PRACTICAL ESSAY 
 
 O N A 
 
 Cement and Artificial Stone , 
 
 Juftly fuppofed to be that of 
 
 The GREEKS and ROMANS, 
 
 LATELY RE-DISCOVERED 
 
 By Monfieur L O R I O T, 
 
 Mailer of Mechanics to His Moil Chriftian Majefty, 
 FOR THE 
 
 Cheap, eafy, expeditious and durable Conftru&ion 
 of all Manner of Buildings 5 
 
 AND 
 
 The Formation of all Kinds of Or%am,ents of Architecture, 
 even with the commoneft and coarfelt Materials. 
 
 Tranflated from the French Original, lately published, by the exprefs 
 Orders of the Above-mentioned Monarch. 
 
 Ruinarum urbis ea maxime caufa, quod furto calcis fine ferrumine fuo 
 coementa componuntur. Plin. Hift. lib. 36 cap. 23’ 
 
 f ■ ■ ■ ■ —/ ■■■■■■ 111 11 1 
 
 THE FOURTH EDITION. 
 
 DUBLIN: 
 
 PRINTED BY J. CHAMBERS, 
 
 FOR 
 
 JAMES WILLIAMS, [No. 21] S KINNER-R© W. 
 
 M.DCC.LXXVI, 
 
T O THE 
 
 KING. 
 
 SIRE! 
 
 *TT' 
 
 I HE original of this Effay having 
 been publifhed in France, by the fpecial 
 Command of the French King; it feems 
 but natural, that the tranflation of it 
 fhould make its appearance, here in 
 England, under the aufpices of Your 
 Majefty. Indeed, the importance of the 
 Subject might alone fuggeft to me the 
 propriety of feeking, for it, the patron- 
 age of a Monarch, whole knowledge of 
 A 2 and 
 
DEDICATION. 
 
 and acquaintance with, all the means of 
 making His llibjecls happy, can only be 
 jfurpafled by His zeal to employ them. 
 May I, therefore, Sire, moft humbly beg 
 leave to lay it, for that purpofe, at Your 
 Majefty’s feet, and fubfcribe myielf, with 
 the warmed affection and moft profound 
 veneration, 
 
 May it pleafe Your Majefty, 
 
 Your Majefty’s 
 moft dutiful 
 
 and moft obedient fubject, 
 
 The Tranflator. 
 
A 
 
 PRACTICAL ESSAY, &c. 
 
 I^^Otwithhanding the great degree of per- 
 fection, to which the arts have attained within 
 a few centuries, it cannot be denied, that, in 
 looking over the writings of the ancients, and 
 examining their monuments, we meet with cer- 
 tain figns of their having been acquainted with 
 fome fecrets, to which we moderns are utter 
 Changers, We are, no doubt, very rich without 
 them ; but that is no reafon why we fhould not 
 endeavour to recover them; and, inhead of 
 trufting to chance, employ both obfervation and 
 experiment for thatpurpofe. 
 
 Of this., one of the mod: important branches 
 of architecture is a linking proof. Though the 
 genius of our modern mailers in that art, form- 
 ed by the hudy of thofe monuments left us by 
 the ancients, has fucceeded fo far, as to produce 
 edifices capable of vying with their patterns, it 
 may be fairly faid, that we are hill at a great 
 remove from the Greeks and Romans with re- 
 
 A 3 fpcCt 
 
■ ( 6 ) 
 
 fped to the running up of buildings with the 
 degree of rapidity they ufed to do • and yet be- 
 llowing on them that degree of folidity, which 
 feems to defy time itfelf; and all this, with al- 
 moil every kind of materials they could lay their 
 hands upon. 
 
 It is, no doubt, an eafy matter to raife lad- 
 ing edifices, by piling, one upon another, enor- 
 mous blocks of frone : But, then, there are fe- 
 veral countries, of very confiderable extent, in 
 which no fuch materials are to be had ; and 
 there are others, in which, though thefe mate- 
 rials abound, they are of too loofe a texture to 
 refill, for many years, the viciflitudes of the 
 weather. Befides, this way of going to work 
 is monftroufly expenfive. It is what very few 
 iimple fubjedls can pretend to; and, according- 
 ly, few of the houfes built by them are of any 
 duration. Nay, hates themfelves are notv often 
 obliged to renounce the execution of the moil 
 ufeful works, on account of the enormous ex- 
 pence attending them in the modern method. 
 
 But the Romans, it is plain, generally em- 
 ployed, efpecially in thofe public works in 
 which ufefulnefs was more to he attended to 
 Ilian ornament, a far lefs expenfive mode of 
 conhrncHon. The principal parts of fuch works, 
 if not the whole of them, ufually confifled of 
 materials of a very fmall bulk, but kept together 
 by a mortar or cemeait of a very binding qua- 
 lity. 
 
( 7 ) 
 
 lity. What a fine method ! one can hardly fum 
 up all the advantages attending it. In it, they 
 could make ufe of every kind of fluff already 
 exifting on the furface of the earth, and even 
 Hones every where almoft to be met with in the 
 beds of rivers and torrents, though worn round, 
 nay, and polifhed, by their conftant attrition 
 againfl each other or other bodies, (i) They 
 had no occafion for the unwieldy apparatus of 
 heavy carriages to bring their materials to the 
 fpot, or cumbrous engines to raife them; con- 
 fequently, they loft neither time nor labour in 
 the execution of thofe tedious operations ; all 
 went diredtly to the forwarding of the work it- 
 felf, which, of courfe, muft have fhot up with 
 uncommon rapidity. How, otherwife, could 
 they have executed, even with their numerous 
 armies, thofe immenfe piles ; thofe aquedu&s 
 of feveral leagues in length, and fometimes 
 rifing to the level of mountains ; and all this 
 often, merely to fupply fome middling town 
 with water, not only for the neceffary, though 
 common, purpofes of life; but even thofe ol 
 luxury and abundance ; fuch as baths, foun- 
 tains, &c. 
 
 (i) Of* this we have an inftance in the ruins of an ancient Roman 
 building on the banks of the Rhone at Lyons, a little above St. dare s 
 quay. It is eafy to fee, that even the pebbles found in ihe bed 
 of this river make a part of the work; but tney are fo ftrongly 
 bound together, that it is much eafier to break them, than to make 
 them let go their hold of the cement, which fills all the interfaces be- 
 tween. them. 
 
 A 4 Thefe 
 
( 8 ) 
 
 Thefe confiderations did not efcape Monfieur 
 Loriot, fo defervediy celebrated for his many- 
 very ufefui mechanical difcaveries and inven- 
 tions ; and it was in confequence of them he 
 made thefe enquiries and refearches, the fruits 
 of which I am now going to communicate to 
 the public. Ever taken up with the thoughts 
 of ferving his country and mankind, by culti- 
 vating and improving the fine and the ufefui 
 arts, the great number of thofe vaft remains of 
 Roman grandeur, fcattered over our fouthern 
 provinces, could not fail of fuggefting to him, 
 that the folidity, fo confpicuous in them, could 
 not be owing to any fecret confined to any one 
 portion of mankind, nor to any merely local 
 advantages, nor to any peculiar excellency in 
 the quality of the materials; but that it muff 
 be the refult of fome common and eafy method, 
 within the reach of every man of the world of 
 workmen, employed in thefe erections. But, 
 perhaps, we had better follow the example of 
 Monfieur .Loriot; and, like him, particularly 
 analyfe thefe lfupendous monuments, and 
 thence regularly deduce the manner, in which it 
 may be prefumed the Romans conftrudled them. 
 
 Mofl of thefe monuments exhibit nothing 
 but enormous mafies in point of thicknefs and 
 height, the heart of which, but juft faced, with 
 an aim off fuperficial coating, evidently con fits 
 pf' nothing but pebbles and pfhq* fniall f ones, 
 
 thrown 
 
( 9 ) 
 
 thrown together at random, and bound by a 
 kind of mortar, which appears to have been 
 thin enough to penetrate the fmalleft interlaces, 
 and fo form a folid whole with thefe materials, 
 which ever kind was firft laid to receive the 
 other, when poured into it. 
 
