L A M P A S- 
 
 DESCRIPTIONS 
 
 OF SOME 
 
 O F 
 
 Lamps & Waterpoifcs. 
 
 Together with feme ether 
 
 PHYSICAL and MECHANICAL 
 
 DISCOVERIES. 
 
 MADE BT 
 
 ROBE RT HOOKE, 
 
 FeioTb of the J^oyd Society. 
 
 LONDON,. 
 
 Printed for John Martyn, Printer to the Royal Society,-dt- 
 the Bell in St. Paul’s Cbmh-jrard. i 677.. 
 
■(*» 
 
 L M T A S: 
 
 OR, A 
 
 D E S C R I P T I ON 
 
 OF SOME ...I 
 
 Mechanical Improvements : 
 
 LAMPS 
 
 Hypothefis of Fire and Flame I'did 
 |5|pN| about eleven years fince publilh in 
 <gsb|g| the 16. Obfervation Pag. 103, 104, 
 
 Wj|§* and 105. of my Micrographia, which 
 
 fOIG? hath fo far obtained, that many Au- 
 
 3 §jP§iy IjpjM thors have fince made ufe : of it, and 
 |P Pii f|ig ipl«8 aflerted it 3 nor have I-yet met with 
 one confiderable objection againft.it. 
 It fhall not therefore be my bufinefs at prelent to dif- 
 courfe of, or farther explain that Theory,which any 6 he 
 upona drift inquiry into, I queftion.not, will find• e^ute 
 fufficienfto confirm' him in, but . rather to mention lome 
 plealant and beneficial ufes thereof and to hint Lome 
 Mechanical contrivances for the fupplying the Palmhtm 
 Oylor Spirit by the lame Degrees by which it is cbnfutried 
 . intheflameof a Lamp, that great dillolvent.: - Iv'-'■! 
 
 I do” not here defignto flbew'a way how to make a' per¬ 
 petual Lamp, that being a Chimera'which my Hypothe¬ 
 fis of. flame doth feem to deftroy, for the diflolvend muft 
 intimebedifloived But to. (hew. a way-how -to make 
 ; ' B - ..the 
 
w 
 
 the Receptacle of a Lamp in fuch manner as that it {half 
 continue to fupply the Pabulum to the flame equally and 
 for a verylong time till it be all confumed. The con- 
 fideration of which Problem firftpnt me upon the en¬ 
 quiry after a counterpoife for Liquors or Fluids, which 
 is alfoofvery great ufe in Hydraulicks, as I fhall here¬ 
 after have occafion to manifeft. 
 
 ■ This lean do by very many contrivances, depending 
 from very differing Principles, all and every of which 
 maybe fitted fo as to fupply. the Oyl or Pabulum of the 
 Lamp in fuch quantity,.and after filch manner and pro¬ 
 portion as fhall be defired. I fhall now omit all the other 
 ways-of: performing this effeft, though , divers of them 
 are as. much or more confiderable than any of thefe I 
 here mention.. And having promifed in the 32 Page of 
 my defeription of Heliofcopes to publifh a Counterpoife 
 for Liquors,! fhall only explain feveral ways by the help 
 of thefe Counterpoifes to do whatfoever can be required, 
 as to the manner, and quantity of fupply ing Oyl to the 
 flame. • 
 
 The chief defignof the Counterpoife in this inquifiti- 
 onis to keep the Superficies of the Liquor ( whether 
 Oyl, Spirit of Wine, Oyl of. Turpentine, or the like ) 
 whatever quandtythere be in the Veffel, always to the 
 fame, height, fo that the faid Pabulum fhall always be . 
 equally diftant from the bottom of the flame, and the 
 Wick or flame being once placed at a convenient height 
 or diftance abovethe Superficies of the Oyl, fhall not be 
 deferted by the faid Superficies till the whole quantity be 
 confumed 5 but it is as eafie. to contrive it, to fupply it by 
 decreafingor increafing degrees, which are conveniences 
 that none of all the Lamps I have ever yet met with have 
 had, that was tolerable for. ufe. The moft ingenious is 
 that which is commonly known by the name of Car- 
 .dans Lamp, as being publifhed and very probably inven¬ 
 ted by Cardan, which doth in feme manner fupply the 
 wafting and decay of theOylcaUfed by the flames Con- 
 . fijmption. But thenit is fubjeft to a great many incon¬ 
 veniences, 
 
CO 
 
 yeniences, which make it intolerable anddifufed : The 
 -jrft is, though it doth fupply the defe&s of the Oyl to 
 the Wick, yet it doth it notconftantly and equally, but 
 byftartsand gluts; for after the receptacle by the Wick 
 is filled, the Superficies of the Oyl continues to fink by 
 degrees a confiderable Ipace below the flame, before 
 there be any more fupply added from thegreat Magazine 
 or Repofitory,and till the Air can break in, (which itdoth 
 very unequally ) fothat there lometimes comes down lb 
 great a quantity that the receptacle is over-filled, and 
 the flame extinguilhed, and thefe gluts are more unequal 
 the bigger the Magazine be in proportion to the Recep¬ 
 tacle by the flame, and the more the quantity of the 
 Oyl be that is lulpended, and the more the Air (pace be 
 above the Oyl, and the more tenacious or fluggilh the 
 conftitution of the Oyl is. 
 
