanding the almoft conftant running of Carriages, 
 and the Banks being all made Ground, there did not fall one 
 Handful of it in upon us. When we had got down to about the 
 third Stage, or a little under Low-water Mark, we had all above 
 us compofed of various forts of made Ground; but from and about 
 that level we found the Ground begin to incline to fine fandy blue 
 Clay, fometimes mixed with Shells, and fometimes with Leaves, 
 which we took to be Bay-leaves, all of which, we concluded had in 
 former Times been left there by the Sea and River, becaufe we got 
 in it a fmall Tree almoft rotten, with fome of the Branches ftill 
 upon it; at the Butt it was about 4 Inches Diameter, but no one 
 could tell with Certainty what fort of Wood it was of; from all 
 which, I concluded that I did not raife any frefh or natural Earth. 
 
 It is not my Intentions to give a minute Detail of all the various 
 Circumftances relative to our Proceedings, for that, perhaps, 
 
 * G would 
 
( 42 ) 
 
 would be more tirefome than inftruclive; and therefore, I only give 
 a concife Abilra£t of a few Particulars taken from our Diary, in order 
 to convey a juft Idea of the whole of that Work ; but having made 
 one very extraordinary Difcovery in this Place, which alarmed 
 every Man in the Work, and greatly furprized a vaft Number of 
 Gentlemen that faw and examined it, I fhall relate the principal 
 Parts of it in the next Chapter,' and referve the Explanation of 
 Fig. 2r. for a more convenient Opportunity. 
 
 C H A P. VII. 
 
 An extraordinary Difcovery at eleven Feet leneath Low-water 
 
 Mark. 
 
 AVING got fome Part of the North End of the Pit funk 
 down to about ten Feet beneath Low-water Mark, and 
 quite free from Water, except fome fmall Quantity that foaked 
 from the Bed of the River, which was then about the fame Space 
 above us, and that we conveyed into the S. E. Corner for the Screw- 
 pump; the Men that were finking for the Land Abutment per- 
 ceived one Spot in the Ground that grew very wet, but did not 
 much regard it; but in finking the next Spade which was about a 
 Foot deeper, when they had laid open that wet Spot, we were all 
 greatly alarmed by the very ftrong boiling up of the Water juft in 
 that Place. I fent immediately for my Book of Barings, and found 
 that wet Spot was Boring N°. 28. 1 immediately called for one of 
 the Boring-pipes, and had it drove down to the Rock, and the 
 top of it was 3; Feet above that Floor, on driving of which the 
 boiling entirely flopped. This gave us fome Spirits, and the Men 
 went on with their finking that Floor, but at this Time the Tide 
 was at Ebb; but when the next Tide rofe to about fix Feet, it 
 began to boil over the Head of the Pile, and increafed in force as 
 the Tide rofe, and fo greatly wet the Work that we found it ad- 
 vifable to plug up the Pipe, and fo we continued to hurry on the 
 Work, without taking any further notice of the boiling, except 
 looking on our Jetteau as a Matter of Curiofity, which during the 
 
 Time 
 
( 43 ) 
 
 Time of High-water and after it, when we would pull out the 
 Plug, would play upwards of a Foot above the Head of the Pipe 
 with great force. 
 
 The Rev. Doctor Hudfon, who was a very curious and conftant 
 Obferver of our Proceedings, came to the Work the next Morning, 
 and I brought him with feveral other Gentlemen to the Work, to 
 fee our curious Jetteau: He called for a Glafs, and they all tafted, 
 fnielled and attentively obferved its Colour. They then dropped a 
 Piece of Silver into the Glafs, which was foon turned to a dark 
 yeliowifh Colour; and at Length, they all concluded that it was a 
 mineral Spa, and advifed me to fend directly for Doctor Rutty, for 
 whom I went myfelf, and he cheerfully came with me, the Gen- 
 tlemen waiting for us : He tried all the before-mentioned Experi- 
 ments over again, and acknowledged, that it feemed very like the 
 Water of Swaddling-lar\ but concluded, that any Sea-water that 
 partook of putrid Water, running from a foul Sewer, might have 
 the fame Effects that had, and he defired me to fend fome of it 
 home with him, which I accordingly did. 
 
 This Affair engrofled my whole Attention, and put me upon 
 making the following Experiment. See Plate 4. Boring N°. 28, 
 and fee thatN°. transferred to Plate 5. which is the Boring men- 
 tioned above. I then had two other fimilar Pipes drove at ten Feet 
 diftance from it to the Eaft and Weft, viz. 29 and 30, and I bored 
 them in the like Manner at Low-water, and as the Tide came in, I 
 found the Water rife in all the three Pipes exactly alike, and at or 
 foon after High-water, they all played together when we took out 
 the Plugs, near a Foot above the Heads of the Pipes, which were 
 all on a level; and as the Tide fell, they abated in their Force, but 
 never funk lower than the- tops of the Pipes, which as I fa id above, 
 was 3; Feet higher than the bottom of the Pit, and confequently 
 j I Feet under Low-water Mark. 
 
 The next Morning Doctor Rutty, and Doctor Hudfon came to 
 the Work, where they met the Gentlemen that were thert the Day 
 before, and he, Doctor Rutty, then affured us, that it was. no 
 Species of Spa-water, but he believed, a* large Body of fubterraneous 
 Water, that ran alAbf on the Surface oi the Rock, and : ccmoiur*i- 
 
 G % cated 
 
( 44 ) 
 
 cated with the Sea-water, and partook alio, of the foul Waters of 
 the Bed of the R iver and the Sewers. He then produced us as 
 much Salt as would cover a Shilling, which he faid, he had ex- 
 tracted from one Pint of that Water, which was not near fo much 
 as a Pint of Sea Water would produce; and concluded with giving 
 me this friendly and ufeful Caution, " take great Care that you 
 do not let that Water break up upon you, for if you do, you will 
 never conquer it." 
 
 This Opinion of Doctor Rutty s coroborating with my own, it 
 was inftantly circulated among all the Men in the Work. They 
 all unanimoufly joined in exerting themfelyes to the utmoft of their 
 Abilities; for that Water alone, was not the Caufe of our Anxiety, 
 as we were at that Time thirty-one Feet deep under the Surface of 
 the Pavement, which was within ten Feet of being perpendicular 
 over us, and all being made Ground, with a fine Sea fandy bottom, 
 which notwithftanding all the Precautions we had taken in fink- 
 ing and fhoring up our Breaft-work, we well knew, that if the 
 fmalleft Quantity of Water mould then get into the Pit, it would 
 moft afluredly lap and foften that fine Sand, which together with 
 the continual making of the Ground by the Carriages, would ren- 
 der it impoffible for us to prevent its burfting in upon us, and in 
 all Probability pull in the Corner-houfe along with it. 
 
 Hereupon we agreed, that it would be beft and fafeft for us to 
 defift from finking any deeper, though that was no fmall Difap- 
 pointment to us, as we then bad thoughts of going down to, or 
 very near the Rock, nor otherwife had we any Difficulty to en- 
 counter with in accomplishing it ; for the Floor we were then level- 
 ling and clearing out next to the Bank, was perfectly free from 
 Water, except what little fprang up with the three Pipes; but 
 remembering Doctor Rutty* s Caution, which I knew to be well 
 founded, I proceeded with all poffible Expedition to make the 
 Mafons fecuye the bottom of the Breaft-work. 
 
 September 23, The Mafons began to lay the thorough Founda- 
 tion, but particularly to fecure the bottom of the Breaft-work, 
 which extended about 1 5 Feet from the Bank, and in the mean 
 Time the Labourers were clearing out and levelling about %o Feet 
 
 more, 
 
( 45 ) 
 
 more, which being juft accomplifhed they were hurrying in Stones 
 to be ready for the Mafons, except one Man, who was left to throw 
 out and level fome fmall Matter which they left undone; but all 
 the alarms and frights we had met with, were nothing to a frefli 
 Difcovery which that Man firft obferved; the Floor (which was 
 clean, fmooth and dry) opening, I was inftantly called, and when 
 I got on the Spot, could clearly perceive the Ground fwelling up 
 and opening, (See N°. 31, in Plate V.) and it fopn extended to 
 about the Length of 10 Feet, turning rather foutherly at the Weft 
 End, and the Crack or Opening was about three or four Inches wide 
 in the Middle. The Tide was then about ten Feet high, and in 
 the Middle of the Crack we found the Water beginning to fpring 
 up, which gently increafed to about a Foot Diameter, and fprang 
 pretty faft. I called for another Pipe of the fame Length, and had 
 it drove down in the Centre of the Ebullition, or Boiling up, till 
 it came to the Rock, and having bored and cleared it as before, 
 which eafed and gave it vent, we found the Water rife up, and in 
 FacT: the very lame fort as came up in the three former Pipes, and 
 to the fame level, altho' this Pipe was 1 7 Feet to the South of them; 
 and we plugging up this Pipe alfo, the Men did all in their Power 
 to get in Stones and Mortar ready for the Mafons, and in the mean 
 Time the Water that fprang up through the Crack, rofe 1 8 Inches 
 deep in the lower Part of the Pit; but providentially we then had 
 the Mafonry built above fix Feet high againft the Bank ; but when 
 the Ebb came it defifted, and we foon got out the Water, and 
 laid the largeft and flatteft of our Stones upon the Crack, fpread- 
 ing fome Litter under them, and before the next Tide had that 
 Part of the Foundation almoft as high as the other ; for, from the 
 Time of our getting the Bridge taken down to High-water, we 
 wrought both Night and Day, without one Minute's Intermiffion, 
 as we had two fets of all forts of Men that relieved one another 
 alternately every eight Hours, not excepting even Sundays, when 
 our urgent Occafions required it: Yet, notwithftanding we had 
 luckily conquered that fubterraneous Water at fo critical a Time, 
 it never failed every Tide, whilft we wrought in that Pit to con- 
 tribute greatly to the increafe of the Pump-mens Labour; but as 
 
 we 
 
( 46 ) 
 
 we wrought with unremitted Perfeverance and great Expedition, 
 we moft fortunately prevented its Burfting up upon us. And of 
 this I am well allured, that if we had not that Inftant loaded that 
 opening of the Ground, the lubterraneous Water would certainly 
 have broke in upon us, and if it had, there could have been no 
 Kind of Ppffibility of ever building a fubftantial Bridge in that 
 Place, conlidering the Condition that every Thing was then in, 
 and fo many thoufand Pounds worth of Labour and Materials 
 would have been totally loft, and our then hopeful Projects entirely 
 at an End, as Doctor Rutty had told us. 
 
 CHAP. VIII. 
 
 A Continuation of the AbJlraEl of our Diary, and laying the Foun~ 
 dations of the North Pier, 2 1 Feet beneath the ufual High-water 
 Mark. 
 
 1"¥7E made the firft Trial of our Coffer-dam on June 27th, 
 V V and it kept out 3 Feet 6 Inches of that Tide. July 3d, we 
 fcrewed down the Sluices when it was High-water, and kept them 
 down till half Ebb, in which Time the Water in the Dam fell three 
 Inches, and thus we tried and proved its Stanchnefs feveral Times, 
 both backward and forward; but the South Eaft Corner of it that 
 ftood on the great Depth of Stones that had been carried down 
 by the Floods into that deep Pool, was like a French Drain (as 
 before-mentioned) which we began to defpair of ever getting made 
 even tolerably ftanch. 
 
 July 7th, we fcrewed down the Sluices at low Water, and before 
 high Flood, difcovered that the Tide Water had wrought its Way 
 in under that South Eaft Corner through the Stones and Rubbifli 
 of the old Bridge, and began to fpring up about 20 Feet within 
 our Dam after a very furious Manner; on the firft Appearance of 
 which, I ordered the Sluices to be fcrewed up and let the Tide in, 
 by which we drowned the Springing, which did us very little harm; 
 and at low Water I fet all the Drudge and Water-men to that Cor- 
 ner, bo tli without and within, and in fhort, we took out and re- 
 moved 
 
( 47 ) 
 
 moved from that Corner every Stone that was in our Power, and 
 filled the Vacancies with Clay, & c. 
 
 Aug, 3d, The Sluices were fcrewed down at low Water, and 
 when there was nine Feet Flood without, the Water had rofe only 
 thirteen Inches within. 
 
 5th, After an exceeding heavy Rain there came down a fudden 
 rapid Flood, and tore away many of the Ships and Lighters from the 
 Quay, fnapping their Moorings as a burned Pack-thread, and did 
 them great Damage, but we were prepared for it, and kept open 
 our Sluices, fo that the Water then rofe as faft within as it did 
 without; but it did us no other damage than delay us a little, and 
 warn away fome of our Clay; and after all this, the next Day we 
 proved the Dam again, and during the whole Tide, the Water 
 within rofe only four Inches. 
 
 EXPLANATION of Fig. 2. in faid Plate 13. 
 
 Wherein note, F. The Rock. G. Strata of fine fandy Loam,, 
 which is in this Place, three Feet fix Inches thick from the Rock, 
 on which the rough Stone Work begins. H. The laft Courfe of 
 the rough Stone Work, which is laid with very large Stones carefully 
 bedded and wrought clofe in their joints, to guard the thorough 
 Foundation between the Piers from ever being difplaced, or torn 
 up by the Water, which is about four Feet deep at low Water. 
 i. u i. Fig. 3. Are the Ends of three Four-inch Planks that ftretch 
 quite a-crofs the Foundation, and on which the Sills of the Centres 
 k. reft. When you are doing the like Work, obferve that between 
 thefe running Planks and Sills, to lodge in Wedges of about %[ 
 Feet long, leaving about one Foot of them out, and when you 
 come to ftrike your Centres, defcribe or mark them deep, that you 
 may know how far you bring each of them out, by {hiking each 
 Wedge on each Side, and by that Means you will work out the 
 Wedges by Rotation^ till you have eafed every one of them about 
 one Inch, and then proceed after the fame Manner, till you have 
 eafed them all about another Inch, and fo proceed till you have 
 got them all out; after which you may go on with taking them 
 down after the ufual Manner. And this I recommend as a much 
 
 faier 
 
( 48 ) 
 
 fafer and a more practicable Method, than Screw Wedges, which 
 fome have very warmly recommended. 
 
 September 28th, at 3 o'Clock in the Morning we fet the firft 
 Cut-ftone of the Land Abutment, without any Parade, which 
 Time would not admit of. 
 
 November 1 ft, we compleatly finiflied the North Pier, fpringing 
 high, and cut the fix Inch dovetail Piles, that cafed the thorough 
 Foundation j uft at the Surface of it, half through, fo as we mig'ht 
 eafily break them off" there when we pleafed. 
 
 6th, We took up the ftrait Beams that went a-crofs the Pit, in 
 order to let the Carpenters put up the Centres of the North Arch. 
 
 EXPLANATION / Plate XIV. Scale $ Feet 1 Inch. 
 
 Fig. 1 ft, Reprefents the Plan of the Foundation of the Weft 
 end of the North Pier, with the rough Mafonry wrought up about 
 the Piles, and inclofed with a Row of fix Inch dove-tailed Piles, 
 fuch as you will fee in Plate XV. Fig. 6. which were half cut off at 
 the Surface of the thorough Foundation, and then broke off, leav- 
 ing the lower Part to cafe and guard that Foundation. The other 
 two Rows of fquare Piles and their Sheeting, hold the Clay, 
 which together make the inner Coffer or Pit. Fig. 2. Section of 
 the fame, and the Weft End of the Pier. Wherein note, A. Rock. 
 B. The Bottom of the rough Mafonry. C. Low-water Mark, 
 which is eleven Feet from B. 
 
 EXPLANATION /Plate XV. Scale 5 Feet to 1 Inch. 
 
 Wherein note, Fig. 1. Shews the Bond of the Cut-ftone in the 
 bottom or firft chained Courfe, of the Pier, with a Part of the 
 rough Stone Foundation, covered over with large thick Stones 
 Home to the dovetailed Piles, the Surface of which is four Feet fix 
 Inches beneath Low-water Mark. Fig. 2 and 3. fhew the Bond 
 of the Cut-ftone in the other two Chain Courfes. The Chain of 
 the firft Courfe was near three Inches Square, and the Chains of 
 the other two about % Inches Square, and all funk their full Depth, 
 
 and 
 
( 49 ) 
 
 and run with Lead. Fig. 4 and 5. are two different Methods of 
 making dovetailed Piles. Fig. 6. is the Method that Belidor feems 
 to have made life of, and I followed the fame; but in my Opinion, 
 Fig. 4. is both the beft and cheapeft, for many obvious Reafons. 
 
 The Method we took in laying the Foundation, was this; after 
 we had drove the Oak Piles down to the Rock, which you faw in 
 the laft Plate, we fpread a plentiful Coat of Roach-lime and fliarp 
 Gravel over the Ground, and laid a Courfe of large flat Stones, and 
 filled and hearted them in clofe about the Pile for about a Foot high ; 
 then we covered that Courfe with another plentiful Coat of the dry 
 Grout (i. e the Roach-lime and fliarp Gravel) and the next Courfe 
 and all the reft was laid with Mortar after the ufual Manner, only 
 with this Difference, that every Stone fwam in Mortar, and each 
 Courfe was grouted as above; and fo we went on till we came to 
 the level for the Caps that were laid over each row of Piles, and 
 then wrought up and levelled them, on which we laid three Beams 
 ftretching the whole Length of the Pier from Sterling to Sterling, 
 and filled up about them with the Mafonry; but the thorough 
 Foundation that lay under the Arches, was laid and fecurely bedded, 
 and many of the Stones were rather pitched upon their Ends and 
 wrought clofe together, fo that there is a fubftantial Stone Floor 
 for the Bed of the River between the Piers, on which we fpread a 
 Courfe or Stratum of about a Foot thick of fliarp coarfe Gravel mixed 
 with new and old Lime-rubbifli, and we covered that with a plen- 
 tiful Bed of fuch coarfe gravelly Stuff as we could collect within the 
 Dams, which together, made on an Average about %\ Feet thick; 
 my reafon for laying this covering on the Surface of the Foundation, 
 was principally to preferve the green Mortar that lay on that Surface, 
 from being waflied away before it would get proper Time to cement ; 
 and as I had 4* Feet from that Surface to the Low-water Mark, I 
 concluded, that for the prefent Time two Feet deep would anfwer 
 the Purpofes of Navigation, and we finiflied all the reft of that 
 thorough Foundation in like Manner, except the South Arch. 
 
 I am fenfible there was no fort of Neceffity for piling this Foun- 
 dation, as there was fuch a Depth of Mafonry under the Piers, 
 however, as it could not be fo ftrong as on the South Side, where 
 
 H they 
 
( 5° ) 
 
 they were built on, or very near the Rock, I thought it advifable 
 (as we had plenty of Piles) rather to err on the fafe Side. 
 
 CHAP. IX, 
 
 Concerning different Methods of centering, for large Stone Bridges^ 
 and a Continuation of the AbftraS of our Diary. 
 
 THAT Part of a Centre, which I fhewed you in Plate XIIL 
 Fig. 3. is fufficient for our prefent Purpofe; but fuch Centres 
 are only proper where there is fuch a Foundation, but in other 
 refpedte it would not anfwer. 
 
 In Plate XVI. (Scale 8 Feet 1 Inch) you have two other 
 Methods of centering with Crown Beams, the Prick-polls refting 
 on 4 Inch Plank ftretched parallel to the Piers upon the thorough 
 Foundations, as above-mentioned; but in Cafe you have not fuch 
 a Foundation, your whole Dependance muft be upon your Piers, 
 as in Plate XVIL (by the fame Scale) in which you have three dif- 
 ferent Defigns; and notwithstanding they are drawn for 36, 41 
 and 46 Feet Spans, yet if you confider every Thing in Proportion, 
 they may very well anfwer for double thofe Spans : And I appre- 
 hend, that Fig. 2. fliews you a very fafe Way to fupport them, 
 viz. In the three projecting Courfes of your Piers, make your up- 
 per fet off about 10 or 12 Inches, more or lefs, according to the 
 fize of your Arches, as at a. a. and on thofe fet-ofFs ftretch 
 your Plates, and on them reft your Spur-braces as in the Draft, 
 never forgetting to put in the Wedges before-mentioned, for in. 
 Truth, no Centres ought to be put up without them; for by eafmg 
 your Centers gently, every Part of the Arch has Time to come to 
 its proper bearing, and many an Arch as well as Vault, has been 
 difbcated by linking them abruptly. 
 
 December 4th, There came down a terrible Flood, but we ex^- 
 petted it from the heavy Rains we had, and prepared for it. The 
 jirft high Water afterwards rofe to 12 Feet 6 Inches, and every 
 high Water afterwards rofe to 1 2 or 13 Feet for fix fucceffive Days, 
 and even at low Water the Floods kept up to 8 or 9 Feet, during 
 
 all 
 
all which Time, our Sluices being open, we fuffered little or no 
 Damage, except lofs of Time, and the difturbing our Stages, 
 Utenfils, &c. for all the Water being at the fame level within and 
 without, it was perfeftly ftill and quiet within the Dam. 
 
 From the 4th of December 1753, to the 23d of February 17 54, 
 the Floods continued extremely high, and often to 13 Feet at high 
 Water, which greatly retarded our W T ork; but otherwife, did not 
 do us any confiderable damage: However, we were now enabled 
 to put the rough Mafons to get ready the Foundation of the fe- 
 cond northerly Pier, which we executed juft like the former ; and 
 within the Space of four Nights and Days, we had it ready for the 
 Stone-cutters, that is, on the 27th, the Stone-cutters laid the firft 
 cut Stone of the 2d northerly Pier. 
 
 March 19th, We began to drive the firft of the Piles of the 
 Coffer-dam for the 2d principal Operation on the South Side. See 
 Plate XVIIL Scale 40 feet t Inch. 
 
 29th, Second northerly Pier fpringing high. 
 
 30th, The Stone-cutters began to lay the firft Courfe of.the 2d 
 
 northerly Arch. 1 r n. t»- 
 
 April 8th, The Coal-gabbards were flopped for the hrft 1 ime r 
 and miffed three Tides, when we cleared a Way for them under 
 
 the northerly Arch. 
 
 a ad, They began to pull down the Excife-office; by the delays 
 given to us on that Account, we loft eight Days of the fineft 
 Weather we had had for a Year paft. 
 
 25th, Part of the Cuftom-houfe Quay fell, by which we diico- 
 vered another old Quay-wall, 6 Feet within that. 
 
 May 23d, Both the North Arches open and free for the Coal 
 Gabbards. 
 
 25th, There came down a fudden rapid Flood from the Moun- 
 tains, which waihed away a great deal of the Clay, which we were 
 putting in the Coffer-dam. 
 
 June 5th, From the 25th of laft Month to this Day, we had 
 conftant Land-floods ; the Ebbs feldom fell under 3 ; or 4 Feet. 
 Thefe Floods deftroyed a vaft deal of the Clay, but with great 
 
 H % Difficulty 
 
( 5* ) 
 
 Difficulty we got the Current turned entirely into the North Chan- 
 nel, to its full Depth. 
 
 14th and 15th, The Land-floods at Low-water were from 8 to 
 9 Feet. 
 
 25th, This and former Days we had great Labour in taking up 
 the Ridge of loofe Stones, which lay in a direcl: Line quite a-crofs 
 the River below Bridge, as before-mentioned; but dear bought 
 Experience had taught us to fpare neither Time nor Coft to get 
 thofe dreadful Pefts removed from under the Dike. 
 
 July 27th, Thefe fix Days we had exceeding rapid Mountain 
 Floods ; high Water generally about 1 1 Feet. 
 
 Augufi 4th, We finifhed the rough Stone Foundation of the 
 South Pier of the middle Arch. 
 
 5th, The Stone-cutters began to fet the lame Pier. 
 
 1 2th, In drudging for the South-eaft corner of the Dam, we met 
 with very large Cakes of the petrified Sand, that the Floods had 
 carried down into the deep Water, which they were forced to break 
 to fmaller Pieces, by driving well-fhod Piles into them. 
 
 28th, We flopped all the Pumps, as we had no further Occafion 
 for them. 
 
 From the 20th to the a 8th of September, we were obliged to 
 flop the Carriages, from going along EJfex-quay y on account of 
 our finking for the South Abutment, in doing which, we raifed 
 Part of the Foundation of Newman $ Tower, which had been very 
 judicioufly laid on the folid Rock, and we were alfo obliged to 
 quarry in fome Places two or three Feet deep of the Rock, to bring 
 it to a proper level, and omitted two Courfes of the Cut-flone of 
 that Abutment, as the third of the projecting Courfes were laid 
 upon the folid Rock. 
 
 OBober 7th, The Abutment finifhed, fpringing high, and the 
 fame Day we began to lay the Foundation of the South-quay 
 Walls. 
 
 CHAP. 
 
( 53 ) 
 
 CHAP. X. 
 
 The proper Method of building Quay Walls, and a Continuation of 
 
 the Abjlratl of our Diary. 
 
 "f SHOULD think myfelf very reprehenfible, did I forbear to 
 J difcover the true Proportion ol Quay Walls, which I was taught 
 by an eminent and worthy Gentleman, Major Mar cell ; but pre- 
 vious to the Proportions, there are other Things to be considered, 
 the principal of which is, the Nature of the Ground on which it 
 is to be built, and to be fure, if it be not ftrong enough, that 
 you make it fo by piling, and that the Foundation of the Wall be 
 laid of a fufficient Depth, the front Courfe of large and long 
 Headers, that will admit of making a good fet-off; all which being 
 duly confidered, you are then to calculate how far that Founda- 
 tion is to project. 
 
 The Major's rule is this, a That the out-fide of a Quay Wall, 
 ought to batter one fixth Part of the Height of it." And left you 
 fhould not clearly underftand this mod excellent rule, I fhall per- 
 haps make it the more intelligible, by giving you an Inftance of a 
 Wall, that is to be twelve Feet high from the Surface, or level of 
 the Foundation before-mentioned. 
 
 Every Foot your Wall rifes mud batter two Inches, then your 
 12 Feet high mufc batter 24 Inches, and to this add 18 Inches 
 for the Thicknefs of your Parapet, which will make three Feet 
 fix Inches, for the Bottom of the Wall that ftands on the Founda- 
 tion, and allowing at leaft three Inches for the let-off, your Foun- 
 dation muft be three Feet nine Inches broad; obferving that the 
 back of the Wall is to be carried up perpendicularly, and the Stones 
 laid firm, and after a Workman-like Manner againft the Bank, for 
 if you only build the out-fide fair, and fill the back and infide care- 
 lefsly, or perhaps, with a fcanty Allowance of Mortar, that Wall 
 could not ftand long, let the batter be what it would. 
 
 In order to carry on this Wall properly, you are to make a Plumb- 
 Rule fit for the Purpofe, with one fide of it Plumb, and the other 
 
 Side 
 
( 54- ) 
 
 Side to fit the battering Side; but if you are carrying on a new Quay 
 Wall of any confiderable Length, you ought to work by a batter- 
 ing Frame, always obferving, that the top of your Frame (which 
 we fuppofe to be 18 Inches broad) be exactly level to the level of 
 the Bank, otherwife, you will find you will be either too broad or 
 too narrow when you come to the Surface of the Bank; and indeed, 
 all thefe rules ought to be obferved in building a Wall againft any 
 other Bank. For fuppofe you build a Plumb Wall againft any 
 Bank, which I have generally feen pra&ifed, the Rain or Wet is 
 continually carrying down a Quantity of loofe Particles, which be- 
 come a Wedge between the top of the Wall and the Bank ; and 
 like taking a Sword in the feeble of the Point, the further it goes 
 the more Power ic will gain, and thereby increafe its own Purchafe, 
 till it at Length totally demolishes it. 
 
 November ift, We began to put up the Centres for the two 
 foutherly Arches, and prepared to do the fame for the Centre 
 Arch. 
 
 January icth, i 755, The Haunches of the two northerly Arches 
 being compleated, we made a fafe and commodious Foot-way to 
 the Dike, which we railed in, and which proved of great Advan- 
 tage both to the Public and our Work. 
 
 March 5th, The fecond South Arch was finiflied, and we began 
 to build the crofs Walls from the Crowns of the Arches, in order 
 to make the Carriage Way. 
 
 stipril 1 ft, The middle Arch being almoft clofed, we employed 
 Men and Carts to bring in Rubbifti to raife the Pavement about 
 the North End of the Bridge. 
 
 3d, The Paviour began to Pave. 
 
 8th, The Jaft and Center Arch being clofed, I immediately 
 boarded in a Carriage Way of 20 Feet broad, over the middle of 
 the Bridge, in order that the impatient Public might have the be- 
 nefit thereof as icon as poffible; and on the fame Day, having got 
 one Side of it paved, I invited the Right Hon. the Lord Mayor, 
 being Alderman Perchal Runt, and the two Sheriffs to be the firft 
 three 3 as accordingly they were, that were drove over the Bridge. 
 
 i-oth, 
 
( 55 ) 
 
 10th, The Bridge was left open for the ufe of the Public in gene- 
 ra^ which made two Years and eighty Days, fince the Day on 
 which they were deprived of the ufe of the old Bridge, which was 
 January 19th, 1753. 
 
 EXPLANATION / Plate X VllL Scale 40 Feet to 1 Inch 
 
 Shews you the fecond principal Operation with the thorough 
 Foundation, Piers and Part of the Abutment to the Northward, 
 and the new Coffer-dam on the South r on which I need not enlarge 
 any further* 
 
 EXPLANATION of Plate XIX. Scale 1 6 Feet to 1 Inch- 
 Fig. 1. Exhibits the Plan of the northerly Pier of the Center 
 Arch, Handing on the thorough Foundation, which is laid over 
 with large Stones, Hough and Ham, and fome pitched upon their 
 Ends, and all of them wrought clofe and carefully bedded in Mor- 
 tar, and the whole covered with a plentiful Coat of dry Grout, and 
 that covered with a thick Bed of Charp Gravel, to preferve the 
 Mortar till it Cements; on the Extremities of which, you fee Part 
 of the two Rows of dovetailed Piles which are drove down to the 
 Rock, and cut off at the Surface of the Foundation, which is four. 
 Feet and a half under the Low-water Mark, as mentioned before 
 in the Explanations of Plates XIII and XIV. 
 
 Fig. 2. Shews the Center Arch, and half of each of the next ad- 
 joining Arches, compleatly finifhed, wherein note, A. The Rock 
 in that Part of the River. B. Part of the natural Bed of the River. 
 C. Thorough Foundation quite a-crofs the River, built as above 
 and before- mentioned. D. Five Rows of Oak Piles drove down 
 to the Rock, with a Grating of Timber on them, and wrought 
 into the Mafonry. E. The like Grating of Timber under the x 
 foutherly Pier. F. Low, and G. High-water Marks. 
 
 Fig. 3. This Figure reprefents Part of the Superftruclure, which 
 extends 51 Feet from out to out of the Plinth of the Balluftrade. 
 The Foot-ways are 8 Feet each, and the Carriage-way 31 Feet. 
 
 This, 
 
C 56 ) 
 
 This, according to my original Plan, was to be paved with Fire- 
 ftone, in 5 or 6 Inch Courfes, each Courfe to be fcabbled or rough 
 punched at about 1 Inch or rj Inch convex, fo that the Feet of 
 the draught Horfes might take a firm hold of them; and thefe 
 Courfes were to be from 18 Inches to about 2 Feet in Depth, and 
 fet with good clofe Joints in fwimming Beds of good Mortar, and 
 for this purpofe I took Care to leave a proper Depth on the crown 
 of the Center Arch. And now I hope that what I have offered con- 
 cerning this Bridge fully expreffes every Thing necelTary for you to 
 know concerning it. 
 
 Tho' the intended Brevity of this Work obliges me to be as concife 
 as poffible, yet I think, I ought to embrace this Opportunity to relate 
 a particular Incident that lately happened at this Bridge; but I muft 
 firft recommend it to you to recoiled the covering I had laid on this 
 thorough Foundation between the Piers, as mentioned in the latter 
 End of the explanatory Notes on Plate XV. 
 
 This laft Winter has been very remarkable for exceeding high 
 Land-floods in this River, but particularly one that came fuddenly 
 down from the Mountains on the lad Day of January, t 775, with 
 fuch Violence, that it broke the Moorings, and carried off eight 
 Gabbards from the Coal-quay ; five of them were flopped for fome 
 Days by EJfex-hridge, and three of them carried directly down the 
 River; one of thefe five lodged againft the Sterlings of the middle 
 Piers, and the Flood continuing very violent ten fucceeding Days, 
 it was quite impracticable to get her ofT. 
 
 As my young Reader may, perhaps, not be acquainted with the 
 natural Effects of fuch an Obflruftion, it is neceffary to obferve, 
 that Shoals or Sharps in navigable Rivers, have frequently been 
 deepened and carried off by lodging loaded Gabbards quite a-crofs 
 them, becaufe they flop the Current at the Surface, and prefs 
 powerfully on the Water at the Bottom, which confequently en- 
 creafe the Strength and Velocity thereof, and fo break up and 
 carry off the Bed of the River in fuch Places. 
 
 But I fhall give a recent and more familiar Inftance: About tea 
 Years ago, a rapid Land-flood broke the Moorings of a Raft of 
 Timber at the Barrack-flip, and carried it down to S$ueen$-bridge, 
 
 where 
 
( 57 ) 
 
 where it unluckily lodged quite a-crofs the middle Arch. The 
 Piers of this Bridge were built on the Surface of the Bed of the 
 River, as moft of the former Bridges were. This Raft of Timber 
 obftructing the Current of the Surface, in like Manner increafed the 
 Power of it at the bottom, and within the Space of a few Hours 
 totally demolifhed the Bridge. But to proceed. 
 
 During the ten Days that this Gabbard lodged againft the Ster- 
 lings of the middle Piers, I felt not the lean: Perturbation, but on 
 the contrary I found my Heart exult with inexpreffible Pleafure, 
 being thoroughly convinced, that if all the Arches were flopped 
 up in like Manner for many fucceffive Years, that they would have 
 no more effect on that Foundation than if it had been a folid Rock: 
 However, after the Flood had fallen, Curiofity induced me to ex- 
 amine the Effects of it, and 1 really was furprized to find, that 
 even the firft Foot Stratum of the covering which we laid over the 
 Foundation was not in the leaft Degree molefted. Indeed, the 
 upper Parts of the covering were by that and former Floods moftly 
 wafhed away, but not ftripped of it intirely in any Place, and even 
 if it was all wafhed away, yet the Mortar on the Surface of it is by 
 this Time fo effectually cemented, that the Current paffing over it 
 could not make the leaft Impreffion on it ; and the red Firr dove- 
 tailed Piles that cafe and inclofe it down to the Rock (being in 
 Water) will moft afTuredly laft firm and found for numerous Gene- 
 rations to come ; and in the Interval, the Mafonry will in reafon- 
 able Time cement to fuch a Degree, as if the Mortar and Grout of 
 the whole were actually petrified, and even fo, as to put it out of 
 the Power of Time to deftroy it. 
 
 For thefe Reafons I moft earneftly recommend it to you, to do 
 all in your Power to make thorough Foundations in like Manner, 
 quite a-crofs fuch Rivers as you may happen to be employed in, 
 that you may enjoy the like tranquil State of Mind, during the 
 remainder of your Life, which I experienced when I faw the Gab- 
 bard lie a-crofs that Arch. 
 
 I 
 
 SECT. 
 
( 5* ) 
 
 SECT. L 
 
 Concerning other necejfary Matters relative to the hiilding of Stone- 
 Bridges. 
 
 T HAVE now cheerfully communicated a fhort account of our 
 I Proceedings at Effex-Bridge, and mentioned every Thing I 
 thought materially neceffary for the young Student in the Art of 
 Bridge-building to know, of which, the principal is the Ufe and 
 Conftru&ion of Coffer-dams; and I am fure he may by this Time 
 form a clear Notion of their Utility in Works of this Nature, nor 
 can I conceive the leaft Idea of any other Way to lay fuch fub- 
 ftantial and thorough Foundations as may be done by their Means. 
 
 I muft indeed, confefs, that the building of the Bridge, was at- 
 tended with a great deal of Labour Night and Day, for upwards of 
 two Years and a half fucceffively, but that was chiefly owing to the 
 Foulnefs and Loofenefs of the Ground, which would not have been 
 the Cafe, had we been working on clean and frefli Maiden Ground, 
 for on fuch, there would be but few Difficulties to encounter with; 
 and therefore, to prevent your being difcouraged, I muft remind 
 you again, that Mr, Labely was quite miftaken in his Calculation 
 (mentioned in Page 31,) for notwithftanding the exceeding great 
 Roughnefs of our Ground, the Rapidity of the River, and the very 
 great Depth we were obliged to fink, and that the whole Circuit of ' 
 of our Dams was much larger than what he would want for one of 
 his Piers, yet, after we had got our Dams .{launched, there did not 
 foak for many Tides fucceffively, (exclufive of the fubterraneous 
 Water, mentioned in the 7th Chapter) a fingle Hogfliead of 
 Water into our Pit, notwithftanding its exceeding great Depth; 
 but it is not my Intention to leffen the Reputation which that great 
 Artift has juftly eftabliftied, although to prevent your being dif- 
 couraged from fuch undertakings by what he has advanced, and 
 for your further Improvement, I believe, without running the 
 hazard of Cenfure, I might venture to make fome further remarks 
 
 upon 
 
( 59 ) 
 
 upon it, but I fliall leave that to your own Sagacity, by your com- 
 paring what he has /aid, to what we actually performed. . 
 
 When you come to Work upon frefti Maiden Ground (as I 
 mentioned above) you will find no fuch Difficulties, but will have 
 fure ready Work, even at the Depth we went to at the North End, 
 and probably on fuch frefh Ground, you need not fink much 
 deeper than about three, four or five Feet under the Bed of the 
 River, unlefs you intend to lay a thorough Foundation; but if 
 you do not, that will be fully fufficient, provided you drive down 
 fuch Piles as I have recommended in Plate 1 5, Fig. 4, all round 
 your Foundation, till they get into firm Ground. 
 
 In (hallow, frefli W'ater Rivers, the Difficulties and Expences 
 attending this Manner of working, are quite inconfiderable; but 
 you mull always obferve, that let the Water be what Depth it will, 
 you proportion the Strength of your Dams to the Depth that you 
 are to fink from the Surface of the high Water. In fuch Rivers as 
 are under fix Feet deep, you may make your Dams very flight, ex- 
 cepting in fuch Rivers as are fubje£t to fudden Mountain Floods : 
 Recoiled what Z. B. Alberti has left us (fee Page 9) which are, 
 I think, the fulleft and cleareft Diredions I have met with, and 
 according to the fame Manner which he there directs, I advife you 
 to make your Dams in fuch Rivers as are under this Depth; but 
 in fuch Water as is only about a Yard deep, one row of Stakes 
 may anfwer your purpofe, and in fhallower Water, Sods may prove 
 fufficient; but be well prepared and extremely expeditious, left a 
 Land-flood fhould come upon you, yet, even if it did, the Ex- 
 pence would be but inconfiderable. 
 
 There have been feveral Methods pra&ifed by illiterate Country 
 Mafons, who have built good rough Stone Bridges over fuch (hal- 
 low Rivers as thefe, and lome of them in much deeper Water. I 
 fliall mention a few of their Methods; fuch as, ift, Kefh-work, 
 that is, a kind of large Baikets, made of the Boughs and Branches 
 of Trees, about the fize of four or five Feet Square; thefe they 
 fink in rows, by throwing Stones promifcuoufly into them till they 
 ground, and then filling them up till the Water is about Knee-deep, 
 whereon they lay Timber a-crofs, and fo begin to build their Piers, 
 
 I 3 banking 
 
tiff f fllllfp' ;j f *» I if ■ ; ?g|pj. ■ : . . 
 
 banking the Kiftiesall round with other Stones and hard Stuff thrown 
 in, in like Manner, fcfli Keeve-work, that is, making large VefTels of 
 red Deal Boards, hooped both with Iron and ftrong Oak Hoops, 
 which they fill and fink in like Manner, filling the Vacancies be- 
 tween the Circles, and banking them round with the like rude 
 Stones, &c. 3d, Cbeft-work, i. e. making large Chefts of 5 or 6 Feet 
 Square of red Fir Plank, dovetailed and clafped with Iron at the 
 Angles, and thefe they alfo fill and bank in like Manner, which is 
 generally among fuch Workmen deemed a good Method, becaufe 
 they lie fo very contiguous to one anothe-r, and are very durable. 
 4th, Cafe-work, which is of the fame Nature, only much larger and 
 ftronger, fome of them being 12 or 15 Feet Square, and filled and 
 banked after the fame Manner. The 5th, is generally made ufe of 
 by eminent Workmen in much larger Works. They call it Cafe- 
 work, the French Caisson. They are made of large Timber, pro- 
 portionable to the intended Ufe, and in Bridge-building, will admit 
 of the whole Pier being built within them. Their bottom is a 
 Grating of ftrong Timber, and their Sides of fquare Scantling and 
 thick Planks, which are to be difengaged from the bottom, when 
 the Pier is built within them to above the low Water mark, and 
 then they are to be made ufe of for the next Pier. They are made 
 perfe&Iy ftaunch, and a Pit is drudged in the Bed of the River, 
 as deep as they think fufficient, wherein the Weight of the Work 
 finks thefe Cafes. All which Methods and feveral others, I moll 
 minutely confidered before I defigned Effex-hridge, and found that 
 none of them would anfwer my purpofe; but having carefully pre- 
 ferved my Remarks, Plans and Sketches on thofe various Methods, 
 and at innumerable Times fince digefted them moft accurately, 
 and alfo improved the Obfervations I made on the Petrifaaions be- 
 fore mentioned; I apprehended and endeavoured to contrive fome 
 others, which I prefume among us, may be called new Methods, 
 which probably may prove more effectual in moft Cafes than any 
 of them, which I have defigned to anfwer either in frefti or fait 
 Water of very confiderable Depths, and which I fhall referve for 
 the Subject of the fecond Part of this little Work. 
 