 It is enough therefore to confider thefe ruins, 
 with the fmalleft degree of attention, to be 
 convinced, that all the fecret of this mode of 
 conftrudion confifted in the method of prepar- 
 ing and ufing this ftrange kind of mortar ; a 
 mortar not liable to any decay ; bidding defiance 
 equally to the perpetual erofions of time, and 
 heavieft ftrokes of the hammer and pick-axe. 
 At leaft, when any little ftone, and it muft be 
 a round one, gives way to them, the mould of 
 cement left by it is found equally hard with 
 the compleateft petrification. 
 
 How different, then, muft this ancient mor- 
 tar be from the beft of our modern! the latter, 
 one would imagine, never dries perfedly but 
 to fall to duft again at the leaft touch. Of this 
 the remarkable crumbling away of our moft 
 recent buildings is an evident proof. 
 
 Another of the extraordinary qualities of 
 this Roman cement, is its being impenetrable 
 to water. This is not a mere conjedure. It 
 is a fad, which the aqueduds of theirs, ftill 
 in being, leave not the leaft room to doubt -of; 
 fur, in thefe works, they never employed ei- 
 
( 10 ) 
 
 ther clay, maftich, or any other refinous fub- 
 fiance, to prevent the waters making their way 
 through them. The areas of thefe canals, 
 refting fometimes on the ground, fometimes 
 on a wall, and fometimes on arches built for 
 the purpofe, as well as their roof and fides, 
 confifting of the fame kind of final! ftones 
 bound together by this extraordinary cement $ 
 with this difference, that the infide furface was 
 compofed of finer and fmaller ingredients; 
 which, at the fame time that it does not look 
 any thing like a coating made at fecond hand, 
 and of courfe capable of being fcalded off, carries 
 evident marks of its being the refult of a pe- 
 culiar operation, which it may not be impof- 
 fible to imitate by attending to the obfervati- 
 ons, that will occur in the courfe of this Effay. 
 
 Thus, then, it plainly appears, that thefe 
 works were carried on by means of caffoons. 
 The trenches made for the foundation formed, 
 of themfelves, the lowed; tire; and, furely, 
 nothing could be eafier than to fill thefe with 
 the materials ready prepared for that purpofe; 
 tho’ the Romans, no doubt, did it with their 
 largeft and heavier! fiones. After bringing the 
 work to the furface, they had recourfe to planks 
 made to fit into each other, fucceffivelv extend- 
 ingthem in length and in heighth, and binding 
 the oppofite ones at fuch a diftance from each 
 other, as to form the thicknefs of the wall; 
 
 and 
 
( II ) 
 
 and withal with fufficient flrength not to de- 
 viate ever fo little, from the perpendicular, on 
 either fide. 
 
 It was, thus, that they formed, as it were in 
 a mould, thefe enormoufly mafiive walls, com- 
 pofed, as we have already feen, of every 
 fpecies of pebbles and other fmall Hones, which 
 our modern architeds know not what to do 
 with for want of a mortar qualified to confli- 
 tute with them one folid compad body. 
 
 We may eafiiy conceive, at what a great 
 rate, even a fmall number of hands, if well 
 fupplied with materials, mtift have been able, 
 by this means, to pufh on any work in the 
 building way. For this purpofe, nothing more 
 was requifite than to have in readinefs a fuffi- 
 cient number of troughs full of the proper 
 mortar; throw at random into the caffoons, 
 the pebbles and other fmall Hones ; and then 
 faturate the latter with the former; all which 
 might be perfedly well done, by the fmallefi 
 degree of attention to get as much Hones as 
 poiiible into the cafioon ; and then make the 
 mortar fill up all the interfiices between them; 
 and, with regard to vaulting and arching, they 
 had their centers, as well as the moderns. 
 When they had an aquedud to build, then, as 
 the interior furfaces of its channel required a 
 coating of that peculiar cement, which is Hill 
 obfervable in them to a certain thicknefs, and 
 
 which 
 
( 1:3 ) 
 
 which we have already taken notice of, they 
 began by laying it on the planks of the interior 
 caling and the centers, previous to the throw- 
 ing in of the coarfer materials 9 and thus form- 
 ed a cruft, which effectually kept the water 
 from any ftones of a.fpungy nature, that would 
 otherwife have imbibed it. 
 
 Without ihis method of caftng, they would 
 never have been able to conftrudt, either walls 
 of fo prodigious a thicknefs, or channels of fo 
 furp riling a thinnefs. In a word, the effedl of 
 this cement muft have been very quick, tocoa- 
 lefce, and let as readily as our gypfes and pla- 
 fters, and diredtly refift the preffure of the other 
 materials laid upon it. In fadt, the lead ftirink- 
 ing or fuelling muft have proved fatal to works 
 of this kind, not one of whofe parts, perhaps, 
 yielded a fohd and horizontal bafts to anv other. 
 
 *1 his fixednefs and perfeverance within the 
 fame volume conftitute another important qua- 
 hty, which the flendereft obfervation muft con- 
 vince us the Roman cement is endued with • 
 and being the laft as yet difcovered, we may 
 proceed to fum up all the excellencies peculiar 
 to this extraordinary compofttion. 
 
 In the firft place, then, this cement, from a 
 liquid, turned very quickly to a folid ftate, and 
 hardened with time as plafter does. 
 
 Secondly, it acquired a furprifing degree of 
 tenacity, and laid fuch hold of the fmalleft 
 
 ftones, 
 
( i3 ) 
 
 ftones, it came in contad with, as fcarce to 
 bear being parted from them. 
 
 Thirdly, it was impenetrable to water. 
 
 Fourthly, it continued always of the fame 
 volume or bulk, without either fwelling or 
 ihrinking. 
 
 One would imagine, that fo many extraor- 
 dinary qualities fhould have fecured this com- 
 pofition from the effeds of violence and time, 
 and kept thefecret of it alive to the lateft pof- 
 terity. Yet, it may be fafely affirmed, that 
 this valuable fecret has been loft to all intents 
 and purpofes ; and that, notwithftanding the 
 continued and hearty fighs and refearches of 
 all Europe, nothing like it, till now, has been 
 difcovered by the moderns. For, if, in fome 
 parts, the buildings are more folid than others, 
 it is merely owing to the extraordinary good- 
 nefs of the lime, fand, and other materials em- 
 ployed in them. 
 
 No doubt, Monfieur Loriot was not the firft 
 to examine the nature of the Hill exifting re- 
 mains of Roman grandeur. Nay, many other 
 lovers of antiquity may have been equahy 
 careful to compare all the circumftances of 
 thefe monuments, from which any infight into 
 their conftrudion could be derived ^ and many 
 have even analyfed more methodically the ce- 
 ment in them j but no one, befides himfelf, 
 
 that I know of, has as yet been bold enough 
 
 to 
 
( 14 ) 
 
 to affirm, that, with all his reflexions and 
 trials, he had been able to recover the Ion? loft 
 fecret of its compofltion. 
 
 Is it poflible, then, that thefe gentlemen 
 fhould have concluded, along with the vulgar, 
 that the Romans, not finding any materials in 
 their country fit for fuch cement, brought them 
 to Italy; or, if they found any, that the 
 yeins, which then fupplied them, have been 
 long fince exhaufted ? Abfurd, however, as 
 fuch conjedures muft be, they are not of fo 
 difcouraging a nature as thofe of the wine- 
 dreflers in the environs of Befangon, who 
 make no fcruple of telling each other that the 
 aquedud of Arcier (2) is indebted for its foli- 
 dity, to the ufmg of bullocks blood in the 
 making of its cement; a circumftance, they, 
 no doubt, infer from the reddith and bricky 
 clouds in it. But thefe clouds are of no weight 
 with obfervers better qualified to judge of the 
 matter, who, whether they abide by the evi- 
 dence of their eyes, or have recourfe to ana- 
 lytical decompofition, can find no ingredients 
 in it, but fuch as are to be found in the com- 
 monefl: mortar now in ufe. 
 
 (z) Quin et aqua; fupereft ductus per millia quinque, 
 
 Ad mea qui quondam mcenia vsxit aquas. 
 