 The fecond inconvenienceof Cardans Lamp is that the 
 Airisapttorarifieitwithheat, fo asfometimes to drive 
 down fo much Oyl as to overflow the receptacle, and 
 choak the flame. 
 
 The third Inconvenience is, that the Wick by the fink¬ 
 ing of the oyl doth fooner decay theflame,being fometimes 
 a little higher and lometimes lower upon the Wick; for 
 if the Wick rile up into the hollow dead part of the 
 Cone of the flame, the {beams and coals of the Oyl will 
 be lo caked together as to dead the flame and much to 
 diminilhthe light and heat thereof, whereas if the Wick 
 be but Ihort, and luffered only to go but a very little 
 within the urtder-Superficies of the flame, it will not be 
 fo ftoppedand caked with thofe feculencies. Therealon 
 of which is evident, for the flame, as I formerly proved, 
 
 byheatintoftieformof a vapour, finoak, or fteam, the 
 free Air that incompafleth this fteam keepeth it into a Cy¬ 
 lindrical form, and by its diffolving property preyeth 
 upon or diffolveth thofe parts of it that are outwards and 
 next to the Air, lb as by the laid diflbiution itcontinueth 
 the heat, and produceth the light which we obferve; but 
 B 2 thole 
 
( 4 ) - 
 
 thdfe paiits of the' body offteams that rife from the Wick,' 
 which arein the middle, and not contiguous to the'out¬ 
 ward Air, are not diffolved or turned into fliinirig flame- 
 by the Air till they rife towards the top of the Cone of 
 flame, where.the free Air can come to reach, and fo to dif- 
 folve them, and thence gathering about the Wick in the 
 Center of the Cone of flame they choak, dog, and 
 quite ftifle it that the flame will quickly go out. That- 
 this is fo, any one may eaflly find if he examine the flame 
 of a Lamp or Candle, by the help of a piece of glafs 
 For by the tranfparency thereof he will plainly perceive: 
 that all. the-middle of the Cone of flame neither fhines: 
 nor burns .but only the outward Superficies thereof-that? 
 is contiguousto thefree and unfatiated Air, and that th& 
 middle parts may be collefted in the. form of Soot, or very: 
 fine powdered coal duft. 
 
 ■ Take then a piece of' Glafs, whether Window-GIafs, 
 Looking-glals Plate, or the fide of a .Viol, it matters nofl 
 Or, which isbeft of all, a thin Plate of Selemtfcoi Mifio- 
 wwTalk, and hold it Horizontally in the middle : of the 
 flame, fo as-to cut off the.top or upper part of the Cone 
 thereof, thenprefently,..before itbe.choaked.withlbot, : 
 look down upon it, .and you (hall plainly fee that all; the. 
 middle parts of the Flame and the Wick have no Alining 
 power or light at all 5 nor are they diffolved by the Air, 
 hut remain inthe form ofSoot, but that only the Super¬ 
 ficies or outfide of.thefaid Conedothburn,.fhine,.and 
 eonfiime. into and mix with the.ambient Air. 
 
 In the lame manner, if.you hold the Glals-.or Selenitic 
 perpendicularly, and apply the. fide of it lb as to cut the 
 flame per -axmconi, that the Air cannot come to one fide 
 thereof, you may plainly, perceive that the Ihining part 
 of the flame is, only.that which-js contiguous-to, and 
 preyed upon by the free. and .unfatiated:,Air, .and that 
 where that Air. cannot -dome, free without being glutted 
 and fatiated in its way, there-neither. the confumption of 
 the Oyl, nor the heat and light of the flame is produced,- 
 but only aioo.ty, choaking, andftifling fubftance.,. 
 
m. 
 
 ;■ To taake'th'en fHe/rdafon, of the Phenomena obferva- 
 ble about the lafting or ftifling of the flame of a Lamp’, 
 the more clear and eafi'e to be underftood and compre¬ 
 hended, give me leave to explain the manner. of its pro- 
 duttion and continuation by a Scheme, delineation, and • 
 defcription thereof. 
 