 I am 
 
( 6x ) 
 
 I am fully convinced, that the Society of Ar tills that have been 
 lately eftablifhed in Dublin, through the generous Affiftance of the 
 Dullin Society, has already proved of infinite Service in this King- 
 dom ; and that fuch a noble Eftabliftiment cannot fail in Time, to 
 produce very ingenious and ufeful Men among us, many having 
 already began to fhine forth in different Branches of Science, and 
 particularly in Architecture. This, I think, inconteftibly proves 
 that the People of this Country, have as good natural Abilities as 
 thofe of any other, and were they to meet with equal Encourage- 
 ment, there can be no Doubt, but they would carry the Sciences 
 and the Arts to as great a Perfection; Encouragement being the 
 kindly Sunfhine, which expands the budding Flowers, and makes 
 them produce much good Fruit. 
 
 The Guild of Merchants, as an Encouragement to that Society, 
 moft generoufly p;aid 50/. for the beft, 30/. for the fecond beft, and 
 20/. for the third beft Defign for the Royal Exchange: And the 
 Corporation of this City followed their laudable Example, in pro- 
 curing Defigns for the Blue-coat Hofpital. And there is no Doubt 
 but when Orntond-hridge has fallen down, but they will continue to 
 exercife the fame moft ufeful Generality, and perhaps, much enlarge 
 thofe Sums, as the Nature of that extraordinary kind of Work, 
 and the prefcribing proper and effectual Methods for laying the 
 Foundations in particular, require a great deal of Labour, and 
 juftly merit a very liberal Compenfation. 
 
 Jn Hopes that many young Students in Architecture, may not 
 only become Candidates, but aCtually merit the higheft Prize, I 
 intend freely and fully to furnifh them with proper InftruCtions for 
 that purpofe, to the beft of my Knowledge, but chiefly with re- 
 fpeCt to the Foundation, and the principal Lines fuitable to that 
 Bridge; but in order to exercife their own Ingenuity, I fhall leave 
 the Decorations to themfelves. 
 
 I have fhewn what a lofs I was at, and what infinite Trouble I 
 had to find out and procure effectual Methods to lay the Founda- 
 tion of EJfex-bridge. I have given a fuccin6t Narrative of the 
 whole of my Proceedings in that Work. I alfo fet forth the good 
 Fortune I had in getting Colonel Belidor\ Method of making 
 
 Coffer- 
 
( 6a ) 
 
 Coffer-dams, in the very critical Time I wanted it, for I had every 
 Thing elfe to invent, to contrive and to reduce into order. The 
 whole of thefe feveral Particulars you have now before you, and on 
 a thorough grounded Knowledge I allure you, that the various Cir- 
 cumitances relative to the re-building of Ejfex-bridge that is done, 
 and Ormond-hridge that muft foon be done, are exactly fimilar to 
 one another, excepting, indeed, that the latter will be much lefs 
 in lize, and not near fo troublefome nor expenfive as the former; 
 but lam very certain, there is no other Method to accomplifh it 
 than that by which I compleated the other. The whole of what 
 relates to the firft, and all that is neceffary for the latter, you have 
 alfo now before you ready at Hand, without giving you the leaft 
 Trouble to contrive or invent any Thing. And I hope my young 
 Countrymen will now exert themfelves, and ufe their utmoft En- 
 deavours to make themfelves Mailers of the Art of Bridge-building, 
 and not lay the Corporation of the City, or other Gentlemen under 
 a Neceffity of procuring Artifts from other Countries, when they 
 have, or may have as fit Perfons for their Purpofes at home. 
 
 CHAP. xr. 
 
 Concerning Ormond-Bridge, with the Soundings and Borings ad- 
 jacent^ and Remarks on the Bed of the River. 
 
 If N the Year 1 68 2, Sir Humphrey Jervis built a Bridge of Timber 
 in this Place, which flood but two Years, which was, probably, 
 .partly owing to the injudicious Conftruclion of it, or more proba- 
 bly to the intolerable loftnefs of the Ground it was built upon ; but 
 be that as it may, in the Year 1684, the Corporation of the City 
 began to build the prefent Bridge. See Plate XX. Scale 20 Feet, 
 1 Inch. 
 
 In April 1752, this Bridge was in the utmoft Danger of fharing 
 the fame Fate that EJJex-lridge had fo lately met with; on which 
 my Brother John and I were ordered to go and examine it, which 
 accordingly we did, and we found that the South Pier at A, had 
 greatly (ailed : The Bed of the River on which it ltood was waflied 
 
 away 7 
 
( 63 ) 
 
 away, and the firft Courfe of the Stone-work alfo, for about feven 
 Feet under the Pier, and Part of the fecbnd Courfe, and that that 
 Part of the Pier had no fupport, but the Strength , of the Mortar 
 and the bond of the Work. ' 
 
 This Difcovery induced us to examine the true Caufe thereof, 
 in order to determine on the Methods for repairing it, which we 
 could not effectually do without boring the Bed of the River, to 
 find out what fort of Ground it was built on; and having at that 
 Time made fome correct Soundings and Borings, and otherwife 
 very ftrictly examined it, and having now the -Drafts, Soundings 
 and Borings thereof by me, I do apprehend, that within fome very 
 fliort Time, it muft inevitably fall; and as I am now fo healthful 
 as to be able to reconfider them, it may be of ufe to the Public in 
 general, and to the Corporation of this Hon. City in particular, to 
 form fuch a Defign for the rebuilding of the fame, as fhall appear 
 the molt, eligible. 
 
 For this Purpofe I here give the Public the true Soundings and 
 Borings, fo far as we at that Time took them; wherein note,, 
 That the Dots under the Numbers of the firft 12, and oppofite to 
 the other 12 Borings, are the Spots into which we bored. Our 
 high Water mark at EJfex-hridge (See Plate XIX. Fig. 2. G.) was 
 transferred by the level of the Water to this Place, allowing the 
 fame ten Feet from low to high Water, although, in Fact, it is not 
 juft the fame, becaufe the Bed of the River rifes higher the further 
 one go up it. 
 
 NT 
 
 Feet. 
 
 Inches. 
 
 9 
 
 8 
 
 8 
 
 0 
 
 8 
 
 3 
 
 25 . 
 
 11 
 
 12, 
 
 6 
 
 3 
 
 0 
 
 10 
 
 3 
 
 *5~ 
 
 9 
 
 BORINGS. 
 
 From high Water mark to the Bed of the River, S. Side. 
 Coarfe, loofe Sand or Gravel. 
 Soft blue fandy Loanfc 
 
 Rock. 
 
 To the Bed of the River. 
 
 Coarfe, loofe Gravel. 
 
 Of foft, fandy, blue Clay or Loam. 
 
 Rock. 
 
 N°. 
 
( 64 ) 
 
 
 Feet. 
 
 Inches. 
 
 3 
 
 9 
 
 II 
 
 
 6 
 
 3 
 
 
 7 
 
 5 
 
 
 2 3. 
 
 7 
 
 4 
 
 '5 
 
 0 
 
 
 0 
 
 5 
 
 
 « 
 
 o 
 
 0 
 
 
 29 
 
 5 
 
 5 
 
 10 
 
 3 
 
 
 L 1 
 
 w 
 
 
 4 1 
 
 9 
 
 r 
 0 
 
 9 
 
 1 1 
 
 
 9 
 
 7 
 
 
 r 9 
 
 A 
 
 7 
 
 10 
 
 2 
 
 
 9 
 
 7 
 
 
 
 9 
 
 8 
 
 1 
 
 4 
 
 
 I vJ 
 
 O 
 
 
 2 I 
 
 4 
 
 9 
 
 I O 
 
 1 
 
 
 Q 
 
 0 
 
 4 
 
 
 . n 
 I O 
 
 3 
 
 10 
 
 9 
 
 2 
 
 
 8 
 
 2 
 
 
 j 7 
 
 4 
 
 » i 
 
 0 
 
 0 
 
 
 8 
 
 7 
 
 
 18 
 
 7 
 
 To the Bed. 
 
 Harder and coarfer Sand. 
 Soft blue Clay or Loam. 
 Rock. 
 
 To the Bed. 
 
 Coarfe, gravelly Sand. 
 
 Soft blue Clay or Loam. 
 
 Rock. 
 
 To the Bed, (North Side) 
 Soft blue, fandy Clay or Loam. 
 Rock. 
 
 To the Bed. 
 
 Exceeding foft, fandy Clay or Loam. 
 Rock. 
 
 To the Bed. 
 
 Exceeding foft, blue Clay, or rather Mud. 
 
 Rock, 
 
 To the Bed. 
 
 Very foft blue Clay, or rather Mud. 
 Rock. 
 
 To the Bed. 
 
 Exceeding foft blue Clay, or Mud. 
 Rock. 
 
 To the Bed. 
 
 Exceeding foft Loam, ot Mud. 
 Rock. 
 
 To the Bed. 
 
 Exceeding foft Mud. N. B. The Men found this fo 
 foft, that they thruft down the Rods in a Minute 
 without boring, and they believed they could do the 
 fame with a ten Foot Rod, after they were through 
 the upper Cruft of Sand and Rubbifh. 
 
 Rock. 
 
( 6S h 
 
 N°. 
 
 ' Feet. 
 
 Inches. 
 
 
 12 
 
 1 1 
 
 6 
 
 To the Bed. 
 
 
 IO 
 
 2 
 
 More ftiff and 
 
 
 21 
 
 8 
 
 Rock. 
 
 The dotted Line which inclofes the South Pier, is the outward 
 bounds of the Coffer-dam, which we made to keep off the Water, 
 till we under-pinned that Weft End of it, where we found that 
 there was nothing fupporting the upper Work, but the Bond of 
 the Stones, and the Strength of the Mortar as before-mentioned, 
 for "that Pier had not a Frame of Wood planked in the bottom, 
 under nor round it, as the Piers of Effex-hridge had, but the bot- 
 tom Courfe of it was laid on the naked Bed of the River, as I be- 
 lieve all the reft of the Piers are. Some of them have funk to the 
 Eaftward, and fome of them, but particularly the North Pier, to 
 the Weftward, one Foot nine Inches at B. more than at C. and 
 greatly dillocated that Arch, which I believe has been rebuilt, for 
 by the Courfes of the Stones in the Piers, it is evident that no Arch 
 could poffibly ftand, when one End of the Pier had fettled fo much 
 more than the other, and confidering all thefe Borings together, 
 it is fomewhat furprizing it has flood fo long. 
 
 The large Dotts in the dotted Line, were taken in order to 
 know the different Depths of the Water, whence to calculate 
 the Length of the Piles for the Dam; but they alfo are of fome ufe 
 now, in giving us the Depths of the Water from high Water mark, 
 in thofe feveral Places, viz. 
 
 N°. 
 
 1 Depth. 
 
 N°. 
 
 | Depth. 
 
 
 Feet. 
 
 Inches, 
 
 
 . Feet. Indies. 
 
 i3 
 
 5 
 
 3 
 
 *9 
 
 Ill 
 
 j 
 
 3 
 
 14 
 
 5 
 
 9 
 
 20 
 
 12 
 
 I 
 
 J 5 
 
 8 
 
 
 2.1 
 
 2 0 
 
 O 
 
 16, 
 
 1 1 
 
 9 
 
 22 
 
 20 
 
 O 
 
 n' 
 
 12 
 
 9 
 
 23 1 
 
 i'3 
 
 3 
 
 18 
 
 12 
 
 3 
 
 241 
 
 1 9 
 
 3 
 
 K 
 
 Remarks 
 
( 66 ) 
 
 Remarks on the Bed of the River, Sec, 
 
 Although we only pierced the Bed of the River in 24 Places, 
 yet that was fully fufficient for our Purpofe, and indeed, I think, 
 they are alfo pretty fufficient for my prefent Confederation, upon 
 which 1 can fafely conclude, that the Ground oppofite Charles- 
 Jfreet, (where the Bridge muft be built) is not able to fupport the 
 Weight of a Bridge; and if you turn back and re-examine the 
 Borings of N°. 5, 6, 7, 8, 9, 10 and 1 1, you will coincide in Opi- 
 nion with me; but I do not by any Means advife you to depend 
 entirely on thefe Borings, but take a Carpenter with you at low 
 Water, and let him bring a Hand-fpike pointed at one End with 
 him, and a nine Foot Pantile-lath or a Quarter- four, and let him 
 break through the Cruft of the Ground, by firft driving or working 
 down the Hand-fpike 2 or 3 Feet, and I will venture to engage, 
 that he can thrufl down the Pantile-lath to the Rock, in any Place* 
 you pleafe to fix on thereabouts, efpeclally at 9, 10 and 11; nor 
 need you have any other Implements to prove the moft Part of 
 our Borings; and thefe Experiments will be of Ufe, and give you 
 a true Idea of the Nature of the Ground you are going to build 
 upon; and that will alfo partly difcover the Reafon that the 
 Wooden-bridge before-mentioned, lafled but two Years, and ex- 
 cite your Admiration, that the prefent Bridge has flood fo long, 
 without fuffering the fame Fate. I fhall now lay before you the 
 principal Lines of my Defign of a Bridge fuitable to that Place, and 
 effectual Methods for the Accomplifhment of it. 
 
 CHAP. XII. 
 
 The principal Lines of a Defign for Ormond-Bridge, with proper 
 InJlrutJions for the Execution thereof 
 
 EXPLANATION ^Plate XXI. Scale 20 Feet 1 Inch. 
 
 Fig. 1. 
 
 NOTE, A. The Rock, (fuppofed upon an Average to be 
 about 12 Feet under low Water mark). B. Part of the 
 
 natural 
 
( *7 I 
 
 natural Bed of the River. C. Thorough Foundation of Mafonry, 
 (three Feet high). D. Low-water mark (three Feet above ditto. 
 Foundation). E. High-water mark, (taken at 10 Feet on an 
 Average). F. Pavement, (five Feet from the Soffeto of the Center 
 Arch). From low Water mark to the fpring of the Arch is 6 Feet. 
 Thence to the Soffeto of the Arch 10 Feet 4 Inches, and F. 5 Feet: 
 In all 2 1 Feet 4 Inches. G. G. Pavement 1 9 Feet. Declivity 
 % Feet 4 Inches in the Pavement from F to G. 
 
 It may not be amifs here to obfer/e, that a great deal depends 
 on a judicious erecting of the Sounding-boards. Try the Depth 
 at feveral Ebbs, obferving that it is much more advifable to calcu- 
 late from the loweft Ebb, for fear of raifing the Summit of the Pave- 
 ment too high, and be fure that all thefe Dimenfions agree toge- 
 ther from your low Water mark. The next material Thing is to 
 confider the Water-ways. 
 
 The Voids and Solids, or the Piers and Arches of the prefent 
 Bridge, and of this Defign compared. 
 
 Prefent Bridge. This Defign. 
 
 Plate XX. 
 
 Ft. 
 
 Inch. 
 
 Ft. 
 
 Inch. 
 
 Plate XXI. 
 
 Ft 
 
 Inch. 
 
 Ft. 
 
 Inch. 
 
 South Arch 
 
 20 
 
 0 
 
 0 
 
 0 
 
 South Arch 
 
 2 5 
 
 6 
 
 0 
 
 0 
 
 South Pier 
 
 0 
 
 0 
 
 1 1 
 
 3 
 
 South Pier - - - 
 
 c 
 
 0 
 
 5 
 
 6 
 
 2d Southerly Arch - 
 
 24 
 
 3 
 
 0 
 
 0 
 
 2d Southerly Arch - 
 
 2b 
 
 6 
 
 0 
 
 0 
 
 Ditto. Pier 
 
 0 
 
 0 
 
 1 1 
 
 10 
 
 Ditto. Pier - - - 
 
 0 
 
 0 
 
 6 
 
 0 
 
 Center Arch - - 
 
 27 
 
 8 
 
 0 
 
 0 
 
 Center Arch 
 
 3i 
 
 0 
 
 0 
 
 0 
 
 3d Pier - 
 
 0 
 
 0 
 
 1 1 
 
 0 
 
 3d Pier 
 
 c 
 
 0 
 
 6 
 
 0 
 
 4th Arch - 
 
 25 
 
 2 
 
 0 
 
 0 
 
 4th Arch - 
 
 28 
 
 6 
 
 0 
 
 0 
 
 4th Pier 
 
 0 
 
 0 
 
 10 
 
 1 1 
 
 4th Pier - - 
 
 0 
 
 0 
 
 S 
 
 6 
 
 5 th or North Arch 
 
 20 
 
 0 
 
 0 
 
 0 
 
 5th or North Arch 
 
 
 6 
 
 0 
 
 0 
 
 Total 
 
 m 
 
 i 1 
 
 4-5 
 
 0 
 
 Total 
 
 r 39 
 
 0 
 
 23 
 
 0 
 
 N. B. Abutments 10 Feet each. 
 
 In fixing upon the Scite of this Defign, obferve that the middle 
 of the Bridge muft be oppofite to the middle of Charles-Jlreet, but 
 not in direct Line with it, becaute the River and the Street form an 
 acute Angle, and the Bridge muft be on right Angles with the Cur- 
 rentj otherwife the Piers will incline athwart the Stream, which 
 
 K 2 always 
 
( 68 ) 
 
 always ought to be avoided, as far as other Gircum fiances may rea- 
 fonably admit of it. 
 
 Fig. 2. Shews the Plans of the two foutherly Piers, and the 
 Inclofure of the thorough Foundation, which muft at the lead be 
 50 Feet broad in the clear of the Piles that, inclofe it. Fig. 3. 
 Shews what the Superftrudhire will be when finifhed. 
 
 EXPLANATION*/ Pl at e XXII. Scale 30 Feet 1 Inch. 
 
 This Plate reprefents the firft general Plan of Operation in lay- 
 ing the foutherly Foundations; wherein note. A. Pool for Pump 
 Engine. B. B. Water Trunks. C. The Pit for building the South 
 Abutment and Pier. D. Pit for building the 2d South Pier, 
 
 EXPLANATION of Plate XXIII. Scale 5 Feet 1 Inch. 
 
 Fig. 1 . Plan of the middle Dike of the Coffer-dam, through the 
 Center Arch. 
 
 Fig. 2 . ConftrucTion of the Coffer-dam, wherein note. A. Low- 
 water. B. High-water. N. B. After the Frames are drove down 
 as deep as you can drive them, they are to be ftrained together, fo 
 as to give them a fix Inch batter in the middle row, and the outward 
 Rows in the fame proportion as formerly directed. 
 
 Confidering the exceeding foft Ground on which this Dam is to 
 be erected, it is very probable, that after the Clay is put in them, 
 they will be liable to incline either to one Side or the other, and 
 whenever you can perceive that, or you obferve that the Clay 
 lpreads out the middle Frame, in either of thefe Cafes, and either 
 within or without the Dam, you are to proceed after the fame 
 Method already fully laid down in Plate VIII. C. e, f, g and h, 
 explained in Page 32. 
 
 EXPLANATION of Plate XXIV. Scale 5 Feet to 1 Inch. 
 
 Fig. i. I apprehend, that I have been fo explicit on Plate XIII. 
 Fig. 1. that I need not repeat here, as this Draught and Scale may 
 
 fully 
 
fully anfwer your Purpofes; only obferve, that G. is the Superficies 
 of the prefent Pavement, which is 25 Feet from the level of the 
 bottom of the Pit; and if you find it neceffary, you may go ano- 
 ther Foot deeper. H. Is the End of the Land-tye. 
 
 Fig. 2. Section of the Land Abutment and half of the South 
 Arch^ wherein note. A. The Rock. B. The bottom of the Pit, 
 (unlefs you go another Foot deeper, as above-mentioned). CL 
 The Surface of the thorough Foundation, which is here fuppofed 
 to be three Feet high; but if you add the other Foot in Depth to 
 it, do not forget that Foot afterwards in all your other Dimenfions. 
 D. Low-water mark 3 Feet. d. Center from which the Arch - 
 was defcribed. E. Springing of the Arch, F. High-water mark, 
 f. Soffet of the Arch which is 8 Feet 6 Inches, that is \ of the fpan, 
 from E. to f. G. Surface of the Pavement. 
 
 EXPLANATION of Plate XXV. Scale $,Feetto 1 Inch 
 
 Wef End of South Pier. 
 
 Fig. 1. Is the Plan of the Coffer (or Inclofure of the inner Pit) 
 for laying the Foundations. Fig. 2. Is the Section of the fame. 
 Fig. Is the Foundation of the Weft End of the South Pier;, 
 wherein obferve,, that there are five Piles in each row, at about 14 
 Inches afunder, and about three Feet diftance in the rows. In the 
 North Piers of Ejfex-lridge you may obferve they were four Feet 
 afunder each Way, becaufe the Ground was there tolerably ftrong, 
 but here it is intolerably foft, and therefore, it is requiftte they: 
 fhould be drove clofer; yet we muft not depend too much upon 
 the Piles, but endeavour to make the Mafon-work as fubftantial as 
 poffible, in order to which, let me recommend the procuring good 
 ftout rough Flags fcabbeled to three Feet long (the Diftance of the 
 rows the long Way) and after laying at the leaft, half a Foot thick 
 of ibarp Gravel, covered with two or three Inches tfiicfe 0 
 lime over your Ground, bed thofe coarfe ftrong Flag< 
 which will fill the three Feet rows from Pile to Pile; then 
 Pieces of Flags, that will fill between the Piles the other - 
 
C 70 ) 
 
 from thenceforward, let each Stone fwim in g6od ftrong Mortar, 
 clofely and carefully wrought. Another Method may be this: 
 Sink the bottom of your Pit feven Feet under low Water mark, 
 and allow the Foot before-mentioned to be filled with that Bed of 
 ftiarp Gravel covered with Roach-lime, and then your Mafonry will 
 be three Feet as above. The Reafons for this will be hereafter 
 mentioned. 
 
 Fig. 4. Is the Se&ion of the Weft End of the South Pier, and 
 the Foundation on which it is to ftand : Obferve, to be fure of 
 your Diftance from the Rock, before you cut your Piles to their 
 Length, and let them be rather too long than too fhort, and in 
 driving them (which will be eafily done) that every one of them 
 goes down to the Rock: Cut them exa£tly fquare and level, fo 
 that your Caps may lie firm upon them, and be careful, that your 
 ftretching Beams lie firm and folid upon all your Caps. Thefe 
 ftretching Beams ought to be 50 Feet long at the leaft (as before- 
 mentioned) if you can conveniently get fuch, that they may reach 
 quite acrofs the Foundation: That is, the clear of the dovetail Piles 
 that cafe and fecure it, efpecially the middle Beam, but the reft 
 may be proportionably {horter; and that the Mafonry be made 
 level to the Heads of the Piles, take Care that the Caps may lie 
 folid on them alfo: And the fame Care is to be taken when you are 
 levelling to bed your ftretching Beams, and that the Mafons do 
 mod pun£tually obferve the Directions before given for them. The 
 next Pier is to be done after the fame Manner. 
 
 EXPLANATION of Plate XXVI. Scale 5 Feet 1 Inch. 
 The Plan and Seffion of the North Pier fpringing high. 
 
 The Bed of the River at this End of the Bridge, being much 
 fofter than at the other End, you ought to endeavour to make them 
 both alike flrong : In order to which, I propofe that this Pier fliould 
 ftand upon Piles, For if you recolle£l the eleventh boring, I be- 
 lieve you will conclude with me, that notwithstanding all the Care 
 and Cautions given to the rough Mafons, their Work between the 
 
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( T* ) 
 
 rows of Plies will be In danger of fubfiding, and fo that Pier would 
 confequently and principally ftand on thofe fingle rows of Piles. 
 It muft, therefore, certainly be the fafeft Way to Pile the whole as 
 you fee it herein drawn, with the grateing of Timber on them. 
 You may obferve there is a Supernumerary row of Piles at each Side, 
 left they fhould not exactly fquare with the feite of the Pier, and 
 to leave a little fet-off for your firft projecting Courfe; the tho- 
 rough Foundation is to be laid with large well-headed Stones againft 
 the Piles, and the Spaces between them to be fluffed full of fmall 
 Stones, Roach-lime and Gravel, to keep all firm and fteady, that 
 they may not lean either to the one Side or the other in that floughy 
 Ground. Note, A. the Rock. B. Bottom of the Foundation. 
 C. Low-water, and D. fpringing of the Arch as before. 
 
 EXPLANATION of Plate XXVII. Scale 5 Feet 1 Inch. 
 
 SeSion of the thorough Foundation, and the two middle Piers fpring- 
 ing high. 
 
 I hope what I have already faid has been fo explicit, that I need 
 not repeat it. If I was to make any Amendments on this, it would 
 be to make the rows of Piles only two Feet afunder inftead of three, 
 but that only in this North Pier, as even here, that Pier ftan^S 
 on the fofter Ground of thefe two Piers of this Arch. 
 
 I fhall now again give fome friendly Cautions, that I could wifh 
 were deeply imprinted in your Mind as general Rules ; that is, 
 never pretend to draw a Defign, or engage in any Work of this 
 Nature, without moft ftri&ly examining the Strength of the whole 
 Ground that is to fupport it; and if you find the Ground under 
 any of the Piers, or any Part of them, is not equally ftrong, that 
 either by piling, or fome other effedual Method, you bring the 
 whole upon an Equality, fo that your Work may ftand firm and 
 fecure for Ages to come. If you are to build a Bridge over a na- 
 vigable River, it might be, that in fome former Time Ballaft-men 
 might have drudged a Hole, which was immediately filled up with 
 Slough (which I take to be the Caufe of the Pier finking of Weft- 
 
( n ) 
 
 mrnjler Bridge) upon which, perhaps, one End of a Pier might 
 ftand, or under one End of a Pier there may be a Rock, and under, 
 the other foft fpringy quick Sands or the like ; or further, perhaps, 
 you may have a folid Rock on one Side of a River, and very foft 
 Ground on the other, from all which, and many other fuch Cafes, 
 it is indifpenfably neceflary to fearch diligently into the Bed of the 
 River, at the leaft, within the full extent of the Ground you intend 
 to occupy : And confider alfo, how will you be able to anfwer for 
 your Conduct, in pretending to build a Bridge that for aught you 
 know, may tumble down before it is even finiflied, or at belt may 
 not ftand many Years till it begins to totter or lean to one Side or 
 other; and if it is over a navigable River, recollect what I told you 
 before of the Bridge built by Trajan r that fo totally deftroyed the, 
 Navigation of that Part of the Danuhe, that they were forced to 
 cut a new Channel for the trading Veflels, to avoid the Ruins of it, 
 which you know cannot be done in any trading Town or City. 
 
 We have heard that the finding out the Difeafe, is one half of 
 the Cure, and there are Remedies for all forts of Difeafes, but the 
 great Art is to difcover them; and in the prefent Cafe, when you 
 know the Evils you are to guard againir, you confequently ought 
 to find out Ways and Means to prevent them. Your Bed of the 
 River we will fuppofe, in the Condition we have been confidering; 
 fnrely then, there cannot be a more effectual Method to ftrengthen 
 and bring the Bed to a fufficient Equality, than that which the three 
 eminent Architects have mentioned of turning off the Water, by 
 making an Enclofure or Coffered am: In the Execution of which, 
 you will find much Pleafure and Satisfaction, provided you ohferve 
 this repeated Advice, that is, to fpare neither Time nor Trouble 
 to drudge out and remove all the Stones and Rubbifh from under 
 the Dikes of your Dams, and if you do fo, I can anfwer for it, that 
 every Thing elie may be moft effectually executed. 
 
 But it is alfo pi-oper to apprize you, that among the feveral other 
 Methods that have hitherto been made ufe of, there is one not yet 
 mentioned, which foft fiutchey Ground, perhaps, will move fome 
 Perfons to recommend, and that is, piling for the Piers, or as Mr. 
 Lahcly deridingly calls it, building upon Stilts ; and you (hall now 
 
 ynder- 
 
( 73 ) 
 
 isnderftand the Difference between that Method, and this which I 
 recommend. 
 
 The general Method of building Piers of Bridges upon Piles is 
 this: They drive down Piles elofe together to near low Water, 
 cut them level and fquare at the Heads, and lay thereon a Grating 
 of Timber, whereon they begin to lay the Cut-ftone Work of their 
 Piers, the bottom of which may probably be about two or three 
 Feet above low Water: This is a very tedious Way, becaufe the 
 Tide always interrupts their Proceedings, but in Cafe that fliould 
 be difpenfed with, yet confider how feeble fuch Piles would ftand 
 in foft flutchey Ground, that the leaft PreiTure from either Side, 
 would give them all a lean to the oppofite Side: Befides, thefe 
 Piles mull have feveral rows of Piles drove round them, which will 
 leave very little Room for the Water, and that will increafe its 
 Strength, by which it will tear up the Bed of the River between 
 the Piers, and require continual repair from the Day they conclude 
 the Work finifhed, and fo the Bridge would continue in a totter- 
 ing Condition, and bring a conftant Charge either on the Corpo- 
 ration of the City, or the Public, and probably would foon /hare 
 the Fate of Sir Humphrey Jerviis Wooden-bridge before men- 
 tioned, and many others. 
 
 Now obferve in faid Plate XXVII, that a. is the Rock; b. Bot- 
 tom of the thorough Foundation; c. Surface of the fame; d. low 
 Water mark; e. would probably be about the Surface of the Grat- 
 ing, whereon the Stone-work would begin, and fo the Stone-work 
 of this our thorough Foundation beginning at b. would be about 
 8 Feet below that of theirs, and all that foft Slutch would be thrown 
 put, and a firm Stone-work put in the Place of it, which as I ob- 
 served before, would wedge in and keep thofe Piles tight and firm 
 together, and whence, your Ovedeers may be able to determine 
 which of thefe Methods are mo ft eligible. 
 
 It is not improbable, that the Perfons who recommend this 
 Method of building the Piers upon Piles, will offer this Argument 
 to enforce it: That it will be a vaft deal cheaper than the Method 
 which I propofe, and I admit, that for the prefent it may be fo; 
 but iuppofmg it were poffible to make it to ftand any Time, it 
 
 L would 
 
( 74 ) 
 
 would be infinitely more expenfive toward the Concluflon, befide 
 the danger of its falling immediately after the Centers are ftruck. 
 
 Mr. Lahely has informed us Page 40, " that at Moulins, in 
 France, they attempted to build a Stone-bridge upon Piles, driven 
 about 15 Feet into the Bed of the River, the tops of which were 
 ftrongly fattened- together, and reached about five or fix Feet above 
 the Surface of the Bed of the River, but the Moment they attempted 
 to cafe the Centers on which they had turned the Arches, the whole 
 tell into Ruin." Therefore, be advifed and confider, that you have 
 now before you effectual and proper Methods, by which you may 
 eafily accomplifh this Work, all fully proved and ready to be 
 put into Execution, with numerous Cautions diiperfed throughout 
 the whole, which you know was not the Cafe with me, who had 
 every individual Thing to invent and to contrive, fo as to anfwer 
 thefe Purpofes; never having either feen, heard, nor even read of 
 any of them, faving only what I have already mentioned : And 
 therefore, you will find, that you will have nothing to do but to 
 follow thefe plain and eafy Methods, all of which you are now 
 made fully acquainted with. 
 
 END of Part the First* 
 
( 75 ) 
 
 BUILDING in WATER. 
 
 PART II. 
 
 Concerning an Attempt to contrive and introduce quick and cheap 
 Methods, for erecting fubftantial Stone-buildings and other 
 Works, in frefh and fait Water, quaking Bogs or MorafTes, for 
 various Purpofes; fully laid down and clearly demonstrated, by 
 twelve practical Propositions^ but not in any Cafe exceed- 
 ing ten Fathom deep: Together, with a Plan for a fpacious and 
 a commodious Harbour for the Downs in England, projecting 
 to zq Feet deep at low Water. 
 
 CHAP. XIIL 
 
 Concerning fome Methods made ufe of by the Antients, and on par- 
 ticular Qualities of Lime, Mortar and Grout. 
 
 Y Thoughts on this Subject, took their rife from an Obfer- 
 vation 1 made on our taking up the Foundations of Effex- 
 indge, where we found that the Bed of fharp Gravel, on which 
 the Piers had been built, was actually petrified feemingly into a 
 clofe folid Stone, by the fmall Quantities of the petrifying Qualities 
 of the Lime, that had funk down into it, in about 70 Years, but 
 principally fince erecting the Effigy in 1722, which you have feen 
 particularly noted in Chap. VI. Sect. 2. Together, with what I 
 obferved concerning the exceeding great Strength of the Mortar in 
 the Foundation of the Pier, which I repaired in Ormond-bridge, 
 and which is mentioned in my explanatory Notes on Plate XX. 
 Letter A. 
 
 L 2 Having 
 
< 7* ) 
 
 Having taken proper Notes and Obfervations thereon, and com- 
 pared them with what Palladia has mentioned in his i ft Book, Ch. 9. 
 Seel. 6. concerning fome 44 Walls called Reimpiuta, or Coffer-work y 
 44 which were made by the Antients, by taking Planks laid Edge- 
 44 ways, according to the Thicknefs of the Walls, filling the Void 
 44 or Space between them, with Cement and all forts of fmall Stones 
 44 mingled together, and continued after this Manner from Courfe 
 44 to Courfe : There are Walls now at Sirmion, upon the Lake di 
 44 Garda, built after this Manner." I fay thefe principal Matters, 
 and what I have learned from feveral other Roman Authors and 
 antient Hiftorians, have at length, produced what I am now about 
 to lay before you, not in the lean: doubting, but you will take 
 them into Contemplation, and improve the hints I ftiall give you, 
 lo Far as you mall find them worthy your Notice; and likewife, to 
 be productive of public or private Utility, thofe being my Mo- 
 tives for writing and publishing thefe Sheets, which I confefs, has 
 brought on me a very arduous Tafk, becaufe I am confeious of 
 my great Incapacity to perform fuch an undertaking; but yet, I 
 prefume, that if through the Courfe of my little Practice, any ufe- 
 ful Occurrences have happened in my Way, it is better to leave 
 them in the Pofleffion of the Public, even irregularly cloathed in 
 their poor homely fpun Apparel, than to carry them with me to my 
 Grave. And now as you know the Motives that have actuated 
 my Endeavours, and the End I propofe in this Part of my Work, 
 and as I have fuch great Objects in View, I hope I mall be honoured 
 with a ferious and candid Perufal : That the Scope and Defigns of 
 this W T oik may be regarded, the real Importance of my Remarks 
 and Contrivance confidered, and not my Language or Expreflions 
 to be anatomifed, as if thofe only were to employ the Attention of 
 my Readers; for I ftudy neither Stile nor Diction, any further than 
 what I think neceffary to communicate and render my Sentiments 
 intelligible to my Readers, mod zealoufly endeavouring to reduce 
 all my adequate Ideas into the Forms and Figures exhibited on the 
 enfuing Plates, which henceforward mull principally govern and 
 direct the Thread of my Subject. 
 
 SECT. 
 
( 77 ) 
 
 SECT. I. 
 
 Concerning Coffer or cafed Walk or Foundations, abridged from 
 
 L. B. Albert i. 
 
 WHAT Palladia calls Coffers, the Tranflators of Albertj 
 call Cafes, which in Fad are the fame Things. In Alberti\ 
 3d Book, Ch. 5. he recites various Methods made ufe of by the 
 Antients, both in laying Foundations and in building. Walls in 
 Cafes, and among the reft, he expreffes himfelf in thefe Words ; 
 « I have obferved, that in other Places the Antients, who were won- 
 " derfuily expert in making of great Works, followed different 
 « Methods in filling up the Foundations. In the Sepulchre of the 
 « Antonini, they filled them up with little Pieces of very hard 
 " Stones, each not bigger than an Handful, and which they per- 
 " fe&ly drowned in Mortar. In the Forum Argentarium, with, 
 " Fragments of all forts of broken Stones. In the Comitia, with 
 « Bits of the very worft forts of foft Stones. — I have known other 
 <c Inftances, where the Antients have much the fame forts of Foun- 
 " dations, and Strudures too of coarfe Gravel and common Stones,. 
 « that they have picked by chance, and which have lafted many 
 u Ages. 
 
 a Upon pulling down a very high and ftrong Tower ztBologna r 
 " they difcovered that the Foundations were filled with nothing but 
 " round Stones and Chalk, to the Height of nine Feet, the other 
 « Parts were built with Mortar; we find, therefore, that very difte- 
 " rent Methods have been ufed, and which to approve moft, I con- 
 << fefs myfelf at a lofs, all of them having endured fo long firm and 
 " found"; fo that I think, we ought to choofe that which is the leaft 
 " expenlive, provided we do not throw in all Manner of oldi 
 « Rubbifh, or any Thing apt to moulder." After his mention- 
 ing many other Things concerning Walls, he concludes this Chap- 
 ter with thefe Words, 44 I therefore lay it down as an indifpenfable 
 " Rule, that all the firft Courfe of Work from the level ^ of the 
 « Foundation, fhould be compofed of the harden^ foundeft and 
 7 r " largeft 
 
( 78 ) 
 
 a largeft Stones;" but after that Courfe he treats largely of carry- 
 u ing up the out Sides, with cut Stones and filling (or Huffing as he 
 calls it) the infide with fmall Stones, and Lime-liquid: And he 
 concludes his 8th Chapter with this Obfervation, 44 Laftly, we are 
 44 taught, what I find conftantly obferved among the Antients, 
 44 never to admit any Stone among the fluffing that weighs above one 
 44 Pound ; becaufe, they fuppofed that fmall Stones united more 
 44 eafily, and knit better with the Cement than large ones." 
 
 In his loth Chap, are thefe Words, 44 There are fome, who ob- 
 44 ferving here and there in the Works of the Antients, large Stones 
 44 which where they join feem daubed over with red Earth, I ima- 
 44 gine that the Antients ufed this inftead of Mortar." Chap, nth, 
 he fays, 44 but as we fhall fometimes be obliged to make ufe of 
 44 other forts of Stones, whereof fome are not cemented with 
 44 Mortar," or Grout I fuppofe, 44 but only with Slime," fome tell 
 us, 44 that the Slime which is ufed for Cement, ought to be like 
 44 Pitch, and that the beft is that which being fteeped in Water, 
 4f is floweft in difTolving, and will not eafily rub off. Others com- 
 44 mend the fandy as beft, becaufe it is moft tradable. — In antient 
 44 Structures, we often meet with very ftrong Walls, made of no- 
 44 thing but Rubbifh and broken Stuff, thefe are built like the Mud 
 44 Walls in Spain and Africa, by fattening on each Sides Planks or 
 44 Hurdles, to keep them together till they are dry and fettled, but 
 44 herein they differ, for fome fay, that the Antients filled up 
 44 their Work with Mortar-liquid, and in a Manner floating." 
 Numerous other Authors have tranfmitted thefe or the like Methods; 
 but thefe are fufficient for our prefent Purpofe, let us, therefore, 
 in the next Place confider the Natures and peculiar Qualities of fome 
 pf the Materials, which we are to make ufe of, for there are many 
 Tilings neceffary to be coniidered and ftriclly obferved, before we 
 £nter info a full Difcuiiion of our Subject. 
 
 SECT. 
 
SECT, II, 
 
 Concerning Lime } Mortar and Grout. 
 