 Defpotots apud Chifl, Vefont, 
 
 And, 
 
( IS ) 
 
 And, indeed, how can the Romans, with 
 all their power, be fuppofed to have brought 
 from fo great a diftance the mountains of ma- 
 terials neceffary for fo many and fuch vaft con- 
 ftru&ions! and, furely, it is equally abfurd to 
 think, that they fhould have difcovered, pre- 
 cifcly at the time when, &nd on the fpots 
 where, they wanted thefe materials, fuch pre- 
 cife quantities of them, as not to leave their 
 fucceffors the lead opportunity of doing the 
 great things they did. No, fuch ideas might 
 be judly deemed extravagant, even though 
 their cement, on being decompofed, Were to 
 yield any extraordinary fubdance, or exhibit 
 any phenomena the moderns were yet unac- 
 quainted with. ' _ 
 
 But, Mondeur Loriot, after examining, in 
 the courfe of his travels, almoft all the mo- 
 numents of this kind left by the Romans in 
 France; after confidering all the materials na- 
 ture afforded in the places where they erected 
 them; after, in fhort, comparing and combin- 
 ing ail their poflible local refources; found 
 himfelf obliged to confefs, from the cleared: 
 convi&ion, that they employed no materials 
 but what we dill employ; that their cement 
 ow T ed all its excellency to the lime, fand, brick - 
 dud, and other materials of that kind, with 
 which they made it; but that they had ano- 
 ther method of mixing up thefe materials, and 
 ufmg the, mixturef 
 
 This 
 
( 16 ) 
 
 1'his fyfiem, uncommon and bold as it might 
 then appear to be, not only kept polfeffion of 
 his mind ; but funk deeper into it from day to 
 day, in confequence of the new obfervations 
 he had frequent opportunities of making, till, 
 at length, in the beginning of the year 1765, 
 he took upon him, for the firfl time, to prefent 
 the Royal Academy of Architecture a memo- 
 rial, in which he gave his opinion, and laid 
 down his reafons for it, with regard to both 
 thefe points 5 to wit, the famenefs in the fub- 
 fiance of the materials, and difference in the 
 manner of mixing them. And, having alrea- 
 dy convinced himfelf of the inertnefs and fuf- 
 ficiency of lime that had been flaked for any 
 confiderable time, he fcrupled not to affert, 
 that the Romans ufed quick-lime on their 
 fcaffolds; and that it was to its vivifying qua- 
 lity we were to attribute all the wonderful ef- 
 fects of this cement. 
 
 The Marquis de Marigny, director and fur- 
 veyor-general of the king’s works, having re- 
 ceived a copy of this piece, condefcended to 
 read it with all that zeal for his majefty’s fer- 
 vice, the advancement of the ^rts, and the- 
 welfare of the public, for which he is fo dif- 
 tinguifhed. He immediately faw that the fine 
 profpeCts it afforded, were far from being vifi- 
 onary- and he no fconer faw it, than he did 
 Monfieur f.oriot the honour ot writing to him, 
 
 to 
 
( l l ) 
 
 to encourage him in the purfuit of fo promifmg 
 a fcheme. His letter is dated the 1 3th of Fe- 
 bruary, 1765; and contains a great number 
 of obfervations, analogous to Monfieur Lori- 
 ot’s fyflem on the ufe of quick-lime in Italy, 
 and particularly at Naples, in conjunction 
 with what they call rapillo and po&zolana. 
 
 This letter gctve room to another memorial ; 
 ana both were prefented together to the fame 
 academy. But this body, then, it may be, 
 taken up with objeds more worthy of its at- 
 tention, or biafied perhaps by the report made 
 to it concerning thefe memorials, received 
 them with a great deal of coolnefs. But, how- 
 ever mortified Monfieur Loriot muff have been 
 at this treatment, he was not difcouraged by 
 it. Inftead of imputing it to the academy in 
 general, he attributed it to fome of its mem- 
 bers in particular, from whom he knew he had 
 no favour to exped; and to a prejudice again!! 
 his opinion, which he could not but allow to 
 be pretty natural, and tolerably well ground- 
 ed, fince it U countenanced by the two only 
 ancient writers upon the fubjed, whofe works 
 are come down to us. 
 
 In fad, thefe gentlemen did not forget to 
 objed to him the teftimonies of Virtruvius and 
 Pliny; efpecially that of the firfl, who, in his 
 architedure, bellows the greatefl praifes on the 
 lime which has been the longef! flaked; fo as 
 
 B to 
 
( IS ) 
 
 Lo leave but little hopes to any; future artifls 
 of being able to introduce the ufe of quick- 
 lime, or at lea ft lime flaked in the very ad of 
 tiling it. Monfleur Loriot, therefore, thinks 
 it incumbent on him to difcufs the paflages in 
 thofe authors, which have beeti alledged againft 
 him; and floew, that all the proof, which 
 could be drawn from them to the prejudice of 
 his fyftem, is at beft of a negative nature, and 
 withal fo very confined* as not to defervd being 
 put in competition with fuch well attefted 
 fads, as he produced in fupport of it. 
 
 In the firft place, with regard to Vitruvius, 
 it does not appear, that he has any where con-* 
 demned the ufe of quick-lime; for, vrhen, in 
 the fecond chapter of his feventh book, he re- 
 commends that which has been long flaked, 
 it is merely for the making of plafler, on ac- 
 count of its being then too well diflolvcd, to 
 contain any grains or lumps, which might 
 fp'oil the work.(3) There is, befides, fome 
 reafon to fuppofe, that Vitruvius was by no 
 means as well acquainted with the pradice of 
 a-rchitedure, as with the theory of it; for, he 
 
 (3) De maceratione calcis ad albaria opera: fuch is the title of this 
 
 chapter \ which is the J'econd of the feventh book Turn de 
 
 aibariis operibus eft expiicandum. Id aiitem crit rede, fi gleb® calci« 
 opt Im®, ante nnilto tempore qiJam opus fiierit, mafcerabuntur. Nam- 
 
 que, cum non penkus macerata, fed recens fumitur habeas 
 
 latenres crudos calculos puftulas emittit Qxii calculi diffol- 
 
 vutit et diiTipant tedoiii poluicme?. 
 
 does 
 
( *9 ) 
 
 does not cite a ilngle building as of his owil 
 ereding; and, in this cafe, it is very poffible-, 
 he might have overlooked an operation con- 
 fined to the fcaffold. 
 
 Pliny, indeed, feems to have affirmed more 
 clearly, in the twenty-third chapter of the 
 thirty-fixth book of his hiftory, that the older 
 lime is, the better. (4) But, unlefs we take 
 particular care to dittinguifh, in this paffage 
 of his, the ttyo propofitions it contains con- 
 cerning lime ; and, firtt, make ourfelves tho- 
 rough matters of the firtt propofition ; we fhall 
 drive in vain to underttand the fecond. This 
 author, who wrote from a colledion of mate- 
 rials, in conformity to which, he digefted his 
 chapters with fuch peculiar precifion, as often 
 leaves his readers in the dark, in this place 
 evidently fpeaks of lime in two different 
 ttates; one, in which it is poffeffed of all its 
 ttrength, all its adivity, all its fer rumen-, which 
 Monfient Loriot, in his firtt memorials, ftiles 
 its gluten^ and it is the abfence of this qua- 
 lity, which Pliny, in the firtt part of the fore^ 
 going paffage, means by the words, calcis fine 
 ferrumine fuo, 
 
 (4) Ruinarum urbis ea lr&xirfie csufa, quod, furto calcis, fine fer- 
 rumine, fuo eoemehfa componuntur. Intrita quoque quo tetuftior, 
 <ed melior. In antiquarum (antiquis) iEdium legibtfs iriveriitur, ne 
 receniiore trinm uteretur redemptor; ideo nulla (null#) tedtoria 
 sorum rlnise fcdavere. 1 ’lin. Hilt. lib. 36. chap. 23. 
 
 B a. Thus, 
 
( *0 ) 
 
 Thus, then, the naturalift, as no ftrangeir 
 to th^ abufes which in his days already began 
 to creep into the building art, chiefly attributes 
 the quick decay of the then modern buildings 
 at Rome, to a defalcation her archite&s now 
 began to make in the competition of their mor- 
 tar; (5) a defalcation, which he ftiles a theft, 
 furto^ and the fubjedt of this theft was a lime, 
 the withholding of which deprived the mortar 
 of that tenacity and ftrength it ufed formerly to 
 derive from its prefence; furtotalcis fineferru - 
 itiine fuo , ccevienta componuntiir. 
 