 , Let A Atheninthefecond Table reprefenta body of' 
 6yl, or any other combuftible fluid fubftance,the Superfi- ; 
 cies whereof B B ^ Horizontal, and pretty near plain. [ I, 
 lay, pretty near, becaufe it is always either Concave, or 
 Convex, more or lefs according to feveral circumftances 5. 
 to wit, the capacity and thenatureof the Veflel EE, in. 
 which -it is contained - r for-if the Veflel be final], and that. 
 the Oyl hath a greater congruity with it than, the Air, ' 
 the Superficies of the Oyl will be very much concavated 
 efpecially towards thefides of the Veflel as at C C ^ but. 
 if the Veflel be incongruous to Oyl, the Superficies, will 
 be Convex as at D D, the reafim.of which I have long. 
 fince explained in another place. ~] 
 
 Let F Fthen in the third figure reprefent the Wick,, 
 which'coniifts of a great number of very fine Cylinders or. 
 hairs of Cotton, f ff twifted and laid very clofe together, 
 into, and bctween which the Oyl ( having a very great' 
 congruity therewith) doth readily infinuate it felf and ad¬ 
 here, and is by thepreflure of the Air ( much greater, 
 Without than between thofe Cylinders or hairs)forced up . 
 to a confiderable height between them, ( as to the height. 
 of an inch and half, or two Inches) and if. by any means, 
 the Oyl be taken out at the top thereof, the remaining 
 part of the Oyl in'the Velfel will afcend to lupply the va¬ 
 cancy of the part drawn off, which is evident inFiltra-- 
 tion. About the fides of this Wick the Oyl will be lure. 
 to afcend,, and the Superficies thereof will be concava¬ 
 ted as at G G, becaufe unlefs ,t;here'be a. congruity be-, 
 tween the Oyl and the Wick there will be noafcentof 
 the Oyl therein, and therefore that fubftance that the. 
 Oyl doth not readily adhere .to cannot be a fit material for. 
 that pur.pofe,;,. 
 
 Now. 
 
Now . to this Wick thus filled with Oyl apply the 
 flame of a Lamp or Candle, or any other fubftance ex- 
 tremelyhot, as a glowing piece of Iron, Copper, or the 
 like, and by this means the parts of the Oyl in the Wick 
 will be very much heated, and expand themfelves in va¬ 
 pours into the contiguous Air by the fleams hhh h h,and 
 fill all the Ambient fpace of the Air HH therewith, 
 which vapours being very much rarified, and confe- 
 quently lighter than theincompaffing Air,are by the grea¬ 
 ter gravity and preffure thereof carried upwards by the 
 Curve Lines hik. Thefe at firft gulh out of the Wick 
 at Right Angles, but by the protrufion of the Air are 
 quickly turned into a kind of Parabolick Curve hik 
 The motion of the Particles in which is fwifteft in kk, 
 that is to a certain degree of Altitude. The motion of 
 afcent increafing fomewhat after thenature of the motion 
 of defcent in heavy bodies, I lay fomewhat inthat nature, 
 for if theafcending bodies were uniformly lighter than 
 the Ambient they would be the lame, but becaufe the 
 rarefa&ion andnature ofthem is variedby Circumftances, 
 therefore it hath but part of that Anailogy. 
 
 To proceed then with the Explication,* I lay, thefe 
 fleams of the Oyl thus afcending, if they are heated 
 to a lufficient degree of heat are preyed upon, and 
 dilfolved or burned by the Ambient Air 5 which dilfolit- 
 tion hath this effed, firft, that it produceth light , next, 
 that it produceth heat enough to make the lucceeding 
 parts of the fleams that rulh out of the Wick and follow 
 after it to belufficiently heated for diflolution by the Air, 
 the heat of which produceth the lame operation upon a 
 third, and that upon a fourth, and that upon a fifth, and 
 fo lucceffively fo long as there are fleams of Oyl to be 
 diflolved, and plenty of frelh and unfatiated Air to 
 dilfolve. The a&ion alfo of this dilfolution cauleth heat 
 fufficient to raife up the lucceeding parts of the Oyl into 
 the Wick, and expand them into vapours, and fo to make 
 them fit to be further heated and dilfolved. It is further 
 obfervable in the flame of a Lamp, that thole vapours 
 
(?) 
 
 that iflueout of the Wick are by degrees diffolved, and 
 not all in a moment, for the parts of the flame that are 
 lowermoft about H have a kind of feint blew light until 
 they cometol, wherethey feem to have their brighteft 
 and cleared: light and heat,the laid vapours not being hea¬ 
 ted to that degree at their firft breaking out that they af¬ 
 terwards acquire by the farther aftion of the Air upon 
 them. At I they feem to be in their higheft degree of diflo- 
 lution, and from thence upwards are made one with the 
 diflolving Air, fo that they are not but by other means 
 difcernable to the eye of the obferver 5 fo that the Ihining 
 part of this Conical Ihapedlpace of the flame is only the 
 outfideof the Cone, it being that part where the Ambient 
 Air preys upon the afcending eruptions of the Oyl, 
 namely, where the.Chain of (mall Circles intercept the 
 Curve lines of the motion of the afcending eruptions. 
 