 T HAVE from my Childhood, been well acquainted with the 
 J Nature of Lime and Sand made in Mortar, of all forts, that 
 have been ufed in Buildings in thefe Countries, and tried numerous 
 Experiments with them; on which, together with what I have ob- 
 ferved and learned from old experienced Workmen, during the 
 Courfe of upwards of fixty Years, I think, I can fafely affirm, that 
 good Mortar, that is, Mortar made of pure and well-burnt Lime- 
 ftone, and properly made up with fharp, clean Sand, free from any 
 fort of Earth, Loam or Mud, will within fome confiderable Time 
 actually petrify, and as it were, turn to the Conliftence of a Stone- 
 I remember I had one of my Remarks from an old Scotch Mafon, 
 which I fhall give you in his own identical Words, that is, 
 IVhen a hundred Tears are paft and gane. 
 Then gude Mortar is grown to a Stain ; (or a Stone.) 
 My Father (who was a Workman about the Year 1675) often 
 told me, and my own repeated Obfervations convince me, that the 
 Methods Mafons pra&ifed in former Times, in building Churches. 
 Abbeys, Caftles or other fumptuous Edifices in this Country, was 
 to this effect. After they laid the out-fide Courfes with large 
 Stones, laid on the flat in fwimming Beds of Mortar, they hearted 
 their Walls with their Spawls and fmalleft Stones, ancj as they laid 
 them in, they poured in plenty of boiling Grout, or hot Lime-liquid 
 among them, fo as to incorporate them together, as if it were with 
 melted Lead, whereby the heat of it exhaufted the Moifture of the 
 out -fide Mortar, and united mo ft firmly both it and the Stones, and 
 filled every Pore (which as the Mafons term it) fet, that is, grew 
 hard immediately, and this Method was taught to our antient 
 Mafons, by the Romijh Clergy that came to plant Chriflianity in 
 thefe Countries, and I affirm, that in many of fuch old Buildings, 
 I have feen the Mortar, as it were, run together and harder to break 
 than the Stones were. 
 
 But 
 
( 8o ) 
 
 But with refpect to the Matter in hand, I admit that Mortar 
 will not fet or grow fo foon hard in Water as upon Land; but I 
 am fully convinced, that good Mortar will in reafonable Time 
 grow as firm and as fubftantial in Water as upon dry Land; but 
 not dwelling upon mere Reports, I fhall come to Facts, and I do 
 alfo affirm, that in pulling down EJ/ex-bridge, and repairing 
 Ormond-bridge, we found the Mortar of the lower Courfes of the 
 Piers better cemented to the Stones, than it was in the upper 
 Works; for a wet Stone or a wet Brick imbibes the Mortar, and 
 holds it fafler than a dry Stone or Brick will do; the Duft and Dry- 
 nefs of either crufts the Mortar immediately, and the wet Stones or 
 Bricks fuck and unite with it, as for inftance, take two Bricks 
 equally well burned, wet one of them and lay it on a Bed of Mor- 
 tar, and at fome Diftance from that lay on the other dry, let them 
 lie fo as long as you pleafe, and then take them up, and you will 
 find the wet Brick will bring up its Bed of Mortar with it, but the 
 dry Brick will feparate and leave its Bed of Mortar behind it. 
 
 There are feveral forts of Lime-ftone, fome indeed, let much 
 foaner and harder under Water than others, but any good Lime 
 properly mixed, and tempered with fharp clean Sand, will bind and 
 cement as effectually under Water as above it, as I hinted before. 
 
 What I mean by good Lime, is that which is made of clean, 
 clofe-grained Lime-ftone. All Marble is Lime-ftone, but all 
 Lime-ftone is not Marble. All Marble will take a polifh, but 
 all Stones that will burn to Lime, will not take a polifh. For* 
 inftance, Chalk will make Lime, but it will neither polifh nor 
 make good Lime for any Purpofe; therefore, I advife you to choofe 
 the clofeft grained, the hardeft, and confequently the heavieft 
 Lime-ftone for any Work, but particularly for Water-works. 
 
 I need not explain what I mean by fliarp, clean Sand, but I 
 fhall give this One Caution, that it is better to put too much Sand 
 in your Mortar than too little. I know Workmen choofe to have 
 their Mortar rich, becaufe it works the pleafanter, but rich Mor- 
 tar will not ft and the Weather fo well, nor grow fo hard as poor 
 Mortar will do; if it was all Lime it "would have no more Strength 
 in Comparifon, than Clay. 
 
 Now 
 
( 8i ) 
 
 Now let us fuppofe, that a Peck of Roach-lime was flacked into 
 White-wafli, and then mixed with two or three Barrels of fharp 
 Sand, fo that , every individual. Particle of Sand partook, and as it 
 were, got a white Coat of this Liquid-lime, fuch Mortar, that 
 would only appear to be mere Sand, fuppofing fuch could be 
 wrought into Mortar, would fooner harden and petrify, either in 
 or out of Water, than if there had been ten Times that Quantity 
 of Lime made up with it ; but neverthelefs, obferve, that I do not 
 recommend that Proportion for Mortar, though it might anfwer 
 for our prefent Purpofes extremely well. 
 
 It is not within my Province to account for the petrifying Qua- 
 lities of Lime-ftone, Lime or Lime-water, though I have often 
 heard, feen and read of feveral very remarkable Inftances of each 
 of them, but it is fufficient for my prefent Purpofe, that they have 
 thefe petrifying Qualities to great Degrees; but all forts of Lime- 
 Hone have not this Quality in the fame Proportion, yet I believe, 
 no Lime-ftone whatever can have more excellent Qualities than 
 fuch as we have in, perhaps, every County in the Kingdom : And 
 indeed, it has fome ufeful Qualities not much known among the 
 Generality of Workmen, as for inftance, our Lime-ftone will make 
 exceeding good Tarrafs for Water-works, for which purpofe you 
 are to prepare it thus: Get your Roach-lime brought to you hot 
 from the Kiln, and immediately pound or rather grind it with a 
 Wooden-maul, on a fmooth large Stone, on a dry boarded Floor, 
 till you make it as fine as Flour, then without lofs of Time, fift it 
 through a coarfe hair or wire Sieve, and to the Quantity of a Hod 
 of your fetting Mortar (which on this Account ought to be poorer 
 than ordinary) put in two or three Shovels-full of this fine Flour 
 of the Roach-lime, and let two Men for Expedition fake, beat 
 them together with fuch Beaters as the Plaifterers make ufe of, and 
 then ufe it immediately. This, I can allure you will not only ftand 
 as well, but is really preferable to any Tarrafs. 
 
 I will give you another Inftance which will be hereafter found 
 to come within our Subject, /. e. the making Cifterns in which 
 Tarrafs is generally ufed in ordinary Work, build all your outfide 
 and infide Rows or Courfes with wet Bricks, and with Tarrafs- 
 mortar made as above directed; obferving, that your Mortar is to 
 
 M be 
 
( 8 2 ) 
 
 be a little too foft for Work, and then the heat of the Lime-flour 
 will bring it to a proper Confiftence immediately; but never throw- 
 Water upon it when you are beating it, for that will chill and flack 
 your Lime-flour, which you ought moft carefully to avoid, but 
 make the Men temper it with the utmoft Expedition, and what 
 you want in Water to make it fit for your Work, give it in Elbow- 
 greafe ; and this Rule ought to be obferved in making all forts of 
 Mortar. 
 
 The Grout which you lay your middle Row with, mull be thus 
 made (in a Tub or Bucket) pour your Water on the Roach-lime, 
 which muft be pure and well burned, very leifurely; and when it is 
 boiling, you may flrain it through either a wire c r hair Sieve, fo 
 as it may be tolerably free from Stones, and then let it be ufed 
 directly, and be fure your Sand is fliarp and clean, and when you 
 are ufing it, do not take the thin that is uppermoft, but ftir it up 
 and take plenty of the Sand with it; but in Mafons Work, when the 
 outfide and infide Courfes of cut Stone are let, pour in this boiling 
 hot Grout, and inftantly lay down your middle Courfe of wet Bricks 
 between them, in double or fingle Rows of Stretchers, braking Joints 
 as ufual, according as the Largenefs or Smallnefs of the Work may 
 require, and thac will prefs and fqueeze the Grout into all the infide 
 Pores that are next to it, and fo they will all unite, and by the 
 heat of the Grout and Drynefs or the -Bricks, they will all fet to- 
 gether immediately, and become flaunch and folid ; but if you were 
 nuking a Ciftern of rough Stone, mix one fourth of the Powder 
 of Tiles, or well-burned Bricks with your Mortar. 
 
 CHAP. XIV. 
 
 Coffer-work applicable to varous domejlic Purpofes, as tntroduBory 
 
 to building in deep fV* ater. 
 
 T HAVE already obferved, that the Word which the Tranfla- 
 J_ tors of L. B. Alberti have rendered Cafes, the Tranflators of 
 Palladia have rendered Coffer s\ and that it is evident, thofe two 
 Words convey to us the fame Thing in Fa£t; but in what I am 
 
 now 
 
now about to lay before you, I have confined myfelf to the Word 
 tranflated into Englijh from Palladio, that is, Coffer-work, as I ' 
 apprehend for feveral Reafons, it is mod proper for our Purpofe; 
 and as we have now fixed on a technical Term for this Method of 
 working, let us in the next Place, endeavour to apply and extend 
 that Method to building in Water, wherein we fhall have great 
 Occafion for Timber. 
 
 SECT. I. 
 
 Concerning Oak and Fir 'Timber. 
 
 WE have very little Timber now of the Produce of this 
 Kingdom of any kind, but large Quantities of both Oak 
 and Fir imported; on which \wo fqrts, I fhall make a few 
 Remarks. 
 
 Oak, is generally allowed to endure all Seafons and Weathers, 
 better than any other fort of Timber, and fome People are of 
 Opinion, that it is the beft of all others in Water. I know the Pier 
 or Piles, which we began to run out in this Harbour about the 
 Year 1728, have long fmce fufficiently proved, that it was not by 
 any Means adequate to that Purpofe, tho' I do believe, that there 
 is not any Country that produces better Oak Timber than ours, 
 notwithftanding, thofe Piles rotted and decayed in a very fhort 
 Time; but whether that was owing to the Nature of that particu- 
 lar Timber, or to any Thing peculiar to our Harbour, I know not, 
 but it reported there is a fort of Worms that either breed in or are 
 nouriflied in thofe Piles, that totally deftroy them. 
 
 There are, indeed, feveral Methods that have been made ufe of 
 to preferve Timber. Sir Hugh Piatt, informs us, that the V we- 
 tians make ufe of one, which feems very rational, viz. to burn and 
 fcorch their Timber in a flaming Fire, continually turning it round 
 with an Engine, till it has got a hard black crufty Coal upon it—- 
 Others inform us, that the Dutch preferve their Gates, Portcullis's, 
 Draw-bridges, Sluices, &c. by coating them over with a Mixture 
 of Pitch and Tar, whereon they ftrew fmall Pieces of Cockle and 
 
 M 2, other . 
 
( »4 ) 
 
 other Shells, beaten almoft to Powder and mixed with Sea-fand, 
 which incrufts and arms it wonderfully againft all aflaults of Wind 
 or Weather; but for my own Part, I conclude, that the Venetian 
 Method is preferable, becaufe I believe, it is the Sap that is either 
 in Oak or Fir, that is the principal Caufe of their decaying fo foon. 
 Befides, that Sap probably breeds and nourifhes the Worms that 
 are natural to it, but there are not any Worms peculiar to the 
 Water that I have ever heard of. 
 
 Worms generally breed in the Sap of all kinds of building Tim- 
 bers, and have a powerful Effect on them, either without or within 
 Doors; and all old and dry foft Woods breed them in great Abun- 
 dance, juft as Mites are bred in Cheefe; and fome of thefe Worms 
 are a quarter of an Inch in Length, and near a tenth of an Inch in 
 Thicknefs ; and in very footy old Cabbins where foft Woods are 
 generally made ufe of, they are to be found in great Abundance. 
 For thefe Reafons, you ought to be exceeding careful how you 
 make ufe of any fort of fappy Timber, but particularly in all 
 Works that ftand the Weather, for the Sap is of a corrofive Nature, 
 and for that Reafon ought not to be made ufe of, efpecially before 
 it is a little feafoned in any Work that requires to be durable. 
 
 I know there are Carpenters who pretend it is neceffary to paint 
 their Work dire&ly, and I admit that in fome Cafes it may; but 
 it ought to be done with Judgment, and not merely to varnifh 
 over and hide the Imperfe&ions of their Work. As the Preserva- 
 tion of Timber is a Subject fuitable to our prefent Purpofe, I ad- 
 vife you never to paint either green or fappy Timber of any Kind. 
 
 When I was building the Manlion-houfe of Ramsfort y one Day 
 after Dinner, Mr. Ram obferved to his Company, that he had 
 fome Time ago, cut up fome of his own Fir Timber into Scantling, 
 out of which he had a great Number of Field-gates made, and that 
 feveral of them that had been hung up near his Houfe, he had 
 had painted immediately, but thofe that were at a Difkance through 
 feveral Parts of his extenfive Demefne, were not painted ; that thofe 
 which were painted were all quite rotten, but thofe that were not 
 painted continued firm. The Company feemed furprized at this 
 Information, and Mr, Ram enquiring of me the Caufe of this appa- 
 rent 
 
( s 5 ) 
 
 rent Phenomenon, I readily anfwered, that the painting of the 
 fappy Wood, encrufted and confined the Sap, and prevented its 
 being exhaufted by the Sun and Weather, and being continued 
 within it, preyed upon, putrified and deftroyed the hearty found 
 Wood. As to the Wood that had not been painted, the Sun and 
 Weather confumed and exhaufted its Sap, and thereby rendered it 
 of a proper ConGftence, and made it well feafoned. It is for this 
 Reafon I advife againfl: painting, or otherwife encrufting fappy 
 green Wood, unlefs you have fome very powerful Reafons for it. 
 
 I once happened in Company with a very ingenious Gentleman, 
 one Mr. Smithy who was fo kind as to communicate a Secret^ to 
 me, whkh ftruck me greatly, and I inftantly put it in Pradice, 
 and am now convinced it is an excellent Method to make red Fir 
 Timber near as durable as Oak, /. e. After your Work is tried up 
 or even put together, lay it on the Ground with Stones or Bricks 
 under it to about a Foot high, and burn Wood (which is the beft 
 firing for that Purpofe) under it, till you thoroughly heat and even 
 fcorch it all over, then, whilft the Wood is hot, rub it over plen- 
 tifully with Linfeed-oil and Tar in equal Parts, and well boiled to- 
 gether, and let it be kept boiling whilft you are ufing it ; and this 
 will immediately ftrike and fink (if the Wood be tolerably feafoned) 
 one Inch or more into the Wood, clofe all the Pores, and make it 
 become exceeding hard and durable, either under or over^ Water;; 
 and if there (hould be any fappy Parts in it, they will receive fuch 
 benefit by the Fire and Heat of this natural and penetrating Liquid, 
 that they will alfo thereby become exceeding durable. Good red Fir 
 prepared after this Manner, will for many Ufes laft as long, if not 
 longer even than Oak Timber, efpecially in Water; and if good 
 Fir Timber is conftantly kept in Water, it will keep frelh and found 
 much longer than Oak. 
 
 I have often feen ftating and plaiftering Laths, clove out of Bog 
 Oak and Bog Fir; in cleaving the Fir Laths, I frequently obferved 
 the Turpentine as frefh and firm in it as if it were perfect Rofin; 
 and I have heard of the Splinters of this Wood being ufed not only 
 for Torches, but by poor People fometimes as Candles. In the 
 Butt of a clean Trunk of a Bog Fir-tree, it will fplit thin and tough 
 
( S6 ) 
 
 like Whale-bone. It is a generally-received Notion that the Tim- 
 ber Trees which are found in fuch Abundance in fome of our Bogs, 
 have lain there ever llnce the great Deluge, but be that as k may, 
 the Bog Oak Timber is always found to be fhifhcy, dozed and 
 fhort grained, and not near fo found as the Fir Timber, tho' both 
 taken up at the fame Time out of the fame Bog. I lence I think 
 we may fafely conclude, that red Fir Timber is exceeding durable, 
 and confequently unexceptionable as to our prcfent Purpofe, pro- 
 vided it be kept entirely under Water ; therefore, let us determine 
 to make our Coffers of good found red Fir Timber, and keep them 
 under Water as much as we conveniently can. 
 
 SECT. II. 
 
 Of the Conflruilion of Coffers, and the Ufes to which they may be 
 properly applied, for building in fV ater. 
 
 T) EFO RE we can fix upon the Conftruclions of the Coffers, we 
 j£) mull have fome Particulars propofed, becaufe that which might 
 anfwer for one Purpofe, might not anfwer for another: I intend, 
 therefore, as briefly as poflible to fhew fome of the Ufes to which 
 they may be applied. And you may be affured, I mall leave you 
 Room enough to exert your own Genius, by adopting them to other 
 Purpofes. 
 
 I am fenfible that at the firft Appearance of any new Project, fome 
 msy be vehemently for, and others againftit; but I hope you will 
 not fuffer yourfelf to be prejudiced on either Side, but deliberately 
 examine the whole of what I propofe. And I mall begin with fuch 
 a plain and eafy Proportion, as will come within even the Capacity 
 of any fenfible Journeyman to form a Judgment upon, and 
 thereby lead you gradually into the practical Part at a mere trifling 
 Expence. 
 
 PROP. 
 
( 8; ) 
 
 Prop. I. A Gentleman has a Bafon of Water in his Garden, he 
 requires a fure, quick and cheap Foundation to he laid therein f uf- 
 fcient to fufiain a Statue of Lead, on a Stone Pddeflal, the Plinth 
 of which is three Feet fquare^ the Water fx Feet deep. 
 
 METHOD laid down /«Plate XXVIII. Scale 2 Feet 1 Inch. 
 
 Fig. 1. Reprefents the Plan or Bottom of the Coffer, which is to 
 be made of only Inch and half Plank, which you fee will require fix 
 Planks of about fix and a half Feet long each, and in the Middle 
 acrofs them, there is to be a Ledge nailed on with Dog-nails, and 
 dovetailed at each End into the oppofite Sides, and all the Bottom 
 and upright Planks are to be dovetailed together alfo. 
 
 Fig. 2. Shews you the Elevation or out-fide thereof, in which 
 you fee there are leven Planks placed ere£t, with three Belts fur- 
 rounding the whole, and they alfo are to be dovetailed at the 
 Angles, and ftrapped with Iron : Each of the four lower Straps, a. 
 are to have a third Plate turning down, and nailed in a diagonal 
 Manner on the Bottom, which you fee dotted out, and each of the 
 four Squares are to have a ftrong proje&ing Neck, through the Ends 
 of which there are to be either Rings or Holes, to run Ropes through 
 them, each of which Ropes is to be at lead three Times the Depth 
 of the Water, that you may the eafier mamge it in the launching 
 and fixing it in its Birth: Each ot thefe Ropes is to be doubled 
 together, and fixed to a Wooden-block to buoy them up, which 
 you may throw into the Coffer till you want them. In this 
 Fig. 2. A. is the Bottom of the Water. B. Is the Surface, b. 
 Brace Bars, and c. the Plinth of the Pedeftal, which will feem to 
 ftand on the Surface of the Water; for you may remember that we 
 refolved to keep all our Wood within the Water, d. Bank or 
 filling to preferve the Lime-water. — Having thus fully confidered 
 the Conftruction of the Coffer, let us confider the Nature of the 
 Foundation that is to be laid in it, /. e. the Stuffing, which is to 
 make it a folid and a fubftantial Foundation for the Pedeftal. 
 
 SECT. 
 
( 88 ) 
 
 SECT. III. 
 
 Of fluffing the Coffers and Petrifications, laid down and to he cm- 
 
 Jidered as general Conclufions, 
 
 THE Word Coffer is borrowed from Palladio, we fliall borrow 
 the Word fluffing from Albert /, who has treated largely upon 
 it; and ftrictly obferve, that before the Coffer is launched, you 
 are to be provided with fufficient Quantities of very fmall Stones, 
 clean and fharp fandy Gravel, and Roach-lime ready at the Kiln 
 whenever it is called for; and with thefe Materials you are to fill 
 or -fluff the Coffer, fo that the whole may be juftly proportioned 
 and fluffed as folid and as compact as poffible. 
 
 In order to learn the true Proportions and Quantities of the 
 fluffing, I made the following Experiment. I had a Box made of 
 one exact cubical Foot, which held 200 Stones fit for the Purpofe, 
 each Stone on an Average, weighing about feven or eight Ounces, 
 the whole confequently weighed 90 lb. nearly. The fame Box held 
 about 80 lb. of tolerably dry, fliarp and rather fine fandy Gravel, 
 without any fort of Stones, except thofe fmall ones which are 
 ufually among Sand. Part of thofe Stones I put again into the 
 Box in thin Layers, filling all the Interftices or Vacancies with the 
 Sand, and after that Manner it contained 80 lb. of the Stones, and 
 40 lb. of the Sand, and I know it would alfo have held the pro- 
 portionable Complement of Roach-lime, that is 10 lb. made liquid* 
 as before treated of, which together gives the juft Quantities and 
 Proportions of io, 40 and 80, or t, 4 and 8, which will be much 
 eafier remembered, and muft be ftrictly obferved; and to this Pur- 
 pofe, you muft depend on fome careful and faithful Rough-mafon 
 or Bricklayer. And alfo, pleafe hence to obferve, that one cubical 
 Foot of this fluffing will weigh 1301b. which is nearly the fame 
 Weight of one folid Foot of Portland Stone. 
 
 There are three different Methods for making ufe of the Lime 
 in fuch Work as this; one is, to mix the Roach-lime made liquid, 
 with its Proportion of Sand and fmall Stones in fuch Manner, as 
 
 may 
 
( 8 9 ) 
 
 may cloath every Stone and Particle of Sand with it. The fecond, 
 to flack and turn them all up together like Mortar. The third, to 
 lay each of the three, as it were, in very thin Layers, flill obferv- 
 ing the fame Proportion, take which of thefe Methods you pleafe, 
 provided the Roach -lime be, however, carefully and judicioully 
 mixed with the Stones and Sand, for if thefe Materials are not 
 equally mixed, how can you expect them to petrify and unite into 
 one folid Mafs? But if they are properly mixed together, the whole 
 fluffing of this Coffer, will actually petrify, and become one folid 
 and compact Subflance, as hard and as clofely united together as 
 if the fame was in one Block or Rock, and it will be many hun- 
 dreds of Years before the Coffer (being in Water) will be in the 
 leafl decayed. 
 
 I have fome other Cautions to give you concerning the fmall 
 Stones you are to make ufe of. Let none of them exceed an 
 Handful, or one Pound Weight, as before mentioned; and if you 
 can conveniently, let them all be Lime-flone, broke into Stones 
 of about that frze, carefully preferving the very dud and leafl Scrap 
 of them for Ufe. 
 
 I before declined touching on Petrifactions, and I now fuppofe 
 that you do admit that there is a petrifying Quality both in Lime 
 and in Lime-water, and there are inconteflible Proofs of this 
 petrifying Quality being in Lime-ftone, even without Calcination. 
 As for Inflance, Doctor Thomas Molyneux fays in his Natural 
 Rijlory of Ireland, Page 184. — u There was one Urn found in 
 u a little fandy Hill, near Cooks-town, on the Road to LiJJon, in 
 u the County of Tyrone, it was covered with a great rude Lime- 
 " flone, which being removed in order to make Lime, the Urn 
 u was difcovered in a Hole encompaffed with fix Stones of equal 
 " Bignefs, which made a Hexagon, in which the Urn ftood. The 
 " Water that had fallen on the Urn from the Lime-flone, or the 
 (i Air condenfing, had petrified and made a Stone-cruft on the 
 " outfide thereof." And further obferve, that if the poor fcanty 
 Pittance of that petrifying Quality, that foaked from the Lime of 
 the Piers of Efjex-Bridge into the Bed of Gravel, that was on all 
 Sides open and expofed to the Rapidity of the . Water, had fo 
 
 N power! ul 
 
( S° ) 
 
 powerful an Effect as before- mentioned ; we may certainly con- 
 clude, that pure Lime-water will petrify fharp Sand, but cannot 
 make it cement. And the fluffing of thefe Coffers, will actually 
 petrify alfo, (particularly if they are done in the Manner above- 
 mentioned) and that in a much fhorter Term than may, perhaps, 
 be expected. If you fearch among the Roman or antient Hiftorians, 
 you may find numerous Accounts confirming the petrifying Quali- 
 ties of thefe three. Materials, when they are mixed together: And 
 befides thofe I have already furnifhed you with, confult Chambers s 
 Dictionary, under the Article Road, and read F. MeneJIriers 
 Obfervation, which I {hall give you in its proper Place. 
 
 As I have defired you to preierve and ufe even the Powder, or 
 fmalleft Fragments of the Lime-ftone, I fliall here affign my Reafon 
 for it, which is, that the Powder of frefh quarried Lime-ftone, 
 (which you will find to have a fulphureous fmeli, partaking greatly 
 of the fmell of Gunpowder) has this petrifying Quality to a very 
 high Degree, and that Calcination heightens that Quality, is uni- 
 verfally agreed to; but yet it does not operate in that Manner, 
 trfed alone. For inftance, if Lime be left to lie by itfelf, either 
 cn Land or in Water for thoufands of Years, it would neither 
 petrify nor come to any Degree of Hardnefs, nor would Sand 
 alone petrify ; but when thefe two unite, they begin to operate 
 powerfully upon one another. 
 
 In order to come at a thorough Knowledge of this petrifying 
 Quality, I would recommend the following Experiment: Take 
 ten Pounds of Lime-ftone frefh quarried, pound it into very fine 
 Powder, and take the like Quantity of fharp, clean and fine Sand ; 
 get thoroughly burnt Roach-lime hot from the Kiln, the like 
 Quantity; put it in a Veffel and pour Water upon it leiiurely, and 
 flir it gently till you find it is all difiblved, and as it were melted, 
 into a hot Liquid; rub and thoroughly mix the Flour of Lime-ftone 
 with the Sand, and without letting that Lime-liquid have Time 
 either to cool or evaporate, ftir in and mo ft effectually mix and 
 work them all together very Riff, and beat them thoroughly on a 
 clean boarded Floor, and then make this Mortar into Blocks, about 
 the Size of a Brick ; bury one of thefe Blocks in very damp or wet 
 
 Ground, 
 
( 9* ) 
 
 Ground, put another entirely in Water, and keep a third in lom'e 
 dry Place: Now I am confident, that each of thefe Blocks will in a 
 reafonable Time actually petrify into Stone, and become as much 
 To as if they had been cut or wrought out of a Rock, and that 
 they will endure Calcination, and become good Lime afterwards, 
 bat not fo rich as that was from whence they derived: And with 
 refpect to Time, that which is depofited in the Bowels of its own 
 natural Mother, will grow the fir ft into Stone; that laid in the 
 Water, will be the fecond, and that which is kept in the dry Place, 
 will be the laft and of a fliort brittle Nature: But the firft, if in a 
 large Block, will not only become hard, but ftout and ftubborn, 
 and would ftand and give great Refiftance to a Hammer or Punch: 
 The fecond, would be more free: And the third, fly off fliort. I 
 apprehend that this little Experiment is worthy of Attention, be- 
 caufe, by afcertaining the Time of thefe Depoiits, and trying the 
 Blocks from Time to Time afterward with a Tool or the Point of 
 a Penknife, fome ufeful Knowledge might be obtained; but be 
 that as it may, thefe are fome of my Reafons for recommending 
 Lime-ftone. However, where that cannot be conveniently got, 
 you muft make ufe of fuch hard Stones as you can get, but be fure 
 you have them broke to the Sizes above-mentioned, for fuch will 
 moft affuredly cement and unite together with the Lime and Gravel, 
 and each of the Stones will contribute to fuftain the Confidence 
 repofed in them; whereas, if one large Stone was put in among 
 them, it would not unite but ftand up ftiff, and thereby be a great 
 Means of ftiifting the Weight from itfelf, and throwing it on the 
 fmall Stones that furround it, and confequently would overturn in- 
 ftead of fupporting the Weight which it was deftined to bear. For 
 thefe, therefore, and many other Reafons, I moft earneftly recom- 
 mend. it to your Practice, to ufe no other but fmall Stones in your 
 fluffing. 
 
 You are alfo to take particular Care, that your landy Gravel is 
 ftiarp and clean, and of that Degree of Finenefs as may contribute 
 proportionably to the Solidity of the whole, and not to throw your 
 Stones in one Place, and your Lime and Sand in another, but let 
 them be all equally mixed throughout the Work, and all this can 
 
 N 2 ■ be 
 
( 9* ) 
 
 be eafily done; for let the Water be of what Depth it will, or your 
 hurry ever fo great, this you may do, and you are not to neglea it. 
 And obferve alfo, that this fort of Work can be much more ~ £r -~ 
 tually done in Water, than upon dry Land, even admitting that 
 it was to be done with wet Grout, becaufe thefe three Materials 
 being thrown in proportionably together, each Stone and every 
 Particle of the Gravel and Sand, will take FofTeiTion of a Place 
 fuitable to it; but the Sand in particular, will continue in quick 
 Motion till it finds out a place of reft proportionable to its Size, 
 and inftantly fill up the mod minute Vacancy, (provided that you 
 obferve thefe Dire&ions properly) and immediately become as 
 compact and as folid as a Bank of a Gravel-pit that has been 
 formed by Nature. 
 
 But after all I have laid, you may, perhaps, imagine that this 
 fluffing, even fo managed, will not be fufficient for our prefent 
 Purpofe, without giving it a long Time to fettle and cement; arid 
 I grant it would not be amifs to allow it fome fhort Time, to give 
 the finer Parts of the fluffing Time to fubfide, fupplying it with 
 thefe finer Parts, till it will receive no more; and if thefe hard and 
 fubftantial Materials are made folid and compaft, and clofely con- 
 fined together, how can they fettle or prove infufficient even before 
 they are cemented ? Now I afk you, do you believe, or did you 
 ever hear any experienced Man fay, that clofe gravelly Ground was 
 not a fubftantial Foundation? And is not this in all Refpe&s, at 
 leaft equal to it? Becaufe, it is adually Stone refting upon Stone, 
 of different Sizes down to the minuteft Particle of Sand all com- 
 paded together into one folid Mafs. Palladio has furnifhed you 
 with his Opinion in the tenth Page, and fays, " You fhould choofe 
 " a Place where the Bed or Bottom is even and uniform, and is 
 " either of Stone or of Gravel, becaufe Stone or Grave} are excel- 
 " lent Foundations in Water." And herein lies the grand Advan- 
 tage that will attend all thefe Projeds, /. e. they are to be executed 
 in Water, and if we fupply the Water with due Proportions of this 
 Huffing judicioufly, it will take great Part of the trouble from us, 
 and will, as it were, difpofe of every Particle of the fineft Sand, 
 and with incredible Expedition convey it into fuch Interlaces and 
 
 fmall 
 
( 93 ) 
 
 fmall Pores, as it will find fit to receive it, and if it does not fit 6) 
 get room in one Place, it will inftantly cond'uft.it downwards by 
 its own Gravity, till it gets it properly fettled, which I prefume, no 
 human Art could fo effectually accomplim*; and 1 think it alfo ad- 
 vifable to propofe the following Experiment. 
 
 When this little flight Coffer is made and fluffed with wet 
 Grout, to within five or fix Inches of the Top, level it fo that 
 every Stone on the Surface, may come to a proper and equal 
 bearing, and cover it all over with a Coat of Grout; expofe it then 
 to the View of judicious Perfons, and get their Opinion of it, and 
 then Floor it all over with cut Stone, after a Workman-like 
 Manner: It will then effectually fuftain the Weight of the Statue, 
 which in this Cafe is the Thing required; but in order to fum up 
 and finally determine the Utility of thefe Speculations, which are 
 in a large Degree the Bafe and Foundations of the following Pro- 
 pofitions ; let us particularly recolleft, examine and confider well, 
 what Alherti has tranfmitted down to us; that is, " Upon pulling 
 u down a very high and ftrong Tower at Bologna, they difcovered 
 u that the Foundations were filled with nothing but round Stones 
 iC and Chalk to the Height of nine Feet." 
 
 Let me, therefore, recommend it to you, to get a fquare Pit dug, 
 fuppofe of 9 Feet deep and as many broad, the Length at Difcre- 
 tion, and let that be done near a Pump, or convenient to fome 
 Water, and when it is filling with thefe Stones and fandy Gravel, 
 fupply it moft plentifully with Water, to convey the Sand into all 
 the Vacancies, but put neither Lime nor Lime-water in it, and 
 when it is filled level to the Surface, throw more Sand and plenty 
 of Water over it, and let the Men (with the back of their Shovel) 
 beat down all irregular Stones, and make an even Surface as before 
 mentioned, but do not then Floor it with cut Stone, but get fome 
 Gentlemen or other flcilful Perfons to view, to prove and examine 
 whether or no that is a fubftantial Foundation, whereon to erect 
 the moft weighty Building immediately. And if it be given in the 
 Affirmative, as moft certainly it will, then confider alfo, that if the 
 Lime or Lime-water was properly compounded with thofe materials, 
 then would the whole be endued with this great and remarkable 
 
 Ad van- 
 
( 94 ) 
 
 Advantage, viz. The longer it will fland, the harder and more 
 durable it will grow; and if the Pit was a Mile Cube and fluffed 
 in like Manner, it would be all the fame in effe£t 
 
 SECT. IV. 
 
 Concerning two other more weighty Purpofes to which thefe Methods 
 
 may he applied in ftill fV ater. 
 
 Pro?. II.TF ET us fuppofe that a Gentleman has an elegant 
 j j Vifto, terminated ly a fpacious Canal, the IV iter in 
 which is twelve Feet deep, and he requires a Foundation to he laid 
 in it, whereon he intends to ere El an Ohelifk of 36 Feet high. 
 
 METHOD laid down in Plate XXIX. Scale 5 Feet 1 Inch. 
 
 Wherein note, Fig. 1. Half of the Plan or Bottom of the Coffer, 
 which is to be made of four or five Inch Plank. Fig. 2. Half of 
 the Sedion. Fig. 3. Half of the outfide erea, dovetailed and 
 furrounded with 5 Belts, and Fig. 4. Half of the Platform which 
 is floored with cut Stones of 4 by 2 Feet, and a Foot thick, 
 a. The Rings for Hauling and fixing the Coffer, b. Brace Bars, 
 Chains or Beams as mod convenient, c. Scite of the Obelilk. 
 d. Plinth of the Pedeftal, e- Bank to confine the Lime-water. 
 
 Let us alfo fuppofe, that a Nobleman hath a large Piece of 
 Water adjoining his Pleafure-garden, from a particular Place in 
 which, he and his Company have frequently been highly delighted 
 with beholding feveral beautiful Profpeas, from his Pleafure-boat ; 
 and he has a very public Spirit, and is defirous to enlarge the 
 general Beauty of that highly improved Country, the better to en- 
 joy the Benefit of the wholfome Air, he is determined to have an 
 eleo-ant oSa^onal Pavilion or Pleafure-houfe of 18 Feet Diameter, 
 built in that particular Place; that the refpedlive Windows may 
 take in the Views of the natural Landfcapes: And he alfo appre- 
 hends, that when the Windows are fully illuminated, a Band of 
 7 Martial 
 
( 95 ) 
 
 Martial Mufic, &c on rejoicing Nights, will contribute greatly 
 toward the Amufement of the Nobility, and the adjacent Neigh- 
 bourhood. Therefore, 
 
 Prop. III. Ton are required to build a Pavilion of cut Stone, in a 
 Lake of freflj JVater eighteen Feet deep; the Platform to he en- 
 clofed with a Parapet of the fame, extending 3 4. Feetfquare. 
 
 METHOD laid down in Plate XXX. Scale 8 Feet 1 Inch. 
 
 Fig. 1. Is the Plan or Bottom of one half of the Coffer. Fig. i*. 
 Section or infide of the fame as if it were floored with cut Stones. 
 Fig. 3. Elevation thereof. F. Bottom of the Water. G. Surface 
 of°the fame. H. The Bank, and Fig. 4. The Platform floored 
 with cut Stone of one Foot thick. Wherein note, a. Launching 
 and hauling Rings, b. Reprefents the Situation of the Brace-bars, 
 which in this Work ought to be much rather fmall Boom-chains, 
 and Brace-beams alternately, c. Scite of half of the Pavilion, 
 d. Walk, round the fame. e. Parapet-wall. 
 
 This Coffer is to be furrounded with a double Belt above, and 
 three fmgle Belts below them, as in the laft Proportion; and they 
 are to be dovetailed and plaited with half flat Bar-iron. All thefe 
 Belts are to be both bolted or fpiked to the Hull or upright Piles, 
 and alfo pinned with Oak Trundles of about \ Inch Diameter, 
 which are to be driven in the outfide, and wedged within-fide. 
 Both the upright Piles of the Hull, and all the Belts, you may 
 fee by the Scale, are to be fix Inches thick. The fluffing the fame 
 as before directed, and to prevent Repetition, I lhall omit feveral 
 other Matters, which you fliall be made fully acquainted with, 
 through the Progrefs of the following explanatory Notes, which 
 you are to apply according to your own Judgment. Let us now 
 endeavour to point out another Method of working in V/ ater, for 
 inftance, in frefh Water Rivers. 
 
 CHA P, 
 
( 96 ) 
 
 CHAP. XV. 
 
 Concerning another Method for laying of the Foundations for the 
 Piers of Stone Bridges^ in large and deep Rivers. 
 
 THERE have been various Methods pra&ifed in laying the 
 Foundations for the Piers of Bridges, in large and deep 
 Rivers; but they have generally proved fo extravagantly tedious 
 and expenfive, that the Public have been quite diflieartened and 
 deterred from even attempting fuch a Work, notwithstanding they 
 labour under great Inconveniencies for want of them, efpecially 
 in large Towns and Cities, and in all populous Countries, through 
 which fuch large and deep Rivers run. 
 
 Now I hope by this Time my Readers have been able to form 
 fome kind of Idea, concerning what I mean by Coffers; and if fo, 
 let us apply our utmoft Endeavours to remedy the great Difadvan- 
 tages which the Public are labouring under, by contriving fome 
 other fure, quick and cheap Methods for that Purpofe; in order to 
 which, I recommend it to you in the firft Place, to make yourfelf 
 thoroughly acquainted with the Bed of the River on which you 
 intend to work : Some, you muft be fenfible are hard, fome foft, 
 fome partly confiding of both, fome are very fmooth and even, and 
 others may have large Rocks or tumbling Stones, &c. You muft, 
 therefore, make a firm Refolution, never to fit down to defign the 
 Bridge, nor to confider the Conftruaion of your Coffers, till you 
 have moll carefully tried, and fearched diligently into the Bed of 
 the River, which you may eafily do by the Methods formerly di- 
 rected, let the Depth of the Water be what it will in Moderation ; 
 And when you have colle&ed and figured down your Soundings 
 and Borings, you may proceed, and confider the grofs Dimenfions 
 of the Bridge, and the Conftrudions of your Coffers. 
 
 But I prefume, we may venture to eftablifh one general Rule, 
 concerning Bridges in particular: u e. To proportion the Bridge to 
 the Depth of thi Water; as for inftance, if the Water be three 
 Fathom deep, your CofTer muft be 19 Feet high, and at leaft 18 
 
 Feet 
 
( 97 ) 
 
 Feet broad in the clear, and it will ftand as firm as a Cube. And 
 you rauft adhere clofely to Palladios Rule, which is, u that the 
 <c Foundation muft be as thick again, as the Wall intended to be 
 u faifed upon it;" but you muft by no Means follow his next 
 Direction, /. e. " to make the Foundation wider in foft loofe 
 u Ground," for that would make the Bridge quite prepofterous ; 
 but you muft ftrengthen the foft Ground with Piles to fuch a 
 Degree, as may bring it to an Equality with the reft of it, (as I 
 did at the two northerly Piers of Effex-bridge, fee Plate XIV.) I 
 fay, if the Water is 1 8 Feet deep, your Coffer muft be at leaft i 8 
 Feet broad, and confequently the Pier g Feet thick; which (if 
 executed as reprefented in Plate XV. Fig. i, 2 and 3,) will admit 
 of an Arch of 54 Feet Span; and it is my Opinion (with Sub- 
 miflion to fome eminent Gentlemen) that the Breadth of a Bridge 
 fhould be determined by its Heighth alone, or that the whole 
 Bridge taken together, muft bear fome Analogy to the Depth of 
 the River; for the higher the Superstructure, the greater extent 
 the Foundation requires; but as there are numerous Books extant 
 on this Subject, you may confult them, and let us keep to our 
 Text with refpect to the Foundations of Piers, and on this Subject 
 as before, we mall begin in fhallow Water. 
 
 SECT. I 
 
 Prop. IV. T T is required to build the Piers of a Stone Bridge, in 
 A. a f re ft> J^ater River of one Fathom deep ; the Bed 
 of the River, Loam or Jharp and clean fandy Gravel: "The Propor- 
 tions of the Bridge left to Difcretion. See another different 
 
 METHOD laid down in Plate XXXL Fig. 1. {laid down by 
 
 a Scale of 5 Feet 1 Inch.) 
 