 Pliny does not fay, that the abufe confifted 
 in making mortar without lime; for, we arc 
 not to imagine, that, in his days, the Roman 
 archite&s were w r ild enough to entertain any 
 fuch thoughts; or, if they were, that he would 
 not have contented himfelf with the mention 
 of this fubftradtion in abfolute terms; and not 
 have dignified with the name of ccementa the 
 paltry compounds adopted in the room of them. 
 No, he fpeaks of the with-holding of a fpecies 
 of lime, which alone could confer on the mor- 
 tar thofe valuable properties, every builder 
 mufl; with to find it poffefled of; and this we 
 cannot allow to have been fiaked-lime, fince 
 the leafl: experience is fuffieient to convince us, 
 
 ($) It is well known, that the word ccementum is not always ufed 
 by the latiri authors to fignify cement or mortar. But, in this palfage 
 of Pliny, it can fignify nothing elle. 
 
 that, 
 
( 21 ) 
 
 that, let fuch flakedffime be ever fo old, and 
 ufed in ever fo great a proportion, though in 
 one degree of combination it may afford a 
 fomewhat better mortar than in another, it will 
 never afford a mortar, in any refpedt equal tp 
 the good mortar of the Romans. 
 
 There may be, therefore, according to Pliny, 
 a theft of lime, a criminal thriftinels with re- 
 gard to it, to which we are to attribute the 
 badnefs of the mortar, which about this time 
 began to be ufed in Rome, and proved the 
 fource of thofe ruins that disfigured her. But 
 ibis theft cannot be that of lime which, has 
 been long flaked, fince there is no mending 
 mortar by refloring it to ever fo large a quan- 
 tity of fuch long-flaked lime. 
 
 The confequences therefore, arifing from 
 Pliny’s affertion, and our own experience, are 
 very obvious. In the firjft part of the paffage 
 in queftion, he cannot poffibly mean that lime 
 which has been flaked, but a medium, to which 
 fhe mortar is indebted for its flrength and 
 efficacy. (6) This truth will appear more and 
 more evident, in proportion as Monfieur Lo- 
 ript’s difcovery unfolds itfelf; and we ffiall, 
 
 (6) In .the beginning of this chapter, Pliny, it is evident, fpeaks of 
 the employment of quiqk- lime, which he calls calcis quant •vehemen- 
 tijfmte ; fo that every thing he fays, till we come to thofe words inlrxta 
 quonue , t$c. which lhew that he is going to confider lime in another 
 ilate, is to be underftocd of the quick-lime. 
 
 B * 
 
 of 
 
( 22 ) 
 
 of tourfc, be apt to afk ourfelves, how it 
 could come to pafs, that, indead of looking 
 into Pliny, for authorities in fupport of a blind 
 and bad routine, we did not immediately per- 
 ceive, what is, in fad, the principle of a wife 
 pradice, well known in -his days, and which 
 his writings, with a little more rededion on 
 the fide of the reader* were fufficient to per- 
 petuate? But the mifchief of it is, there are 
 few readers who know how to read as they 
 ought to do; and fit down to their books with 
 all the difpofitions requifite to get the better 
 of old prejudices. 
 
 The fecond part of Pliny’s text, intrita quo-. 
 que , &c. evidently means another fpecies of 
 lime, or aqother date of jt, different from that 
 which made the fubjed of his fird he fets 
 them in oppofition, as it were, to one another. 
 In the firft place, with regar4 to their names, 
 he calls the fird calx dm ply, or calx cum fer- 
 famine fuo , calx quam vehemeritijfimj, and gives 
 the fecond an epithet fufficient to indicate the 
 new date, in which he has been conddering it, 
 calling it calx iutrita>{j) lime 4 i Solved and 
 flaked. Secondly, with regard tq their effeds, 
 
 (7) Intrita. Can this word be underftood of air-flaked, as well 
 as Wafpr-flicked lime ? if it may, Pliny muft be allowed to have left 
 room for a double conflruction by ufing this expreflion. We fliall 
 have hereafter oecafion to fhew, that air flaked liiue is not deprived 
 f? all the qualities obfotvahi'e in water-flaked- lime. 
 
 it 
 
{ 23 ) 
 
 it is the fir ft, which bellows on mortar its 
 ftrength and confiftency 5 if you withhold it, 
 you deprive the work of the folidity it ought 
 to have : the fecond is valuable on account of 
 its having been long flaked, and being of 
 courfe perfectly diflblved, by which means the 
 works in which it is ufed are uot liable to any 
 cracks or flaws j advantages, he adds, en- 
 joyed by our fore-fathers, in conference of 
 their laws relating to building: which forbade 
 the ufe of this kind of lime, within three 
 years after the flaking of it.” 
 
 But let the authority of Vitruvius and Pliny 
 be what it wills and, by the bye, it is plain, 
 thefe authors have not been well underltood ; 
 it is of little confequence to Monfieur Loriot; 
 he has fads to fpeak for him ; fad experience, 
 indeed, has convinced him, that he mull, not- 
 .withftanding, engage with prejudice and jea- 
 loufy, much more formidable enemies, it mull 
 be allowed, to a man, who profelfes to invent 
 and reform,' than any detached palfages in au- 
 thors, who have long lince paid the tribute of 
 nature, have now no longer any friends of ca- 
 bal in their favour, and may, in an enlighten- 
 ed age like this, be fafely contradicted, as of- 
 ten as there appear any fubftantial reafons for 
 doing it.(8) Monlieur Loriot therefore pro- 
 fs) The author here means the perfecution Monfieur Loriot fuffer- 
 ed with regard to the machines of his invention ccnftru&ed at Pom- 
 pean. 
 
 B 4 tells, 
 
( u ) 
 
 tefta, that he will employ no other weapon 
 ugainft his enemies, but his fuccefs; nor any 
 means to convince his detradors, or at lead 
 file nee them, but that of bidding them come 
 and behold with their own eyes the trials, in 
 great, of his method, which he is actually 
 making, in the light of mankind, in thofc 
 works with which the king has been pleafed 
 to charge him. (g) 
 
 But, to return to our hiftory of Monfieur. 
 Loriot’s interefting difeovery, the enquiries 
 begun by him on the plan he had lain down to 
 himlelf in 1765, having fuffered interruption, 
 as well from feme journies he was obliged to 
 undertake, as from fome private works for the 
 king’s nfe, (10) the Marquis de Marigny, 
 whole zeal to forward every undertaking he 
 has once found pf confequence to the im- 
 provement of the arts, and that of building in 
 particular, knows no bounds, took advantage 
 of a tour which Monfieur Loriot had occafion 
 to make to his eflate of Menars, in 1769, to 
 yngage him to recoiled: and purfup his ideas 
 
 (9) Monfleyr Loriot is actually lining with It s cement the vaulted 
 roof of the orangery at Verfailles, where every body is free to come 
 and’ fee with what rapidity the work goes on, and with what quicknefs, 
 ins. cement takes without the betraying the lead difpoikion to ciack or 
 fpw. 
 
 (to) \ iz. The mode’s of fome flying tables, (to. biff- volant es,) 
 which ate to be executed at Trianon, and which every connoiffeuf 
 »p the capital has been and admired. 
 
 with 
 
( 25 ) 
 
 with regard to the cement of the Romans ; 
 and withal make fuch trials, as might fpeedily 
 bring his feheme to that degree of perfection, 
 of which it might be capable, and which he 
 thought it fo well deferved. 
 
 This requeft had the force of a command 
 with Monfieur Lpriot ; but a command fo much 
 the more eafy to obey, as the Marquis at the 
 fame time gave orders for Supplying him with 
 every thing neceflary to perform the talk he 
 had impofed on him ; being determined, that 
 all the trials, both in the great and in the 
 fmall, fhould be made entirely at his own rifk 
 and expence j a noble inftance of difinterefted- 
 nefs, fuch as is rarely to be found even amongft 
 thofe, who would be confidered as firft-rate 
 patrons and protestors of the fine arts ! 
 