 This Figure and Ihape of the flame and vapours may 
 be plaiply leen by the help of a Metalline Concave 
 placed at a certain diftance and Pofition, and allb by, ob¬ 
 serving the lhadow of the Candle call: by the beams of 
 the Sunupon a lheet of whitepaper, or white Wall, but 
 that way of a Concave fyecuhm is incomparably beyond 
 it, .becaufe it doth fo vefy plainly lhew the form and 
 manner of the fleams riling above iiii, .as about 
 kkkk,&c. 
 
 The. Air after it hath performed the aftion ofDiflo- 
 lution, and is fatiated and incorporated with the parts of 
 the. Oyl at ii i, afeend by k k k, but Ihine not. All the 
 fleams or eruption of the vapours of the Oyl out of the 
 Wick fff Ihine not between the Wick ffand ii, but 
 begin to be diflolved, and to Ihine as they approach 
 the frelh Air at ii, where the diffolutioniscompleated. 
 
 The upper parts of the flame Ihine more than the 
 lower, the parts having been heated to a much greater 
 degree by the longer Ipace of paffage they have had 
 through the hot Concave part of the flame, and contigu¬ 
 ous or very near to the glowing fides thereof at i i i. 
 
 All the under parts of the Wick neither ihine nor 
 burn, . 
 
(?) 
 
 burn, but are as it were eharkd by the extremity of the 
 heat of the Conical Superficies of the flame, they are de¬ 
 fended from burning at the bottom by the frelh accefs of 
 new Oyl from the Veflel underneath; and the middle 
 parts are defended from burning or {hining by reafon the 
 Air cannot approach them before it be fatiated at the 
 . Conical Superficies i i i by the diffolution of the fleams 
 . of the Oyl it there meetethwithi But the upper parts of 
 the Wick do burn and fhine, if they be high enough, into 
 the fmaller part of the Cone of flame that the Air before 
 it be fatiated can reach at them. And if any part of the 
 Wick fall into the faid Conical and fhining Superficies of 
 the flame,it doth both fhine and confume, and fuffers the 
 fame diffolution into the Air as the fleams of the Oyl, 
 and if any part of this Wick be without this Conical Su¬ 
 perficies at iii, it is prefently confirmed and reduced, to 
 Allies; as by many experiments differing ways made is 
 very plainly vifible. . ' 
 
 This plainly gives the caule why knots and Tophus’s 
 do as it were grow to the Wick of the Lamp like Co many 
 Mulhrqoms on a rotten Tree, which as foon as they are 
 removed out of the middle and dead part .of > the .flame 
 are immediately confirmed by, and diffolved into: the 
 ■Air, and fhine like a coal of fire, as being indeed nothing 
 elfe. _ •. 
 
 - Hence we may give a plain Reafon! why upon applying 
 any cool Superficies very low into the flame of a .Lamps, 
 there .is immediately condenfed upon it a great quantity 
 of foot, .namely, that the middle parts-of the Cone of 
 flame, being nothing but a great number of o.yly fleams 
 afcending, are not fired nor confumed by the Air,till they 
 can-come to be wrought upon by the.free and unfatiated 
 Air. Now if the Air be fo intercepted that it cannot 
 come at them, and the fleams be cooled by the plates 
 coldnefs that the Airis not able to prey upon ordiflblve 
 themfor want ofapreparatory heat fufficient, they mull 
 remain in the. form of' burnt;Oyl, or Lamp-black. 
 
 ■ r. I have be£p ; fomew.hat the longer, and more particular 
 
f9) 
 
 in this defcription and explanation of my Theory of the 
 flame of a Lamp or Candle, that fo the Reader under- 
 ftanding the nature and caufes thereof the more fully and 
 plainly, he may the eafier difcover the inconveniences 
 that may occur in the burning, heating, fhining, durati¬ 
 on, &c. thereof and the looner and more readily and 
 fcientificallyfind a cure and prevention of thole inconve¬ 
 niences, which he that is ignorant of can but hood¬ 
 winked grope after, and at bed can but hope poffibly 
 after long puzling himfelf in vain attempts and blind 
 trials, nothing to the purpofe, hemayat length (tumble 
 upon that which had he been inlightned by the true The¬ 
 ory,he would have readily gone to at the firft glance. 
 