 Represents the Sedion of the Coffer, and /the Pier fpringing 
 high, asjf the Foundation had adually been laid. Wherein note, 
 A. Bed of the River. B, Ordinary low Water in Summer. C. 
 Conftruaion of the Cofftr, which is to hold the Stuffing, as for- 
 
 O merly 
 
( 98 ) 
 
 merly directed. D. One of the Brace Bars, which may be an Inch 
 and a half fquare. E. Shews the Bond of the Cut-ftone-work of 
 the Pier; and F. the banking. 
 
 Fig. 2, 3 and 4, are laid down by a Scale of 1 Foot 1 Inch, and 
 exhibits the Plans and different Views of the Piles, that are to com- 
 pofe the Coffer, and after what Manner they are to be pointed, 
 which may, perhaps, require to be burnt a little in the Fire; but 
 in thefe Kinds of Beds they need not be fhod or pointed with 
 Iron. 
 
 This Coffer rifes one Foot above the low Water in Summer; 
 but generally fpeaking, that Foot will be as if it was all under 
 Water, according to our former Intentions. Now, the Coffer is 
 eight Feet wide in the clear; becaufe, had it been made exadtly 
 cubical, the Pier would be but 3 Feet, which would be too dimi- 
 nutive; and for this and the like Reafons, you were not to be 
 confined, as the Proportions of the Bridge were left to your own 
 Difcretion. 
 
 There are feveral Ways of making what they call dovetailed 
 Piles, three of which I have given you in Plate XV. but I prefer 
 N Q . 4. to any other fort that I have ever feen, becaufe it is fure, 
 cheap and quick: the leaft gravelly Pebble will tear and fplit off 
 the dovetails in N°. 5. and N°. 6. I ufed at Ejfex-hridge\ but I 
 found it to confume and wafte a vaft deal of Timber and Time, as 
 I told you before. You fee in N°. 4. or in Fig. 2, 3 and 4, in the 
 prefent Plate, the Tongue of one Pile falls into the Groove of the 
 other. The Piles I fuppofe to be 1 % by 6 Inches, which is 
 thicker than what is neceflary for this little Coffer; but if a (lender 
 Pile would meet with ftiff Ground, it would not drive, and thefe 
 will be pretty ftout to bear a proportionable Force. The 6 Inches 
 thick are divided into three Parts, two Quarters, that is Scantling 
 of near two Inches fquare, forms the Groove, and another of the 
 fame Size makes the Tongue, and are all put on with proportionable 
 Spikes, Pins or Brads. Their Connexion will be more fully exhibit- 
 ed by the next Plate. — Plate XXXII. Fig. 1. Scale 5 Feet*o \ Inch. 
 Which is the Plan of that half of the Coffer that lies to the Stream, 
 but the Stern of the Coffer may be about two Feet longer. The 
 
 Line 
 
i?i 39. 
 
( 99 ) 
 
 Line a. fliews what Proportion of the Coffer the firft Courfe of the 
 cut Stone is to occupy, b. the Brace Bars. 
 
 Fig. 2. laid down by a Scale of i Foot i Inch. Wherein note, 
 that c. reprefents the Cut-water Pile. d. The Piles of the Coffer, 
 e. The Belt that inclofes them, which is to be dovetailed at every 
 Angle, and plated with half flat Bar Iron. 
 
 Fig. 3. by the fame Scale, f. The corner Pile at the obtufe Angle, 
 g. The Piles of the Coffer that go into it. h. The Belt as above, 
 which is to be tightly braced together by the Brace Bars. b. Which 
 in Plate XXXI. is marked D. and you there fee that they are to be 
 about x Foot 8 Inches below the Heads of the Piles, and level to 
 the top of the Piles is the Surface of the Platform of cut Stones, 
 which are to be four by two Feet, and one Foot thick each; on 
 which Platform or Floor, the Stone-cutter begins to fet the firft 
 proje&ing Courfe of the Pier. i. In Plate XXXII. is the Middle 
 of the Bridge; and k. the extent of the Parapets. 
 
 : In driving down the Piles, you muff begin with the Cut-water 
 Pile, and obferve, that in the fourth Joint that you are to run a 
 cut of your Saw acrofs both the Tongues and Grooves, but not to 
 take that upper Part off, 'till you are going to drop down your 
 Belt; and you are to make the fame Preparations for all the other 
 Brace-bars; and when you are going to drop them down, rip off 
 the upper Parts of the Tongues and Grooves to make Room for 
 the Brace-bars., 
 
 I ought to have told you before, that thefe Belts muff be made 
 very flack, fo that they may go eafily on, and if they do not, and 
 you are fure tlhere is nothing in the Way to obftrucl: them, you 
 muft force theim down with a fingle Maul, 'till you come to the 
 Surface of the Water; and if you choofe to put any of them lower, 
 you muft drive them the reft of the Way, after the fame Manner 
 as a Cooper drives down a Hoop. 
 
 The moft of thefe Piles may be drove down into fuch a Bottom, 
 with a fingle Maul, but you muft alfo have fome large and weighty 
 double-handled Mauls, efpecially for the corner Piles, and if the 
 Bed proves fucfi as we have fuppofed, a Carpenter, a Boatman to 
 keep your Float or Pont fteady, and three flout Labourers* may 
 
 O 2 drive 
 
( ioo ) 
 
 drive at the lead fix of thefe little fhort Piles in an Hour, and by 
 having frefli Men to fucceed them every eight Hours in Summer 
 Timet you may quickly difpatch the Coffer, provided, you have 
 made proper Preparations for it as before direded, always obferving 
 to lafh all the Piles you drive in the Day very tight, leaft an un- 
 expeded Rain fhould come on, and for aught you know, bring 
 down a Flood upon your Work; and in Cafe you have caufe to 
 fufpea a Flood, brace your Cut-water Pile with temporary Braces, 
 in the fame Manner of a. b and c. in Plate XXIII. and from thence 
 difperfe the Braces to the right and two obtufe Angles of the 
 flem of the Coffer. 
 
 SECT. H. 
 
 Prop. V.TT* is required to build the Piers for a Stone Bridge, in 
 £ a fmooth frejh Water River of ftxteen Feet deep, the 
 Bed of the River Loam', the Proportions of the Bridge left to Dif 
 cretion, as hefore. 
 
 METHOD laid down in Plates XXXIII, and XXXIV. 
 
 Scale 5 Feet i Inch 
 
 Plate XXXIII. Fig. i. Seftion of the Coffer. Wherein note, 
 A. The Bed of the River. B. Ordinary low Water in Summer. 
 C. Sedion of the Coffer. D. Seftion of the Pier fpringing high, 
 (landing on the Platform or Floor of cut Stone. E. The Bank to 
 be of the fame fort of Materials of the Stuffing, Lime only ex- 
 cepted. 
 
 Fig. 2. is laid down by a Scale of a Foot to an Inch. Wherein 
 note, a. Is part of one of the Piles that compofe the Coffer, having 
 the Groove ripped off the upper Part of it, to receive the Brace- 
 bar, b. Part of one of the Belts that furround it. c. The Nut 
 that fcrews it tight together, d. The Screw, e. The Brace-bar 
 fallen down into its Place, and is to be keyed under the End of the 
 Screw-bar, d. in which there is to be an oblong fquare Hole made 
 to receive it. 
 
 Plate 
 
PL S3. 
 
( xoi ) 
 
 Plate XXXIV. Scale 5 Feet 1 Inch. Is the Plan of the Coffer 
 for one half of one of the Center Piers. Wherein note, A. Middle 
 of the Bridge. B. Outfide of the Parapet, which from out to out 
 is 47 Feet. The Center Arch is to be 48 Feet fpan. C. Firft Stone 
 of the Cut-water in the firft projeding Courfe of the Pier 
 
 It may perhaps happen, that you may meet with fome Difficulty, 
 by fixing your Chain-braces fo exadly, as to fall dire&ly into the 
 Joints appointed for them, and alfo, in fplicing the long Sides of 
 the Belts, fo as they may not wreck in dropping them down ; and 
 if you apprehend that, then follow the Method laid down 111 Fig. *, 
 which fliews how the Belts are to lap and break Joints, by which 
 you will remove all the Difficulties, and make the Coffer extremely 
 fubftantial, by dropping down your Brace-bars in pairs, as you lee 
 in this Figure drawn horizontally. . 
 
 But I muft give you a Caution, with regard to your Huffing this 
 or the like Coffer. If you have a Bed of fharp, clean fandy Gravel, 
 your firft Stratum ought to be plenty of Roach-lime, in order to 
 cement and petrify that Gravel, and then proceed with the reft as 
 formerly direded; but in Cafe your Bed mould happen to be fine, 
 quick Sand, or foft fpungy Ground, notwithstanding your piling 
 the infide of your Coffer at 2, 3 or 4 Feet afunder, yet, in fome 
 Cafes it may be very neceflary, before you put in your Chains, to 
 make a Belt pretty large, and drive it down (as I told you Coopers 
 wrougn t)to the Bottom of the Water, as f. in Plate XXXIII. and 
 that will keep all tight together below, and the banking, E. is to 
 extend from Pier to Pier, and ten Feet above, and fifteen Feet 
 below the Point of the Starlings of the Coffers, which will there 
 make a firm new Bed for the River. 
 
 I recommend it to my young Reader, to bend his Attention to. 
 the Methods fully laid down in this and in the laft Propofitions, 
 and principally exhibited in Plate XXXI. as I am convinced, that 
 it may prove very ufeful not only for building in Water, but alfo 
 in quaking Bogs or MorafTes, that have fmooth penetrable Bottoms, 
 but efpecially Loam or foft Clay. Remember then, when you are 
 engaged in fuch Works, in a ftill or gentle running frefli Water* 
 quaKing oosr or Morafs of a moderate Depth, that you may make 
 ^ 00 effectual 
 
( ) 
 
 effectual Coffer-dams, by driving down fuch Piles as thefe, anfwer- 
 able to the Intention and Size of your Work; only obferving, that 
 in forming the Angle, it will not be necellary to make ufe of fuch 
 grofs Scantling, as reprefented in Plate XXXII. Fig. %. letter e. 
 Becaufe Scantling of the fame Size of d. d. will anfwer effectually, 
 by pinning and fpiking the Grooves on the corner Pile, and the 
 Tongue on the next returning Pile, and all their Heads may rife 
 two or three Feet above the Surface, and there they may be cut 
 off level, and a Ribbon run a long the outfide of them, from 
 whence you are to dovetail ftrait Beams or Braces of fmall Scant- 
 ling to keep all tight together, whilft you have Occafion for them ; 
 and when all that is done in a Workman-like Manner, then get 
 the Water, Slough or Mud taken out, corking any Leakages that 
 may happen to appear according as the Water finks; and when 
 you have thus got the Coffer clear, ftrengthen the Bottom by 
 driving down fquare Piles, or by laying a Grillage of Timber on 
 it as before directed, and thereon let the Mafons go on with their 
 Work after the ufual Manner; and when they have brought up 
 their Work to a proper Height, thefe Piles that compofed the 
 Coffer are to be drawn out, and applied to another Pier or Part 
 of the Work. 
 
 Single Rows of fuch Piles, may alfo be extremely ufeful, in 
 preventing or flopping fubterraneous Leakages or Ouzings under 
 Coffer-dams, Dikes, Sluices, Flood-gates, Wires, Canals, Mill- 
 races or the like; and likewife an excellent Method to preferve 
 and to keep in the Ground that is under the Piers, either of a new 
 or what remains under an old Bridge, provided they can be drove 
 down., for thefe will take very little Room off the Water-way, and 
 will be exceeding tight and clofe tongued and grooved into one 
 another, which is much better than any Thing that can be done 
 by fquare Piles. In fhort, I cannot exprefs the great Advantages 
 which I apprehend, may accrue or be deduced from this Method. 
 
 But in many Cafes it may be neceffary to drive two Rows of thefe 
 Piles, leaving a convenient Space between them, which is to be 
 filled up with good and well rammed Clay, and that will unite 
 with the Bottom^ and make exceeding ftaunch Coffers, or would 
 
 alfo,, 
 
( *o3 ) 
 
 alfo, effe&ually enable you to make ftaunch dry Docks, parti- 
 cularly where feveral of them are ranged contiguous to one another, 
 either in Tide-rivers, or within an inclofed Harbour in the Sea. 
 
 S E C T. m 
 
 Concerning the building of Stone Piers, in a deep Tide-river , on a 
 
 hard rough Bed. 
 
 I HAVE already obferved, and every Body may know, that 
 there is a vaft deal of Difference between the various Natures 
 of the Beds of Rivers; and for that Reafon we muft invent fuch. 
 Methods, as are capable of being varied in fuch Manner, as may 
 make them fuitable to our Purpofes ; but as I aim at Concifenefs, I 
 fhall neither perplex you with a Multiplicity of Proportions, nor 
 deprive you of fufficient Room to exercife your own Ingenuity; and 
 therefore, I fiiall State my next Proportion, fo as to comprehend 
 fome of the mo ft extraordinary and difficult Circumftances. 
 
 Prop. VI. Let it he required to lay a Jure, quick and cheap 
 Foundation for the Piers of a large Stone Bridge, in a fpecious 
 Tide-river, greatly expofed to the Agitations of the main Ocean, 
 the Bed of the River exceeding hard and rocky- in the Middle 
 of which, there are fix Fathom deep of low TVater, whence 
 the Bed rifes gradually on loth Sides \ the fpring Tides fome- 
 times rife four Fathom more\ the Size and Proportions of the 
 Bridge, left to Difcretion. 
 
 METHOD, yfc Plates XXXV. XXXVI. XXXVII. XXXVIII. 
 
 In which I purfue the Methods pointed out by the fir ft three 
 Proportions. Plate XXXV. Scale 30 Feet to 1 Inch. Wherein 
 note, 
 
 Fig. 1. Reprefents the Platform of the Coffers, for one of the 
 Middle Piers in two feparate Parts, with the Plan of the Pier upon 
 them. 
 
 Fig. 2. 
 
( I0 4 ) 
 
 Fig. 2. Exhibits the Elevation of the Coffers, with the Pier 
 fpringing high. Wherein note, a. the natural Bed of the River, 
 fuppofe then, at the Diftances of b. b. you are to drop down Stones 
 (none of them need be above a hundred Weight) in two direft 
 Lines acrofs the River, by which you are to make two Stone 
 Dikes or Banks, of 1 2 Feet high or more, thefe Stones are to be 
 of all leffer Sizes down to fandy Gravel; and then you are to pro- 
 ceed and fill up the Pit, that thefe two Dikes or Banks will form 
 to the level Line, c. c. with very fmall Stones, Gravel and Sand, 
 and as much Roach-lime as you can conveniently fpare for it, 
 always obferving to throw the largeft Part of it next the Stream 
 of Ebb or Flood, and at other Times you may convey it by large 
 wooden Troughs faftened to the Sides of the Gabbards. This 
 Line, c. c. is the Bed or Scite of the Coffers, and may be made 
 higher or lower as other Circumftances may require. And according 
 as'the Coffers are fettled in their refpe&ive Places, or at any other 
 Time when you find it moft convenient, you may go on with 
 banking or filling up the Pit after the fame Manner, till you level 
 it to the Lines, d. d. The low Water mark is e. And f. reprefents 
 the Breadth of the Bridge from out to out of the Parapets, 54 Feet. 
 And the Center Arch is to be 84 Feet fpan, as you will fee more 
 particularly deliniated in the next Plate. 
 
 Plate XXXVI. by the fame Scale, gives you the principal Lines 
 of the three Middle Arches. Wherein note, that a. is the natural 
 Bed of the River, b. The Bed on which the Coffers are to ftand. 
 
 c. The Bank or artificial Bed of the River, as before mentioned. 
 
 d. Low-water, and e. High-water marks, f. The Pavement.^ 
 
 I do not doubt but fome Readers may objea, that thus raifing 
 die Bed of the River and thefe large Coffers, will dam and obftrud 
 the Current. In anfwer to this, you may be very well allured, 
 that in all deep Rivers, the Current runs principally, and with the 
 greateft Velocity toward the Surface of the Water, and confe- 
 quently, thofe can only increafe the Celerity, but cannot obftruft 
 the Current; and in fome Degree, this is alfo the Cafe in all Stone 
 Bridges, and therefore, that Objection can have no Weight, be- 
 eaufe, it is evident, that no disadvantageous Conclufions can be 
 
 drawn 
 
( I0 5 ) 
 
 drawn from it, even were the Bed raifed to four. Times that 
 Height. 
 
 But from thefe Obfervations you may alfo colled other material 
 Remarks, that perhaps, may prove inftrudtive and ufeful to you in 
 feveral Refpects, concerning the Motions and Velocity of Rivers. 
 As for inftance, Suppofe that for fome particular Purpofe, you are 
 required to calculate and to make a juft return of the daily Quantity 
 of Water any fmall River may produce during the Summer Seafon. 
 Obferve then, that previous to that Calculation, you are to make 
 ftricl: Enquiry, and to make yourfelf thoroughly acquainted with 
 feveral Parts and Places in that River, and in all thofe Parts and 
 Places to take correct Sections and Plans thereof, on which you 
 are to lay down your Depths or Soundings, ftrictly obferving the 
 Surface and Declination of the Bed, and the Declivity and Irregu- 
 larity of the Banks; and note, that the Friftion that arifes from 
 thefe, greatly contribute to lelfen the Celerity of the Water. 
 
 The Thread, that is, the Middle of the Current of the River, 
 runs the freeft, and is the leaft retarded by thofe Obftacles; and 
 that Thread, efpecially during the Time of a Frefti or Land-flood, 
 is always to be found nearly over the deepen 1 Parts of the River, 
 and thofe deepen: Parts are very variable, and produced according 
 as the Declivity and Circumftances relative to the Bed and Banks 
 may direct; and in dead or flow running Water, this Thread 
 cannot be difcovered by the Eye; and therefore, for thefe Reafons, 
 I fay, you are to make yourfelf thoroughly acquainted with all 
 the Parts and Places, where you intend to take the Velocity or 
 Celerity of that Water; that is, how far it runs in fome certain 
 flated Time, which is to be done by ftraining two parallel Ropes 
 or Lines, acrofs the River at certain Diflances from each other, 
 ftridly obferving, how many Minutes or Seconds a Bit of Cork or 
 fome other fuch light Matter will take to run a certain Space, which 
 you ought to try near each Bank; and alfo, in the Middle of each 
 of thofe Parts or Places of the River, alfo ftri&ly obferving, whe- 
 ther or no, they are haftened or retarded by the Wind; and fo, 
 after fumming up all together, you may be enabled to calculate the 
 true Velocity on an Average, and thereby compute and meafure 
 
 P the 
 
{ io6 ) 
 
 the cubical Feet of Water, that you may reafonably Conclude to 
 pafs through and may be produced by it in the Time required, 
 making rather large Allowance for wafte, &c. 
 
 There have been numerous Perfons involved in very ferious and 
 difagreeable Circumftances, both of private and public Natures, 
 on the Credit of fuch Calculations as thefe; efpecially, where they 
 have much exceeded the Truth, and thereby deftroyed and 
 rendered hopeful Schemes abortive, that might perhaps, otherwife 
 have been attended with private and public Utility. 
 
 Hence alfo, you may conceive fome ufeful Ideas, concerning the 
 Motions and Velocity of Rivers in general, but diftinguifh and 
 remember, that rapid Land-floods roll down and principally a£ls 
 from the Surface to the Bottom in all deep Rivers, as I hinted above, 
 and that when a Flood Tide flows into the Mouth of a River over 
 a (hallow Bar, it operates from the Bottom to the Surface, by dam- 
 ming up, and totally overpowering all the frefh Water that comes * 
 within its Influence. But to return. 
 
 Now, I hope, I have furnifhed you with general Ideas of the 
 Nature of the Works, which you are going about; let us in the 
 next Place, confider the Conftru&ion of thefe Coffers. See 
 
 Plate XXXVII. Scale 5 Feet to 1 Inch. Fig. 1. Reprefents the 
 Section of the Coffer; but obferve as before mentioned, that this 
 Coffer would be too large to be made in one, and therefore, I 
 propofe, that it be made in two feparate Parts. Whereon note, 
 that a. is the Bottom, b, b. The double Sills between each pair 
 of them ; the upright Planks that compofe it are to be placed ere£t, 
 and are to be the Tenons of the Hull, and then they are to be 
 pinned and bolted together, c. is the Keel or Middle Sill, and as 
 probably you cannot get Timber long enough for them, you muft 
 run a breaking cut through the longeft you can get, fcarf them to 
 fit your Length, and turn them End for End, and bolt them firmly 
 together with Nuts and Screws; between thefe, you are to grate 
 the Bottom with two Courfes of fix Inch Plank, croffing one ano- 
 ther. Both the upright and horizontal Piles of the Hull are to 
 be tongued and grooved as in Plate XXXI. Fig. 2 and 3, and all of 
 them to be pinned together at their Interfe&ions, and all the out- 
 ward 
 
( io7 ) 
 
 ward or horizontal Piles are to be dovetailed at the Angles, and 
 there plated with whole flat Bar; and there are to be five launching 
 and hauling Rings at the three right and two obtufe Angles of each 
 Semi-coffer, (as formerly direded in Plate XXX. letter a.) e. is 
 the banking or artificial Bed of the River, which you fee rifes 6 Feet 
 high all round the Coffer, reprefented by c. in the laft Plate, f. 
 Low-water mark. g. Temporary diagonal Braces, to prevent its 
 warping in launching. You fee thefe Braces have a Bears Mouth 
 upon the upper End of each, and are to be fitted and nailed to 
 the Ribbon, h. and when the Coffer is fluffed about two or three 
 Feet high, they are all to be knocked off, as of no further ufe. 
 
 Though I have drawn the four Tiers of Brace Bars to be made 
 of fquare Iron, yet if it is as convenient to you, I would rather 
 advife you to make ufe of fmall Boom-chains for that Purpofe; 
 but ufe which you. will, it may be advifable to ftrengthen them 
 with the fix Inch Plank, to go quite through, and to be dovetailed 
 at each End, through the Hull that is through the upright and 
 horizontal Piles; and you may obferve in Plates XXXV. and 
 XXXVI. that I have only belted the Hulls as before, but on fecond 
 Thoughts, I think it the fureft Way to let them lie as clofe to one 
 another as they can, and fo I have reprefented it in this 3 7 th Plate, 
 Fig. r. which makes the Hull 12 Inches thick throughout. 
 
 Fig. 2. Reprefents the front of the Pier Handing on the Plat- 
 form, or Floor of Cut-ftones, which covers and inclofes the fluf- 
 fing of the Coffer, which muft be run Home to the Hull of the 
 Coffer, when the Ribbon h. is taken away. 
 
 You fee, for the Reafons before given, that I keep as near as 
 the Bond of the Work will admit, to have the Stones of the Scant- 
 ling of 4 by 2, and a Foot thick; and if you carry up the front of 
 the O&agon in Afhler, they will anfwer effectually, but if in 
 Ruflic Work, each Courfe muft be about 2 \ Feet high, including 
 the Champhers, and k. is the Height of the Arch Stones, the 
 which if rufticated alfo, the Champher muft run through the whole 
 Soffeto of the Arch; but all this is beyond our prefent Purpofe; 
 let us therefore, return to the finifhing of the Coffer. See 
 
 P 2 Plate 
 
( 108 ) 
 
 Plate XXXVIII. Scale 5 Feet to 1 Inch. Fig. 1. Reprefents the 
 refpeclive horizontal Situations of the Chains, and the reft of this 
 Figure mews you the Surface of the Cut-ftone Floor, that is to 
 finiih the Coffer within the Hull. Fig. 2. Shews you the Scite of 
 the three projecting Courfes of the Pier, and the third Courfe of 
 the Body of the Pier, and the Bond of the Work in that Courfe. 
 In thefe fix Courfes, that together carry you to the fpringing^ there 
 may be three of the Courfes chained with two Inch fquare Bar, 
 funk quite down into their refpective Courfes, and run with melted 
 Lead as ufual. 
 
 I have already advifed that all the Cut-ftone Floor, or Platform, 
 is to be carefully and clofely fet in fwimming Beds of choice good 
 Mortar, and all the Joints with Tarrafs Mortar, and if you do not 
 think that fufiicient to withftand the Effects of the Water, you 
 may at any Time afterwards fcrape the Joints clear for about two 
 Inches deep, and either fill them with melted Lead, or rather cork 
 them with the fhavings of Lead, but only for fo far, as exceeds that 
 firft projecting Courfe. The feven ftrong Lines, d. reprefent the 
 Cramps, that are to cramp the Hull and the cut Stone Floor toge- 
 ther, which you will hereafter find more fully defcribed; only 
 obferve, that they are to be lodged in the fecond Courfe of the 
 Stone. 
 
 And now I have furnifhed you with an Idea of my Intentions, 
 pray point out any one individual particular in this Method, that 
 is attended with the leaft Degree or appearance of Impoflibility, 
 or even of any extraordinary Difficulty. Surely, you will not 
 pretend to fay, there is any Difficulty in making the two Half- 
 Coffers, which may be put together by a very few Journeymen Ship 
 and Houfe Carpenters, and a few Blaek-fmiths, with the Afliftance 
 of a few Sailors and Labourers, in a Fortnight's Time; and if you 
 are required to ufe any extraordinary Expedition, you may eafily 
 have them launched and fluffed within another Fortnight, pro- 
 vided you take proper Care to have every Thing you will want 
 timely and conveniently provided, and that you have proper Crafts 
 to carry in your fluffing, which by the Afliftance and Direction of 
 your ten-buoy Ropes belonging to your two Semi-coffers, the Men 
 
 may 
 
( io 9 ) 
 
 may work at low or high Water, either by Night or Day, according 
 as you find neceffary; and if this Coffer can be fluffed within a 
 Fortnight, pray might not another fet of fuch Men' do the like 
 Work within the fame Fortnight? 
 
 Let us now compare fmall Things to great ones. We are very 
 well allured, that Apollodorus compleated Trajan 's Bridge within 
 the Summer of the Year of our Lord 104, and that the ten out- 
 ward Piers were built on artificial Foundations, made by wheeling 
 in vaft Quantities of large and fmall Stones, and other filling 
 (perhaps like the fluffing fo much ufed by the Antients) but by all 
 my Induftry I could not find out, by what other Methods he made 
 the Foundations in the Middle of the River. Now if I was to 
 prefume to enter the Lift of Conje&urers, along with fome great 
 Folks, I fliould conclude, that the Methods he took to build the 
 inner Piers were, to rife or bank up the Bed of the River (of which 
 you (hall hear further) and to fet fuch Coffers as thefe thereon, 
 and from thence proceed with the Stone-work as ufual; (and I have 
 already told you where to find the true Methods which he muft 
 actually have taken) and if the Foundation of one Pier can pro- 
 bably be carried up to low Water mark in a Fortnight, could not 
 twenty fuch fets of Men, do twenty fuch Pieces of Work in the 
 fame Time? And if fo, where is the Wonder that Trajan 's nume- 
 rous Army compleated that Work within that Time? Nor need 
 you be afraid to compleat fuch an one as we are now projecting, 
 we will fuppofe of 1 9 Arches, even within the compafs of the fix 
 Summer Months, if there was a Neceffity for it, and Money fuffi- 
 cient to carry it on, provided you had fufKcient Time, and you 
 had previoufly provided and prepared every Thing you wanted for 
 the Purpofe, before you launched your Coffers. 
 
 SECT. 
 
( no ) 
 
 SECT. IV. 
 
 Concerning Bridges principally contrived for the Ufe of London- 
 derry, Waterford, and Wexford, and for fuch other large 
 and deep Rivers. 
 
 * I THROUGH the Courfe of my Endeavours to contrive and 
 |L find out effectual Methods for building Bridges and other 
 Works in deep Waters, Londonderry, fVaterford and IVexford, 
 (each of which I have viewed) have conftantly enjoyed a prime 
 Place in my Mind; and being thoroughly acquainted with many 
 intolerable Difadvantages, that not only the Inhabitants in, and 
 the Proprietors of thofe and the adjacent Places, but the Public in 
 general daily fuftain, through their want of Bridges; thefe Confider- 
 ations alone, have excited my moft zealous Endeavours to find 
 out proper Methods to redrefs thoie Grievances, and not in thofe 
 Places only, but in many others in like Manner; and with that 
 Intent, I here freely tranfmit and communicate to you my Senti- 
 ments and Ideas on this important Subje6t. And I am fure that 
 they are confidered, and well weighed to the utmoft extent of 
 my Capacity, and that they are not only practicable, but by a 
 prudent Application of what I am now laying before you, 
 may be productive of immediate Utility, and anfwer according to 
 the Appellation beftowed on them, of being fure, quick and cheap 
 Methods, for thofe and the like falutary Purpofes. 
 
 The Concifenefs of this Work, and not being able to procure 
 proper Sections of thofe Rivers, prevented my laying them down 
 particularly, nor have I formed any Defign exceeding fix Fathom 
 low Water; but I hope they moft clearly point out, Methods for 
 building in a much greater Depth. As for inftance, let us fuppofe 
 a River of fifty Feet deep at dead low Water, and let us examine, 
 after what Manner our general Rules muft condu£t you to draw 
 Defigns for that Depth. The principal of which dire&s, " that 
 " the Coffers fhould at the leaft extend to a Cube of the Water 
 
 " they 
 
( I" ) 
 
 a they fland in ; and that the Size of the Bridge ought to bear 
 u fome Proportion to the Depth of the Water in which it is to 
 44 ftand." Now if the Water be 50 Feet deep, the Coffer muft 
 at leaft be 50 Feet broad, the naked Body of the Pier 25 Feet, 
 and confequently the Arch muft Span 150 Feet. I grant that fuch 
 a Span would not by any Means anfwer for our poor Country, 
 becaufe the Expence would rife infinitely above any Thing 
 that we could have the leaft Hopes of accompliffiing. Now to 
 remedy this, the Method is obvious, turn back to Plate XXXVI. 
 and obferve the Line b. which is the Scite of the Coffers and diftant 
 from a. but fix Feet, which is placed in the Middle of the River. 
 Now, we muft fuppofe a. to be 20 Feet beneath b. and let a. be 
 fuppofed to lie as far as you pleafe either to the right Hand or ta 
 the left, and let a. and b. be either more or lefs than 20 Feet; the 
 Method is, to raife up and make an artificial Bed of the River, 
 with fuch fmall Stones and Gravel as formerly directed, till you 
 bring it to the Line b. and to extend it in Breadth on the Bottom 
 in Proportion to its Height; and then every Thing elfe will fall 
 in, in due order. Hence it is evident, that let the Depth of the 
 Water be what it will in Moderation, the Rules may help to 
 conduct: you in drawing Defigns for any other reafonable Depth. 
 
 But perhaps, after- a .ll I have faid, you may object, that this 
 banking or artificial Foundation would not be fufficiently ftrong 
 for the Purpofe. 
 
 You have been repeatedly informed, that in building Trajan's 
 Bridge, dpollodorus had 44 the ten outward Piers built on an 
 44 artificial Foundation, by wheeling in vaft Quantities of large 
 44 and fmall Stones, and other filling, after the ufual Manner of 
 44 carrying a Mole into the Sea." — Let us here obferve, that our 
 Hiftorian fays, 44 after the ufual Manner of carrying a Mole into 
 44 the Sea." And that notwithftanding thofe Rivers are greatly 
 agitated at fome Times by the Sea, yet not liable to be quite fo 
 much fo, as 44 a Mole projected into the Sea," whofe Surface is 
 expofed to the Waves of the Ocean. Therefore, it is evident, that 
 if this Method was fufficient for fuch an enormous Bridge, furely 
 there cannot remain the leaft Objection againft the Stability of ours. 
 
 But 
 
( «* ) 
 
 But pray give me leave to engage your Attention in a more par- 
 ticular Manner. It muft be admitted, that this Country cannot 
 afford to carry on any expenfive or very fumptuous Work for want 
 of Money; but if we have a Scarcity of Money among us, I am 
 confident, that we have fuch very great plenty of fmall Stones and 
 Gravel, that in every navigable River in this Kingdom, you may 
 be abundantly fupplied with thefe common and in a Manner in- 
 fignificant materials, and together with the Labour of a few Gab- 
 bard-men and Labourers, fuch an artificial Foundation may be 
 accomplifhed at a very fmall Expence; and that either of thofe 
 three Corporations, with the aid of fome of the principal Proprie- 
 tors adjacent, even in Cafe they got no help from the Public, need 
 not in the leaft be afraid of compleating fuch a Work. And as 
 thefe common Materials can be fo eafily procured, it will confe- 
 quently follow, and the leaft Degree of Prudence will direct you 
 to raife the Bed of the River as high as you think convenient with 
 thefe cheap Materials, in order to fave Labour and other Materials 
 that would prove infinitely more expenfive. And thus reducing 
 the Depth of the low Water, perhaps to eight Feet, allowing four 
 Feet of that for the Banking, and four for the Navigation; you are 
 thereon to build the Bridge, according to the Plans and Methods 
 hitherto and hereafter exhibited, or according to any other Propor- 
 tions, that you may think moft agreeable to their refpective Situ- 
 ations, paying due regard to the Heights of the Banks, Quays, ferV. 
 and particularly cbferving, that the higher you raife the Bed, the lefs 
 Money you will require to build the Bridge; but I fay you muft pay 
 due regard to the Navigation of the River above the Bridge, for if 
 you leave low Water deep enough for that Purpofe, you need not 
 fcfuple in fome Rivers, to raife the Bed fo, as to reduce that Part of 
 River to a perfect Ford, which all People fearch for that are con- 
 cerned in the like Work, and which, you may make perfectly fub- 
 ftantial, if you adhere to our former Conclufions. Therefore, if 
 Nature has not provided a Ford agreeable to your Purpofes, you 
 may have it in your own Power to fupply that by Art, which you 
 find you cannot enjoy by Nature. Hence you may alfo deduce an 
 excellent Method of making or rendering a dangerous Ford, much 
 
 more 
 
( m ) 
 
 more fafe for Travellers, even for Carriages of any kind, and the 
 Expence will be but a Trifle to a County, where they might not 
 be able to build a Bridge. 
 
 Thefe brief Confederations, I thought previoufly necelTary to 
 prepare you to form a clear Conception of the particular Methods 
 which I have contrived for, and I advife you to lay them before 
 the Gentlemen of your Committee, but that fhall be the Bufinefs 
 of the next Section. 
 
 SECT. V. 
 
 On an exceeding cheap, and mo II fubflaitial Method of building a 
 Bridge, in a very deep and fpacious River, which may be grafted 
 on any of the former Methods. 
 
 HAVING fully proved and demonftrated on the fix Propo- 
 fitions, fo far as the Nature of my prefent Defign requires, 
 that thefe are eligible Methods to build Stone-bridges in deep 
 Rivers; it is incumbent on you to make yourfelf thoroughly 
 acquainted with thefe Matters, and to apply your Attention and 
 the utmoft extent of your own Genius, to confider and improve 
 them according as you find it neceflary: And after all, you may 
 probably find yourfelf far fliort of Arguments fufficient to fatisfy 
 every Member of your Committee, which are generally compofed of 
 Gentlemen of various Abilities; fome of whom, may perhaps, 
 readily conceive and approve of what you offer, but others, may 
 differ widely from them. In this Cafe, I advife you to enquire 
 among your Acquaintances, and take Notice yourfelf, which of 
 the Gentlemen feem to be befl acquainted with the furprifing Per- 
 formances of the Antients, in Works of this or the like Nature; 
 for fome of thefe will be the moft likely to 'fupport your Argu- 
 ments, and this may incline the Majority in your favour. But 
 fuppofe you fail herein, I have ftill a powerful Argument which 
 cannot fail of meeting with the Attention of the Board, viz. that 
 you fhould proceed with your Coffers, by either of the Methods 
 
 pointed 
 
( **4 ) 
 
 pointed out in the laft Section, which will bring your Foundations, 
 that is the Lip of the Hull, one Foot above the low Water mark, 
 as reprefented by d. in Plate XXXVI. and thereon erect Piers either 
 of hewn or rough Stone, or both juft as they agree, which would 
 fufficiently anfwer your Purpofe, and which you may begin upon 
 the Platform, Plate XXXVIII. Fig. i. But it would do beft to 
 begin them on the fpringing Courle, reprefented in Fig. 2. and 
 alfo in Plate XXXVII. Fig. 2. and thereby to make a fubftantial 
 temporary Bridge with Timber, at fuch a trifling Expence as would 
 not be worth Notice, in Comparifon to what it would coft, if 
 done in any other Method that I have ever heard of. 
 
 This Thought when firft fuggefted, actuated by the Motives 
 before mentioned, actually carried me beyond the Limits of my 
 former Intentions, which related to laying Foundations in Water 
 only. However, I indulged it fo far, as to endeavour to furnifli 
 you with a Defign of fuch a temporary Bridge, as may perhaps, 
 fully anfwer the mo ft fanguine Expectations of your Board and the 
 Public; and which I fhall defcribe and demonftrate, on the follow- 
 ing Proportion. 
 
 Prop. VII. You are required to lay down fure, quick and cheap 
 Methods* for the luilding of a moji fubjiantial temporary Bridge, 
 with Stone Piers; the Arches ( or the Spaces between the Piers ) 
 are to he made of Timber \ the River at feme fpring Tides is ten 
 Fathom deep y as was more fully defer ibed in the laji Propoftion. 
 
 METHOD laid down in Plate XXXIX. Scale m Feet 
 
 to 1 Inch* 
 
 Let us here fuppofe, that the Coffers are fluffed and floored 
 over with cut Stone, as reprefented in Plate XXXVIII. Fig. 1. on 
 which you are to be determined, whether you are to go on with the 
 cut Stone Work to the fpfinging Courfe, as Fig. 2. and alfo Fig. 2. 
 in Plate XXXVII. or whether you are to begin the temporary Pier 
 on the Floor or Platform of cut Stone; but I fhould advife you to 
 the former, becaufe it will be better, and there will be fo much done 
 for the next Generation; but in either of thefe Cafes, obferve, that 
 
 Plate 
 
( "5 ) 
 
 Plate XXXIX. is defigned from the high Water mark of the laft 
 Proportion, and extends to half of the two middle Piers. Wherein 
 note, e. Is the high Water mark, which is the fame of e. in Plate 
 XXXVI. and in both. f. Is the Surface of the Pavement, g. The 
 lower, or principal Braces, which ought to be made of found hearty 
 upright Oak, of 1 8 by i % Inch Scantling. And the King-poft, h. 
 may be the fame; but all the reft of hearty and found red Fir. 
 i. The Collar-beam. k. Principal, 1. and m. The two main Braces, 
 n. and o. The principal Beams, which you fee lie one upon the 
 other (but it would be advifeable to lay Slips of found Oak Plank 
 between them, upon a flant, to turn off the Rain Water, and par- 
 ticularly the out-fide ones, to keep them from rotting) Thefe four, 
 viz. X\ m. n, and o. Are to ha-ve breaking Cuts run through them, 
 and turned End for End, and then bolted together, provided that 
 your Span is as great as this. The Prick-pofts p. and q. are de- 
 figned to fhorten the bearing, and unite their Strength. All thefe, 
 that is, i, k, 1, m, n, o, p, q, are to be about a Foot fquare; and 
 <£ach of the Frames are to be placed about four Feet diftant from 
 each other, the outward ones are to be tried up, The crown 
 Beam r. is 18 by 12 Inches. The flooring Joifts which lie on the 
 Beam, o, are to be nine Inch Scantling, and (paced at 18 Inches 
 afunder. On thefe Joifts the flooring Planks are to lie, which are 
 to be fix Inches thick, this Floor may be firft covered with Pitch and 
 Tar, and then with common Slates, and one or two Courfes of 
 Bricks on them, laid in fwimming Beds of choice Mortar, clofely 
 wrought and grouted. Thefe Slates are to preferve and prevent 
 the Mortar from corroding the Planks, and over the Bricks lies 
 the Pavement of the Carriage-way, f. for which fee Plate XIX. 
 Fig. 3. and the Foot-ways may be the fame as therein alfo deli- 
 neated. Thefe Slates, Bricks and Stones, if properly executed, 
 will effectually throw off the wet, and help to preferve the Timber; 
 but do not forget that I have mentioned different Methods for that 
 Purpofe, but they are to be applied at your own Difcretion. And 
 I think it would alfo be very advifable, to have this Bridge inclofed 
 with a Stone Balluftrade, at leaft over all the Arches; but in this 
 Cafe, there muft be a pair of Frames placed together at the Extre- 
 
 mities, 
 
( "6 ) 
 
 mities, to fupport the Parapets, which muft reft on a heading 
 Courfe of cut Stone, of about 4 Feet long each, and Chain-barred,' 
 &c. for if it is inclofed with Timber, it will be a perpetual Expence 
 to keep it in order. 
 