 Monfieur Loriot, being by this means made 
 as eafy as he could with, prepared the materials 
 for his different mixtures, in the intervals of 
 leifure left him by a mechanical w r ork, which 
 he had undertaken for the purpofe of railing 
 water at Menars ; and, in the courfe of the 
 year 1770, had the happinefs to difeover a kind 
 of myftery in nature, which, for feveral ages 
 paff, had not, it is mofl probable, manifefted it- 
 fe If to any body but himfelf; a myffery, on 
 which all the merit of his difeovery is founded. 
 
 Taking fome lime, which had been a long 
 tipae flaked, opt of a pit covered with boards, 
 
 and 
 
{ 2 ^ ) 
 
 and a conftderable quantity of earth over them 
 again, by which means the lime had preferved 
 all its original freftmefs, he made two parts of 
 it, and plaftied and beat them both perfectly well. 
 
 He then put one of thefe parts, without any 
 addition, into a glazed earthen pot; and, in 
 that condition, fet it to dry, of itfclf, in the 
 fhade. Here, in proportion as it loft its moif- 
 ture by evaporation, it cracked and fplit in 
 every direction ; parted from the tides of the 
 pot; and crumbled into a thoufand pieces, all 
 of them equally friable with the bits of lime 
 dried up by the fun, which w r e ufually meet on 
 the banks of our lime pits. 
 
 With regard to the other part, Monfieur Lo- 
 not juft added to it one third of its quantity of 
 powdered quick-lime, and then had the whole 
 well kneaded, in order to make two kinds of 
 lime perfedly incorporate with each other. This 
 done, he put this mixture likewife into a glazed 
 earthen pot, as he had done the firft ; when, be- 
 hold, it foon began to heat, and, in the fpaee 
 of a few minutes, acquired a degree of coniif- 
 tence equal to the beft plafter, w hen prepared 
 in the beft manner. In fhort, it fet and confo- 
 Iidated almoft as readily, as metals in fufton, 
 when taken from the fire; and turned out a 
 kind of inftantaneous lapidincation, having 
 dried completely within a very fmall fpaee of 
 time, and that toof without the leaf! crack or 
 
( 27 ) 
 
 flaw. Nay, it adhered fo ftrongly to the tides 
 of the pot, as not to be parted from them with- 
 out breaking it. 
 
 The refult of this addition of the quick lime, 
 furprifing as at firft fight it may feem, is, not- 
 withltanding, fo eafily explained and accounted 
 for, that it feems fomewhat ftrange, that Mon- 
 fteur Loriot fhould be the firft to fufped and 
 difcover it. In fad, what can be plainer, than 
 that the fudden letting and confolidating of 
 thefe two fubftances, when thus united, muft 
 neceflarily arifo from the quick-lime’s being 
 carried, by a perfed amalgamation or admix- 
 ture in the inmoft recefl.es of the flaked lime, 
 faturating itfelf with the moifture it there meets 
 with, and thereby effecting that inftantaneous 
 and abfolute deficcation, which, becaufe we 
 are fo well accuftomed to it, we fo little mind in 
 the ufie of gypfes and pi afters. 
 
 But, the moft valuable of all the extraordi- 
 nary qualities in this compofition is, its not be- 
 ing liable to any cracks or flaws, when the in- 
 gredients are in the exad proportion they 
 ought to be ; or to give way in any fenfe, either 
 by fhrinking or fwelling; or, in fhort, ever un- 
 dergo the leaf! alteration from that ftate, in which 
 its fixation left it ; a phoenomenon we may ac- 
 count for on the fame principles w ith the fore- 
 going. Whereas mortar, or common cement, 
 never dries but by the evaporation of its moi- 
 fture i 
 
( 28 ) 
 
 Sure; Monfieur Loriofis cement becomes per- 
 fe&ly foiid without the ieafi: evaporation ; its 
 moifiure continues in, and makes part of it; 
 the defecation is altogether inteftine; and, as 
 the mafs continues the fame, and moreover the 
 component parts of it are brought fo near each- 
 other, it is impoiTible any cracks or flaws fhould 
 enfue; for, cracks and flaws can arile from no- 
 thing but the evaporation of a Superfluous 
 moiSure, and the approach to each (Other of 
 thofe parts, which that moiflure had till then 
 kept afunder. 
 
 Monfleur Loriot had likewife the fatisfadlion 
 to fee, that his compofition was endued with 
 the lurprifing quality of being and continuing 
 impenetrable to water. For this purpofe, he 
 made new trials; he formed, with his cement, 
 lomc veffelg of a form proper to hold water; 
 weighed them, filled them, and, after the water 
 had flood in them a conflderable time, emptied 
 them; when, on weighing them a fecond time, 
 he could not find that they weighed either 
 more or Iefs than before he filled them. 
 
 After feveral repetitions of thefe trials, and 
 always with the fame fuccefs, it now onlv re- 
 rnamed to find out what effects, if any, time, or 
 rather the viciflitudes of the weather, might 
 have on this mixture of the two kinds of lime, 
 as well as on feveral other compofitions, in 
 which Monfieur Loriot had made it up with 
 
 other 
 
( 2 9 ) 
 
 other materials fit for mortar; but, after mak* 
 ing for this purpofe a great number of new ex- 
 periments, all the conclufion he could draw from 
 them was, that not only the original mixture of 
 the two kinds of lime, but every other to which 
 he added it, inflead of giving way to greateft 
 drynefs or moifture, heat or cold, in the air, en- 
 creafed with age in folidity and compaCtnefs. 
 
 Monfieur Loriot now no longer made any 
 fcruple to affirm, that the mixing of powdered 
 quick-lime with any kind ol mortar or cement 
 made with flaked lime, was the beft way to 
 give it all the perfections builders could with to 
 fee it poffeffed of. This is the key to the difeo- 
 very advert ifed by him; and the moft interefl- 
 ing confequences flow lpontaneoufiy from it. 
 However, I fhall proceed to point out the chief 
 of them. Further reflections and trials, nay 
 chance itfelf, may, in the courfe of time, bring 
 to light a great many more. 
 
 From the two kinds of lime fo forcibly 
 laying hold of and embracing each other, as 
 it is plain from experience they do, fo as to 
 conflitute but one folid body, it naturally fol- 
 lows, that they muft likewife be able to feize 
 and fhaclde feveral other kinds of fubfiance, 
 that may be mixed up with them, according 
 to their greater or lefler degree of fuitablenefs 
 itp each other in point of furface and texture ; 
 
( 3 ° ) 
 
 fo as to add confiderably to the mafs we are 
 -about to employ. 
 
 Now, fand and brick-dull are the foreign 
 bodies which have as yet been found to anfwer 
 belt for this purpofe. 
 
 Take, therefore, any quantity of very fine 
 brick-dull, and twice as much fine river fand, 
 the former well lifted, and the latter well 
 fcreened, with a fufficient quantity of old 
 flaked lime to form, with water, an amal- 
 gama as ufual, but withal, wet enough to flake 
 a quantity of quick-lime equal to one fourth 
 of the brick-dull and fand taken together; 
 then add the quick-lime in powder to the brick- 
 dufl; and fand; incorporate them well without 
 lofs of time, and ufe them dire&ly, as the 
 leaft delay may render the ufe of them defec- 
 tive or impqffible.(i i) 
 
 A coating of this mixture, applied to the' 
 bottom and fides of a canal, bafon, or any 
 other kind of building, wdiich is to contain or 
 fland over water, has the moft extraordinary 
 effects, though laid on ever fo thin. What 
 wonders, therefore, might we not expedl from 
 this cement, were fuch buildings to be origi- 
 nally conftrudied with it ! 
 
 The dull of charcoal incorporates very 
 kindly with the fame materials, in a quantity 
 
 ( m ) See the observations hereafter to be made on the quality of the 
 quick-lime. 
 
 eqnal 
 
( 3 1 ) 
 
 equal to that of the quick-lime; and, though 
 the lead colour, which arifes from this addi- 
 tion, makes no effential part of the mixture, 
 it may ftill have its ufes on certain occafions; 
 but, it is otherwife with regard to the bitu- 
 men contained in the charcoal ; fince this fub- 
 ftance cannot but form a rampart extraordinary 
 againft the water, no way inferior to that 
 afforded by the other materials with which it 
 ispnade up. 
 