 I could have further expatiated into the contem¬ 
 plation of this moft admirable Phenomenon of flame, 
 producing heat and light, the two moft (pirituous 
 and moft potent Agents in Nature, and the ways of 
 Intending and Diminifliing them, and the ufes that may 
 ibe made of them, but that it is not my prefent defign 
 •to annex a difcourle on thofe fubjefrs, which doth 
 more properly belong to another Lefture I (hall (hort- 
 ly publHh. I (hall therefore at prefent proceed only 
 to (hew (bme, Mechanical contrivances for counter- 
 poifing Liquors inVeflels, fo as to keep them running 
 or lupplying a ftream always with equal (wiftne(s,what- 
 ever quantity there be of the faid Fluid 5 which as they 
 are very convenient for perfecting Lamps for divers ufes, 
 which they could not otherwife perform, fo in Hydrau- 
 lick.' they are of moft admirable benefit for divers 
 efiefts, hardly to be performed without them, as I (hall 
 hereafter manifeft. But firft, I will explain (ome few 
 ways by which more conveniences may be obtained, and 
 more inconveniences prevented in the ufe of Lamps for 
 Chymical, Mechanical, and Philofophical ufes than by 
 this way of Cardan , or any other I have met with: For 
 this I look upon as one of the Tools to be made ufe of 
 ' in theWork-houfe or Elaboratory of Nature, without 
 a good Apparatus of which, be the Workman otherwife 
 C never 
 
never fo well accomplifhed, he will never be able to pro¬ 
 duce any very confiderable effeft; and with them, even 
 a Bungler otherwife, will, if well furnifhed, do won¬ 
 ders to fiich as know not the means by-which they are. 
 done. 
 
 It may poffibly feem very ftrange to fome to hear,that 
 by the flame of a Lamp Plants may be made to grow, 
 bear Leaves, blow Flowers, ripen Seeds ; that the Eggs 
 of Fowls and Infetts may be hatched, and brought to- 
 life and perfeftion ; thatMetals, even the hardeft, Glafs, 
 Stones, d?c. may be almofl in a moment melted, loft- 
 tied, liquified, hardned, &c. that thoulands of repara¬ 
 tions of conjoyned and naturally united bodies may be. 
 effe&ed, and they referved diftinft 5 and as many other 
 bodies, naturally diftinft, and very differing, may be 
 united and compounded into Homogeneous mixtures, 
 fome fcarce feparable afterwards ; that Glafs may be 
 fhaped and moulded like Wax 5 that almofl: allthefen- 
 fible qualities of bodies may be increafed, diminifhed, 
 annihilated, and created; and fome alio of the qualities ■ 
 infenfible ( otherwife than by the effects ;) and yet even 
 thefe, and.many more, may be effefted by thisTool or 
 Inftrument, if rightly ufed, as I could manifeft if I had 
 now time. But I {hall not here any farther expatiate on 
 it, poffibly I may hereafter but at prefent I (hall only 
 proceed to the • defcription of one fort of thole In- 
 ftruments which ferve to fupply the Oyl or Pabulum of 
 a Lamp conveniently by any degrees, and in what quan¬ 
 tity is defired. This fort doth depend upon fome con¬ 
 trivance of Counterpoifes for the Liquor in the. Re¬ 
 ceptacle thatisto feed the Lamp, and may be made ufe of 
 in Hydralicks as well as Lamps to feed and continue any 
 running.ftream any time defired. 1 
 
 Thefe Counterpoifes then of Fluids might be made to 
 feed the flame of a Lamp equally for. any time affigned, 
 and confequently would make a kind of Perpetual Lamp’ 
 bixtthe Pabulum.kCd£ will be fome ways or other unapt 
 for,fi}ch.an.cfFe( 9 ;as Oyl 'hath a.foulnefs whereby the 
 Wick/ 
 
00 
 
 Wick is choaked or flopped, (b as that - it will no longer 
 afcendin it; Spirit of Wine will in length of time eva¬ 
 porate andlofemuchof its nature; and other Oyls have 
 their feveral defefts which make them uncapable ofcon- 
 tinuing the flame very long. But there are none of thele 
 that I have met with but may be in great meaftire avoided 
 by the help of fome Chymical or Mechanical contri¬ 
 vances, fome iriftances whereof I (hall hereafter give, 
 which the Theory of Fire and Flame doth readily 
 hint. 
 
 The firfc way then I (hall now defcribe is by a round 
 Box, the inward Cavity of which is divided by a Dia¬ 
 phragm into two equal parts, and fitted with a proper 
 Counterpoife, the Axis of whofe motion lieth Horizon¬ 
 tally. The contrivance of which will be more plainly 
 underftood by the Delineation thereof in the fil'd: place, 
 where the fecond Figure reprefents the whole Indrument, 
 with its Globe, Frame, Pededal, Socket, and lighted 
 Lamp. 
 