 I need not be at the Trouble of enlarging on the Strength of 
 thefe Timbers, as 1 prefume, it is obvious enough, that they are 
 fufficiently ftrong, to fuftain the Weight of any Carriage whatfo- 
 ever, perhaps, for a hundred Years without any Expence worth 
 mentioning; but you are to obferve, that the Pavement muft have 
 reafonable Time to cement, and that it is to be plentifully covered 
 with Gravel, before any weighty Carriages are allowed to draw 
 over it. As to the Expence of the Timber neceflary herein, that I 
 have not eftimated, but I can venture to fay, that 1 believe all this 
 Timber and Workmanftiip, would not very much exceed the 
 Expence of the Centers, Sheeting, &c. that would be neceflary to 
 turn fuch a Stone Arch- upon. As to its Durablenefs, if there be 
 proper Care taken to prepare and preferve the Timbers of the. out- 
 fide Frames in particular, which are to be expofed to the Weather, 
 but efpecially at the Joints, u. w. and to throw the Water off from 
 rotting the Buts of .them that go into the Wall, I am confident 
 that the reft of it, which has the benefit of the open air, and fo 
 effectually fheltered, muft in the whole laft at leaft as long, as Fir 
 Timber can be expected to laft in any other building. 
 
 Thus, you now fee before you, the Method which I have fo 
 particularly recommended to the Confideration of the Gentlemen 
 of thofe three Corporations, or of any other Community, that are 
 in the like Situations; and all that I think now remains, is briefly to 
 move one Confideration more with refpect to Roads, which are 
 neceflarily connected with our Subject. 
 
 I. have already obferved, and the leaft Degree of common Senfe 
 will direct, all Perfons concerned in projecting a Bridge in any 
 Country Place, to look out for a Ford or fome fhallow Part of 
 the River, becaufe, it will probably, be both cheaper and the 
 more expeditious. And that by purfuing thefe Methods, it is 
 evident, you need not be under the leaft Anxiety with refpect to 
 the Depth of the Water, provided it be in Moderation. There- 
 fore, 
 
( "7 ) 
 
 fore, before you fix on the Scite of the Bridge, (if that be left to 
 you to determine) you are to procure correct Maps of the adjacent 
 Country on both Sides of the River, view the Grounds yourfelf, 
 and confider not only the Roads that are made, but alfo fuch 
 Roads as muft be made hereafter ; and then fumming all up toge- 
 ther in your own Mind, you are juftly and impartially to recom- 
 mend the beft Scite for the Bridge, that you are convinced will be 
 moft for the Advantage of the Public in general, without paying 
 the leaft regard to any one particular Proprietor of the adjacent 
 Lands, nor fuffer yourfelf to be knowingly led into an Error, that 
 may either injure your Character, or prove prejudicial to the Public, 
 without fairly and fully extricating yourfelf from any Charge that 
 may afterwards be brought againft you, let the after Confequence 
 be what it will. 
 
 If you fhould happen to be in any Ways concerned in Military 
 or Naval Affairs, then thefe Methods may alfo in other Refpe&s 
 become of ftill greater Advantage, but efpecially in remote or 
 defolate Countries. 
 
 His prefent Majefty has of late Years made great Acquifitions, 
 and extended his Arms almoft over the whole Globe. It is evident 
 that thefe Methods may probably be attended by very falutary 
 Confequences, to the Inhabitants of thofe Countries in general, 
 where large Stone Bridges could not be accomplifhed in deep Rivers, 
 for want of a fufficient Number of Workmen, and proper Materials 
 for it. But further, 
 
 If a new Bridge happens to be built in any Country Place, the 
 Public ought to be conducted to it, and that cannot be done with- 
 out making new Roads; in the Execution thereof, various Difficul- 
 ties may happen to be met with. There is no Doubt but it will be 
 defigned, that this new Road will be carried in dire£t Lines; per- 
 haps, Part of a frefli Water Lake may Intervene; and frequently 
 frefh Water Lakes, quaking Bogs, MorafTes or the like, happen in 
 the Way and obftrudl laudable Defigns, obliging the Undertakers 
 to carry the Roads many Miles about, to the no fmall Disadvan- 
 tage of the Public. Now let us endeavour to furmount thefe 
 Obftrudlions, and confider what eligible Methods may be purfued, 
 
( »8 ) 
 
 ia order to carry a Road in a right Line through fuch Places, not 
 only to accommodate the Public, but as being productive of various 
 other Advantages to private Property, in draining and reclaiming 
 flooded or boggy Grounds, by interfering the Current, and giving 
 it a more advantageous Direction. 
 
 CHAP. XVI. 
 
 Concerning fame Endeavours to apply Coffer-work to other private 
 and public Purpofes^ on Land or in Frejh Water. 
 
 IT is not my Intention, neither is it poffible for me to point out 
 all the various Purpofes, to which Coffer Work may be ap- 
 plied ; but I fhall now give an Inftance, wherein I think both pri- 
 vate and public Utility are greatly concerned, in order to excite 
 your own Ingenuity to extend it. 
 
 Our Country greatly abounds with deep molly and marfliy 
 Grounds, numerous Loughs and frefh Water Lakes, to the great 
 Lofs and Detriment of the Proprietors and Public in general : Let 
 us, therefore, try whether or no any of thefe Methods may prove 
 ufeful either for the reclaiming of Ground, or fhortening the Roads 
 in populous Countries. As for inftance. 
 
 S E C T. i 
 
 A GENTLEMAN'S Country Seat lies contiguous to a 
 fpacious frefli Water Lake, which in Winter greatly over* 
 flows, and renders a large parcel of his Eftate not only ufelefs, but 
 alfo entirely obftrucls a fhort Communication from that Neigh- 
 bourhood, to an adjacent Market Town. Therefore 
 
 Pro;% VII L It is required to make a cheap temporary Road 
 through part of a Lough, 9 Feet deep, on a Marley Bottom, that 
 may alfo Jerve as a Mole or Bank to confine the Water from over- 
 flowing the Land\ or in fome Cafes to dam it off y till a Jubftantial 
 hnbankation may be ereffed. 
 
 METHOD 
 
jv. 40 
 
 TJ 
 
 F.2. 
 
 E 
 
( "9 ) 
 
 METHOD laid down in Plate XL. Scale 8 Feet to i Inch 
 
 Fig. i. Reprefents the Sedtion of the Mole, wherein note, A. 
 is the Surface of the Winter Water, which is 9 Feet deep to 
 B. The bottom of the Water. C. C. Two Rows of fquare Piles, 
 to be fheeted on the infide with 1 I Inch Plank, which muft be 
 ledged together, and floated in on Edge between the Piles and 
 temporary Poles, to keep the Sheeting upright in its Place till the 
 Stuffing is put in, and then the Poles are to be taken away. 
 D. The Chain that Braces both Sides together, which need not be 
 very ftrong as thefe Piles are battered. E. The Road or Surface 
 of the Mole, and F. The Bank of any common filling. 
 
 Fig. 2. Is part of the Plan of the Mole with the Sheeting on the 
 infide, and the double Ribbons on the outfide of the Piles (like 
 Fig. i f Plate XXXIV.) with the Chains that are to ftrain them in, 
 and keep them to their batter, which may either be very ftrong 
 Plow Chains, 01 Inch fquare Bar Iron, &c. 
 
 You are to begin your Stuffing and Banking at the Shore, whence 
 you are to be fupplied with it, and to carry them both on together 
 and your Carts and Cars having fufficient Room, they are all to 
 come m on the right Hand, and return to the left, to keep them 
 from interfering; and whilft this is doing, your Carpenter is going 
 on with another range on each Hand before them. 
 
 ■ If this lies within View of the Gentleman's Houfe, probably you 
 will be required to enclofe it with Chinefe Rails; for which Pur- 
 pofe, you are to prepare your Pofts as dire&ed in Chap. XIV. 
 Sea. 1. and drive them down by the Sides of the Heads of the 
 Piles; but if it lies remote, you may drive down ftrong rough 
 Stakes, and plat them with the Branches, for this is only a tem- 
 porary Work, and there ought not to be much Money expended 
 on it, becaufe, if it conquers, and effeaually keeps off the Water 
 the Gentleman, or the Public, or both, may be, perhaps, better 
 accommodated with a fubftantial Road, or Imbankation. After 
 you have fully confidered the next Propofition, or by the Direc- 
 tions formerly given for Quay Walls, you may build a double Wall 
 
 on 
 
( no ) 
 
 on the reclaimed Side, at any convenient Diftance, and this will 
 perhaps, erTedually keep the Water off from you in the mean 
 Time; but let us alfo fuppofe, and lay down Methods for making 
 a fubftantial Turnpike Road, through a fliaking Bog, which may 
 happen to intervene, and ered Forts or other weighty Building in 
 the fame. 
 
 SECT. II. 
 
 The Method of making a fubftantial Turnpike Road, through a 
 quaking Bog of 15 Feet deep, and to eretl Forts or other weighty 
 Stone Buildings in the fame. 
 
 E are informed that many fuch Roads have been made by 
 the antient Romans, fome to the extent of feveral Miles 
 in Length; but in our poor Country, we have no right to pretend 
 to copy after them; but as Neceffity is the Mother of Invention, 
 let us try if we can contrive to form a Method of accompliflimg a 
 Work of this Nature, which is fo abfolutely neceflary, not only 
 for the reclaiming fome of our Bogs, but alfo for the uniting the 
 Neighbourhoods of two fertile Countries, that at prefent feem as 
 remote from one another, as if they were in different Climates. As 
 for Inftance : 
 
 Between two very populous Countries, we will fuppofe, there 
 lies a Valley of many Miles in Length, the greateft Part of which 
 is liable to be covered with Water in the Winter; and even in the 
 Summer, it is fuch a quaking Bog, as deters either Man or Beaft 
 from venturing upon it: The Public have therefore, taken it in 
 
 Hand and refolved, 
 
 Prop. IX. To make a fubjlantial Turnpike Road, through a flak- 
 ing Bo% of i 5 Feet deep, to be inclofed with parapet W alls of rough 
 Stone and Lime, of five Feet high on each Side, and 30 Feet broad 
 in the clear. In ^Summer Time, this Bog is generally covered over 
 with a Scraw, or Scurf of moffy Grafs, under which the Slut this 
 fo exceeding fo ft, that a Stone of one Pound IVeight will meet no 
 OPpofition, 'till it finks to the Bottom, which is afiifffandy Marl 
 
 Surely, 
 
( t2l ) 
 
 Surely, you muft allow, that above all other Works, thofe that: 
 are done by the Public, ought to be performed after the moft fub- 
 ftantial and durable Methods: Let us therefore, now confider 
 how this Work may be fo accomplished. See 
 
 METHOD. Plate XLI. Scale a Feet to i Inch, 
 
 Fig. i. Exhibits the Sedion of the Road. Wherein note, 
 A. Is the Surface of the Bog. B. The Bottom of it. C. The 
 Dovetail Piles that form the Coffer. D." Temporary Piles or 
 Planks that are to feparate the Stuffing. E. The Coffer for the 
 Walls; and F. the Coffer for the Road. E. is to be fluffed with 
 fmall Stones, Lime and fharp clean Gravel, as before directed; but 
 F. is to be fluffed or filled with the hardeft gravelly and ftony 
 Stuff; you can conveniently get. Then the Planks D, are to be 
 drawn up, as of no further ufe in that Place; becaufe the Stuff that 
 is to make the Road, would not by any Means be fufficient for the 
 Foundations of the Parapets. And you fee the fluffing E. is to be 
 covered over with cut Stones of 4 by 2 Feet, and a Foot thick ; and 
 hence you fee the Parapets are battered to 18 Inches thick. The 
 fluffing of both E. and F. will fettle confiderably, but they will 
 fettle perpendicularly, and drive and difperfe the Slutch of the Bog 
 before them ; and according as you find them fettle, you muft ftill 
 continue to fill them up from Time to Time, as Occafion may 
 require, f The Chain that braces them all together. G. Parapet 
 Wall. H. Surface of the Road, which you fee is rrcre fuppofed 
 to be but one Foot above the Surface of the Bog. I. Is the Banks 
 which are to be raifed at Difcretion according as you go on, to 
 help to Buttrefs and Brace in the Piles that form the Coffer. 
 
 Fig. 2. Is Part of the Plans of the Coffers, with the Situation of 
 die Braces. In which obferve, that the Braces are placed together 
 m Pairs, which may have, about ten Piles between each Pair, as 
 before dire&ed in Plate XXXIV. Fig. 2. 
 
 I do not pretend to fay, that this Method is entirely of my 
 own Invention, but to my Succefs in confuting feveral antienV 
 Hiftories, wherein I found fufficient Matter, together with what 
 
 R I have 
 
( 122 ) 
 
 I have before mentioned, for my grounding this Contrivance, not 
 only for the prefent, but alfo the following Propofition upon. 
 And notwithstanding I take great Pains to be conctfe, yet, I lhall 
 refer you to one particular Place, which you will find abridged m 
 Chambers's Didionary, under the Article of Road, which I before 
 mentioned, and as that Book may not be in your Hands, I lhall 
 here tranfcribe exaftly what he fays. 
 
 " Road, an open Way or Paffage, forming a commodious 
 M Communication between one Place and another. 
 . " The Romans of all People took the moll Pains in their Roads. 
 « The Labour and Expence they were at, to render them fpacious, 
 » ftreifrht and fmooth, are incredible.— Ufually they lengthened 
 ■« the Ground by ramming it, laying it with Flints, Pebbles, or 
 " Sand; fometimes by a lining of Mafonry, Rubbilh, Bricks, 
 " Potlherds, &c. bound together with Mortar. 
 
 « F. Menefirier obferves, that in fome Places in the Lyonnots, he 
 " has found huge Clutters of Flints cemented with Lime, reach- 
 " ihg ten or twelve Feet deep, and making a Mafs as hard and as 
 « compaa as Marble itfelf, and which, after refilling the Injuries 
 « of Time for 1 600 Years, is ftill fcarce penetrable by all the 
 « Force of Hammers, Mattocks, He. and yet the Flints it con- 
 « fills of, are nor bigger than Eggs."— Pleafe to obferve, that 
 this coroborates with the former Accounts given of the petrifying 
 Qualities of thefe Materials. ^ 
 
 I do not fay that this Road of ours, will be as firm and as iuo- 
 ftantial as thefe Roman Roads, becaufe we only purpofe to itutf 
 the Coffers on which the parapet Walls are to Hand, with thole 
 choice Materials; but I affirm, that if we were able to go to the 
 Expence of fuch a Work, and this Bog was 20 or 30 teet deep, 
 it is praaicable to make a Road through it as firm and as compact 
 as theirs; becaufe I am fure our Country abounds with as good 
 Materials for that Purpofe, as perhaps, any other produces, except 
 the principal Material, Money, to carry on fuch a Work. 
 
 But notwithfianding our great Scarcity of this principal Material 
 In all Works, yet Matters, perhaps, might be fo managed, as to 
 carry on a ufeful Work of this fort at a very moderate Expence; 
 J and 
 
( "3 ) 
 
 and here we have a fair Opportunity to introduce one of the 
 Methods I pointed out, in the latter End of the fecond Section of. 
 the laft Chapter, which I advife you to recall to your Mind, arid I 
 ihall now enlarge a little further upon it. 
 
 If fuch a Road is to be made through fuch a fliaking Bog, you 
 are to make fuch Coffers as is therein before directed, and exhibited 
 in Plate XXXI. and throwing out the Slutch, &c. build a llender 
 Pier in each of them of rough Stone, for about a couple of Feet 
 above the Surface, and thereon to turn flight rough Stone, or hard 
 Brick Arches, agreeable to the extent of your Defign ; and as you 
 go on, draw up the Piles and apply them to the next Piers in like 
 Manner, as alfo therein before mentioned; and to facilitate the 
 Work, you may have feveral fets of fuch Piles. If Stones are fcarce 
 and Timber plenty, you may make a fubftantial temporary Caufey 
 over the Piers, but by all Means I would prefer the Arches. 
 
 It is well confirmed that numerous fuch Caufeys, have been made 
 through Morafles by the Antients, and that fome of them have 
 extended to eight Miles in Length, and thirty Yards in Breadth. 
 
 Numerous Forts and other fumptuous Edifices, have likewife 
 been erected by them in Morafles; but the Concifenefs of this 
 Work, will not admit of my tranfcribing Abftradts from them. 
 Let it therefore fuffice, that I here briefly point out one of the 
 Methods which I firmly believe muft have been the Method 
 practifed by fome of them. And I alfo conclude may moft readily 
 be executed at a very moderate Expence by us alfo. As for inftance: 
 
 Let us fuppofe, that you are required to prefcribe quick and 
 cheap Methods for building a fubftantial Foundation for a Fort, or 
 any other weighty Building of Stone and Lime of 200 Feet fquare, 
 or any other large Extent, in a Morafs or quaking Bog of 15 Feet 
 deep, on a penetrable Clay or loamy Bottom. 
 
 Having thoroughly examined the intended Scite, and prepared 
 Plans and Materials for the Purpofe, by this Method (fo fully ex- 
 plained above) you are to erect a competent Number of Pillars of 
 flrong rough Mafopry, fuppofe of eight or ten Feet fquare, and 
 perhaps eight, ten or fifteen Feet Difrance from each other, and 
 thereon turn fegment Vaults and Arches, which will give you a 
 
 R % ' Platform, 
 
( «4 ) 
 
 Platform, whereon you are to erect the intended Building, always 
 paying due regard to the Pillars throughout the Superltructure. 
 This Method is fo eafily underftood, that I need neither form any 
 Defigns, nor enlarge any further on it. 
 
 But I fhall give you another Inftance, in which this fort of 
 Coffer Work may alfo in many Cafes be fuccefsfully applied, and 
 have alfo been probably made ufe of by the Antients, in making 
 inland Navigations through their Morafles. 
 
 SECT. III. 
 
 Coffer TV irk applied to the making of a navigable Canal, through a 
 
 jhafong Bog 1 5 Feet deep, 
 
 'Tp 1 H E Valley before-mentioned, extending on almoft a dead 
 JL level, for great Part of the Space between two navigable 
 Rivers, with feveral opulent Market-towns adjacent; we will fup- 
 pofe, that the Public have alfo taken in Hand, to turn the fame to 
 a national Advantage, and refolved, 
 
 Prop. io. To make a navigable Canal as a Communication be- 
 tween thofe Rivers, through the raoft convenient Parts of the Valley. 
 You are, therefore, required to lay down fure, quick and cheap 
 Methods to carry fuch a Canal through Part of a fhaking Bog, 
 fifteen Feet deep, as before. See 
 
 METHOD. Plate XLII. Scale 1$ Feet to i Inch. 
 
 Fig. r. Reprefents a Se&ion of the Canal. Wherein note, 
 A. Suiface of the Bog. B. Bottom of the fame. C. Dovetailed 
 Piles that form the Coffers, after the Manner of Figure 2, 3 and 4, 
 in Plate XXXI. D. Brace-bars, Chains, or Scantling, and E. Bank, 
 which is to be raifed at Difcretion. 
 
 Fig. 2. Reprefents the Plan of the fame, {hewing the four Rows 
 of Piles, Chains, Ribbons, &c. 
 
 Thefe laft two Proportions, if properly attended to, may alfo 
 beprodu&ive of fure and effe&ual Methods of reclaiming extenfive 
 W-,-^- ' « ., Bogs, 
 
( * 2 S ) 
 
 Bogs, and thefe Methods may be effectually applied to 20 or 30 
 Feet deep if neceflary, and are fo eafily underftood, that I need not 
 enlarge upon them. 
 
 But before I conclude frefh Water-works, I think it advifeable to 
 point out one Advantage, that may accrue in the Way of Trade 
 and Commerce, particularly to fuch Merchants as traffic in foreign, 
 tmimproved Countries; that is, to make either temporary or durable 
 Quays, or to run out Tongues or double Quays, into fuch Rivers 
 as belong to their Settlements, and that at a trifling Expence. For 
 which Purpofe> obferve, that if the Bed of the River be hard or 
 rough, you are to defign the Coffers purfuant to fuch Methods, as 
 are deducible from Plates, XXVIII. XXIX. XXX. XXXV. 
 XXXVI. XXXVII. but if foft and loamy, then you may purfue 
 fuch Methods as may be collected from Plates XXXI. XXXIIL 
 XL. or XLI. and from the explanatory Notes thereunto refpe&ively 
 belonging, together with what you will hereafter find defcribed; 
 always obferving, to proportion the Coffers to the requifite Depth 
 of Water, and in durable Work, on thefe Coffers you are to begin 
 the Quay Walls as formerly directed; provided, Stone and Lime 
 can be conveniently obtained; but if fuch cannot be procured and 
 that Timber abounds, you may make temporary Quays, of fuch. 
 Heights as you think may anfwer your Purpofe: And obferve al'fo t 
 that by thefe Methods, you are to make Quays for launching your 
 Coffers, &C. 
 
 In ftill Lakes or fmooth running Water, you may eafily contrive 
 by thefe Methods, to run out temporary Tongues or double Quays 
 with Timber, to fuch Height and Lengths, as to afford likewife 
 a Harbour for fmall Veflels; but by no Means attempt it in any 
 Place that is liable to be greatly agitated, except you have cut Stone 
 from near the Surface of low Water; but I need not enlarge on 
 thefe Matters in this Place, as I intend in the following Sheets to 
 treat largely on fuch Harbours, as will be abundantly fufficient to 
 withftand the Violence of the mo ft turbulent agitated Sea. On 
 which Subject, we fhall firft begin by laying down Methods to build 
 a Beacon in fhallow Water. 
 
 CHA P. 
 
( «6 ) 
 
 CHAP. XVII. 
 
 Coffer-work applied to Buildings, that may he tberehj effe&ually 
 
 executed in the Sea. 
 
 T HAVE had very little Acquaintance with Marine Affairs of 
 J[ any kind; and therefore, Iprefume, I may hope to meet with 
 fomewhat of Indulgence in my treating on Things of this Nature, 
 and alfo for your own friendly Endeavours to affift me, in hopes 
 of bringing thefe important Matters to fome Maturity ; as I have 
 already infinuated, that there are but few Arts or Sciences, that 
 have been brought to Perfection, by the utmoft Endeavours of the 
 firft Contrivers of them. 
 
 It is now upwards of 2 3 Years, fince I firft obferved the Petri- 
 factions mentioned in Chap. VI. Sect. 2. and from that Time to 
 this, I have applied my feeble and utmoft Abilities, in endeavour- 
 ing to turn and improve my Obfervations to the real Advantage of 
 the Public in general; and I think, it would be inexcufable to 
 {mother or conceal the Notions that occurred thereupon. But I 
 entreat a patient Attention to what I am now about to mention, 
 and I hope that my Plans and Defigns will not be condemned as 
 impracticable, until the real Merit of them are thoroughly weighed 
 and coniidered; though I muft confefs, that if ever you have feen 
 the Sea in a violent Storm, as I have feveral Times obferved with 
 a trembling Heart, I ought not to wonder at your entertaining 
 iome Doubts of Succefs, but at the fame Time do not forget, that 
 the Sea. is not at all Times fo violently agitated; and therefore, 
 let us endeavour to contrive fuch fure Methods as may reafonably 
 promife Succefs, and be accomplifhed with great Expedition, at 
 any Time when a favourable Opportunity offers ; for it is not the 
 Sea alone that you have to encounter with, but the moft aftoniih- 
 mg and dreadful Effects of the Tides and Winds. 
 
 As to the ebbing and flowing of the Tide, we are moft comfort- 
 &b!v circumftanced ) fpr, generally fpeaking, we can tell to wonder- 
 ful 
 
( "7 ) 
 
 ful exa&nefs, when it will flow, and when it will ebb; when we 
 may expect high Tides, and when we may hope to have low 
 ones. But I believe no Man has been able to tell precifely the 
 Height that fome fpring Tides may rife to, nor the Height and 
 Power of the Winds when united with them. In this Cafe, there- 
 fore, you mull: paint to your Imagination, the moft powerful Effects 
 of them you can poffibly conceive, and dengn your Work after 
 fuch firm and fubftantial Methods, that it may be able to with- 
 ftand their utmoft united force: And in order to exert our beft 
 and utmoft Endeavours, let us begin with a fmall Beacon, or Light- 
 houfe, befoce we attempt the more weighty Matters intended* 
 
 SECT. L ; 
 
 Concerning the building of a Beacon, or Light Houfe in the Seal 
 
 Prop. XI/ I n O build a fubftantial Stone and Lime Beacon, or 
 Light Houfe of 20 Feet Diameter in the Sea r the 
 dead low W ater being about eight Feet deep\ and fpring Tides 
 fometimes rife- ten Feet more. 
 
 METHODS laid down in V l at z* XLIII. XLI V. XL V. and 
 XL VI. Scale 1 % Feet to 1 Inch. 
 
 Plate XLIII. Fig. 1. Furnifhes you with an Idea of the Land- 
 Front of the lower Part of the Light-houfe, ftanding, as it were,, 
 upon the Coffer, fluffed and floored as formerly dire&ecl Wherein 
 note, A. Bottom of the Water. B. Low-water mark. C. High- 
 water mark. Fig. %. Shews the Ground-plan of the principal; 
 Timber of one half of the Coffer, exclufive of the Grating. Fig. 3.- 
 Reprefents the Surface of the other half of the Coffer, floored witb 
 the Cut-ftones, and cramped as before directed; and alfo, the 
 Plan of the lower half of the Light-houfe, which is to be wrought 
 folid with cut and large fcabbeled Stones, except the Stair-cafe. 
 
 Plate XLIV. Fig. 1 and 2, {Scale 1 % Feet to 1 Inch.) Shews the 
 principal Timber and the Grating. In which obferve, that all the 
 
 principal! 
 
( "8 ) 
 
 principal Timbers are to lie exactly over one another, and fo are 
 all the extreme Timbers that furround them. Fig. i. Reprefents 
 half of the ift Courfe, and Fig. %. half of the 2d Courfe, which 
 together make the Grating or Bottom two Feet thick, in both of 
 which, the principal, or diagonal Beams, are to extend 60 Feet 
 8 Inches ; four Inches being allowed for the fet-off, that is to be on 
 the 2d Courfe: And as you cannot get Timber of 60 Feet long, 
 you are to take particular care that the Timber of the 2d Courfe, 
 fhall break Joints with the Timber of the 1 ft Courfe, and that they 
 be both firmly fpliced and bolted together, to prevent their wreck* 
 ing, fwagging of diflocating by any Accident or Mifmanagement 
 in the launching of the Coffer. And befides thefe Iron Bolts, there 
 muft be an Abundance of Oak Keys, both through the principal 
 and through all the outward Timbers. By Oak Keys, I mean, that 
 you fhould get a competent Number of Pieces of Oak tried up, of 
 about 2 Feet long, 9 Inches broad and 4 thick, each. The Mor- 
 tices for them, muft be made quite through each Piece, and exa£tly 
 anfwerable to each other; and thefe Keys muft be drove into the 
 Mortices, and pinned with Oak Trundles of about full Inch 
 Diameter, fo as both the under and upper Courfes of all thefe 
 principal and outward Timbers, may be firmly united together. 
 And you fee that between thefe outward Timbers in each Courfe, 
 there is to be a Vacancy of eight Inches, and in this Vacancy the 
 upright Piles are to ftand, which Vacancy, and the Manner of 
 framing the diagonal and outward Timbers together, you may fee 
 laid down in Fig. 3. {Scale 2 Feet to 1 Inch) and when thefe two 
 Courfes are compleatly united together, you are then to put on 
 your angular Plates on the upper Courfe, and in Cafe you have no 
 Sea-braces, then each of thefe Plates are to have three Wings, two 
 of them are to encompafs the Angle, and the third is to go under- 
 neath the End of the diagonal Piece, with two Bolts through each 
 of thofe Pieces, as you fee marked out in dotted Lines. The Neck 
 that proceeds from thefe three Wings muft be of about the Subftance 
 of full three Inch fquare Iron at the leaft, with either a Hole, or a 
 Ring, to receive the buoy Ropes, as has been formerly directed; 
 
 and 
 
and if you have Sea-braces, you will find them defcribed in fheir 
 proper Place. 
 
 Plate XLV. Fig. x. Scale, 5 Feet to i Inch. Is the Seflion of one 
 quarter of the Coffer, as if it was compleatly fluffed, with the cut 
 Stone Floor, and the four firfl Courfes of the Light-houfe built 
 upon it. Fig. 2. (fame Scale) is the Plan of the upper Timbers of 
 that Quarter, with the Brace-bars and other Iron Work. Fig. 3. 
 Scale 2 Feet to 1 Inch. Shews you how the three Rows of Piles are 
 united together. You fee that the Hull is compofed of three Piles 
 or Planks of eight Inches thick each, and their Breadth at Dis- 
 cretion They are all to be tongued and grooved as formerly 
 directed, and firmly pinned and bolted; the three Piles taken 
 together, making, as it were, one folid Thicknefs, of which the 
 middle Row (as you may fee by the Seaion of the- Hull, Fig. 1 ) 
 is the Tennon, and goes down two Feet between the outward 
 i imbers, which are the Bafe of the Hull ; through each of which 
 outward and inward Pieces, and through each of the upright Piles, 
 there are to be Oak Trundles drove, of an Inch and a half 
 Diameter. I, n this Fig. 3. you alfo fee the corner Polls, into 
 which the diagonal P iec es are to be double dovetailed; and alfo, 
 the Tongues of the two next upright Piles are to be let into 
 Grooves which you are to prepare for them therein, and fo are the 
 Lnds or Tennons of the infide horizontal Piles alfo. Thefe corner 
 Polls are to be made of Oak, in two Parts, which are to be firmly 
 keyed and bolted together, after you have made all the Grooves 
 and Dovetails belonging to them; and you mufl recoiled the 
 Vacancy left between the out-fide Timbers in the laft Plate, and 
 make two Tennons m the Foot of this Oak Pofl, or double Pofl, 
 exactly to fit and lland in the Vacancies, one on each Side, to fit 
 the dovetail of the diagonal Beam, in which two Places they are to 
 land, as it were, on two Legs ailride the diagonal Beam, wherei. 
 they are to be fecurely bolted. And I mull repeat, you are not to 
 forget that m the Middle of the Interferon of all the upright and 
 
 Lit! u\ u t th£re 3re t0 be Fnch and half Oak Ti undies 
 drove t.ght through them, and wedged in the infide. Every Pile 
 of the outfide is to be dovetailed at the Angles, like fo many Belts, 
 
 S to 
 
C i3° ) 
 
 to confine the whole Hull together, and you fee how the Iron work 
 is to be applied thereto; but you mud alfo ftriclly obferve, that all 
 the Tongues and Grooves, both in the" upright and level Piles, are 
 to be done after a Workman-like Manner, fo that the fineft Particle 
 of the Sand, or even the Lime-water, may not be fucked out 
 through them by the Waves. Indeed the Joints in the Bottom 
 may be an Inch wide, becaufe when it is launched, it will let the 
 Water into it, which will help to fink it, and the finer Particles of 
 the fluffing will foon fill them all up, of which you muft here 
 allow an extraordinary Proportion, and the Bank will fecure them 
 all. 
 
 Plate XLVI. Fig. i. Scale 12 Feet 1 Inch. Reprefents the 
 Se&ion of the whole Coffer, as if it were fluffed and floored with" 
 Cut-ftones; and the Se&ion of the lower Part of the Light-houfe, 
 as if it were Handing upon it. Wherein note, A. The Bottom of 
 the Water. B. Low-water mark. C. High-water. D. The firft 
 Floor of the Light-houfe. E. Part. of the fecond Floor. F. Well- 
 hole of the Stairs; and G. The Bank to be raifed at Difcretion ; 
 but ftri&ly obferving not to let any Stone exceed a Handful in 
 your banking : Becaufe, a large Stone is to the W 7 aves, as a large 
 Tree is to the Wind, which will give great Opposition to it, when 
 at the fame Time it will pafs gently over diminutive Shrubs; which 
 is evident by the Breakers on the Strand. Befides, large Stones 
 make large Cavities, and large Cavities contain large Quantities 
 of Water, and large Quantities of Water operate much more 
 powerfully than fma'il ones, which I fhall demonftrate hereafter. 
 
 Fig. 2. (by the fame Scale) Shews you the Plan of the upper 
 Timbers of the Coffer, the Plan of the- Stairs, and the firft Floor 
 of the Light-houfe, with the circular Bar that is to be let into that 
 Courfe. Fig. 3. Reprefents the Platform or Surface of one half 
 of the Coffer, fluffed and floored with the Cut-ftone; and the eight 
 ftrong Lines reprefent the Cramps, which muft be made of 1 \ Inch 
 fquare Bar, and funk fomething more than their full Depth into 
 the Stones, fo that the melted Lead will entirely cover them, and 
 when they are eaten with raft, they are eafily replaced, or more 
 added if neceffary. Fig. 4. (Scale 2 Feet 1 Inch.) Shews you the 
 
 Method 
 
( i3i ) 
 
 Method of cramping the Hull and the Cut-flone together, viz. 
 The fquare c. goes through the three Piles or eight Inch Planks, 
 with a Screw-nut on the tnfi.de. The upright of c. has a fquare 
 Hole in the upper End of it; and the End of the Cramp, d. is to 
 take hold of that Hole, which you are to thruft into it after you 
 have cut or funk the Channel acrofs the Heads of the Piles, or 
 Hull, and the cut Stone, which you may more clearly perceive by 
 Fig. 5. {Scale 2 Feet to 1 Inch) Wherein note, that c. fhews the 
 Hole, and d. the End of the Cramp that goes into it; but if it 
 fliould happen, that fuch a Building was to be erected in any Place 
 greatly expofed to ftormy Flood-tides, efpecially off the Atlantic 
 Ocean, I particularly advife, that you may add eight projecting 
 Steps in like Manner, and in the ftead of thofe three; and then~ 
 the naked Body o>f the Light-houfe will ftand on the Summit of 
 the eight Steps, which are juft at the High-water mark, which 
 will put the Light-houfe quite out of the Power of the Waves, 
 as you fee it marked out at H. And you may alfo extend the five 
 principal, or diagonal Sills (in Plate XLIII. Fig. 2.) fix Feet to- 
 ward the Sea, and thereon fix your five Sea-braces, as in Plate 
 XLVL Fig. 1. Letter I. and on the Ends thereof, you may fecurely 
 fix the five hauling Rings, at the End of each of the five Sills, 
 
 In Cafe you are required to erect a more fubftantial Light-houfe, 
 fuppofe of 40 Feet Diameter, the Coffers mull at leaft extend 120 
 Feet, and be made in two or four feparate Parts, juft as the 
 Timber, and other Circumftances, may heft anfvver your Defign ; 
 but in this Cafe, you may fet it upon eight Steps as above men- 
 tioned, each of which is an Arch in itfelf, and \ of the Length of 
 each Stone will be tied in covered and fecured with the next 
 Courfe that is over it, and fo the Waves will not have any Power 
 to difturb them in the leaft Degree. 
 
 And in Cafe you fhould think it neceflary to fectire the Coffer or 
 Coffers more effectually, you may environ and fecure them with 
 double or {ingle Guard-coffers; but if you do them in that Manner, 
 you are to omit the Sea-braces of the inner Coffers, that they may 
 be funk as clofe to each other as poflibly you can; and let the Sea- 
 braces be fixed to the Guard-coffers, as before directed, in Fig. u 
 
 S 2 Letter 
 
( ) 
 
 Letter I. Obferve alfo, that in fluffing the Coffers in the Sea, you 
 mud be much more liberal in the Proportion of Lime, than what 
 we concluded upon for frefli Water-works, becaufe it will be in 
 much more danger of being both wafted and weakened; therefore, 
 if you can procure Lime at a moderate Price, beftow it bountifully 
 on fuch Work as thefe ; for it is the Lime alone, that creates the 
 Petrification, and by all Means, that ought to be promoted. And 
 if I have been too penurious in proportioning that expenfive Article, 
 let your own Difcretion, tempered with a little experimental 
 Knowledge, conduct you therein. 
 
 I am confident, and I hope it has appeared evident, that this 
 petrifying Quality is moft affuredly one among numerous other 
 moft ufeful Properties, peculiar to Lime-ftone; but how this 
 petrifying Quality is to be heightened or haftened in frefh and 
 fait Water, that indeed, is not within my fcanty Province to 
 determine; therefore, I moft humbly beg leave to recommend it 
 to the ftudy of curious philofophical Gentlemen, acquainted with 
 the Qualities and Operations of Compounds, as I prefume there 
 is a great Probability, that thefe my poor Gleanings may be thereby 
 brought to Maturity, and that by an induftrious Cultivation thereof, 
 they may be rendered productive of Utility in Matters of fuch 
 exceeding great Moment to the Public in general. There are 
 many other Things necefTary to mention, but you will find them 
 difperfed through the following Pages. 
 
 SECT. II. 
 
 Concerning the building of a Stone Pier in the Sea. 
 
 Prop. XII/TP 0 build a Jingle Pier-head of Cut-pne ^ in the Sea, 
 J[ the dead low JVater at neap Tides bang 20 Feet 
 deep, and high fpring Tides rifing 2 o Feet more. 
 
 Previous to our forming thefe or the like defigns, we muft con- 
 fider, that the Tides and the Winds have very powerful Effeds, 
 efpecially when united. Let us therefore, endeavour to find out 
 fome certain and general Rules for this Purpofe; in order to which, 
 
 it 
 
C r 33 ) 
 
 it may perhaps, be necelTary to obferve, that one cubical Foot of 
 Stone, upon an Average, may be fuppofed to weigh three cubical 
 Feet of Water ; but Stone being more ponderous, it will confe- 
 quently be the more powerful in its Oppofition, and the fitter for 
 our Purpofe. Let us therefore confider, as for inftance: In a Hill, 
 quiet Lake, you mull admit that the whole Weight of the Water, 
 refts and ftands upon its own Balis, that is, the Bottom of the 
 Lake; and the Bank, or whatever the Inclofure of it is, fuftains 
 very little PreiTure by that Water. Let us now fuppofe, that Part 
 6f this Lake is inclofed with a perpendicular Line of 20 Feet high; 
 which is the Height here given for the Tide. See Plate XLVIJ. 
 Scale 16 Feet to 1 Inch, which Line is reprefented in Fig. 1. by 
 the Line, a. b. Now if you were required to form a Brace, or rather 
 a Stone Buttrefs, to ftrengthen, and give that Line fufficient Power 
 to keep its perpendicular Situation, fo as to be able to fupport 
 itfelf and to fuftain the PreiTure of that Water, to the Extent and 
 Height of twenty Feet, you muft lay down another Line of the 
 fame Length horizontally, and in right Angles with it, as, a. c. and 
 then draw the hypothenufe, or diagonal Line, b. c. which diagonal 
 Line, b. c. defcribes the Bounds and Power of a Stone Buttrefs, 
 which will be abundantly fufficient to withftahd the PreiTure of 
 this Watef, or at lead equivalent to it; which you may prove thus. 
 Multiply, a. b. by itfelf, the Product will be 400, and a. c. by 
 itfelf, the. Product will be 400 more, add thefe two together, and 
 they will be 800; then take off your diagonal Line, b. c. and by 
 your Scale, you will find it near 28 Feet 4 Inches; and multiply 
 that by itfelf alfo, and it will be equal to the Products of a. b. and 
 a. c. taken together, infignificant Fractions excepted; whence I 
 think it is evident, that the Power of the Line, b. c. is equal to the 
 Powers of the Lines, a. b. and a. c. and confequently defcribes the 
 Buttrefs required for a ftill dead Water. 
 
 But now comes on the main Thing. We are not to encounter 
 with a ftill dead Water, but with the Tide, which is liable at all 
 Times to join in Conjunction with moft powerful ftormy Winds; 
 but ftill, fuppofing that they do not exceed our given Height of 
 20 Feet, (yet what Strength or Power thefe Winds and Tides may 
 
 acquire 
 
( 134 ) 
 
 acquire when united, is not to be eafily determined) but as I told 
 you before, you muft form in your own Mind, the moft powerful 
 Effects of them imaginable, and thence draw your Conclufions, 
 whereon you muft form your Defigns; fo that your Work may be 
 fo fubftantial, as to withftand their utmoft united Forces; and 
 always obferving, in Cafe of any doubt, to keep on the fure Side, 
 throughout the whole Progrefs of your Works: In order to which, 
 let us return and reconfider the Power which appeared fo adequate 
 to the Preffure of 20 Feet high, and 20 Feet broad of ftill Water. 
 From b. and c. draw two other fuch Lines, which will meet toge- 
 ther in the right Angle, d. which will augment our Figure, and 
 thereby produce an exact Cube of 20 Feet, which of Stone, or our 
 Stuffing, upon an Average, would weigh 464 Tons, one half 
 thereof, being 2 32 Tons, hath already appeared to be adequate to 
 the Preffure of the Plain, a. b. which is equal to 20 Feet fquare; 
 the other half of this Cube, being 232 Tons more, makes up a 
 Power, which will certainly befufficient to fuftain the utmoft Force 
 of the Tide and Wind, a&ing together on the Side of the Cube, 
 a. b. 
 