 If all we want is a ftrong coating, then, by 
 adding to the common mortar, confifting of 
 flaked-lime and fand, one fourth its quantity 
 of quick-lime, we fhall have one, which, with- 
 in four-and-twenty hours, acquires a greater 
 degree of confiftence, than the common kind 
 in feveral months- 
 
 Two parts of air-flaked-lime ; one, of lift- 
 ed plafter; and a fourth, of quick-lime ; made 
 up into an amalgama of the confiftence of 
 common mortar, afford a coating, no lefs fit 
 for the infide of buildings, than tenacious and 
 incapable of cracking or flawing. 
 
 But then, w ? e muft, as in ufing the firft pre- 
 feribed mixture, not prepare above a trough 
 Full at a time of thefe new ones; and that on- 
 ly juft as we want to ufe them. 
 
 Inftead of fand, We may ufe loofe earth for 
 buildings that are to be run up in a hurry, as 
 like wife for the coating of walls, both within 
 
 and 
 
I 3$ ) 
 
 and without doors; but the more fan.dy th|$ 
 earth, the better. 
 
 If we cannot conveniently get brick-duft for 
 thofe works, which are.occafionally to receive, 
 or confiantly contain water, we may ufe the 
 Tame kind of loofe earth as a fubftitute to it. 
 It is only making it up into little balls ; then 
 baking them in a lime-kiln, by putting them 
 behind the lime-flones, or in a kiln by them- 
 lelves; and laftly reducing them to a powder, 
 which they may eafily be ; for, this powder 
 will do as well as brick-duff. 
 
 A dry and fiony free-flone, well powdered 
 and fifted, may be ufed inftead of fand and 
 loofe earth; nay, it will anfwer belter, on ac- 
 count of its extraordinary lightnefs, for any 
 condru&ions that are to be fupported by tim- 
 ber-work. 
 
 All kinds of marne, well walked, in order 
 to deftroy that unctuoufnefs of theirs, which, 
 might otherwise prevent their taking to other 
 fubftances, and carefully powdered, are equal- 
 ly proper to incorporate with both kinds of 
 lime. 'Charcoal-duft; (12) and, in general, all 
 the vitrified iubffances afforded by furnaces, ag 
 well as the refufe of fouridaries and forges; 
 in fhort, every kind of rubbifh impregnated 
 with metallic bodies altered by the Are, is equally 
 
 (iz) Allies are -pernicious, and retard the letting yf the linre. 
 
 fubje£t 
 
( 33 ) 
 
 iubjeft to the fetters of the mixtures made 
 with the two kinds of lime; and may, of 
 courfe, be ufefully employed to make cements 
 of any colour we would chufe to have them. 
 
 Nor ought we in cafes of neceffity to over- 
 look pounded ftone ; fo that the hitherto fa 
 ufelefs heaps of flone chips, and diftreffing 
 mountains of old materials arifing from the 
 demolishing of buildings originally conftrud- 
 ed with lime and fand, and which there is 
 lometimes, in the old way, a neceffity for re- 
 moving to a great diftance, may, in this new 
 One, be difpofed of on the fpot to great ad- 
 vantage. The trials Monfieur Loriot has al- 
 ready made of them in the fmall, are fuffici-- 
 ent to vouch for their fuccefs in the great. 
 
 It is, however, but fair- we fhould w*arn 
 thofe, wffio are to colleft the materials for this 
 hew cement, or mix them up, that, on account 
 of the difference, in point of ftrength, not only 
 between the common kind of lime in one di- 
 ilrid and that in another, but even between 
 different parcels of lime made of hones from 
 the fame quarry, according to the time elapfed 
 lince the burning of them, there is no align- 
 ing precifely the exaff quantity of quick-lime, 
 that is to be added to every mafs of the com- 
 mon cement or mortar. In one place, we muft 
 ufe more ; in another, lefs. It is for this rea- 
 fon, Monfieur Loriot has pitched upon a me- 
 
 C diuto. 
 
( 34 ) 
 
 dium, in preferring, for any quantity of fand 
 and brick-duft taken together, one fourth of 
 their quantity of middling lime, when ufed 
 juft as it comes from the kiln ; for, if on the 
 one hand, it happens to be of a fuperior qua- 
 lity ; and, of courfe, capable of imbibing a 
 greater quantity of water, in confequence of 
 its being made a harder ftone ; a fmaller pro- 
 portion of it will do ; as, on the other hand, a 
 larger will be neccffary, if it has been long 
 flaked. 
 
 The works in the neighbourhood of Paris 
 begin to {hew, that one third of the beft lime 
 it affords is not too much; but, this lime is 
 not of as good a quality as the beft common 
 lime in moft other places ; nor this laft equal 
 to that of Senlis, which is the beft we have. It 
 is of the greateft importance to be well ac- 
 euainted with the condition and peculiar pro- 
 perties of the lime we are to ufe, as it is only 
 from a juft combination of it with the other 
 materials we can expeft a perfeft whole, 
 'there is a quick-lime ftrong enough to drink 
 up, before it is perfectly flaked, a great deal 
 more water, than is to be found in the mortar 
 already defcribed ; fo that the mixture made 
 with them, inftead of coalefcing into a good 
 cement, burns up, and falls to duft; whilft, 
 on the other hand, fome quick-lime, on ac- 
 count of its oppofite quality, ftiall meet, in 
 
 the 
 
( 35 ) 
 
 the lame mortar, with more water than it car* 
 imbibe; and fo form with it a compound, 
 which, on the evaporating of the fuperfluous 
 moifture, fhall crack to pieces. I cannot, there- 
 fore, too firongly recommend, even to work- 
 men who have had the greateft fuccefs in other 
 diftricls, the trying of the ftrength of the lime, 
 they are about to employ. They ought, be- 
 tides, to be convinced, that, independently of 
 any local advantages or difad vantages in the 
 nature of their lime, it ceafes to be what it ori- 
 ginally was, in proportion as it grows old, fo 
 as to require a proportionable encreafe in the 
 dofe of it ; and that fometimes even it may hap- 
 pen to be fo bad, as entirely to fpoil any work 
 in which they fhould be indifcreet enough to 
 employ it. 
 
 Therefore, to be always fupplied with frefh 
 lime, efpecially for large and conftant works, 
 we lbould have kilns like thofe in the neigh- 
 bourhood of Chartres, which are fo many fur- 
 naces in the forms of chimneys; filled at top 
 with alternate beds of fewel,< and done broken 
 into final! pieces, and are to be emptied of their 
 lime by a hole at bottom. Another equally 
 confiderable advantage, attending this method 
 of making lime, would be that of enabling us 
 to burn the (tone, in a juft proportion to its 
 quality ; for, we are not to imagine, that eve- 
 ry kind of it requires fo great a diminution of 
 
 C 2 its 
 
( 36 ) 
 
 its weight by that operation, as is generally 
 prefcribed, on the ftrength of certain particular 
 trials; and, the degree of this diminution be- 
 ing once afcertained, all we fhould have to do 
 would be proportioiiably to encreafe or leffen 
 our beds of fewel. 
 
 With regard to fand, there are fome kinds 
 of foffii fand preferable to river fand, on ac- 
 count of the grains of the latter being too 
 much refunded and polifhed by the fridion, it 
 is in moving water liable to undergo. 
 
 There are two different ways of preparing 
 .Monfieur Loriot’s cement. The firft is, to 
 mix up very well, with water and flaked lime, 
 the fand, bridk^duft, or other materials, you 
 chufe to employ for the purpofe, to the con* 
 liflence already prefcribed, that is fomewhat 
 thinner than ufual; then fprinkle into the 
 mixture your powdered quick-lime ; and laft- 
 ly, incorporate the whole well together, to be 
 u fed diredUy^ 
 
 The fecond way is, to mix tip the fand, 
 brick-duft, and powdered quick-lime, by them- 
 felves, in the proportion prefcribed; then, add- 
 ing to them, juft as faft as you want your ce- 
 ment, the proper quantity of flaked-lime and 
 water, work the whole up well with the trowel.. 
 In this way, the fand, brick-duft, and powder- 
 ed quick-lime, may be kept ready made up in 
 facks. large enough to fill one or two troughs, 
 
(37 ) 
 
 fb as fearce to leave the workmen any room to 
 fail in the operation, let them be ever fo igno- 
 rant or carelefs about it. 
 