 A reprefents the Pededal or foot upon which the In¬ 
 drument dands,which may be made of Silver,Braft, Wood, 
 or the like. B CD E F, the Frame faflned to the Pededal, 
 andfhapedintheform ofa Snake, perforated at BandD 
 to receive the Pivotsor Gudgeons of the Lamp G H, and 
 hollow from E to F to'ferve to convey the Oyl or Spirit 
 of Wine from the end of the hollow Gudgeon H to the 
 Wick I, to feed the Flame K; the hole at -E to receive 
 the end of the hollow Gudgeon; H is made a little ta¬ 
 pering, and the end of the Gudgeon His ground fit into 
 it, fcastoturneafily, and yet fotrue, as not to let any 
 Oyl there leak out, the faid Gudgeon being kept dole 
 home by the fpringing of the Arm B ; the Superficies-of 
 the Oyl or Spirit for the Pabulum is always kept by the 
 motion of thefaid Globe upon its Axis G H, cxacHyinthe 
 Line L M, untill it be all confumedj which how it is dond 
 will be better conceived by- (hewing: the- contrivance of 
 the infide of the aforefaid Globe,,how the fame is divi¬ 
 ded, how filled, and how counterpoifedr 
 
 C 2 Suppofe 
 
C”)' 
 
 Suppofe then the. aforefaid Globe cut in funder by 
 the middle Line or Circle N O, and difcovering the In- 
 fide or Cavity thereof to be reprefented in the firft Fi¬ 
 gure, where PA H RZP reprefents the aforefaid Circle, 
 or half lhell of the Globe-} O reprefents the middle of 
 the hollow Gudgeon H* which is the Pole:or Axis about? 
 which the faid Globe doth move. HO Z reprefentsthe 
 Horizontal Line or Plain palling through, the aforefaid- 
 Axis} PR the Perpendicular to that Plain. Let HZ then 
 represent a Diaphragm .or Partition of the lame material, 
 with the Globe, by which the Concavity thereof is divi¬ 
 ded into an upper Hemilphere H P Z O H, and into-an* 
 under Hemifphere H R Z O H. . Let the under Hemi- 
 fphere be filled with Oyl, Spirit of Winor the like- 
 lit material for a Lamp, to burn} and let the upper partr 
 be filled with fome material of half the weight of the, 
 Oyl, Spirit, or other material, or becaufe that will be- 
 lomewhat difficult to do, let there-be a counterpoife of 
 Lead or other ponderous matter fixed lomewhere in the 
 Line PO, lb that the. laid upper Hemifphere lhallhave 
 half the gravity of the under Hemifphere upon the 
 Center of motion O. I lay, whatever quantity of the. 
 Fluid Pabulum is in the Cavity of the-laid under He¬ 
 mifphere, the Superficies thereof lhall always-be in the 
 Horizontal Line or Plain OZ, the counterpoifed upper. 
 Hemifphere keeping it always up to that height. For 
 infiance, fuppofing the laid Hemifphere full, there is no 
 doubt but that the under Hemilphere being double the 
 weight of the uppermoft will be lowermoft, and that- 
 Horizontal Line will lie Horizontally* fince it is evident,, 
 that the Center of gravity of the whole will be below- 
 the Center of motion 0 -, and fomewhere in the Line 
 OR, which is Perpendicular to the aforelaid Plain. Next, ' 
 fuppofe lo much of the aforelaid Liquid Pabulum con- 
 fumed as-to. leave enough only- to fill the fpace 
 G O Z B RC, and-the Diaphragm be moved from its Ho¬ 
 rizontal Pofition H Z, and placed in the Oblique Pofi- 
 tion COD. I. fay, the faid upper Hemilphere 
 CHAPDOe 
 
03 ). 
 
 C H A P D 0 C (hall exactly counterpoife the faid under 
 Hemifphere C R B Z D O C, fo as the Superficies of Li¬ 
 quor lhall be in the Horizontal Plain 6 Z. Make A P 
 equal to PD,:and draw the Line.AOB through the 
 Center O, it is manifeft then that the-Wedge COR. of 
 the-Liquor. doth counterpoife the Wedge R OB on the. 
 other fide the Perpendicular, and that the Wedge POD. 
 of the upper Hemifphere doth counterpoife the Wedge 
 P O A on the other fide, of the Perpendicular, fo that 
 neither ofthefehave aay prepollency to move the Globe, 
 out of this Pofture. Next, it is plain that the Wedge. 
 B O Z of the Liquor will be counterpoifed by the Wedge. 
 A O C, which is double the bignefs of BO Z, and con-, 
 fequently of equal weight,- the parts of the upper He¬ 
 mifphere being put of half the gravity or weight of the 
 under Hemilphere. 
 