 It is evident, that there cannot be any Rule found out, to deter- 
 mine with Precifion, the Strength and Powers of the Tides and 
 Winds united. Let us therefore, at prefent, endeavour to ex- 
 ercife our Reafon on the following experimental Suppofition, viz. 
 Let a Coffer of 20 Feet Cube, the given Height of the Tide be 
 made, fluffed and floored after the Manner herein before, or after 
 directed, and lodged upon any hard level Ground, on the Strand 
 at Low-water mark, the Wind and Tide coming upon this Cube 
 in any Direction, but fuppofe from the point, e. I prefume, that this 
 Colter will be able to fuftain the utmoft Power and Force of that 
 Wind and Tide, for as long a Time as Fir Timber being fo ex- 
 pofed could be expected to laft; but in the- prefent Cafe, I conclude, 
 however, that this cubical Proportion, would be too fcanty for our 
 Purpofe, became if the Wind and Tide attack this Cube obliquely, 
 as from the point f. they gain a great Advantage of the Cube, for 
 they will have the Line, b. c. to difcharge their united Powers upon: 
 And although the point wheneethe Tide flows may be determined, 
 
 yet 
 
( '35 ) 
 
 yet the Wind is variable, whence it is evident, that you muft not 
 dcfign your Pier upon the cubical, but on the diagonal Proportion. 
 Therefore lay down the Line, b. c. from a. to g. and the Line b. d. 
 is to be extended to h. then draw the Line, h. g. which will 
 augment our Dimenfions to about 28 Feet long, and 20 Feet 
 fquare, and will contain about 11 200 Feet folid, at 130 Pounds 
 to the Foot, will contain 650 Tons weight. And fo your Pier 
 bei.ig defigned on this Proportion, every 20 Feet fquare of fuch a 
 Pier,, would have at leaft a weight of 650 Tons to oppofe the force 
 of the Wind and Tide, that may a£t upon fo much of its front; 
 which is a weight fo exceeding great, that I believe there is no 
 confiderate Man, but what muft allow that this Proportion will 
 be abundantly fufficient, but this fliall be more fully demonftrated 
 in its proper Place. 
 
 Now on thefe Principles, let us proceed to defign, and confider 
 the Conftruclion of the Body of the Pier; that is, from the given 
 Low- water, to the Surface, or Bottom of the Parapet. See Fig. 2. 
 (by the fame Scale) whereby the given Heights are reprefented; 
 and note, A. Is the Bed or Bottom of the Water, a: the Low- 
 water mark. b. High-water mark. Divide a. b. into four equal 
 Parts: One of thefe Parts is to be added to a. b. as a moderate 
 Proportion for the Surge, which will then make the Height a. c. 
 — 2 5 Feet, for the Height of the Body of the Pier. Then (fee 
 Fig. 3. by the fame Scale) draw your Bafe Line, a. q. and interfect 
 it with your Center Line, g. e. take the Height, a. c which is 25 
 Feet, and add 6 Inches to it for the 24 Joints of Mortar, and fet it 
 off from e. to d. and thereon form the fquare, d. e. f. g. from f. to 
 e. draw the Diagonal, f. e. which by your Scale, you will find to 
 be near 36 Feet. This Diagonal may be looked on as a reafonabfS 
 Bafe for the naked Body of the Pier, which you muft divide into 
 two Parts, and lay them down from e. to h. and from e. to i. and 
 fo having the Bafe and Height determined, draw the parallel 
 Line, f. e. 
 
 You are alfo to confider, that this Bafe Line of the Body of the 
 Pier, cannot begin at h. i. in the Execution of the Work, becaufe 
 the Hull of the Coffer muft rife three Feet above this dead Low- 
 water 
 
( I 3 « ) 
 
 water mark, a. And that the three projecting Courfes, on which 
 the Body of the Pier is to ftand, will take up three Feet more; and 
 for thefe Reafons you muft transfer h. i. to s. t. which is to be the 
 naked Bafe of your Pier, and fubtracting 6 Feet out of h. 1. (= 25 
 Feet 6 Inches, the laft given Height) there will be i 9 Feet 6 Inches 
 remaining for the Height of the naked Body of the Pier. u. g. 
 Which you muft divide into 6 = Parts, as at t. k. and take one of 
 thefe Parts, and fet it off from k. to m. and do the like with the 
 oppofite Side 1. n. and this gives you the true batter, or diminifhing 
 of the Pier; by which Method, you are to- cut the bevil Moulds 
 for the Stone-cutters, and the battering Plumbs for the Setters, &C. 
 and deducting 1. n. and m. k. from s. t. there will remain n. m. 
 = 29 Feet 6 Inches for the Breadth of the Body of the Pier at the 
 Top, juft under the firft Courfe of the Parapet, which to avoid 
 Fractions (which are not neceffary here) we fhall call 30 Feet, and 
 this furnifhes you with the principal Dimensions of the naked Body 
 . of the Pier; that is to fay, the Bafe s. t. = 36 Feet, the Height u. g. 
 (you know was 19 Feet 6 Inches, but we fhall call it) 20 Feet, and 
 n. m. 30 Feet, and fo 36, 30 and 20, are the principal Proportions 
 for the naked Body of the Pier, for a Flood-tide of 20 Feet, ex- 
 clufive of the three projecting Courfes and the Parapet, and in- 
 cluding the whole together. \ Remember, that one Foot long of 
 this Pier (which you will find reprefented in Plate XLVIII. Fig. 1.) 
 will contain 817 folid Feet, and 20 Feet running Meafure of the 
 fame = j 6340 Feet, at 1 30 Pounds to the Foot, will be 948 Tons: 
 And fo you fee that every 20 Feet long of the Pier, will have 948 
 Tons Weight to oppofe the Power of Wind and Tide, acting upon 
 the front of that 20 Feet long. And this I am fure will be abun- 
 dantly fufficient to oppofe them; and this Calculation will alfo be 
 uleful to you in making your Eftimates, &c. 
 
 All thefe Matters being fuppofed to be clearly underftood, let us 
 in the next Place, confider the Proportions of the Coffers for the 
 Body of the Pier. Draw the Line, x. y. parallel to r. q. take the 
 extent s. t. and fet it off from e. to p. and from e. to o. draw the 
 'Lines p. v. and o. w. and p. o. v. w. gives you the Extent of the 
 Coffers for the Pier. Then to proportion the Coffers for a fingle 
 
 Strait- 
 
( *37 ) 
 
 Strait-pier Head, divide s. u. into two = equal Parts, and lay down 
 one of them, from p. to r. and the other from o. to q. draw the Lines 
 r. x. and q. y. and r. q. x. y. fhews you the Extent of the inner 
 CofTers for this Pier Head, the Guard -coffers being referred to their 
 proper Place. Then, to determine their Height, divide u. t. into 
 6 = equal Parts; one of thefe Parts, added to the given Height 
 A. a. gives you x. z. = 23 Feet for the Hull or outward Height 
 of thefe Coffers. Thus you may augment or diminifli the pro- 
 portions of your Diagram, according as the various Circumftances 
 that may attend your Defign, may refpectively require. Now let 
 us collect ' and lay down thefe principal, and the more minute 
 Dimenfions in fomething of a regular order. 
 
 Plate XLVIII. {Scale 16 Feet to 1 Inch.) Fig. t. reprefents the 
 Section of the Pier compleat, and {landing as if it were erected 
 upon its Coffers (which extend three Cubes and a half of Low- 
 water). Wherein note, A. Bottom or Bed of the Coffer. B. High- 
 water, a. Is the Low-water mark. b. The Top of the Hull. c. Bafe 
 of the naked Body of the Pier. d. The Bottom of the Parapet, or 
 Top of the naked Body of the Pier. And, e. (which you fee alfo 
 comprehends the Plinth and Cord) gives the Height of the Top 
 of the Parapet, which together make 7 Feet or about I of Flood- 
 tide, which is a proportionable Height to keep off the Spray; 
 which added to the five Feet before allowed for the Surge, makes 
 12 Feet above the given Height of a Spring-tide, which you may 
 increafe or diminiih at Difcretion. Fig. 2. Exhibits the Section of 
 the Pier-head, ftanding upon its Coffer (which extends four Cubes 
 and a half) the Height of which you fee is the fame as above. 
 The Superstructure or fmall Building on the Pier-head, wi 11 be 
 hereafter fully delineated along with the other Parts of the Work. 
 
 Plate XL1X. (by the fame Scale) Fig. 1. Reprefents half of the 
 firft Courfe of the Hull and G ratine for the Coffer of the Pier-head. 
 Fig. 2. The iecond Courfe of the fame. Fig. 3. The firft Courfe 
 of one of the Coffers for the Pier. Fig. 4. The fecond Courfe of 
 the fame. Fig, 5. and 6. Shew you \ of the next Coffers for the 
 Pier: On all which I lhall only now remark, that all the principal 
 Beams in both thefe Courfes, are to lie exactly over one another, 
 
 T and 
 
and to be keyed and bolted together, breaking Joints according as 
 the different Length of your Timber will admit, as formerly di- 
 rected, on the laft Propolition. 
 
 I have obferved above, that I am very little acquainted with 
 marine Affairs, and for want of that Knowledge, 1 muft confefs 
 that I am at an entire Lofs to determine, whether this Coffer for 
 the Head of the Pier, had beft to be in one or in two feparate 
 Parts. You fee the conjugate and tranfverfe Diameters are equal 
 to about go by 76 Feet, which really is an enormous Size: And 
 therefore I mail not fully determine this Point; but I advife you, 
 that after you are determined as to the Situation of the Pier, and 
 confidered the various Circumftances relative to it, you may lay 
 down thefe Draughts by a larger Scale, or make a model of the 
 Coffer by a Scale of one Inch to a Foot, and thereon take the 
 Opinion and Advice of fome eminent Ship-carpenter, and afk him 
 this plain Queftion; Whether it is practicable to launch and fettle 
 fo large a Bulk in the Place deftined for it? And on his, or other 
 Mens Opinions, you may determine this point. For this appears 
 to me the fole Difficulty, that can in any Ways attend this' whole 
 Work; and yet I cannot help thinking, that if it be built in a conve- 
 nient Place, and a proper Quay made for launching it, as before 
 mentioned, that in one calm neap Tide it may be grounded in its 
 Place, and then all your greater!: Difficulty will be over; but againft 
 that critical Time, take the utmoft Precautions to have your Crafts 
 ready loaded, and every Thing neceilary to crowd in your fluffing, 
 to keep it down when it is grounded. But notwithstanding the 
 Hurry you will at that Time be in, be fure that your fluffing be 
 properly mixed together, for if they throw Stones in one Place, and 
 Lime and Sand in another, the latter will indeed petrify, but the 
 former cannot, which you may eafily accomplifh by the Precautions 
 I have already given you concerning the fluffing. Your beft 
 endeavours and thofe of your Workmen, are abfolutely neceffary 
 at thefe critical Times, in working as the Tide anfwers, both 
 Night and Day, at Night by the help and Direction of your buoy 
 Ropes, till you fill it to the upper Timber. 
 
( 139 ) 
 
 Upon thefe and other Confiderations, I have defigned this Coffer 
 entire, as being by much the more eligible Way; on which you 
 may further obfcrve, that part of this Coffer oppofitc to A. is 
 explained in the next Plate. The firft Courfe of B. C. and D. te 
 Plate LI. The fecond Courfe of the fam,e in Plate LI I. And 
 a Se&ion at E. F. Plate LIIL Alfo obferve, that in Cafe you 
 think it' neceffary to have Sea-braces (as was fully defcribed 
 Plate XL VI. Fig. i. Letter I.) you are to extend the four principal 
 or diagonal Pieces, that will be next to the Sea, ten Feet each, as 
 at G. whence fpring the four Sea-braces; and if you think all that 
 will not be fully fufficient, you may alfo extend the Ends of the 
 Middle-fills in like Manner, as you fee at H. H. and let Braces 
 fpring from them likewife. 
 
 Plate L. Fig. A. (Scale % Feet to i Inch) Fig. i. Shews the 
 Plan of that principal Beam united to the Hull. Fig. 2. Shews the 
 Se&ion of the famie.* Fig. 3. Shews the Plan of the Middle Brace- 
 beam, going through the Hull. Fig. 4. Sedion of the fame. 
 Fig. 5- Planof the upper Brace-beam; and Fig. 6. Sedion of the 
 fame, and the Manner of, cramping the Hull and the Cut-ftone 
 
 together. ; 
 
 Plate H. Fig. B. C. and D. (Scale 2 Feet to 1 Inch) Fig. B. (as 
 in Plate XLIX.) Shews the firft Courfe of the Ground-work. 
 Wherein n<ote, a. Out-fide Timber of a Foot fquare. b. A vacant 
 Space of 9 Inches wide, left for the Tennon or upright Piles to 
 ftand in. c. Another Timber of a Foot fquare. d. The Beam 
 into which the Ends of the firft Courfe of the Grating is to be let 
 in by a running Mortice; but I believe it might anfwer full as well, 
 and be much more expeditious, and fave a great deal of Timber, 
 "by fpiking and pinning on four Inch Scantling, to make a Groove 
 for them. And on fecond Thoughts, I believe that (in Plate 
 XLIX.) it would be advifable to do the fame with all the principal 
 Timber in both Courfes of Fig. 1. and 2. Fig. C. Shews the 
 Ground-work of the out-fide of the Coffer for the Pier. Wherein 
 note, a. Outfide Beam. b. Vacancy for the 6 Inch upright Piles, 
 and c. Infide Beam. Fig. D. Shews the inner Angle, a. Is the 
 Beam. b. Vacancy; and c. Beam, .&c. 
 
 T a Kate 
 
( H° ) 
 
 Plate LII. Fig. B. C. D. (fame Scale) Shews the fecond Courfe 
 of the Grating, and the Plan of the Hull compleat; but obferve, 
 that all the corner Pofts, viz. a. b. c. are to be made of Oak; and 
 that the fix Pofts E. are to be made of the fame in two feparate 
 Parts, and bolted and keyed together, as was fully defcribed in Plate 
 XL V. Fig. 3. with only this Difference; that the Thicknefs of 
 that Hull was three Times 8 Inches, and this three Times 
 9 Inches. 
 
 Plate LIII. Fig. E. F. (Scale 4 Feet to 1 Inch,) That you may 
 clearly comprehend this Plate, turn back to Plate XL1X. and in 
 Fig. 2. Obferve the dotted Line E. F. which you alfo fee here laid 
 down by this Scale, delineating the compleat Se&ioh of that Part of 
 the Coffer, with the Plan underneath it, and by your comparing it 
 with Plate XLVIII. Fig. 2. you may fully comprehend the Con- 
 ftru&ion of this Coffer, together with what I've already exhibited. 
 However note, that H. is the Bottom of the Water, and reprefents 
 alfo, the Sill that extends to receive- the Sea-braces, provided you 
 have no Guard-coffers. I. The Bank, which you may extend at 
 Difcretion. K. Is the dead Low-water mark; and L. fliews the 
 Height and Rake of the Sea-braces, which may be applied here, 
 or referved for the Guard-coffers, and may either be double or fmgle, 
 juft as the Situation, or other Circumftances may require: And here 
 pleafe to obferve, that as you now know the Ufe and Method of 
 making the Sea-braces, you may alfo occafionally introduce the like 
 in flat-bottomed Coffers; but particularly, they may be of very 
 great Advantage in ftrengthening, fuch as are made for Tongues > 
 Quays or the like, either in the Sea or in Rivers. 
 
 Plate LI V. (Scale 16 Feet to 1 Inch) Gives you the Plan and 
 framing of all the upper Brace-beams, exclufive of the Iron-work, 
 which you fee applied to the like Purpofes in Plate XLV. Fig. 2. 
 
 Plate LV. (fame Scale) Reprefents thefe Coffers compleatly 
 fluffed and floored with the Cut-ftone, and cramped with Iron; 
 in which remember, that every Cramp muft extend to the fecond 
 Courfe of Stone at the leaft, and when this Work is fo far acccm- 
 plifhed, you may proceed with the reft of the Coffers of the Pier, 
 and leave the Coffers of the Pier-head in this fecure Condition, 
 
 during 
 
r 
 
 _TL 
 
 ft 
 
 K 
 
 J 1 
 
 i 
 
 _ru 
 
 _TL 
 
 1 | 
 I 
 
 Ti\ 
 _TL 
 _TL 
 _TL 
 _TL 
 _TL 
 Jl_ 
 JT- 
 _TL 
 
 _n_ 
 Xtl 
 
 \ L 
 
 •re 
 
 _TL 
 _TL 
 _TL 
 _TL 
 _TL 
 
 E 
 
 or 
 
 IT 
 
 • i 
 
( ) 
 
 during Pleafure. Obferving alfo, that after the fame Methods of 
 ConftrudYion, you may augment or diminifh the Size, Shape of 
 Strength of other Coffers, proportionable to any other defign or 
 purpofe according as their various Circumftances may require, or 
 as your own Reafon may direct. 
 
 Plate LVI. (fame Scale ) Reprefents the Plan of the fourth Courfe 
 of the Pier-head, built on the Platform, with the Timbers that are 
 to be framed together, and Chain-barred as formerly directed; 
 and the like Timbers are to be repeated at about High-water 
 mark : And obferve, that the Coffer which you fee left in the 
 Stone-work of the Body of the Pier, G. is to be filled with fluffing, 
 'till you come to the Platform. 
 
 It may alfo be neceflary for you to obferve, that fo much a& 
 you here fee drawn of this Pier-head, is drawn as if the whole was 
 to be wrought with Blocks of Cut-ftone; yet, I do not by any 
 Means recommend that as abfolutely neceflary, for the Remainder 
 of the Body o>f the Pier, except you have fuch Stones very cheap ; 
 but by all Means, let the Headers, Stretchers and Tail-bonds, 
 efpecially in the Side next to the Sea, be done with fuch Cut-ftone 
 as we have hitherto recommended; but the interior Work wilB 
 anfwer effectually, if it Be built with rough Stones carefully laid 
 in fwimming Bed§ 9f good Mortar and grouted. 
 
 I know there have been very eminent Gentlemen, who warmly 
 recommended a peculiar Method of cutting the Stones for the out- 
 fide Work after this Manner, viz. To double Dovetail all the 
 Headers, and to fit the Stretchers to fall in between them,, and fo 
 lock them into one another; but I do not advife you to follow 
 that Method, becaufe it will be tedious, troublefome and immenfely 
 expenfive, and of little or no Advantage to the Duration of the 
 Work, for this material Reafon : /. e. The Wind, and the flux 
 and reflux of the Tide, do operate and principally exert their 
 Power on the Foundation of the Pier and Pier-head, and not on 
 the Body of it, efpecially, if it is built in {hallow Water. On 
 which I fhall give you a full Demonftration in the next Section; 
 nor do I think it abfolutely neceflary for you to finifli the outfide 
 of the Work neither, in plain Alhlers or in ruftic Work, except 
 
 yon 
 
( *M ) 
 
 you do it for the Neatnefs of it: It may very well fuffice, to cut 
 the Stones fquare in the ufual Way in Foot Courfes, and in every 
 Courfe to make a two Inch fet off, which with the help of the 
 battering Plumb, will preferve the diminishing of the Pier, and 
 keep it out of winding, and though it will look a little rough to 
 the Eye, yet it will be very effectual. 
 
 Plate LVIt. (Scale 8 Feet to i Inch) Furnifhes you with a Plan 
 of the Superstructure of the Pier-head, furrounded with the parapet 
 Wall, on the level of the third Step above the naked Body of the 
 Pier, (which was reprefented in Plate XLVIII. Fig. 2.) Wherein 
 note, a. Store-room. b. Stair-cafe. c. A neceffary under the 
 fame. d. Sewer to be carried out under the Cut-ftone Floor, 
 e. Bed-chamber for the Lamp-lighter, &c. f. For his Provifion, 
 Coals, &c. G. The three Steps before-mentioned, the firft of which 
 terminates the Parapet on the Rear of the Pier. 
 
 Plate LVIII. (Scale 8 Feet to 1 Inch.) Fig. r. Plan of the Stairs, 
 Gil-clofet and the Balcony. Fig. 2. Section of the Hall and Oil- 
 clofet. Fig. 3. Section of the Store-room, and half of the Door 
 into the Balcony, the Parapet being omitted. 
 
 Plate LIX. Fig. 1 and 2. {Scale 4 Feet to 1 Inch) Exhibits the 
 Plan and Elevation of the Balcony illuminated. Fig. 3. {Scale 1 
 Foot to 1 Inch.) Is the Section -of one of the Globes, which -rail ft 
 be made of very thick white Glafs; and though I do not take upon 
 me to determine, whether Semi-globes, or common fquare Lamps, 
 will prove moft commodious for your particular Purpofe, yet I will 
 venture to fay, that any of them will be preferable to Coal-fires, 
 for many fubftantial Reafons, that will quickly occur on a little 
 Confideration ; but as I have mentioned Semi-globes, I mail give 
 you my Opinion of them, and whence I conceived my Notion of 
 one fort of them. For forae particular Ufes I had different fets of 
 Moulds made of caft Brafs, fet in Frames of Iron; and at a Glafs- 
 Houfe in Southward I had them filled with the hot Metal; and 
 they took the form, and anfwered my Purpofe effectually. Hence 
 I conclude, that you may eafily get concave and convex Moulds 
 made, that will admit of the Metal to be three Inches thick at the 
 Jeaft in the Semi-dobe; and the convex Mould is to be preffed 
 
 down 
 
( 143 ) 
 
 down with a Leaver into it : See Fig. 4. {Scale 1 Foot to 1 Inch.) 
 Shews you the Section of this Semi-globe; and they may all be fet 
 in Iron Frames, leaving what room you pleafe for your Lamp to 
 ftand in behind them; which I think may be very fmall, for even 
 the light of a fmall Wax-candle placed in the Center of it, cannot 
 fail of producing, to all appearance, a very luminous Ball of Fire, 
 whofe powerful Rays muft needs be very confpicuous, efpecially if 
 the Glafs is' clear and well polifhed. And what then muft the whole 
 Illumination be with nine fuch Semi-globes, extending near 1 2 Feet 
 and 5 Feet high, all as if it were one Body of Fire, that will 
 require very little Care or Expence to fupport it, nor the leaft 
 danger of its difappearing through neglect, and thus you may, if 
 you pleafe, illuminate both your Light-houfe and this Pier-head> 
 and make other ufefiil Improvements on thefe few Hints. Let us 
 now confider the Operations of Winds and Tides. 
 
 SECT. III. 
 
 Obfervations on the Jeparate Operations and united Powers of 
 fVinds and Tides, atling upon the Heads of Jlrait and curved 
 Piers \ built in the ujual fVqy at or near Low-water mark. 
 
 I HO PE we have fully confidered and determined on the Power 
 of the Wind and Tide in general: Let us now in a more par- 
 ticular Manner, obferve their Operations upon the Head of a Pier, 
 that is run out from the Shore in a direct Line, and built on a Bed 
 of fine Sand at Low-water mark as ufual. See Plate LX. 
 
 In Plate LX. Fig. 1. Note, that a. Is the fpringing of the Pier 
 from the Shore, b. Reprefents a double Pier-head, which you? 
 may obferve is much ftronger than the former, c. The open Sea. 
 d. The Harbour, e. The Current of the Flood-tide running 
 by b. into d. And f. the Current running along the Shore to a. 
 The Drifts of all thefe Currents are reprefented by Darts; by which 
 you may obferve, that the Current f. finding itfelf oppofed by the* 
 Pier, which directs and guides it to b. in order to fupply d. and 
 during its Progress, it is prefied forward by that which comes in - 
 
 the 
 
( 144- ) 
 
 the like Manner behind it; and alfo meeting with frefh fupplies 
 from the intermediate Currents, it thereby increafes its Power, and 
 quickens its Velocity, in proportion to the Length it runs, till it 
 meets with the Current e. on which a violent Conteft enfues, each 
 ftriving for Superiority; but e. being much more powerful, foon 
 obliges f. to yield, and prefles it feverely againft b. where they unite, 
 and if fuch a Pier was built at the Mouth of a large Tide-river, 
 and the Tide flows up for many Miles into the Country, the 
 further it is to run the greater Quantities of Water wheels round 
 it, and confequently, the greater will the Velocity be at the Pier- 
 head, where it faps and preys on the Bed of Sand on which it is 
 founded; and at the lame Time the Water carries every Thin<? 
 with it, that its Power is able to conquer. The alarming Effects 
 of this may eafily be difcovered by Fig. 2. 
 
 In this Fig. 2. g. reprefents the extreme Part of a Pier-head, 
 built upon the Sand at h. which is Low-water mark. The fatal 
 Effects of the Current before-mentioned may be perceived by the 
 Curve-line 1. which reprefents a great Cavity, worn away and car- 
 ried off by the two Currents e. and f. from about the Extremities of 
 b. In order to prevent this, and preferve the Pier-head, it has with 
 fome been cuftomary in the like Cafes, to throw down large Stones 
 round it, fuppofmg they would preferve it; but let us in the next 
 Place, confider the powerful Effects of the Wind and Tide acting 
 in Conjunction on the Stones and Pier-head, g. 
 
 We need not enlarge on the ufual Swell of the Sea; but let us 
 briefly reflect: on the Power of an enraged Sea, agitated by a violent 
 Storm; and fuppofe a Wave advancing from f. toward a. Fig. 1. 
 where the Pier gives it a powerful Repulfe, and directs its Courfe to 
 b. and fo advancing along the Pier, a fecond Wave in like Manner 
 pufhes forward the firft, and the third the fecond, &c. And as before 
 the Power increafes progreffively, in proportion to the Length of 
 the Pier; fo that by the Time the Current, which the Impetuofity 
 of thefe Waves will promote, arrives at b. if in Time of Flood, 
 it will there join with an increafe the Power of the Current, e. and 
 after all, it may be very probable, that other Waves may prove 
 much more injurious .to b. even than, thefe. Let us, therefore, 
 
( *45 ) 
 
 fuppofe the Wind blowing in a direct Line, as from i. to b, in 
 Fig. t. or from k. to g. in Fig. 2. and that a huge Wave advancing 
 from k. to g. where the foaming Surge dafliing againft the Pier g. 
 breaks by that powerful Obftrudtion, and then the Remains of it 
 furioufly recoils, as it were to recruit itfelf, and is joined with the 
 next Wave, and makes another Attack upon g. then recoils again, 
 and fo on alternately. 
 
 Now pleafe to obferve, that thefe large Stones have (as I told 
 you before) large Interfaces or Vacancies between and among 
 them ; and the larger the Stones are, the larger are thefe Vacan- 
 cies, and, like a French-Drain, will freely admit the Water to 
 pafs and repafs. Corafider then, when the Wave makes the At- 
 tack, how powerfully it forces its Way through every one of the 
 Vacancies ; and, in tthe Repulfe, think what a moft powerful 
 Suction that Repulfe will create, and how it will agitate the fub- 
 terraneous Water backward and forward, by the quick Motions of 
 thefe Waves; and youi know that the main Drift and Operations 
 of the Water naturally gravitate' to the Bottom, and thereby break 
 and rake it up incefTantly. Now recollect the tumultuous Velocity 
 of the Currents, f. and e. operating (if in Time of Flood) at the 
 fame Inftant, and together with thefe Waves, hurrying all the 
 loofe Sand and difturbed Matters they are able to command along 
 with them, until they have encreafed that Curve-line, J. Then 
 there will certainly be more of thefe large Stones thrown in,; but 
 the Wind and Current operating as before, they will foon fink 
 that Bed of Sand to the Curve-line, m. which by this Time will 
 begin to fap the Foundation of g. but that cannot be readily per- 
 ceived, yet by a few Notes taken from the Sounding-board, it 
 may eafily be difcovered, by obferving the Line m. by Degrees 
 finking down to the Line n. which will ftill continue to advance 
 further and further under g. 'till at Length it will totally del troy 
 an i demolifh it, unlefs it foon meets with a Rock or fome hard 
 Ground ; and if a fingle curved Pier fhould happen thus to be 
 erected, the Operations of the Tide and Wind, may perhaps, act 
 ie irly after the fame Manner as juft now defcribed; fo that 1 need 
 repeat them. Hence it is alfo evident, that the locking of 
 
 U Headers 
 
( 146 ) 
 
 Headers and Stretchers together, no, nor all the Chain-bars, 
 Cramps or Ties you can make ufe of in fuch a Pier-head, cannot 
 preferve k after any confiderable Part of the Bed whereon it ftands 
 is fapped and carried away from under it; which is a Truth fo felf 
 evident, that I need not enlarge on it. Therefore, I recommend 
 it to you to remember this, and to examine your Ground well before 
 you attempt ta lay a Foundation on it, especially at or near Low- 
 water mark; but let us obferve the Operations of Wind and Tide, 
 on a Harbour inclofed with two Piers. See Fig. 3. 
 
 This Fig. 3. Exhibits the Plan of an Harbour inclofed with two 
 Piers; and let us fuppofe, the Tide flowing from the South along 
 the Shore, as from o. to G. and on approaching the Pier, is there- 
 by repuifed and conducted round to q. and w. and in its Courfe, 
 the fmall Dart at r. infinuates, that only a fmall Quantity of the 
 Tide comes into the Harbour, juft fo much as is barely fufficient 
 to keep the Water therein on a level with the ambient Water. 
 The fmall Dart, t. fliews the Current of the Ebb-tide, and if the 
 Current, p. had Liberty to exert its Power, it would be repuifed 
 by an Arch that could not yield to its greateft Forces; but there 
 you fee it joins with o. and continues its Courfe to q. and w. and 
 the Current s. which feems to run diredly to the Pier-head at t. is 
 there alfo diverted and condu&ed to w. and q. but if we fuppofe the 
 Flood tide coming from South Weft, as from u. it will then pafs 
 gently by the Heads of the two Piers, leaving a fmall Quantity to 
 keep'the Water on a level as before; and the whole Current of that 
 Tide pafles alfo on to w. and q. without even attempting any injury 
 to either of the Heads. Befides thefe Advantages, a Harbour of 
 this kind may probably afford an excellent flielter for fmall Veflels 
 to the Northward of the Harbour, provided the direct Lines of 
 thefe Piers extend any confiderable Way into the Sea; whence I 
 think it is evident, that fuch a Harbour, if effe£ually executed, 
 and in a proper Situation, may be reafonably fuppofed to anfwer 
 all the Purpofes for which it was defigned. I think, therefore, we 
 may now endeavour on the Plan before us, to form and lay down 
 principal Rules to defign a Plan, for a Harbour of the largeft 
 Magnitude; but it may not be improper to take into our Obser- 
 vations, 
 
( *47 ) 
 
 vations, that if a Ship is making her Way from the foutherly 
 Quarter, as from s. or u. to H. in a ftrong Flood- tide and violent 
 Storm, it may be in great Danger of running foul upon the nor- 
 therly Pier-head ; and this you muft confider, and take particular 
 Care to guard againft. 
 
 SECT. IV. 
 
 Concerning the Conflrutlion of commodious Harhours of the largeft 
 Magnitude in the Sea^ with Olfe r vat ions on the Operations of 
 the IVaves on the Pier -head. Fig. 4, And alfo\ a concife Sum- 
 mary of the Principles on which thefe Propoftions are founded. 
 
 E F O R E we can proceed in forming any Defign of a large 
 Jf) and commodious Harbour, inclofed with two Piers, as in 
 Plate LX Fig. 3. I think it neceffary to find out fome one Dimen- 
 fion, from which we may derive a Probability of giving due Pro- 
 portion to the whole: And it is evident, that here alfo we muft be 
 governed by the Depths of the high and low Water, which were 
 already fettled in Plate XLVII. Fig. 2. but the Depth of the Low- 
 water is here particularly to be regarded, becaufs deep Low-water 
 will invite large Ships, and large Ships muft have a large Space to 
 .make their Tack, &c. See Fig. 3. which is laid down by a Scale of 
 loo Fathoms, or 600 Feet to 1 Inch. 
 
 In this Fig. 3. you are to obferve, that A. muft be looked upon 
 as your Model, by which you are to Proportion the whole; and 
 here it is to represent the Depth of the dead Low-water, which 
 was given at 20 Feet deep; therefore from the Point A. draw your 
 perpendicular Line, and interfecl it with the Line B, C. take the 
 Depth A. and multiply it by 100, and that will give you 2000 
 Feet, for the Extent of the Line B. C. whicjh you are to divide 
 into ten equal Parts; then take five of thofe'Parts, and fet them 
 down from the Point A. to H. and there draw the Line D. E. 
 The Interferon gives you the Center, from whence defcribe the 
 Semi-circle D. A. E. which is the outward curve Line of both 
 theie Piers, Then fet in 72 Feet, or fix Fathoms, for the inner, 
 
 U % or 
 
( 148 ) 
 
 or principal Coffers of the Pier, (which appeared by p. o.v, w. in 
 Plate XL VII. Fig. 3.) at D. and E. and thence defcribe the inner 
 Arch, and there will remain 1856 Feet for the Cord thereof; and 
 ■upon thefe two Curve-lines at A. you are to form the Mouth of 
 the Harbour, and Heads of the two Piers. See Fig. 4. ^ 
 
 Fig, 4. (Scale 40 Feet to 1 Inch) Reprefents the principal Lines 
 of a Se&ion of one of thofe Heads, taken parallel to the Line 
 A. H. and may convey an Idea of one of thofe Heads, ftanding 
 upon the Coffers. Wherein note, that a. is the Bottom, b. Low- 
 water, c. High-water, cl Center of the Pier-head. e. Platform, 
 (about 64 Feet broad). And you fee that all thefe Coffers to- 
 gether extend ten Cubes of A. (i.e. 10x20=200 Feet). The 
 Letter / is the center Line. g. g . Extent of the two inner or 
 principal Coffers of the Pier-head, which may be environed with 
 flender tongued and grooved Piles, to preferve the Lime-water. 
 
 g. h. Breadth of the Guard-coffers, which are alfo to be en- 
 vironed with very ftout Guard- piles, (the Tongues and Grooves 
 to be put on with Spikes and ftout Oak Pins, or made out 
 of the Solid) to be drove down by an Engine, between the 
 Sea-braces, as deep as poffible, and then banked as before di- 
 reded. /. Is the Lip of the Guard-coffer, and L we fliall fup- 
 pofe to be the Face or Front of the Pier-head. And having 
 explained and confidered all thefe Proportions, let us proceed 
 to form the Mouth of the Harbour- 
 To find out the Centers of thefe Pier-heads : Divide the Line 
 
 F. G. into eight equal Parts. Draw two Lines from the mid-, 
 dlemoft of thefe Parts, till they interfea the inner Arch-Line, 
 which gives you the Centers required; which is equal in Dif- 
 tance to 500 Feet from Center to Center, or the fourth Part 
 of F. G. (i.e. A.= 20 x 25= 500 x 4= 2000.) and each of thefe 
 Centers are the fame as f. in Fig. 4. Whence the Whole of 
 the Coffers projeds 100 Feet, or five Cubes of A. from/, to 
 
 h. on each Hand, leaving fifteen Times A. or 300 Feet, for 
 the Mouth of the Harbour between the Coffers. Thus you 
 have feen that the Depths of the Water laid down in Fig. 2. Plate 
 XLVIL has principally governed the whole of thefe Defigns. The 
 
 Height 
 
( i49 ) 
 
 Height of the fpring Tide, a. b. directed you to Proportion the 
 Pier, and the Depth of the dead Low-water, a. A. enabled you 
 to prop ^ on the Extent of this Harbour; each of which, or any 
 Part thereof, you may by the fame Rules, either augment or di- 
 ffiiniffoj according as various Circumftances may require. 
 
 Haviasr obferved the Operations, and confidered the united 
 towers of Wind and Tide acting upon the Heads of ftrait and 
 curved Piers ; let us, in the next Place confider, that if a Ship is 
 making her Way from s. or u. to H. in a ftrong Flood and violent 
 Storm, fhe may perhaps, be in danger of running foul upon the 
 oppofite Pier-head. 
 
 To this Intent, let us ferioufly reflect on what has paffed, and 
 attentively confider, whether fuch a Work as this would be able to 
 fuftain fuch a violent Shock, as might happen from a large VeiTel 
 being precipitately forced againft it. 
 
 I prefume It is quite out of our Province, to determine precifely, 
 the Power of &ny fuch Weight finking againft either a direct or in- 
 clined Plain, fuch as I apprehend either the one or other of the 
 Sides of thefe octagonal Coffers may fitly be compared to; but 
 let us much rather endeavour in a plain clear Manner to confider, 
 whether we may reafonably hope that this Work (fuppofing it to 
 be properly executed) would be able to withftand fuch a powerful 
 fhock or not: And on this enquiry, we muft firft obferve, (fee 
 Plate LX. Fig. 4.) that the Head of this Pier is fo remote, 4 that 
 even the feeble point of a Bowfprit, would perhaps, fcarcely reach 
 to touch it, and therefore, the Coffers alone muft fuftain the 
 fhock. Now it is neceffary alfo to obferve, that thefe Coffers, 
 taken together, from h. to h. be 200 Feet Diameter, and 23 Feet 
 high, as hitherto determined; and here recollect the fubftantial 
 Conduction of the Coffers formerly laid down, how firmly they 
 are braced, and made perfectly folid and compact with fubftantial 
 and durable Materials; and that the Lip of the outward Hull, 
 may perhaps, feem to be the fcebleft and moft expofed Part of it* 
 Now, in order to reconfider this, turn back and look at Plate LV . 
 You know how that was directed to be done, and this is to 
 done after the fame Manner; and think, how firmly and fb 
 
 . ftantially 
 
( ISO ) 
 
 ftantially that Cut-ftone Platform will brace and ftrengthen the 
 Lip of that Coffer. Confult your own Reafon, or that of any 
 other judicious Perfon, on this plain Queftion, viz. Could any Ship 
 by running foul on the Lip of thofe Coffers in any Direction, com- 
 prefs the Stones of this Platform any clofer than they are here 
 fuppofed to be laid? and if not; How can they yield or give Way 
 to it? But taking it in another light: There is no doubt, but that 
 even fome Mariners will apprehend, that fuch a Coffer would be 
 an infignificant Obftacle to a fir ft rate Man of War under full Sail; 
 but it may be alfo necefTary for them to confider, that this Coffer 
 (exclufive of the immenfe Weight of the Pier-head, and the lofty 
 Beacon, or Light-houfe, that is to ftand upon it) would weigh 
 upwards of fifty thoufand Tons, which we have found to be equal 
 in Weight, to a folid Rock of Portland Stone of thirty-four Fathoms 
 in Diameter, and near four Fathoms in Height; whence, perhaps, 
 he or they may be able to form a clearer Judgment on the Effects 
 of fuch a Rock, lying direclly in the Road of fuch a Ship under 
 full Sail; and on the Decifion, you are to anfwer the Queftion 
 propofed. We mall in the next Place, make fome concife Obfer- 
 vations on the Operations of the Waves on the Pier-head now 
 before us. (Fig. 4.) Hie Depth from a. to b. being 20 Feet. 
 
 Let us confider a large Wave advancing from b. towards the 
 fuppofed Pier-head, L in its Way, the lower Part of it only will 
 meet with, and be retarded by the Obftacle, I the upper Part of it, 
 will break and difperfe on the Cut-ftone Platform, e. and being 
 thus weakened, when the remains of it ftrikes againft k. it will 
 make but a very feeble recoil during the Time of Low-water or 
 young Flood. But let us fuppofe, a Wave advancing in a direct 
 Line from c. to L it will not meet any Obftacle till it arrives at L 
 where its full Power can only ftrike on one point, and dilperfe 
 circularly, which will partly diminifli its Power in recoiling, and 
 the remaining . Part of its recoiling Force, not meeting with any 
 -Obftacle, will be quite fwallowed up in that Depth of Water, 
 And alio obferve, that Waves advancing through the intermediate 
 Space, between b. and c. both their attack and recoil will operate 
 
 entirely 
 
entirely on e. which will be, as if it were, a Stage of Cut-flone of 64 
 Fcet broad, prepared for them to aft on. 
 