 But, I muft own, that all I have been faying 
 might be looked upon as an idle declamation in 
 Monfieur Loriot’s favour, intended merely to 
 heat the imagination and excite the euriofity 
 of my readers, without any reafonable profped 
 of my being able to fatisfy it, did I not give 
 feme proofs, that the fuccefs of his cement in 
 real works, of the moil extenlive and various 
 kinds, has not fallen fhort of the merit attribut- 
 ed to it in confequence of a few confined trials. 
 
 The firfl thing the Marquis de Marigny 
 thought it his duty to afcertain, with a view 
 of rendering Monfieur Loriot’s difcovery ufeful 
 to his majefty, and theftate in general, both in 
 civil and military, private and public architec- 
 ture, was the furprifing quality attributed to it 
 of being impenetrable to water; of fuftaining 
 and containing that element ; nay, of acquir- 
 ing under it a perfed degree of confiftence and 
 tenacity ; and all without flawing, or cracking, 
 or fhrinking, or fwelling; and, with this view, 
 he chofe fome works perpetually expofed to wa- 
 ter for his firfl trials. 
 
 He had, it feems, to conftrud, in his gar- 
 dens at Menars, a faafon to fupply a very con- 
 fiderable hydraulica} machine ; a canal, from 
 forty to fifty toifes Jong, to bring water to that 
 
 p 3 bafon ; 
 
\ 3 ° ; 
 
 bafon ; and fonae fnbterraneous drains to carry 
 off liis wafte water.([ 3) 
 
 Now, there was not one of thefe works, in 
 which he did not make ufe of Monfleur Lo- 
 ■riot’s cement; in one part of them, by way of 
 a fimple coating; where nothing more was 
 wanting; in another, to bind together common 
 Hones huddled promifcuoufly together; and in 
 a third, to flop thefluice of a canal he w|nteff 
 to drain, in order to coat it from one end to 
 another. The effedt of the cement ufed for 
 the lafl of thefe purpofes, after common mor- 
 tar, clay, and every other fimple or compound 
 lubftanee generally ufed on fuch occafions, had 
 faded, proved extremely fudden and deciflye. 
 It had fcarce time to fill up the fiuice, when it 
 withflood the water to fuch a degree, as to dry 
 and harden completely, and in a very fmalj 
 Space of time, whilfl the contiguous Hones 
 were vifibly Sweating at every pore. 
 
 The dome of a fountain, of very curious 
 conifrudiion, being found, in confequencs of 
 the fpongynefs of the Hones of the country 
 with which it had been built, to give way to all 
 the waters w r hich happened to light upon it, 
 and thereby render the leaH flay under it dis- 
 agreeable and dangerous, the marquis had it 
 poped with a layer of this cement; and the eff 
 
 feel 
 
 ((3) Tire Toife Is equal to fix French Feet; and the French Foot is 
 - ahnott three Quarters of an inch longer than the En^lifh Foot, 
 
( 3ft ) 
 
 fefl proved equally fudden and fatisfaftory wit'll 
 that juft now related with regard to the fluice. 
 
 The bafon we juft now took notice of, lituate 
 for the raoft part on the arch of a vault, con- 
 taining all the moving parts of the hydraulical 
 machine fupplied by it, exhibits another ftrik- 
 ing proof of the great advantages to be expect- 
 ed from this cement ; and what adds to the 
 wonder is, that all thefe trials were made in 
 weather extremely unfavourable to them, viz, 
 in autumn; in the beginning of the winter of 
 1.772; and in the fpring of the prefentyear, 
 1773, during which the men w T ere often oblig- 
 ed to work in the rain. In the latter end of 
 OCtober, 1772, they had fcarce done coating a 
 bafon in a yard, where the marquis intended 
 to keep fome water fowl, when a violent {bow- 
 er filled it to the height of fix inches and up- 
 wards; yet the work never fuftered by this fe~ 
 vere trial ; not a drop of the water penetrated ; 
 what efcaped, was merely by evaporation. 
 
 It will, no doubt, be afked, which of the 
 foregoing competitions it was, that Monfieur 
 Loriot gave the preference to in his feveral 
 works at Menars; and it is but juft I fhould fa- 
 tisfy him. 
 
 The cement ufed in the grand-canal of the 
 kitchen garden, forty-feven toifes long, feven 
 feet broad, and three deep; in that of the back 
 kitchen garden; in that of the yard to keep 
 
 C 4 water- 
 
( 4 ° ) 
 
 water-fowl in; on the outfide of a vault, over 
 which there now {lands a fhrubbery; on the 
 dome of the fountain I have already taken no- 
 tice of; as likewife in the mafTy part of a build- 
 ing, which conveys water to the machine; 
 and, riling feven feet within the bafon it fup- 
 p j i cs, ferves as a vent, as well as to carry off 
 the water at top to prevent its over-flowing, 
 when it is not to be let into the little bafon of 
 the machine ; the cement, I fay, employed in 
 all thefe works, was that compofed entirely of 
 i tad and brick-dufl, with quick and flaked - 
 lime. But, the coatings of this conduit, and the 
 baton at which it terminates, were made w ith 
 the addition of powdered charcoal, in the pro- 
 portion already prefer i bed. 
 
 Wim regaid to the coatings of the terrace 
 walls, and fome other parts of the building, 
 tire old plaffermg of which, yielding to the moi- 
 jinrc and other affections of the weather, ufed 
 to peer oft, every winter, he employed nothing 
 m the composition of them, but the already pre- 
 formed quantity of quick-lime added tocommop 
 mortar made of flaked-bme and fan:!, but'fome- 
 what thinner than for common ufe. 
 
 He likewife employed the fame kind qF ce- 
 f nent ^ or *he pHcage of a fubterraneous vault; 
 and afterwards coated it over with the very 
 
 white cemept already fpol 
 pafts qf air-flaked limp 
 
 •oken ofj made with two 
 ip one of quick-1 i'mb 
 
( 4i ) 
 
 and one of plader. And here it is proper I 
 fhould obferve, that lime flaked by the air 
 alone, and in the lliade, a cireumftance eafily 
 known by its being found crumbled to an im- 
 palpable dud, may be ufed to advantage for the 
 purpofe of preventing the cement from fetting 
 as foon as it otherwife would; a thing of fome 
 confequence in coating, when the operation re- 
 quires any extraordinary degree of time and 
 precaution. 
 
 • As often as Monfieur Loriot had occafion to 
 lay his cement on the outfide of any vaults, 
 over which there might be a neceflity of peo- 
 ples walking, he had recourfe in compofing it, 
 to coarfer materials than brick-dud, fand, and 
 the like; by which means, without lofing any 
 of its power to prevent the rain and wet from 
 penetrating fuch works, it rendered the paffage 
 along the inclined Tides of them lefs difficult 
 and dangerous. 
 
 By what we have already faid, the reader 
 may eafily guefs, what a great number of ufe- 
 ful purpofes this cement muff anfwer ; and what 
 uncommon advantages it mud, of courfe, afford 
 in every branch of every fpecies of architec- 
 ture. 
 
 To begin with the mod obvious, let the 
 building be of what nature it will ; and let the 
 materials of it, of themfelves, afford each other 
 ever fo little hold by their fides; or firm foot- 
 
( 42 ) 
 
 ing, if I may be allowed the expreffion, through 
 the fmoothnefs and inclination of their upper 
 and lower furfaces ; this cement will, notwith- 
 ftanding, confer on them a degree of perma- 
 nency and liability, which without it we could 
 fcarce expefl from the bell cut hone. 
 
 What arches, therefore, may we not expert 
 from the ufe of it ! how many ufcful and agree- 
 able forms may we not now venture to give 
 them! by means of this wonderful compofition, 
 we may make them almoft as light as we pleafe, 
 and that, too, with the fmalleft, fmoo theft and 
 roundeft pebbles, -without any appreheniions 
 of their yielding, in any fhape, to any reafon- 
 able degree of preffure. 
 
 Not only we may make aquedu&s with it, 
 but even pipes of any bore to raife water to any 
 height, by juft proportioning their tlhcknefs 
 to the preffure occafioned by thefe two circum- 
 ftances. 
 