 Next, fuppofehalftheOylbeconfumed, andtherebe. 
 only left enough to fill the quadrantal Wedge Z O R'. 
 
 I fay, the. Superficies thereof (hall be in the Horizontal 
 Line OZ; for fincethe upper Hemifphere is half the. 
 weight of the under, the two. quadrantal Wedges P O H. 
 andH O R muft neeeflarily counterpoife. the quadrantal*-. 
 Wedge. R 0 ZoftheOyl. 
 
 Thirdly, Suppofe that more than half, the faid Oyl or 
 liquid Pabnltmt be confirmed, and that there be only left, 
 enough to fill the Wedge B OZ, Ilay, the counterpoi- 
 fing upper Hemilphere now made the under, and placed; 
 in the Pofition AH C R B O A lhall exactly counterpoife. 
 the faid Wedge. of Liquor, fo as that the Super ficies, 
 thereof lhall be in the Line OZ; for the Wedge. ROB. 
 of the afotefaid upper Hemifphere. doth counterpoife 
 the Wedge CO Ron the other fide of the Perpendicu- 
 lar, and the doubleWedge A OH. and HOC will coun¬ 
 terpoife the Wedge BQ Z. . . 
 
 Nor can the. Superficies, of the Liquor be.. any 'whit. 
 higher or lower than the LineO Z, for if it be any whit 
 higher as at E F,. the Liquor muft neeeflarily overpoife. 
 the,.afore(aid Wedge AO C,..by alL the weight of the. 
 
 Liquor; 
 
04 ) 
 
 Liquor contained in FGOZF. And if it be any 
 whit lower as at IK, the Wedge KIB mull be too 
 light for the counterpoifing Wedge A O C by the 
 weight of the Liquor contained in the (pace 
 Z O T K Z, fince I juft .now (hewed that A O C did 
 juft counterpoife Z O B, which was the thing to be 
 proved. 
 
 Now though in thislnftance I have chofen to explicate 
 I have made choice of a Globe, yet that form is not ne- 
 cefiary, but it may be made of any Figure whatfoever 
 that is turned upon an Axis or Poles, fo as whereloever 
 the faid Figure be cut by a Plain to which the Axis is Per¬ 
 pendicular, the Superficies of the laid Figure Hull de- 
 fcribe a Circle, the Center whereof is in the faid Axis, 
 whether the faid Figure be a Cylinder Cone, or any 
 other Conoeidical, mixt, or otherwife, regular, or irre¬ 
 gular figure. Such as the Figures A B C D E F G, which 
 reprefent the Section of the faid Vellel through the 
 Axis. 
 
 The fccond way for the poyfing the Liquor, and 
 keeping the Superficies thereof always to an equal height, 
 is this: . 
 
 Make a Concave Receptacle for the Oyl or Liquor of 
 a Hemifpherical, Semicylindrical, Semiconical, or of any 
 other half-round hollow Figure, where the turned Figure 
 is cut in two parts per Axin , and whereof the Axis is 
 placed Horizontal, and the plain Seftion per Axin like- 
 wile Horizontally,fo as it may be filled with any Liquor 
 up to that Plain; and that the Liquor may notbe apt to 
 dalh, belhaken, or filter over, it will be- convenient to 
 extend the brims of that Receptacle fomewhat above 
 the half-Round, that there may be about half or three 
 quarters of an Inch of Ipace above the Superficies of the 
 Oyl vacant orempty. And that upon whatever Plain the 
 foot ftand, the Plain per Axin may Hand Horizontal, it 
 will be good to fufpend the Receptacle in the fame man¬ 
 ner as. a Sea-mans Gompafs isfufpended, within a frame: 
 
 Fix 
 
(* 5 ) 
 
 Fix this Receptacle, or the Frame that is to , keep the 
 Receptacle, Horizontal upon a convenient Pedeftal$ 
 and fit within the Hollow or Concavity of the Recepta¬ 
 cle a half-round folid poife, turned of the fame form 
 with the hollow of the Receptacle, and cut exaftly 
 through the Axis in two equal parts. Let this folid 
 poife be made exaftlyhalf the weight of the Liquor that 
 is to be poifed, and fit to it two Pivots or Pins at each 
 end of the Axis, which may be exaftly in the Poles of 
 the half-Round, and fit to thofe Pins make two holes in 
 the Centers of the Ends of the Concave Receptacle, in 
 which the Pins may freely move, and fuller the half- 
 Round poife to move round within the hollow of the 
 Receptacle, according as the quantity of the Oyl or Li¬ 
 quor is increafed or diminifhed. Fit to this Receptacle 
 a neck and focket fit for the Wick and flame of the 
 Lamp, and the fame operation will be performed by this 
 as by the.firft contrivance $ to wit,the Oyl will be kept al¬ 
 ways to the fame height in the Receptacle. 
 