 The Motions and Celerity of the Waves, have been fully ex- 
 amined by many eminent Gentlemen; feveral of whom have on 
 very juft Grounds concluded, that the Motions of the Waves, 
 even in a high Storm on the main Ocean, does not fenfibly agitate 
 the Water to any confiderable Degree of Depth, from the Surface 
 of the Caveties thereof; fome fay, not exceeding one Fathom deep: 
 And if fo, then generally fpeaking, the Water at * will continue 
 nearly in its natural tranquil State, and confequently, can neither 
 difturb the Banking, nor fap the Foundation. Hence it is evident, 
 that the utmoft united Powers of Wind and Tide, can neither 
 injure nor moleft thefe Coffers, which is the principal Thing 
 
 required. . . ^ 
 
 But before I prefume to introduce this mod important Fropo- 
 fition into Praaice, I think it advifeable to fum up, and to lay 
 before you in one View, the Principles upon which I have founded 
 thefe 1 2 Proportions, which I fhall reduce to the following fa 
 concife Articles, in order to your forming a clear Conception of 
 their Nature and Utility. , 
 
 I. That found hearty red Fir-timber, kept conltantly in Water, 
 will be extremely durable; and the Iron Cramps eafily replaced if 
 
 neceffary. . ' . \ \ * 
 
 II. That thefe fmall Stones, properly mixed with clean, lnarp, 
 fandy Gravel, in Water, exclufive of Lime, and being clofely and 
 fecurely confined together, will inftantly become firm and com- 
 pact, and confequently be a fubRantial Foundation for any Build- 
 ing whatever. • A ^ M 
 
 HI; That the Stuffing hitherto recommended, will molt allured y 
 turn to a real Petrification; and, that each of thefe Coffers will, 
 in reafonable Time, contain one compaa Subftance, equal to the 
 Strength and Durablenefs of a hard and folid Rock, which will be 
 of the lame fiiape of the clear of the Coffers in which they were 
 moulded; and will be poffeiTed of this remarkable Advantage, that 
 
 the longer it Hands, the harder it will grow. 
 
 D IV. That 
 
( *5 2 ) 
 
 IV. That thefe Kinds of Foundations, in the weightier! Works, 
 may (generally fpeaking) be effectually accomplifhed, with fur- 
 prizing Expedition, perhaps, by an ordinary Ship's Crew, and at 
 a trifling Expence (in Comparifon with other Methods) in any 
 Country, throughout the greateft Part of the Univerfe; as there 
 are, probably, but few Countries that do not afford fuch common 
 Materials as are neceffary for thofe Purpofes. 
 
 V. That thefe Kinds of Coffers may be proportioned to any 
 moderate Depth of Water; and that Coffers of fifty Feet high, 
 may, in moft refpects, be as readily conftru£ted, and the Work as 
 effectually executed in a frefh Water, or in a moderate Tide 
 River, as in any other leffer Depth, the Proportions being duly 
 confidered. 
 
 VI. That in any kind of Buildings that may hereby be erected 
 in the Sea, it may alfo be obfervable, that if the Coffers were even 
 made much llighter, yet, as they will be in a Manner quite be- 
 neath the Power of either Wind or Tide, they may be abundantly 
 fufficient to oppofe them both, and confequently, they can only 
 operate on the Cut-ftoiie, which they cannot injure. I hope, there- 
 fore, that 1 may fafely conclude, that thefe are fure, quick and 
 cheap Methods for compleating fuch Works, which are the three 
 Things that I have endeavoured to accomplifh. With this View, 
 therefore, and on thefe Principles, I fliall now venture to introduce 
 this Propofition into practice, by laying before you, the Plan of a 
 Harbour for the Downs, in England^ which you may apply or vary, 
 according as other particular Circumttances may require, either in 
 that Place or elfewhere. And obferve, that in this enfuing Defign, 
 in the Place of Fig. 2. Plate XL VI II. you may (by a large Scale) 
 draw the Section, Fig. 4. Plate LX. with a Superstructure propor- 
 tionable to it; and lay down the octagonal Plan thereof, fo as to 
 corroborate with the Plans of thefe curved Piers in Fig. 3. and alfo 
 in Plate LXL The Heads of which, I have been obliged, by the 
 imallnefs of my Scale, to draw circular, and to omit all the Guard- 
 Coffers; but I hope, all the other Parts and Proportions of thefe 
 Methods, are fo clear and diftinctly laid down in them, and in the 
 foregoing Plates, that I need not enlarge any further on them; 
 
( i53 ) 
 
 and obferve alfo, that the Height of the foutherly Pier in this 
 following Defign, mud perhaps, be of the fame Dinienfions as 
 formerly laid down, Plate XL VIII. Fig. r. But the Height of the 
 North Pier, is entirely left to your own Difcretion, with many other 
 Circumftances which after ftrictly examining the Coaft, you muft 
 determine on, as the Refult of deliberate Confideration. 
 
 SECT. V. 
 
 Concerning the Conjlrutlion of a Harhour for the Downs, project- 
 ing to %o Feet Low-water, the highejl Jpring Tides fuppofed not 
 to exceed 20 Feet more. 
 
 I HAVE told you that in June 1752, I went to Ram/gate, to 
 confult Mr. Ettridge and Mr. Prejlon, who were pleafed to 
 favour me with a Copy of the Plan of their Harbour. During my 
 Stay there with them, and the Captain that brought them the 
 Portland Stone, great Part of our Converfation turned on different 
 Opinions, concerning a Harbour for the Downs ; and as I then 
 had an Opportunity of hearing many pertinent Remarks on the 
 Subject, to fatisfy my Curiolity, I took a curfory View of the Shore 
 thence to flover; and I afterwards collected feveral other Plans, 
 Charts shd other Remarks; and on my return Home, employed 
 one of my Clerks to copy them, and reduce the whole into a 
 concife little Book, which now lies before me, and which I have 
 many Times ftudied with the greateft Affiduity, in hopes of ac- 
 complifhing what I mod earneftly defired: And at Length, I com- 
 pleated what I am alfo now about to lay before you, as the ulti- 
 mate End of tbefe Propolitions; but obferve, that all the Mate- 
 rials which I collected, were not by any Means fufficient to deter- 
 mine me, efpecially as to the propereft Situation for it, becaufe 
 I had not any Borings, or correct Soundings of high and low 
 Water; I muft therefore, leave thefe Matters at your Door, but 
 fhall give you a few neceflary Hints concerning the Situation in 
 the Sequel. 
 
 X Plate 
 
( *54 ) 
 
 Plate LXI. (Scale 100 Fathoms or 600 Feet to 1 Inch.) 
 
 This Plate exhibits the Plan of the Harbour, which I have de- 
 fined according to the general Rules of Proportion, laid down in 
 Plate LX. Fig. 3 and 4. And herein note, that A. is the Mouth in 
 tweenty Feet deep of dead Low-water. B. The Bafon for the 
 largeft Ships, extending 1856 Feet, or about one third of an 
 Englijh Mile, in the clear of the principal Coffers as before, which 
 in this, or the like Cafes, you may difpofe of after the following 
 Manner: Out of this 1856 Feet, take the odd 56 Feet, and 
 : divide them into two equal Parts, and give one of thofe Parts to 
 enlarge the Thoroughfare at the Rear of the Lots; then divide 
 the 1800 Feet into 18 equal Parts, three of which (being 300 
 Feet) are to be the Depth of the Lots on each Side, and the re- 
 maining 1 200 Feet are to be the Breadth of C. which is to be the 
 Port or Haven for trading VelTels, (which is juft the Breadth of 
 the River Thames at Wejlminjler-hridge). D. Is the Port-head at 
 the Cuftom-houfe Quay, which muft be fix Feet deep at the dead 
 low Water, a. and b. Are two fmall Beacons, c. and d. Two 
 Quays of 32? Feet long, and 70 Feet broad each, E. and F. are 
 twenty Lots for Docks, each Lot feventy Feet Front, and 300 
 Feet deep. Then divide the 300 Feet into three equal Parts, of 
 which you leave two on each Side for the Depth of thefe Lors, 
 and one on each Side for G. and H. which reprefents the t-vo 
 principal Quays, each of which will be 1770 Feet long, and 100 
 Feet broad. Wherein alfo note, that e. and f. are Thoroughfares 
 to the Rear, and 50 Feet broad each. g. and h. Twenty-four 
 Lots for his Majefty's Magazines, being 50 Feet Front, and 200 
 Feet deep each. i. and k. Thoroughfares of 40 Feet broad. 
 1. and m. Thirty Lots of 40 Feet Front, for public Stores and 
 Weigh-houfes. n. and o. Thoroughfares of 30 Feet broad, 
 p. and q. Thirty Lots for principal Merchants Companies, to ftore 
 their Imports and Exports, till further Orders. I. A yard, wherein 
 you are to make the Coffers, &c. and afterwards it is to be the 
 Cuftom-houfe Quay, extending 1200 Feet long, and 300 Feet 
 
 broad. 
 
( *55 ) 
 
 broad. K. Public Stores and Weigh-houfes on the Ground-floor, 
 and Cuftom-houfe and Exchange on the Second-floor, &c, 
 
 I fliall now give you a few fhort Hints concerning your making 
 a proper choice for the Situation of this Harbour. I told you above, 
 that I had only taken a curfory View of the Coaft, and therefore, 
 cannot be expected to fix upon the Scite; but from fuch poor re- 
 marks, as I have been enabled to make or procure, for many 
 reafons I apprehend, that a little to the Northward of Deal^ or 
 fomewhere about IValmer, would be very proper for the purpofe. 
 However, obferve, that I do not pretend to determine this Point, 
 or to enter into any minute Circumftances concerning it; but I 
 fhall juft briefly recommend two principal Guides to conduct you 
 to a proper Situation. 
 
 I. Firfl fet out in a direct Line from the moll promifing Place on 
 the Shore, till you come to fix Feet deep at dead Low-water, and 
 that determines the Scite of letter D. Then proceed in the fame 
 direction, till you come into twenty Feet deep of the like Water, 
 which gives you Letter A. and herein obferve, that the Extent of 
 A. from D. is juft equal to 4396 Feet in the clear; but I prefume, 
 that it would be infinitely better, if A. and D. were double nay, 
 treble that diftance, from each other, for this very important 
 Reafon, becaufe the Merchants of London would be better accom- 
 modated, with a convenient Number of Store-houfes, to preferve 
 both their foreign and domeftic Commodities, according as their 
 different Occafions might require, without giving the leaft delay 
 to their Ships or Men; by which Means, this Port would not only 
 prove a PlaCe of Safety, but among numerous other Advantages, 
 it would anfwer extremely well as a Mart or noted Place to carry 
 on Trade with the whole World. For thefe, and many other 
 weighty Reafons, I advife you not to be afraid of making the 
 Diftance too extenfive between A. and D. for when the Bafon B. 
 is finifhed, the Expence of carrying the Piers home to the Shore, 
 will be very trifling in Companion with the- yearly Value any emi- 
 nent Merchant would put upon one of thofe Lots. 
 
 II. I fliall now in the fecond Place, point out -another Guide to 
 conduct: you to a proper Situation for this Port, which you will find 
 
 X 2 to 
 
to be of fuch vaft Confequence, that neither Time nor coft ought 
 to be fpared to find out and procure it, if poffible; and that is a 
 full command of pure frefli Water. 
 
 I cannot certainly fay, whether or no the River Slower could be 
 taken up, or even a Part of it, conveyed to fome convenient Place 
 for this Purpofe; but I have Reafon to believe that it may, or 
 perhaps, fome other Rivulet may anfwer better ; but be that as it 
 will, I do mod earneftly advife you, to procure plenty of pure frefh 
 Water, fufficient to keep up in the dried Seafon, a fpacious Refer- 
 voir, contiguous to the Rear of K. or fomewhere to the Weftward 
 of the Port; and from this Refervoir to carry two Conduits, one 
 through the Middle of each Quay-wall, as it were from r. to s. and 
 from t. to u. they muft be at the leaft 4 Feet wide, and 7 Feet 
 high in the clear, to be built with well chifleled Stone, in ftaunch 
 Ciftern Work, as formerly directed, each of thefe Conduits muft 
 have a Sluice at the Refervoir, and another near to the Extremity 
 of each Quay as at s. and u. into which common Sucking-pumps 
 muft be fet at about every Ship's Length, in Proportion to the fe- 
 veral Depths of Water, with proper Air-pipes, &c. This I repeat, 
 will be of fuch vaft ufe, that no Money fliould be fpared to pro- 
 cure it. I fhall give you but one Inftance on the whole: Suppofe a 
 Sloop or Tender, fliould come to this Port in great hafte for Am- 
 munition, or Provifion, flie might fail up to the Magazines and be 
 inftantly loaded; and yet, at the fame Time, by the Labour of 
 three or four Men, this pure frefli Water can be pumped, and by 
 Leather-tubes conveyed, even into the Water Hogfheads in the 
 Holds; and with all this flie might fet out again, without paying 
 any regard to the Tide, or lofing the leaft Time imaginable by 
 taking in her loading. 
 
 I do not in the leaft doubt, but that there will be fome political 
 Objections made to this Defign ; becaufe perhaps, this Port might 
 at fome Times contain immenfe Value of Britijh Property, and 
 in Time of War be liable to Hoftilities. In order to obviate that 
 Objection, you may on thefe Principles and Methods erect two 
 fubftantial Forts at L, and M. provided you find thofe two Scites 
 
i 
 
 SO 1 
 
 1° 1 
 
 6c i 
 
 60 i 
 
 \0 I 
 
 30 1 
 
 10 i 
 
 W 1 
 
 00 Q 
 
 0 6 
 
 o 7 
 
 o 6 
 
 0 6 
 
 o 4 
 
 0 3 
 
 0 1 
 
 0 I 
 
 0 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ■ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 1 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
of moderate Depth, by which I prefume that this Port may be 
 fafely protected, and the Channel effectually guarded thereby. 
 
 Plates 62 and 63, furnifh you with the Scales, by which all the 
 foregoing Draughts were minutely laid down, except fig. 3, in 
 Plate 60 and Plate 61 ; which are to betaken off by a Scale of 
 600 Feet to 1 Inch, as before mentioned ; and by comparing the 
 fame with Plate 48, you may make a Scale to anfwer any other 
 Depth of Water, but not to exceed 20 Feet deep, and adjuft all 
 the Proportions according to Plate 47, Page 133. And notwith- 
 ftanding this Defign is of fo large a Magnitude, yet it muft be 
 admitted, that it will not by any Means be difproportionable 
 to the Britijh Empire, efpecially, as it may be a Mart to all the 
 Mercantile World, in cafe there can be no other Place found elfe- 
 where that will be more convenient for that Purpofe, which we 
 may confider among other Matters in the third Part hereof. 
 
 END Part the Second. 
 
 Y 
 
( *S8 ) 
 
 PART III. 
 
 Concerning a Plan for encreafing the commercial and landed In- 
 tereft of Ireland \ and briefly demonftrating that not only 
 Great-Britain, but the whole Britijh Empire may gain confide- 
 rable Advantages thereby. 
 
 THAT it is the Intereft of England, that Ireland fhould 
 grow and flourifh in Trade and Wealth is manifeft : Yet 
 it hath been a grievous Misfortune to us to have it otherways 
 apprehended, not only by many of the Manufacturers, but even 
 the Statefmen of England \ which muft have proceeded from 
 their not underftanding the Affairs of this Country, and not dis- 
 cerning its true Intereft. For it is in Politics as in the human 
 Body, if any malignant Humour proves predominant in any of 
 the Members, the Difeafe becomes general, and in Time may 
 affecl: the whole Body : And I think that any Man of common 
 Underftanding may account for this Miftake, that recolle&s the 
 Firft of July 1690. Were not the very Vitals of their Anceftors 
 and ours promifcuoully mingled together on that glorious Day? — 
 Are not the People of both Kingdoms connected and united to- 
 gether by firm Ties of Affinity and Friendfhip ? Do not wonder 
 then that the general Addreffes of our Patriot Parliament, that 
 echoed the Voice of the whole Nation, reach at length to the 
 Ears of His Majefty, who, ever mindful of the good of his Sub- 
 jects in general, and balancing the Scale of Juftice, has from 
 his Throne pointed out the Means of making us a happy and 
 opulent People," by eftablifhing us in a Free Trade, which me- 
 morable Event happened in the firft Week of March 1780, 
 
 communicated 
 
( *59 ) 
 
 communicated to the Public through the Channels of all the 
 News-papers in this Kingdom to the following EfFecl : 
 
 " A& of the Britifh Parliament, for granting Ireland a FREE 
 « TRADE." 
 
 " Anno regni Georgii III. Regis magnse Britannice, Franciae, 
 " et Hiberniae Vicefimo. 
 
 cc At the Parliament begun and held in Weflminjier the 
 " Twenty-ninth Day of November A. D. 1774, in the 15th 
 " Year of our Sovereign Lord George the Third by the Grace 
 <c of God t of Great-Britain y France, and Ireland King, Defender 
 <c of the Faith, &c. And from thence continued by feveral 
 <c Prorogations to the 25th Day of November 1779, being the 
 " fixth Seflion of the fourteenth Parliament of Great -Britain. 
 iX Chap. 10th. 
 
 " An Ad to allow the Trade between Ireland and the Britijh 
 " Colonies and Plantations in America and the Weft Indies, and 
 " the Britijh Settlements on the Coaft of Africa, to be carried 
 c< on in like Manner, as it is now carried on between Great- 
 " Britain, and the faid Colonies and Settlements." 
 
 This Act is very long, and it is not by any Means neceffary 
 for me to fwell up this little Treatife with it : But however, to 
 prevent Miftakes, I flial] infert the concluding Claufe ; viz. 
 
 <c Providing always, and it is hereby further enabled by the 
 " Authority aforefaid, that this A6t fhall not extend or be con- 
 <c ftrued to extend, to allow any Perfon or Perfons to trade to, 
 " from, or in any Colony or Plantation in America during fuch 
 u Time, and in fuch Manner as the Trade or Intercourfe of 
 " Great-Britain, with fuch Colony or Plantation is or fhall be 
 " prohibited or reftrained by any A& or Acts of Parliament made, 
 iC or hereafter to be made in this Kingdom. But whenever 
 " Trade and Intercourfe fhall be permitted between Great-Britain 
 " and fuch Colony or Colonies, the fame Trade and Intercourfe 
 <c fhall in like Manner be permitted and allowed between Ireland 
 " and faid Colony or Colonies," 
 
 CHAP 
 
( 160 ) 
 
 C H A P. XVIII. SECT. L 
 
 Concerning the Purport or true Meaning of the Words FREE 
 TRADE, wifh fomg Preparatives thereto* 
 
 LET us now endeavour to afcertain the true Meaning of thefe 
 two Words ; for till that is determined, it cannot be known 
 with Certainty whether my Defigns are properly adapted to thofe 
 Purpofes or not. — The Words FREE TRADE have been a co^ 
 pious Topic for Argument to innumerable Gentlemen and others 
 thefe Fifty Years. They have alfo been a Bone of Contention 
 between the Trading People of the two Kingdoms. During 
 that Time there have been fome People induftrioufly employed 
 in fowing Seeds of Divifion beeween them and us : And the 
 more firmly did thofe Kinds of Seeds take Root, by thofe Perfons 
 having ftrong Matters of Fad to ground their Arguments upon, 
 I mail only mention one of them, k e. A Brave and Loyal Peo- 
 ple, labouring even under the deplorable Want of the ordinary 
 NecefTaries of Life. For Inflance, this Moment there are actu- 
 ally between 900 and 1000 of poor wretched People pent up 
 together in one Houfe in Channel-row, and kept from expiring in 
 the Streets by the charitable Contributions of the generous Pub- 
 lic, which perhaps cannot be paralleled in Europe. But let us 
 
 return to our Subject, and ufe our beft Endeavours to contrive 
 Ways and Means to remove all thefe mocking Kinds of Grievances 
 in future ; by the Free Trade we are bleffed with, and which was 
 long ardently wimed for by all Kinds of People in the King- 
 dom. 
 
 Now, if this whole Affair was left to me, I think I would 
 only defire fix plain Englijh Words to be added to thefe two 
 Words to fupport my Plan, for the Redrefs of all thefe Grievan- 
 ces, as laid down and pointed out in the following Pages. One 
 of thefe Words I would wim to be placed between the two 
 Words, viz. The Word, TO, and then the Senfe of them 
 would be FREE TO TRADE, and which might, in fome 
 
 Degree 5 
 
( i6* ) 
 
 Degree, anfwer my Purpofe : But, to prevent Miflakes, let it 
 be fuppofed, that the whole Sentence ran thus : Any Man is free 
 to trade in Ireland ; or that all Men are free to trade (or to 
 follow their own Occupations) in Ireland. Then confequently 
 it is incumbent upon us to difcover how it comes to pafs, that 
 Ireland mould be diftinguifhed from the reft of the World in fo 
 high a Degree, as to have fuch a peculiar Appellation beftowed 
 upon it. 
 
 In order to this Enquiry let us firft examine the Map of the 
 World, and there you will fee how this poor little Spot is fituated; 
 obferve how it flands free and open to trade with the whole Mer- 
 cantile World. View it in the Map of Europe^ and obferve how 
 commodioufly it is fituated for Trade in this Quarter of the 
 World ; but particularly, pleafe to ftriclly obferve and minutely 
 confider Plate 64. And there behold an Ifland, as if defigned by 
 Nature for Commerce ; an Ifland, that has fpacious and commo- 
 dious Harbours quite round the Kingdom, with proper Depths of 
 Water for Ships of the largeft Magnitude, and withal an Ifland 
 of great Extent ; bleffed with every Comfort in Life, and there- 
 fore fit to relieve and refrefh the poor wearied and emaciated 
 Mariner ; and alfo naturally abounding with all the Neceflaries 
 of Life. 
 
 Now if thefe Things are attentively obferved, and ftrict. En- 
 quiry made through all Europe^ where can you find any one Spot 
 fo commodioufly laid out for Trade and Commerce ? And if 
 none fuch can be found, does it not feem, as if the bountiful 
 Hand of Nature had liberally beftowed thofe and numerous other 
 Blefilngs upon it, to make our King and Country great and 
 happy ? 
 
 Let us therefore now proceed, and enquire how all thefe pe- 
 culiar Advantages are to be applied ; and furely it muft natural- 
 ly occur, as it evidently appears, that it was defigned for a 
 MART, or a notable Place of Commerce, for the trading Part of 
 Mankind to meet and to carry on a Free Trade with each other : 
 And hence 1 prefume that the Improvements, which are necef- 
 fary to be made, to anfwer thefe falutary Purpofes, may be dif- 
 
 Z tinguifhed 
 
( x6a ) 
 
 tinguifhed by thefe two Appellations, viz. the exreriour and the 
 interiour Improvements. The outward Parts of this Kingdom, 
 I believe, remain to this Day nearly in the fame rude State that 
 Nature left them in ; and to fit them for the great and important 
 Purpofes of univerfal Commerce, there mull be Tongues, 
 Quays, Docks, Wharfs, and perhaps fome Piers, Beacons, 
 Light-houfes, and other Improvements, to make fafe and con- 
 venient Ports, &C. 
 
 The interiour Parts in many Places alfo continue, in the fame 
 
 rude State, and call loudly for Improvement. In order to 
 
 which our gracious King, and his Anceftors, have already be- 
 gun a moil noble Improvement, i. e. the Inland Navigation, 
 which in Time will join the Navigation of our fpacious Loughs 
 and Rivers together, and convey all our Exports to the Ocean. 
 Our Roads are to be made much more fpacious and convenient, 
 which will require Bridges of various Dimenfions ; — a great 
 Variety of Defigns for thefe and many other Purpofes have been 
 before given. 
 
 The firft Things therefore that are to be done, (hould be to 
 get very correct Surveys of the Coaft quite round the Shore, the 
 Soundings to be correctly taken at leaft to the Diitance of one 
 League into the Sea, and alfo the Soundings within all the Har- 
 bours and Navigable Rivers, fo far as may be contained within 
 the Plans of the refpective Ports, and from thence fo far as they 
 are navigable up into the Country, without meeting with any 
 Shoals, till you come to four Feet deep at low Water. And they 
 are to be inferted in the refpective Maps of the Counties through 
 which they jun or are adjoined. And the Maps of the Ports 
 fhould be drawn for and bound up in large Quartos, fo that not 
 only the Committees or other acting Gentlemen, but the Public 
 in general may have an Opportunity of confidering and proposing 
 fuch Plans or Schemes as they think proper for their Perufal. 
 
 There have been Surveys already made of feveral of the 
 Counties : The Remainder of them ought to be directly put in 
 Hand, and when they are compleated they all ought to be care- 
 fully and minutely laid down in a four Sheet Map of imperial or 
 ' elephant 
 
( i6 3 ) 
 
 elephant Paper, on which every Gentleman's Eftate ought to be 
 carefully pricked out, fo that the Parliament, or any of the local 
 Committees, and the Public, may clearly fee where any of the 
 principal Improvements are to be made ; on all which I intend 
 to treat a little more largely in the Sequel : And in the mean 
 Time I apprehend that the Public in general fhould be apprized, 
 that thefe Matters are in Agitation, and that there fhould be 
 particular and friendly Invitations given to the Merchants and 
 Manufacturers of Great-Britain to traffic and trade with us. 
 And there are alfo numerous other Things to be done and con- 
 fidered, previous to this great Undertaking, which muft be poft- 
 poned at prefent:. But before I enter on any of the principal 
 Matters, in my Plan for the interior Improvements, I muft beg 
 Leave to give a ifhort Account of a little Tour I made through 
 Part of this Kingdom on my own Bufinefs, with fome Remarks 
 I made in it. 
 
 On the 13th Day of Augujl, 1739, I fet out from Dublin^ 
 and after much riding, came to Sir John Bingham ^ \\xCaJlIebar, 
 thence to Newbrook, and from thence I fet out from Mr. Bowens on 
 the 26th, at Six o'Clock in the Morning falling. My Route was 
 for French Park in the County of Rofcommon, which, as I was 
 told, was computed at fifteen Miles, and that I was to go 
 through Breeze and Mourneen, which was one Reafon of my not 
 taking any Breakfaft, as I thought to take it at the former. Bur, 
 behold, the Inn was a little Hut made with Sods, with a Hole 
 on each Side of the Door, of about a Foot fquare, by Way of 
 Windows, which was generally flopped with Straw in cold Wea- 
 ther, and another Hole left open in the Thatch for the Smoak, 
 and a Piece of a Turf hung by a String on a Bit of a Stick by 
 Way of a Sign, and the only Improvement I faw about it was two 
 old Whitethorn Trees, and before me I could not fee any one in- 
 dividual Thing but Heath. However, I pufhed on till I came 
 to Mourneen, and that was juft of the fame Kind and Condition 
 of the former, where nothing was to be had but Whifkey and 
 Tobacco, and the like difmal and cxtenfive Profpecl was all 
 around me. But at length, having grow;i extremely hungry, to 
 
 my 
 
( i6 4 ) 
 
 my great Joy I efpied a pretty little white Houfe, which I 
 ardently wifhed might happen in my Way ; fo it nearly did, 
 and I rode up to the Door, and afked a Servant Maid that flood 
 there, if it was a public Houfe, and fhe anfwered, no ; but I 
 heard a Voice prompting her, and fhe afked if it was a public 
 Houfe that I fought for. I anfwered her I wanted to break- 
 faft. With that a very genteel-looking Gentlewoman advan- 
 ced, and defired me to alight, which you may be certain I was 
 not long in doing. In fhort, I think a more hofpitable Recepti- 
 on I never experienced. Her Name was 0' Mealy> and fhe was 
 
 a Defcendant of the Family of Grana-V eal. 
 
 I foon fet off again, and about 3 o'clock happened on fuch 
 another Inn as thofe two I have defcribed. But I fhall not trou- 
 ble my Readers with my Repaft, yet I fincerely pitied the deplo- 
 rable State of that Family. 
 
 I pufhed on again with the fame dreary Profpect around me, 
 not meeting through the whole Way any Thing that could be call- 
 ed a Road ; indeed, in many Places 1 could hardly difcover even 
 a beaten Path, but what was almoft covered with Heath, nor 
 any Thing elfe to be feen quite round as far as my Eyes could 
 reach ; and yet it could not be called a Mountain, but I believe 
 a great Part of it was boggy, becaufe it all feemed tolerably le- 
 vel. Now whether I milled the right Road through this Heath 
 or not I cannot affirm, but at length I found myfelf quite loft, 
 and could not find any Thing like the Traces of a Road ; and 
 as Night approached, I concluded, that I muft take my Reft by 
 lying down among the Heath with my Horfe tied to my Leg. 
 But alas ! 1 could meet with nothing through the whole Day 
 that was fit to nourifh him, and fo 1 wandered about on Horfe- 
 back, till at length I had the Comfort of Moon-light, and for- 
 tunately for me heard a Man whiftling. I made toward him, 
 and found he was herding a little Field of Oats then in Stocks, 
 and I hired him to guide me to French Parky to which I did not 
 arrive till after Ten o'clock : And I can fafely affirm, that, to 
 the beft of my Knowledge, I did not fee above fix Houfes, fuch 
 as I have defcribed, no* above eight Men and Women, and per- 
 
( i65 ) 
 
 haps, not above half a Score of any Kind of four-footed Beads ; 
 and as I was exceedingly well mounted, I can fafely conclude, 
 that I certainly muft have travelled upwards of forty or forty-five 
 Miles that Day. 
 
 Having now laid the Contour of this moll dreary Landfkip 
 before my Readers, I fliall only draw one fhort Inference 
 from the Whole, on a Suppoiition, that the nine Hundred of 
 niiferable aged People, now pent up together in the Poor-houfe 
 in Channel-row^ as above mentioned, had been then fettled in 
 this fpacious Tra& of Ground, and even two or three Knit Stock- 
 ing Manufactories fet up among them, what a populous and 
 flourifhing Colony might that have been now ! What an Addi- 
 tion might it have produced to the King's Revenue ! What a 
 vaft Number of Soldiers and Sailors might it have afforded for 
 his Majefty's Service! But what an additional Fortune would 
 it by this Time have produced to the Proprietor or Proprietors 
 of that extenfive Country ! — And even now, would a Company of 
 Gentlemen join, and either purchafeor take renewable Leafes of 
 thofe and numerous other fuch wafte Places, throughout this King- 
 dom, and eftablifh thereon Colonies of induftrious People to carry 
 on Manufactories and Trades of different Kinds ; would not this 
 tend to the Emolument of the Nation ? And hence I alfo prove,, 
 that it is abfolutely neceflary for the Public to make fpacious 
 Roads through all thefe Sorts of Places in numerous Parts of this 
 Kingdom, many of which I have feen, even in this Tour, hav- 
 ing rode through fourteen Counties within the Compafs of three 
 Weeks. I fhall not trouble you any farther with this Affair, 
 but leave it to your own Refle&ion, and return to examine in 
 what Senfe thefe two Words, FREE TRADE, are to be taken 
 with refpe& to our Exports and Imports, adapted to the Inten- 
 tions of our prefent Plan* 
 
 S E C T» 
 
( i66 ) 
 
 SECT. II. 
 
 Shewing in what Senfe the Words FREE TRADE are to be talen> 
 with refpeB to our Exports and Imports^ and how they are to be 
 adapted to our prefent Plan* 
 
 I BELIEVE the Merchants of this Kingdom are Gentlemen 
 of as great Underftanding and Veracity as in any other Coun- 
 try whatever : Therefore, with great Diffidence, I prefume to lay 
 my Plan before them, as it is a Matter wherein they are fo near- 
 ly interefted ; and in cafe it does not coincide with their own Sen- 
 timents, with regard to Imports and Exports, they may reject the 
 Whole, or any Part, as they may find confiftent with their own 
 and the public Good. 
 
 I have already demonftrated, that this Kingdom feems, as if 
 it was, by Nature, defigned for a Market-place for the mercan- 
 tile World ; and by our Scheme to be appropriated to that Pur- 
 pofe, to wit, That all Men are free to trade i?i Irela7td y and that 
 is, in this Cafe, to carry on a commercial Trade to its utmoft 
 Extent ; and therefore I humbly apprehend, that it is evidently 
 incumbent on our Merchants to ingratiate themfelves into the 
 Efteem of all the Britijh Merchants, Companies, and others, at 
 Home and Abroad ; and in particular to mew and explain the 
 many and great Advantages that mud certainly arife from their 
 entering into fuch an extenfive Trade with our Merchants, by 
 fending their Commodities to our Market, and alluring them, 
 that they will either buy, fell, change, or exchange whatever 
 they fend with the utmoft Expedition, according to their Advice : 
 That they will not only be ftored at all Times with our own 
 native Commodities, but alfo with all Sorts of^BritJh Merchan- 
 dize, as any Part's of thefe Kingdoms produce, as well as thofe 
 of numerous other Nations alfo. — That they will ad for them 
 as Fadors on Comrniffion ; or if they fend their own Factors, 
 they will accommodate them with Store-houfes, and all other 
 
 Conveniencies. 
 
Conveniencies that may in any Ways be neceffary for them, on 
 reafonable Terms, 
 
 Hence it is evident, ift, That our Merchants (from what has 
 been and will be hereafter faid) can carry on the Bufmefs of Im- 
 ports and Exports at their own Doors. 2d, That all the Mer- 
 chants in this Kingdom ought to affociate, and hold a general 
 Meeting in the Royal Exchange , and "there confider of all fuch 
 Matters and Things as may be neceffary to, or confident with, a 
 Free Trade. But particularly, and* without Delay, to obferve 
 what is pointed out in the latter End of page 162 and in page 
 163, &c. concerning the Maps of the Shores, &c. for no 
 Advances can be made till all thefe Things are confidered, and 
 proper Improvements made in the Ports, fit for Ships of various 
 Burdens, which muft load and unload without grounding. And 
 remember, that I recommend it to your beft Attention to obferve 
 what I have mentioned in the latter End of page 155, &c. 
 Article 2d. For if all your Tongues, Quays, and Wharfs are 
 made after the Methods there mentioned, they will be ftrong 
 Inducements to the Britijh Merchants and others to frequent your 
 Ports, and confequently render them very popular, and alfo be 
 the Means of bringing many Foreigners to refide among us, on 
 Account of our Free Trade. But all fuch muft know, that 
 though all Men are free to follow their own Trades and Occupa- 
 tions, yet no Man can be permitted even to live among us, that 
 is not a true and loyal Subjecl to his prefent Majefty King George 
 the Third and his Succeffors. He muft demean himfelf peace- 
 ably and honeftly ; he muft pay Scot and Lot, as from Time to 
 Time may be cuftomary among us ; and alfo his Proportion of 
 the King's Revenues and Duties, as have been ufually paid toward 
 the Support of the Government, or according as the fame may 
 be hereafter fettled and adjufted by our Legilktupe. All which 
 is confident with Reafon and the Laws of all' civilized Nations ; 
 And therefore any Man that doth not demean himfelf according 
 to our Laws and Cuftoms, cannot expect to live among the good 
 peaceable People of Ireland, I fhall now proceed and lay be- 
 fore 
 
( *68 ) 
 
 Fore you a concife Sketch of fome of the interior Improvements 
 confiftent with a Free Trade. 
 
 SEC T. III. 
 
 On Roads y Fairs, Markets, 6cc. 
 
 BEFORE I enter on the firft of thefe Subje&s, (to prevent 
 Repetitions) I recommend it to you to refrefti your Memory 
 by turning back to page 118, Chap. 16th, Seel:, ifl. and 2d. 
 for there you will find Methods to accomplifh much more difficult 
 Works than any that may fall to your Lot. However, if even 
 a confiderable Expence fhould be necefiary in thefe Cafes, it will 
 be better for the Public to bear it, and have Things done well, 
 than to do Things in a bungling Manner at a trivial Expence. 
 But of this you will be the beft Judge hereafter. 
 
 The Making of good Roads is reckoned among the princi- 
 pal Improvements in all. Countries. The landed Intereft did not 
 begin to rife till we began to make Turnpike Roads, and whilft 
 ever we continue to improve the one, we fliall raife the Intereft of 
 the other. Many of our new Roads arc tolerable, but there is 
 one general Fault in them all, k e. ' their being fo narrow, 
 and fo crooked, and perhaps, much more fo than in many other 
 Countries. The Reafon is obvious. This Kingdom, in ancient 
 Times, abounded with Woods, Bogs and Loughs. The then 
 poor Inhabitants, in a Manner, groped their Way through them> 
 not minding whether the Road they took was long or Ihort, pro- 
 vided they could any Ways accomplifh their Journey ; and the 
 Paths they then trod out, being from Time to Time cleared and 
 improved, at length they became more populous ; . but till with- 
 in this Century, there were but a few of the Inhabitants that 
 difcerned that Inconveniency, and they ftill continued to follow 
 the old beaten Path which ferved their Fore-fathers. But how 
 as we have got a Free Trade, let us ufe our beft Endeavours to 
 improve our Roads, fo as to make them capable of anfwering 
 
 their 
 
( i6 9 ) 
 
 their natural Purpofes, and promoting the Extension and Good of 
 Trade ; efpecially, as both the commercial and landed Intereft 
 may be greatly benefited thereby. And to that End I humbly 
 conceive, that the moll advantageous Improvement that this 
 Kingdom is capable of, will be to make a fpacious and an 
 elegant Turnpike Road from the City of Londonderry to that of 
 ■pork, as nearly on a Level, and in as direct a Line as can conve- 
 niently be accompliflied (See the before mentioned Plate 64.) 
 
 This grand Road you fee will almoft divide the Kingdom into 
 two equal Parts from North to South ; the firft Station reaches 
 from Derry to Rnnijkilling, where it croffes Loughearn ; the next 
 Station runs through Parts of the Counties of Fermanagh, Leitrim, 
 Longford, Wejimeath, and King s-County ; where it will meet 
 with the inland Navigation from the Liffey to the Shannon, at 
 about two Miles above Banagher Bridge, From thence through 
 Part of the County of Tipperary, and by Charieville in the County 
 of Limerick to Cork, which, computed on an Average, I take to 
 be about 170 Irifh Miles. 
 
 This Road I would propofe mould be 100 Feet broad from 
 Quick to Quick (which is nearly the Breadth of James" s -ft reet in 
 Dublin) the Ditches to be 5 by 6 Feet, planted with three Rows 
 of Quicks, and the Top to be fowed either with furze or broom 
 Seed, to preferve the Quicks from Cattle, and a Row of Foreft 
 Trees, planted ten Feet behind the Quicks on each Side ; and 
 this Line alfo reprefents the front Line of the Houfes, that may 
 thereafter be built there, on making the Street, (for fuch it may 
 with Propriety be termed) 120 Feet broad in the clear. 
 
 This Street is to be not only a Turnpike Road, but a Place to 
 hold public Fairs, after the ancient Manner of the Hanfe 
 Towns ; to be held at fuch Times and Places as may hereafter 
 be thought convenient. This Breadth of 120 Feet I would 
 propofe mould be divided into 12 equal Parts, of which four 
 Parts mould be for the Carriage Way ; and. next adjoining, there 
 mould be Houfes of about 12 Feet broad elected for Watch- 
 houfes, Clerks, Weighing-houfes, occasionally, and in the 
 fame Range the Stalls fihould ftand for the Chapmen to cxpofe 
 
 B b fheir 
 
( *7° ) 
 
 their Commodities in Market Hours/ and after to attend their 
 Ware or Store-rooms, &c. &c. 
 
 When this Road is made, there ought to be large and ftrong 
 mile Stones, with large, legible, deep-cut Figures, with foot 
 Walks, finger Pofts, &c. to begin at Derry, and end at Cork. 
 And as it is not only to be a Place for the holding of Fairs at 
 certain Times, but to be a conftant Market, the Public fhould 
 be accommodated with proper Ways to bring their Goods to it, 
 either by Water or Land-carriage. The former is in feveral Parts 
 of the Kingdom in great Forwardnefs, particularly the Navi- 
 gation from Newry to the Moy, at Charlemount-Bridge. The 
 Canals from Belfaji to houghneagh, 1 believe, is very nearly 
 accomplifhed ; by which the Surplus of all the Britijh Commo- 
 dities to the Northwards may be eafily conveyed to our Market ; 
 and the Grand Canal from Dublin to the River Shannon is now in 
 great Forwardnefs ; as are alfo the Drogheda and Kilkenny Canals. 
 All thefe promife vail: Advantage to our prefent Scheme. Then 
 let it be obferved, That (as the Public have been informed) the 
 Flood-gates of thefe Locks are fixteen Feet wide in the clear, 
 and the Locks 80 Feet long in the clear alfo, therefore proper 
 Notice fhould be given to all our good Friends in Great-Britain, 
 to prepare and make all their coafting Veffels agreeable to thefe 
 Dimenfions, and to draw five Feet Water ; and thefe will carry 
 about 50 or 60 Tuns burthen, and fhould have finking Marts. 
 With fuch Veffels as thefe they may crofs the Channel, and 
 bring their Commodities to any Part of our Market they 
 ( pleafe, and deal and traflick with our Merchants, or fuch others^ 
 as they either appoint or accidentally meet there, juft as they 
 think moft to their Advantage. And I would alio have it to be 
 underftood, that as our Iri/h Merchants may be fupplied with 
 all Kinds of Commodities, laid down at their refpeelive Store- 
 houfes, they need not beat the Expence of building Ships of 
 any Kind, except fuch Coafters as above defcribed ; and with 
 thefe they may fail up either into the natural, or artificial navi- 
 ble Parts of Great-Britain, and there change our native or other 
 Merchandize for theirs, as Occafion may require.. 
 