 By means of it, we may, in our canals and 
 bafons, and all other works of that kind, fave 
 ourfelves the expence of abutments, clays, 
 maftichs, and fuch other works and fubftances, 
 which, after all, decay with time, and of courfe 
 ftand in need of continual repairs. No doubt, 
 the beft way by far would be to ufe this ce- 
 ment, even in the folia and mafty parts of fuch 
 conftru&ions ; and, when they have been built 
 
 in 
 
( 43 ) 
 
 in the common way, it will be neceffary to look 
 out for the joints, before we lay it on them. 
 
 Every kind of fubterraneous conflru&ions, 
 whether civil or military, njay, by means of this 
 cement, be rendered, not only habitable, but 
 even infinitely more healthy, than they gene- 
 rally are ; and that, too, though furrounded by 
 water ; fo that our cellars, efpecially thole under 
 court-yards and other open places ; as likewife 
 our neceffaries; ail now fo fubjeft, the former 
 to be deluged on every rifing of the neighbour- 
 ing rivers, &c. the latter, to convey infe&ion 
 to a great diftance, by their contents ouzing 
 through the adjacent earth ; all thefe works, I 
 fay, may be eafily cured by means of this ce- 
 ment, equally proper to keep water in Or out. 
 
 In fhort, wdiat is it we may not make of, or 
 with the afiiffance of, this plaftic matter, and 
 that at one cafl ! watering troughs, ponds for 
 liable and poultry yards, refervoirs againft fire; 
 wholefome cilierns in fortified and other places, 
 where no running or w ? ell water is to be had. 
 
 What floors, what cielings, what copings, 
 what terraces, and that of any form, may we 
 not promife ourfelves from this fubftance ! We 
 now need no longer fuch weighty gutters of 
 Hone or lead, and, of courfe, fuch maffy walls 
 to fupport themy precautions, which, though 
 fo very expenfive, feldom anfwer the purpofes 
 for which they are intended. Inlfead of prov- 
 
( 4 + ) 
 
 ing effeduaily impervious to rain or even the 
 common dampnefs of the weather, they often 
 bring to the ground the buildings they were in- 
 tended to defend. And, in point of dudility, 
 furely, neither tiles, nGr dates, nor milled lead, 
 can pretend to compare with this cement, for 
 rills, drains, fewers, capping for the ridges of 
 roofs, and fuch other works as require a curve 
 or irregular furface. 
 
 Nay, whole roofs may be formed with it, by 
 juft placing the laths a little clofer to each other 
 than ufual, and then laying a eoat of it on 
 them; and, what is more, the flighted timber 
 work will be drong enough to bear the weight 
 of fuch a covering ; a covering, whidh mud be 
 allowed of fingular utility in places, where peo- 
 ple are now obliged to put up with ponderous 
 dag-dones; or a flight diingle, fo liable to catch 
 fire from every fpark. 
 
 Both the exterior and interior ornaments of 
 our buildings may likewife derive from this ce- 
 ment, not only the greated folidity, but the 
 mod pleafing variety. But, in this ufe of it, 
 care mud, no doubt, be taken, not to apply it, 
 either in the way of pargetting, or of orna- 
 ments in relievo, to any walls but fuch as are 
 perfedly dry, led it fhould conce, liter fome de- 
 drudive particle, which, ia procefs of time, 
 slight make their way out; and fuch works 
 
 • themfelves 
 
( 45 ) 
 
 themfelves fhould have time to dry perfedly, 
 before any froft can get at them. 
 
 Moreover, this cement, efpecially that kind 
 of it, which has powdered done in its compo- 
 sition, is, of itfelf, an artificial done, which 
 may be call in a mould, and formed into balus- 
 trades and pilafters, for the Support of terraces 
 and platforms ; and flights of flairs with all their 
 appendages both ufeful and ornamental, ftraight 
 and curvilinear; though, for greater Safety, it 
 may not be amiSs to beftow a rude iron core on 
 the pilafters, &c. whoSe flenderneSs and height 
 may ieem to require Such an addition. 
 
 We might, likewiSe, make it, by calling it 
 in moulds, or fafhioning it on the potters’ 
 wheels, into flower-pots, and even other le^s 
 residentiary veflels, for gardens and parterres, 
 and that of any colour we like beft. 
 
 There are feveral of our provinces, and 
 Several countries in Europe, where there is not 
 a bit of plafter to be found ; and where, of 
 courfe, the dearnefs of it has proved an infur- 
 mountable obftacle to the execution of a great 
 number of the moft ufeful works, particularly 
 with regard to chimneys. But, henceforward, 
 by means of this difcovery of Monfieur Lo- 
 riot’s, any kind of work may be cameo on, m 
 any place, wdth the fame cheapnefs and eafe, 
 as in diflridts where plafter is to be had in the 
 greateft abundance. 
 
 There 
 
( 46 ) 
 
 There is, indeed, one very curious art, that 
 of fculpture, to which Monfieur Loriot can- 
 not as yet take upon him to affirm, that this 
 cement of his may be made fubfervient, fa 
 far as to fupply the place of plafter, clay, and 
 other lefs folid fubfhnce's, liable to {brink or 
 fwell. It is, however, already pad: doubt, that 
 the cement is very proper to obtain the hol- 
 low moulds of fuch figures as we would with 
 to copy; and Monfieur Loriot hopes, that, 
 with the advice andciffiftance of the famous 
 artifts of our capital, he (hall, fome day or 
 other, be able to contribute fomething, on his 
 fide, to the iervice of the art, which they fo 
 affiduoufly cultivate. In the mean time, he 
 will always be ready to anfwer any letters ad- 
 dreffed to him, concerning the poflibility or 
 piODability of applying his cement to any other 
 purposes. 
 
 For our parts, we have nothing more at pre- 
 fent to fay concerning the difcovery and com- 
 pofition of this cement, and the manner of 
 ufing it. Monfieur -Loriot has made no fecret 
 of any thing, not even of his private thoughts 
 with regaret to feveral particular ufes, to which 
 he can at prefent but juft fuppofe it may be 
 applied, as he has not as yet had any opportu- 
 nity to make adfual trials of it, in the great, 
 for fuch purposes. But, if, on the one hand,’ 
 he has had nothing more at heart, than to fa- 
 
( 47 ) 
 
 tisfy the curiofity exprelfed by the public, as 
 foon as it came to be known, that his majefty 
 had ordered the fecret to be publilhed, that 
 every one, who chofe, fhould be able to take 
 advantage of it; fo, on the other, he hopes,, 
 that the fame public will vouchsafe to value 
 his difcovery, not fo much by the llmplicity, 
 as by the ufefulnefs of it ; not fo much by the 
 eafe, with which it may be put in-pradice, as 
 by the length, affiduity, and painfulnefs of the 
 enquiries and refearches of which it is the fruit, 
 and of which, they are now enabled to reap 
 
 the benefit at free coft. 
 
 It is, however, proper w r e fhould here warn 
 fuch perfons, as may have works to execute, in 
 which Monfieur Loriot’s Cement can be ufeful, 
 not to impute to him any blunders, tnat may 
 be committed in the compofition or ufe of it, 
 bv perfons taking upon themfelves to be mailers 
 of his method, without ever adding any prac- 
 tice to the theory they may acquire by the pe- 
 rufal of this elfay ; it being of the utmoft im- 
 portance, in every art, to unite them. Foi this 
 reafon, Monfieur Loriot, while he is employ- 
 ing, in his majeffy’s works, and thofe of the reft 
 of the royal family, the workmen firft formed 
 by him at Menars, will not grudge the trouble 
 of inftruding all others, who may offer them- 
 felves for that purpofe, provided they do not 
 think it beneath them to put, themfelves, a 
 
 hand 
 
( 48 ) 
 
 hand to the work; and then, as foon as he 
 thinks them perfect, will give them a certificate 
 of their having ferved this kind of apprentice- 
 fhip, on fight of which any one may fafely em- 
 ploy them. He will even render them capable 
 of inftruaing others. And, fhould any province 
 or town apply to him for perfons ready for both 
 thefe purpofes, he will, to forward their patri- 
 otic views, make it his bufincfs to fend feem 
 fome of his belt hands. 
 
 finis