 But- 
 
( if 1 ) 
 
 But as thefe tew Canals are not by any means fufficient for 
 thefe Purpofes, we fhould alfo accommodate the Public with other 
 Turnpike Roads, from Eaft to Weft, which fhoujd meet or inter- 
 feel our grand Road, and which would ferve inftead of Canals, 
 until fuch Time as we can get them and others compleated for 
 that Purpofe. 
 
 I obferved above, that the Newry and Belfajl Canals were/ or 
 foon would be, compleated to the Moy, at Charlemount Bridge ; 
 from whence, in the mean Time, I would propofe to carry a 
 Turnpike Road, as near as convenient could be, in a direct Line 
 to Ennijkilling, which is about 32 computed Miles ; where it 
 meets with and interfe&s the grand Road, which I told you 
 above was our principal Market ; from thence I would have it car- 
 ried to Cafilebar and Mayo, thence to Galway, thence to Lime- 
 rick, and from thence to the Grand Road. All thofe Roads that 
 I have marked out with a fingle Line, I would have only 60 Feet 
 broad from Quick to Quick ; and no other of the new Roads 
 ought to be lefs than that in the clear. That from Dundalk goes 
 by Cavan, and crofies the great Road to Abbyboyle. That from 
 Drogheda goes up by the Side of the Black-water near Kells to 
 Rofcommon ; But the Road from Dublin to Athlone and Galway ^ 
 ought to be of the fame Dimenftons of the great Road, viz* 
 100 Feet from Quick to Quick, or 120 Feet from Houfe to 
 Houfe, or Tree to Tree, becaufe it may be expected to be ex- 
 ceeding populous ; for Dublin being the Metropolis, and in the 
 Center of the Eaft Side of the Kingdom, and directly oppo- 
 site to the North- Weft of the trading Part of England,, and alfo 
 very convenient to the South- Weft of Scot/and,. Trade muft cer- 
 tainly center in Dublin. Jn all thefe crofs Roads the carriage- 
 ways ought to be 30 Feet broad, and quicked, planted, &c:. 
 as mentioned for the great Roads ; the Trees 6 Feet behind, the 
 Quick. 
 
 It may alfo be obferved in this- Plate (64) that the Road from; 
 Dublin to Galway is, by Taylor and Skinner s. new Roads, 108 
 Miles diftant, from Dublin to Derry 1 14 Miles, from Dublin to 
 Cork 124 Miles ; fo that each of thefe are nearly of equal 
 
 Diftance 
 
( *7* ) 
 
 Diftance from Dublin, and quarters the Kingdom. Therefore, 
 as I obferved above, it is evident that Trade muft center in 
 Dublin, 
 
 - As the Fairs, that we may prefume would be held in this great 
 Street, are one principal Part of my Plan for a Free Trade, I 
 fliall here offer a few Hints concerning Fairs in general. 
 
 The various Privileges of Fairs cannot be collected, but, 
 " the Privileges of free Fairs confifts chiefly : ift, In that all 
 " Traders, &*c. whether NatiVes or Foreigners, are allowed to 
 " enter the Kingdom, and are under the Royal Safeguard 
 " and Protection, in coming and returning, they and their 
 " Agents with their Goods, &c. 2d, That thofe Perfons, and 
 « their Effects, are exempted from, all Duties, Impofitions, 
 " Tolls, and Services. 3d, That Merchants, in going and re- 
 " turning from the Fair, &c. cannot be arretted, or their Goods 
 
 " flopped, &c. It is the King alone that has Right, by his 
 
 " Letters Patent, to eftablifh Fairs, whether free, or fubject to 
 " Duties, and other Laws and Penalties, &c. — Several Fairs are 
 " held in the open Fields, or on Heaths and Commons, under 
 « Tents, and Barracks, erected for the ^Purpofe, as Stirbridge 
 " Fair in England, &c. others in Places walled in for the Pur- 
 " pofe, and formed into regular Streets, Lanes, &c. for the 
 " Occafion, as the Fair of St. Lawrence in Paris. Laftly, others 
 " are held in open Places and Streets of Cities, as Bartholomew 
 " Fair, Briftol Fair, the Fair of St. Germains, &c. Fairs, parti- 
 " cularly free Fairs, make a very confiderable Article in the 
 " Commerce of Europe, efpecially that of the Mediterranean, or 
 u inland Parts of Germany," &c> — Some Fairs hold for three 
 Days, fome for fix, fome for a Fortnight, or three Weeks. — 
 c< The Fair of Beaucaire, held partly in the City of that Name, 
 " in Languedoc, and partly in the open Country, under Tents, 
 " &c. it commences on the 23d of July, and only holds for three 
 " Days ; yet it is the greateft, and moft celebrated of all the 
 <c Fairs in that Part of Europe, both for the Concourfe of S.tran- 
 " eers from all Parts of the World, and for the Traffic of 
 
 * « all 
 
( i73 ) 
 
 « all Kind of Goods. The Money returned in thefe three 
 " Days amount fometimes to above fix Millions of Livres.'* 
 Chamb, DiB. 
 
 Although I have quoted thefe Notes, I have not taken any 
 one of them as a Precedent, but I rather fuppofe that at fome 
 Time hence we fhould have one Fair in each Year, extending 
 from Derry to Cork, during the Month of June or July, and 
 move on to Maynooth and Leixlip, where the Fair ends ; 
 and fuch as have Bufinefs may afterwards meet with their 
 Correfpondcnts at the Royal Exchange ; and fo the Britijh and 
 other Merchants, Agents, Factors, Chapmen, Dealers, Pedlars* 
 &c. may meet at any appointed Place in thefe great Roads, to 
 vend or exchange their Commodities with each other, or to col- 
 lect them for the feveral Merchants, or others* who may employ 
 them throughout the Kingdom, and there clofe Accounts. 
 
 And as to Markets, I fuppofe that the whole Kingdom is to be 
 a Mart, and that the main Road, or Street, between Derry and 
 Cork, fliould be, as it were, the Seat of Trade, that is the Mar- 
 ket Street, for Manufacturers of all Kinds, and for the Refidence 
 of Agents, Factors, Chapmen, Dealers, Pedlars, &c. as above 
 mentioned ; whofe Bulinefs it will be to buy up and to collect all 
 Sorts of Commodities, and to hold themfelves in Readinefs at all 
 Times, on the fhorteft Notice, to anfwer the Calls of either our 
 Eqft or Weft Merchants, fo as they may, with the greateft Punc- 
 tuality, fupply the Calls of the Eqft or Weft-India Merchants, 
 or their Correfpondents in any other of the Britijh Merchants 
 Companies, there or elfewhere ; fo that not only our native Com- 
 modities, but all other Britijh Merchandize fent to our Market, 
 may be immediately exported to foreign Markets,, and either 
 Cafh, or Goods returned for them, as is ufual in a commercial; 
 Trade. But further, I am fully convinced, that not only thefe 
 few Roads I have mentioned above, but if there were ftill more: 
 of them, that would erofs or enter into the great Street,, they 
 would all be fuddenly inhabited by Artifts,. Tradefmen and Ma- 
 nufacturers, of various Denominations^ provided that the Pro- 
 prietors of the Lands they went through, or their Agents, would 
 
 C c take. 
 
( i?4 ) 
 
 take proper Care to make Preparations for them : But particularly, 
 in obferving and choofing choice Situations for Towns, either for 
 interior or exterior Trade, &c* and if that Choice was judici- 
 oufly made (on which I intend to treat hereafter) there may be 
 the greateft Hope conceived, that within a fliort Period of Time, 
 numerous new and opulent Towns and Cities may fpring up, 
 wherein Ground may fet per the Foot Front, and perhaps fome of 
 them out of wild and wafte Ground, which at this prefent Time 
 is in a Manner ufelefs to Mankind. 
 
 I have faid above, — the Roads that would crofs,or enter into this 
 great Street, would perhaps be fuddenly inhabited ; but I muft 
 add, that in any Parts of this Kingdom, even in thofe that are 
 the moft remote and unfrequented, the making fuch Roads (60 
 Feet broad from Quick to Quick) would foon difcover fuch natu- 
 ral Advantages to a judicious or difcerning Eye, that might create 
 fuch a Populoufnefs, as might vie with fome of thofe in the moft 
 opulent Parts of the Kingdom, and thereby greatly increafe the 
 Revenues of the Proprietors. 
 
 Thefe interior Improvements will alfo anfwer many other falu- 
 tary Purpofes ; as for Inftance, Dublin, Cork and Carick-on-Suirr 
 are noted for carrying on large Manufactories. Their Journey- 
 men have often complained loudly for want of Work, and al- 
 ways have been demanding a Free Trade, &c. Now indeed, 
 they are gratified to the utmofl of their Wifhes : Yet there are 
 many fenfible People, that conje&ure, they will not be content 
 when they fee Manufacturers of their refpe&ive Profeffions 
 brought into their Places of Refidence, to follow their own Em- 
 ployments, either as Mafters or Journeymen ; and then forfooth, 
 they muft rife up in a riotous Manner to ruin or expel them ; 
 not having Sagacity enough to know/ that it would be more 
 prudent to give them a hearty Welcome, and ufe their beft En- 
 deavours to learn all their Ways of Working, and, if they can, 
 to excel them, rather than to drive them away. The evil Con- 
 fequences of fuch rude and injudicious Behaviour may be eafily 
 forefeen, if they were to confider the Preparations which I have 
 juft mentioned for their Reception, in numerous other Parts of 
 
 the 
 
( *75 ) 
 
 the Kingdom, which by their ungenerous and unjuft Behaviour 
 to Strangers, may tend toward drawing on the Ruin of their own 
 Place of Refidence, and alfo deftroy and leffen the Properties of 
 their Families. 
 
 But there is another Thing, which I could wifti that they and 
 fuch other difcontented People would confider, i. e. the Infignifl- 
 cance of all Kinds of Work that can be done in this, or any other 
 Town, or City in this Kingdom, nay, not in all the Towns and 
 Cities in it, if there even were ten for every one that there is now 
 in it, when compared to what our own Merchants could find 
 Vent for through the World ; and fo by endeavouring to keep all 
 the Trade to themfelves, they may fitly be compared to the Dog 
 in the Manger. 
 
 As there may be many Objections to thefe Fairs, let it be un- 
 derftcod, that 1 do not fuppofe they would, or indeed could take 
 Place, till there were proper Preparations made for them ; and 
 therefore whether they take Place or not, they cannot have any 
 difagreeable Effect on my Plan, becaufe the Market will abun- 
 dantly anfwer our Purpofe ; for the Market is to hold all the 
 Year round, Sundays only excepted ; nor can there be any Ob- 
 jections made to that. As for Inftance : If a Shoe Manufacturer 
 has a Parcel of Shoes ready for Sale, any Man that comes to his 
 Houfe on a Week-day to buy his Shoes, he has an undoubted Right 
 to fell them; or if the Shoemaker brings his Shoes to the Houfe 
 of a Factor or Dealer, and gets fome Money and fome Leather 
 for them, they have an undoubted Right to buy and fell as they 
 pleafe, becaufe it is an eftabliftied Law, that every Man s Houfe is 
 his Market ; and on the fame Principles the Factors or Dealers fnay 
 traffic with their Merchants, who may carry on their Exports 
 or Imports all the* Year found ; and confequently, according to 
 this Plan, the whole Kingdom may be properly called The Irish 
 Market. 
 
 The public Utility that will attend this Market-ftreet is obvi- 
 ous. For Inftance : If any Tradesman, or Manufacturer, in 
 or on either Sides of this Street, falls fhort of Money to pay his 
 Men on Saturday Night, it will be quite convenient to him to 
 
 apply 
 
( i7« ) 
 
 a£ply to the Fador he deals with, and get what he wants, either 
 of Money or Materials, to anfwer his Purpofes. And it may be 
 alfo obferved, that if the refpe&ive Manufacturers that fettle in 
 any of thefe Roads, or other interior Parts of the Gountry, do 
 make a judicious Choice of a Place for their Bufmefs, and have a 
 Capital fufficient to carry it on, they will have their Land at a 
 cheap Price, Room in Abundance, Fire, Water, and numerous 
 other Conveniences ; from whence it is evident, that they may get 
 far greater Gain by their Bufinefs, and underfell thofe that live in 
 Towns or Cities under heavy Rents, Taxes, &c. 
 
 I fhall mention another Advantage that will accrue to fuch 
 Perfons as fettle in this great Street, viz. the public Grana- 
 ries, that are to be ere&ed at certain Diftances in it, which are 
 to contain at all Times at the leaft one Year's Provifion of Bread 
 for the whole Kingdom ; fo that the Tradefmen, and all others, 
 either from the Eaft or Weftward, may be fpeedily fupplied at 
 moderate Expence : And befide all thefe, and numerous other 
 Advantages, we muft not forget to obferve, what additional 
 Beauties and delightful Profpe&s will moft afluredly be discover- 
 ed, and in a ffiort Time produce numerous elegant Buildings, 
 extenfive Improvements, delightful Villas, and in fhort, adorn 
 the Works of Nature to fuch a Degree, as may make this King- 
 dom a Kind of Paradife, for Health, Wealth, Pleafure and De- 
 light ; and all thefe may be obtained without encroaching on a 
 fufficient Proportion for Agriculture and Pafture, and every Part 
 judicioufly difpofed of with refpecl: to the Diftribution of the 
 Whole. 
 
 C H A P. XIX. 
 
 On the frugal and effe&ual Management of feveral ufeful Matters 
 and Things relative to our general Plan. 
 
 FRUGALITY is a Virtue that all well-meaning Men 
 generally wiffi to poflefs ; and yet, perhaps fome of them 
 do often miftake their Objetf, and are carried away by the Im- 
 
( *77 ) 
 
 pulfe of their Imagination without the Confent of their Judg- 
 ment ; by which they become prejudiced in Favour of fome par- 
 ticular Objeft which they did not at firft intend, and are thereby 
 led into extravagant Expences. This perhaps may be my own 
 Cafe. I feel myfelf violently inclined in Favour of thefe two 
 great Roads, becaufe I imagine that they will be of infinite Ad- 
 vantage to the Public, and by frugal Management may be ac- 
 compliflied at a meer trifling Expence when compared to their 
 public and private Utility. But of thefe two great Roads, one 
 of them has engaged my warmeft Attention, far above the other, 
 on which I (hall now begin to treat, and leave my Reader to 
 form a cool and unprejudiced Judgment on it. 
 
 S E C T. t 
 
 Conctrning the great Road from Dublin to Galway by Athlone. 
 
 I A M fully convinced of the Utility of the great Road I have 
 defigned from Derry to Cork, provided there are not 
 any material Obftru&ions in the Way. But that is a Matter of 
 fuch a Nature, that no Perfon can expect I mould ferioufly re- 
 commend it from a bare Infpe&ion of fuch incorrect Maps as are 
 now extant. Where I have drawn the Lines, there may, for 
 aught I know, be huge Mountains, or fome other infurmounta- 
 ble Difficulties, that might put the Public to exorbitant Ex- 
 pences. But that is not the Cafe with refpecl to the Matter in 
 Hand ; for I am fully fatisfied, That I may fafely rely on the 
 Map I have perufeS, and the Informations I have received on 
 that Head. 
 
 About eight Years ago I accidentally got Mr. John Trail's Map 
 and Report of the Grand Canal^ and I often perufed it, not only 
 by Way of Amufement, but becaufe it opened a new Train of 
 Thoughts to my Attention: For as I was intent on forming 
 Schemes for the general Improvement of the Kingdom, I clearly 
 perceived that that Map pointed out the very Thing I wanted for 
 that Purpofe ; and as the Whole of that Report (hewed his great 
 
 D d Capacity, 
 
( 178 ) 
 
 Capacity, his Map was a ftill farther Proof of it. I /hall there- 
 fore proceed, and endeavour to point out fuch Matters as I think 
 may be ufeful to our young Surveyors in future. 
 
 As the Works of the Canal have gone on fo exceeding flow, I 
 conceived that it would be very ufeful to make an elegant Road 
 from Dublin to Athlone and Galway. I (hall now mention fome 
 Difficulties which may perhaps be met with, and point out fome 
 Methods to conquer them. 
 
 The Road from Dublin, with proper Improvements, muft re- 
 main as it now is till you come to Leixlip, after which you muft 
 keep to the Weftward of the Obelifk, and pafs about 107 Perches 
 from the South Eaft of the Caftle of Manooth, and following 
 that Diredion, in five Miles and a Half further, you will have 
 an Arm of the Bog of Allen to crofs, and then you keep in the 
 fame direct Line till you come to Caftle Jordan, and from thence 
 to TyrreTs-Pafs ; then croffing the Brufna River, you go on (I 
 imagine) in the fame direct Line to Athlone : All which you may 
 clearly perceive in Mr. Traifs Map, and by it you will find that 
 that direcl: Line will meafure about 45 Irijh Miles, all nearly on 
 a Level. 
 
 \ After you have laid out and got the Philipin Sod turned up, fo 
 that you may be fure of your direcl Line, the firft Difficulty you 
 may expeft to meet with will be that Arm of the Bog, which isa- 
 bout one Mile and a Half broad, which you muft fee bored and take 
 the exacl: Depths, and then you will be able to form a Judgment 
 with refpecl: to the Methods which you are to purfue in that Part 
 of your Work : And although it may be veryJoft, that Circum- 
 ftance need not difcourage you, as you have fuch a Variety of 
 Methods laid down in the fecond Part ; but I would not recom- 
 mend it to you (as not being accuftdmed to fuch Works) to en- 
 counter with more than 10 or 15 Feet ; but be the Depth more 
 or lefs, I can confidently affirm you will meet with either a mar- 
 ly or a firm gravelly Bottom ; and you muft not only examine this 
 Part of your Work, but all other Bogs or Marfties which your 
 Work is to go through before you enter upon it : For it will make 
 you an Objed of Ridicule if you begin it, involve the Public in 
 
 confiderable 
 
: lilgll#:ll3lft|llll- 179 1H Silt; ' W- ^ 7 llill 
 
 confiderable Expences, and then come and tell the Gentlemen of 
 your Board, that you find it impracticable. Therefore, before you 
 begin the Work, make a juft and correct Eftimate of every indi- 
 vidual Part of it. 1 mould not indeed fay fo much on this 
 
 Sead, but in order to prepare you for fuch Difficulty in future, 
 and especially as there muft be a Bridge built m. this Arm of the 
 Bog, being the Source of the River Blackwater, which empties 
 itfelf into the Boyne River, and I am glad to have an Opportu- 
 nity to fet you right in this Matter : For although Plate 41, 
 page 12 is defined for fuch difficult Parts of Roads yet I do 
 nof pretend to fay it will anfwer all Purpofes, nor is it likely to be 
 neceffary for this Place, becaufe Nature has pointed it out as one of 
 the Places by which that Bog may be partly drained ; and to that 
 .End you muft build the Bridge in fuch Manner, as it may not 
 prevent, but rather further the Draining of it, to effect which 
 Lft defirable Purpofe, I (hall now mention a few P^icukrs 
 
 As I do not know the Texture of that Ground, I (hall prepare 
 you for the worft ; and Reafon will tell you, that if the Work of 
 draining that Bog takes Place in future your Piers ought to be 
 funk a confiderable Depth, fo as to admit of- the grea ter Fall 
 from it. 1 mail therefore recommend another Method, fo that 
 you may take that which you think will be cheapeft and fitteft 
 for your Purpofe : In order to which, it is now become neceffa- 
 ry to explain, what I only glanced at in page 120, Seer. 2, on a 
 Road made by the Romans, which I found mentioned by many 
 of their Hiftorians, and particularly in Bowen s Geography, Vol. 
 
 « ? mck°ox 9 Murcia, near the Borders of Hungary, is a Place 
 « of great Antiquity— It is a large populous Town, j M'l« 
 « from the Conflux of the Danube and the Drove* 4° Eaft trom 
 « Valpo, 87 North from Belgrade, and 103 South-Eaft trom 
 « Buda. 'Twos particularly remarkable for its famous Bridge over 
 « the Drove and Tome Moraffes, which was eight Miles long, and 
 « near 30 Yards broad. It confifted of thick Planks of Oak 
 « fupported by 9 or to great Trees in a Row between every 
 « Arch. Dr. Brown fays, 'twas railed on each Side, hadwatch 
 
( i8o ) 
 
 !! T° Wers at , the Dift ance of every Quarter of a Mile with 
 Stairs to the Marll.es on both Sides^nd was upon t b Wn t 
 a very beautiful and ftupendous Piece of Workmanffiip, but 
 deftroyed by the Imperial^ in their late Wars with the Turks 
 
 "who ufed to invade Hungaria by this Bridge." Confided™ 
 
 therefore this Method, along with the variouf other Methods De ? 
 fore la.d down, you may form your Defigns, fo that your Work 
 may prove cheap and ftand fubftantial for Ages to come; butif 
 you find that this will be the moil advifeable Method, you are to 
 confider that Oak, or even Norway Fir, will be very expenfive 
 and provided you can get good large Irijh Fir that has been fallen 
 in June I think you may fafely venture to ufe it for Poll or 
 Piles, for this or the like Purpofes. 
 
 Within about 7 Miles and a Half from this Arm of the Bo e 
 you crofs the Boyne which iffiies from the fame Bog, where you 
 mU alfo want another Bridge perhaps a little troublefome afk 
 
 no bv an t S ° Ut f E ;i° f f B °S *" h ^ "ear KkJ^C 
 not by any Means fo difficult as the former. In four and a half 
 Miles further you enter on another Bog, which will not want 
 any Bridge, nor perhaps any Kind of Difficulty in going on with 
 your Road, till you come to Tyrrel 's-Pafs, nor evtn there be 
 cauie you can eafily make a Road acrofs the End of the Bog that 
 comes from Lough Ennal, and then you come to the River BruC- 
 na, which muft have another Bridge, and from thence, as I con- 
 ceive by an accurate Map of the County of Weftmeatb, you will 
 not meet with any Obfervation worthy of Notice 7 till you come to 
 Athlone,-, and thus upon the Whole, from LeixUp to Atbkne 
 which is 45 Miles of level Ground, you only have three Bridge? 
 of an infign.ficant Nature in fuch an extenfive Work.— And the ' 
 firm arable Ground on which you are to work, I can afiure vou 
 on the Word of Mr. Evans, i/of a firm gravelly Nature 7 
 
 onrCVf I" 6 ch ?"py° ur Attention, and entreat you to reflect 
 on the Beauty and Utility of a Road of ioo, or a Street of r 2 o 
 
 a L vdTh V^ S^' a " in a ^ direa Line, and nearly on 
 
 clipped t Ti° n afirm S raVe]1 ^ Bottom with 
 
 clipped Hedges and Foreft Trees planted on either Sides, or built 
 
( i8i ) 
 
 with decent Houfes of Tradefmen and Manufacturers, happily 
 and comfortably fettled ' in it, with Plenty of Fire and Water, 
 &c. Where will you find fuch an Improvement in Europe ? 
 How delightful mull it be for any Gentleman, efpecially the 
 Owners of the Ground, to take a Morning's Ride through fuch a 
 
 Road or Street ! 1 could enlarge much further on this moft 
 
 pleafing Subject, but leave it to your own Suggeflions ; yet con- 
 sider how beneficial it muft be to all fortunate Gentlemen who are 
 the Proprietors thereof, but in particular about Manooth and Leix- 
 lip) which for many Reafons, I am convinced, will foon become 
 very opulent trading Towns. Let us then in the next Place form 
 fome Kind of Eftimate of the Expence of this Work, exclufive 
 of the three little Bridges, which we as yet know nothing 
 about. 
 
 The whole Length between Leixlip and Athlone^ being 45 Irijh 
 Miles, it will require 90 Miles of Ditching of 5 by 6 Feet, which 
 will be worth 18 Pence by the Perch, or 45/. by the Mile, (ex- 
 clufive of Quicks and Trees) but we fhall fuppofe it at 50/. per 
 Mile, which amounts to 4500/. \ and whenever this Road is in- 
 clofed by new Ditches, and all the old Ditches levelled, it will 
 then be a public Road, though neither the Carriage nor the Foot 
 Ways are compleatly made ; and as there will be Gravel found 
 contiguous to it the whole Way, there is not the leaft Doubt, but 
 there may be many Gentlemen that will chearfully join and finifh 
 it on their being entitled to the Toll. Reflect too on the high 
 Rents that may be paid for the adjacent Land for Parks by opu- 
 lent Tenants, who can readily furnifh the Dublin Merchants with 
 their various Commodities for Exportation, or the Shops for home 
 Confumption ; and at the Weft-end of it furnifh the Factors and 
 Dealers that live in the main Road, or the W T efterly Merchants. 
 Then confider what a Convenience this Street will be for the ad- 
 jacent Inhabitants, and perhaps in a fhort Time may produce 
 many opulent Towns alfo, where the Ground will fet for fo much 
 by the Foot front. Take now all thefe Circumftances into feri- 
 ous Consideration, and try if you can recoiled to have ever feen, 
 or even read, of fo advantageous and extenfive Improvement of 
 1 E e this 
 
( i8a ) 
 
 this Kind, which is calculated alfo as a fafe Communication and a 
 fpeedy Convenience, in a direct Line on level Ground, to and 
 from the Atlantic Ocean. 
 
 But as Frugality, in all Kinds of Affairs, ought to be considered 
 along with Utility ; let us obferve how pleafing this Road from 
 Dublin to the Shannon muft be to the Public. Mr. Trail has told 
 us in page 21, that the total Expence from Dublin to the Shan- 
 non River will amount to 100,368/. 13J. but when that Work will 
 be accompliflied, no Man can tell ; and as it has appeared that 
 our Road may probably be made, exclufive of the three 
 
 Bridges, for - - ^45 00 
 
 And admitting that thefe three Bridges would coft - 300 
 And alfo the Improvements of the Road from Dublin 
 
 to Leixlip might coft about - - - 200 
 
 Then this commodious and delightful Road, by proper Manage- 
 ment, might be accompliflied (if required) within the Space of 
 one Year for about 5000/. and fo admitting of Errors on both 
 Sides, the Proportion as to Expence will ftand : As 5 to 100, or 
 as one Shilling to one Pound ; with the greateft Deference there- 
 fore I recommend this among other Matters to the Attention of 
 thofe whom'it may concern. Hence I infer : ift, That, the more 
 commodious the Roads are, the more Wealth will accrue to the 
 Inhabitants. 2d, That the moft rude and unpopular Lands 
 ftand in the moft Need of Roads to and through them. 3d, That 
 improving the moft minute Part tends to advance the Whole. 
 Let us in the next Place confider fome few Matters relative to 
 reclaiming Ground, flooded either by frefli or fait Water, or 
 Draining of Bogs, 
 
 SECT. 
 
( i«3 ) 
 
 SECT II. 
 
 On reclaiming Ground* 
 
 IN our Books on Agriculture and others, there have been many 
 Methods laid down for this Purpofe ; but as I have not been 
 much acquainted with Works of that Sort, I {hall only jult point 
 out a few Matters to your Attention, which, I prefume, are not 
 mentioned in any of them. In Plate 40, Chap. 16, page 118, 
 you have a very ready Method for a frem Water Lake ; but I was 
 deficient in not recommending the Ufe of Floats to help the 
 Cars and Carts, as they would be much cheaper, and more ex- 
 peditious, efpecially if you can get convenient Banks for loading 
 them ; and this Method is eafily reduced and made proportiona- 
 ble to any leffer Depth of Water. But in Cafe you are required 
 to reclaim Ground off the Sea, you muft take your Method from 
 Plate 28, page 87, filling up the Vacancies between the outward 
 Joinings of the Coffers between the Belts, and banking with hard 
 Stuffing without* and by making it a fubfiantial Rampart on the 
 Inlide next to the Land, fo that the Water may not penetrate 
 under it. On this and the like Works you may collecl: other 
 great Helps for this Purpofe from what you have feen in Chap. 
 17, ftfo I mail now give a few Hints concerning the Draining of 
 Bogs, in which I have had fome little Experience. And on thaty 
 and on all I have either heard or read, it appears to me that tjiere 
 is generally .one Error in the firft fetting out : Gentlemen that 
 have Bogs to drain, do indeed, for the mod Part, take Time 
 enough to confider of it before they begin ; but when they are 
 once determined, they rufh upon it precipitately, and fet 
 Labourers to open Drains in different Parts of the Bog ; where- 
 as the firft Thing that ought to be done, after making the main 
 Drain to carry the Water off, is to broach the Bog, by running 
 a Drift into it, anfwerable to the Fall of the main Drain, as far 
 as they can ; and if it is a quaking or a wet Bog, the only 
 Trouble that will be neceffary is to keep that Drain clear, and to 
 
 allow 
 
( i84 ) 
 
 allow it Time to do its own Bufinefs : And when they advance 
 further into it, and find it difficult to keep the main Drain clear, 
 let them drive down any common, but pretty ftraight Sticks, 
 within two or three Feet of each other, and ftretch any Kind of 
 green Branches behind them, and bract them afunder with other 
 Sticks at above fix or feven Feet high ; and then, as I told you 
 before, let the main Drain be kept open, and if the Banks are 
 high, ufe two long Planks and Box-barrows, &*c. and in Time 
 you may accomplim your Work, perhaps for the tenth Part of 
 the Money that might by fome other Methods be fpent upon it ; 
 becaufe if you help Nature, fhe will go on with her own Work. 
 Therefore when you have adjufted the Levels, and marked out 
 fuch Place, or Places, as you find propereft to begin thefe Ad- 
 vances, and given the Labourers (in whofe Province fuch Works 
 are) thefe Directions, you only need to caft an Eye on it at conve- 
 nient Times, in cafe the Proprietor is abfent or above attending 
 to his own Intereft. 
 
 C H A P. XX. 
 
 Some brief Propofitions, tending to a concife Summary of the Whole , 
 and pointing out eafy Methods for the Accomplipment of this Plan, 
 and demonjlrating its great Utility* 
 
 S E C T. I 
 
 Concerning the Surveyor or Supervifor of thefe Works. 
 
 A PERSON proper to fupervife thefe Works ought to pof- 
 fefs the following Qualifications : ift, He muft be ex- 
 tremely well verfed in the practical Bufinefs of a Surveyor of 
 Land, in all its various Branches, and be able to produce 
 Specimens of his own Works actually performed with his own 
 Hands, ^d, He muft be fober, diligent, and ftrictly honeft. 
 3d, He muft be healthy, active, able and willing to undergo the 
 moft laborious Fatigue that can properly relate to the Bufinefs 
 
 of 
 
of his Vocation, and give due and perfonal Attendance to it. 
 And it may be prefumed, that no Gentlemen will ufe Means to 
 impofe on the Board, by endeavouring, through their Influence, 
 to put any Perfon into iuch a weighty Employment who doth not 
 enjoy thefe, or the like Qualifications. This ought to beftrictly 
 obferved, becaufe many weighty Matters will depend on it. 
 
 SEC T. It 
 
 On fome pra&icable Methods •, humbly prof o fed for the eafy Accom- 
 
 plifhment of the foregoing Plan. 
 
 IT has been handed down as a Proverb, that when a Work is 
 well begun it is half ended ; and perhaps the Meaning is, 
 that when a Work is previoufly well confidered it may probably 
 be well finifhed. And fure there are no Works that ought to be 
 more effectually executed than public Works, in which every 
 Individual is, or at leaft thinks himfelf more or lefs interefted ; 
 and therefore in many Cafes People freely offer their Opinions. 
 I ftiall, therefore, without any further Prefacing, lay my Senti- 
 ments on this Matter before you. Let us then fuppofe, that be- 
 fore our Parliament is prorogued, that they fhould appoint a 
 Committee of both Houfes, to continue fitting in fuch Manner 
 as they think proper, till three Months after the Meeting of the 
 next Seffions of Parliament, and to have Power to take fuch Steps 
 as may appear moft advifable to them toward the general Im- 
 provement, and the commercial Intereft of this Kingdom, and to 
 draw on the Treafury for fuch a Sum, or Sums of Money, as they 
 may find necefTary from Time to Time, within a certain limited 
 Sum, which, by-the-by, need not be very large, becaufe the 
 Money that will be needful, ought chiefly to be expended in 
 making proper Preparations againft the next Seffions, fo that every 
 Member of both Houfes may have an Opportunity to confider, 
 and to approve or difapprove the then intended Defigns as they 
 think will be moft advantageous to the Public, and then to pafs 
 fuqh Acts as they may think necefTary, 
 
 F f When 
 
When the Committee is fo appointed, and have Power to a£, 
 I prefume their firft Step ought to be to appoint local Committees 
 throughout the Kingdom, or fuch particular Parts of it as may 
 feem neceffary ; and that thefe local Committees fhould be 
 chofen, and double Numbers returned by the Grand- Juries or 
 High-Sheriffs of Counties, the principal Magiftrates of Cities, 
 or corporate Towns, or the Minifters and Church-Wardens 
 legally affembled' ; and that thefe local Committees are to confi- 
 der all fuch Matters and Things as may be directed to them by 
 the grand Committee, particularly relative to all Plans, Schemes, 
 Propofals, Eftimates, &c. in any of their feveral Diftrias. 
 
 Thefe Matters being put in the Way of having a due Confi- 
 deration given to them, the next Step ought to be the Procure- 
 ment of fuch a Surveyor, or Supervifor, as is above recom- 
 mended ; and to give him Orders to enquire for, or procure other 
 *compleat Surveyors, to go on with and finifh all the Counties that 
 have not as yet been fully and minutely furveyed, and to take 
 Care that they are delineated with great Exa£nefs, each on a 
 Sheet, or more, of Imperial Paper, dotting out the Mears and 
 Bounds of all the moft confiderable Eftates, (hewing the Bogs, 
 Loughs, Heaths, Mountains, Rivers and various other Things 
 as may appear worthy of Attention, particularly obferving, what 
 I have already flightly recommended in the latter End of page 
 162, &c. to wit, to get correct Surveys made of the Coaft quite 
 round the Kingdom, &c. and that thefe fhould be minutely in- 
 ferted in the Surveys of the Counties at large, and be corredly 
 laid down in the four Sheet Map as alfo before mentioned, and 
 the Reafons affigned for it in page 163, by which Means any 
 Gentleman that pleafes can have an Opportunity of perufmg 
 them, and not have Reafon to imagine that he has been over- 
 looked, nor that other Gentlemen have gained the Attention of 
 the Board further than what Time, Place or other juft Circum- 
 ftances might have entitled them to expect : And therefore it is 
 neceffary that before the grand Committee can determines the 
 Propriety of any Scheme, either for the interior or exterior Im- 
 r v provement, 
 
( i*7 ) f M . 
 
 provement, it ought to be laid down on thefe large Maps for 
 
 ^Hencrft is evident that the grand Committee will not have 
 Occafion for much Money at prefent, nor, according to this Plan, 
 in future, except for Bridges, and the Improvements of the 
 Ports or Harbours. For I have already fhewn in Chap. XIX. 
 Sed I naee 177, that the Expence of inclofing of Roads is in 
 fManne? fnfrgnlficant, and o/thefe depend the principal Parts 
 of our Plan, which need notengrofs muchof the Time of either the 
 grand or local Committees to confider the public Utility that will 
 Lcrue from them where the Expence will be fo trifling, by Reafan 
 of our whole Kingdom abounding with excellent Materials for the 
 Purpofes, which will agree exaftly with the prefent low State oi 
 our Finances, and all Kinds of expenfive Improvements may be 
 deferred till we are in better Circumftances, and a new Policy 
 eftablilhed in the mean Time ; and that Kind of Trade and 
 Commerce which we have been endeavouring to introduce, may 
 inftantly take Place ; and all the lower Ranks of People fettled 
 to work on our prefent Syftem of public Affairs. Let us in the 
 next Place endeavour to demonftrate the public Utility of our 
 
 Plan. 
 
 SECT. HI- 
 
 On the public Utility of this Plan, and briefly demonjlrating that, 
 not only Great-Britain and Ireland, but alfo the whole Bntiln 
 Empire may gain mutual Advantages thereby. 
 
 TH E Advantages that moft certainly may accrue from this 
 Plan, I fliall diftinguifti under thefe three Heads : lit, 1 he 
 landed, ad, the commercial, and 3d, the Britijh Intereft. ill, 
 The landed Intereft may principally appear by confidering the 
 Value of Ground that is now fet to poor People by the Acre : 
 And fuppofing the fame to be fet to opulent Tenants in fmall 
 Farms of well-improved Parks, or in Lots at fo much a Foot 
 front, which by this Plan may moft certainly be the Cafe in 
 
(. 188 ) 
 
 many Places quite over the Kingdom, &c. ad,. The commer- 
 cial Intereft may be conceived, by confidering, that this Kingdom 
 will be a Market Place for all the mercantile World, and that the 
 Wealth of numerous Nations may be brought even to the Doors 
 of our ^Merchants, without going to the Expence of Importation 
 and all our native Commodities brought to their Hands readv 
 to be given in Exchange for them, » c . The real Intereft, and 
 iome or the Advantages that will occur to Great-Britain, I fhall 
 now briefly confider. 3 dly, I prefume it has already appeared 
 evident through the whole Scope of my Plan, that \ have not 
 itudied any Thing more than the permanent Tranquillity of his 
 Majefty s Subjetfs in general ; yet it may be neceffary to fupport 
 my Argument, by demonftrating, that not only thefe Kingdoms 
 but alfo the whole Britijh Empire may gain proportionable Ad- 
 vantages by our Plan ; therefore, for Fafhion Sake, I fhall endea- 
 vour to draw a few concife Conclufions from the Whole. 
 
 FIRST CONCLUSION. 
 
 That totally abolilhing all Affociations of Non-importations 
 from Great-Britam, and opening a daily Market for all Kinds 
 of Britijh Commodities, is an evident Advantage to them. 
 
 SECOND CONCLUSION. 
 
 That as our own Merchants may at all Times be ftored with 
 our flaple Commodities, it will be advantageous to Government 
 to know where their Fleets and Armies may be immediately 
 iupplied with Provifions on any Emergency. 
 
 THIRD CONCLUSION. 
 
 That the Britijh Merchants Companies may gain fome Advan- 
 
 tag ^X^/ m ? T Market at a]1 Times open for them, to 
 vend fuch Merchandize as lye on Hand, and get our native or 
 
 other 
 
other Commodities in exchange thereof for the Ufe of their Set- 
 tlements. 
 
 FOURTH CONCLUSION. 
 
 That the Wealth of Ireland centers in England is a Maxim in- 
 difputably eftablifhed, and confequently the Wealth of Ireland 
 is the Wealth of England. 
 
 FIFTH CONCLUSION. 
 
 That by the Population of Ireland, his Majefty may be readily 
 fupplied with ftout trufty Soldiers and Sailors on any Emergency, 
 who will valiantly fupport the Dignity of his Crown throughout 
 the World. 
 
 SIXTH CONCLUSION. 
 
 That his Majefty has had recent Proofs of the intrepid Courage 
 of his true and loyal Subje&s of Ireland, who, on the firft 
 Whifper of an intended Invafion, inftantly entered into military 
 Affociations, and refolutely determined, that they would ha- 
 zard the Shedding of the laft Drop of their Blood in the Defence: 
 of his Kingdom of Ireland. 
 
 SEVENTH CONCLUSION. 
 
 That as a fatal Quarrel happened between England and our 
 Friends and Relations in America, let us, who are placed ^ by 
 Providence between them, ufe our utmoft Endeavours to alleviate 
 their Misfortunes, fmother all Animofities, and invite ourFriends, 
 on both Sides to come and meet each other at our Market,, 
 and to carry on a friendly Traffic with each other in future,, 
 and to partake of the Benefits that may arife from our Free trade + 
 
 G g and 
 
IP; Sftt ■ , r ( 'm-y' ' .- i Ill§| 
 
 and in Cafe a perfect Reconciliation cannot be fuddenly brought 
 about, let us neverthelefs take all Opportunities to engage the 
 Americans to continue our Friends, and in perfect Alliance with 
 us ; and then fhall we be as it were a Bond of Union between them 
 both, and aft the good Part of Peace-makers : And when the 
 Hour of Reconciliation arrives, we fhall be again one People 
 able and willing to maintain the Dignity of the Britifh Flag 
 throughout the Univerfe, in Defpite of all his Majefty'f 
 Enemies. J . 
 
 FINIS. 
 
THE GETTY CENTER