 This will be eafier underftood by explaining a De¬ 
 flation thereof which is lhadowed forth in the fourth 
 Figure : Where 
 
 AAA reprefents a Pedeftal, which may be madewith 
 three claws ortoes tomakeitftand the fteadier and even- 
 ner upon any Plain or Table. 
 
 B.B reprefent one of the Semicircular Arms that are 
 fix’d to the top.ofthe Pedeftal, this hath-two holes in it 
 attheendsor extremities, as at C is one, the other hole 
 being in the other arm which goes behind the Globe, 
 and therefore cannot be feen, is fuppofed to be Diametri¬ 
 cally oppofite to this at C. Thefe two holes are the Cen¬ 
 ter holes in which two fmall Pins or- Centers, faftned into 
 two oppofite points of the Hoop or Frame are' made fit 
 to move, by whichiineans;thefaid;Hoopis: pix-feived in 
 an horizontal Pofition. : - r . . . ; , 
 
 DD is this Hoaprdr Frame, which, is made to incom- 
 pafs theV.effel or Receptacle :df the Oyl, and is fhaped 
 exaftly dike it. TlusMtmdeyfkong- eiiough .of' Byafs, 
 Iron,:, 
 
0 6 ) 
 
 Iron, Silver, or other material to bear the Receptacle, 
 Poife and Oyl without bending, and hath, as I laid be¬ 
 fore, two Pins or Gudgeons at C, and oppofite to it Di¬ 
 ametrically, or Semicircularly, upon which. the Paid 
 Hoop always hangeth Horizontally. It hath alfo oh each 
 fide in the middle between the aforelaid Pivots, two 
 Centers as at F and E to receive the ends of the Axis of 
 the Receptacleappearing at F andE, by which the (aid 
 Receptacle is always free to hang plumb or in its Perpen¬ 
 dicularity,fo as that the upper edge thereof at F F will al¬ 
 ways lie Horizontally. 
 
 One of thefe Pivots, namely, that on the Right hand 
 is the Pipe to convey the Oyl to the Socket oftheLamp I, 
 in which is fitted a Wick of Cotton to ferve for the 
 flame, KGG reprefents theVefiel or Receptacle of Oyl, 
 which is here defcribed Hemifpherical, that being the 
 moft capacious uniform Figure, but may be of any other, 
 qualified as thofe I mentioned in the firft contrivance. 
 The Brims of this are extended fometyhat higher than a 
 Semicircle, namely, to F F, to keep the Oyl from flafhing 
 or filtring over. This is always kept full with Oyl or 
 other Liquor to the Horizontal prick’d Line L L, which 
 pafleth through the Center or Axis of its Cavity by the 
 Counterpoife moved on the Center C. 
 
 HHH reprefents that Counterpoife which is made ex¬ 
 actly half the weight of the Oyl or Liquor, and the Cen¬ 
 ter of gravity of it muft be fbmewhere in the Line MM3 
 and it ought to befitted as exaftly into the hollow of the 
 Receptacle as.it is poffible, that there maybe left as little 
 fpace as may be between its convex fides and the Con¬ 
 cave of the Receptacle, but yet fo much muft be left 
 that it may movevery freely upon its Center C a whole 
 Semicircle*. This done, and the Receptacle being fil¬ 
 led with Oyl, the fame effett will follow as in thefirft 
 contrivarice, and the Dwnonftration of it being much 
 the fame, I {hall not now fpend time to explain it. But 
 rather proceed to the defcription of a third- way of 
 keeping the Liquor counterpoifed to the fame level. 
 
The third way then is: 
 
 Take any round Veflel, whofe Concavity and Con¬ 
 vexity is turned upon an Axis, and fulpena that Veflel 
 upon two fmall Pivots (but yet big enough to bear the 
 faid Veflel filled with Oyl, &c.) faftned in the Poles of 
 that Axis 5 and leave or cut open a fixth part more or left 
 as you pleafe of the fide thereof, that thereby any thing 
 may be put into or taken out of the Cavity of the Veflel 5 
 then poife the Veflel exa&ly on thofe Centers, that no 
 fide be heavier than the other 5 then fit into it a float of 
 Brafs, Silver, Tin, Lead, &c. Convex on the under fide, 
 foas juft to fill to the Cavity of the Veflel. And on the 
 upper fide, Plain, or Convex, or any other convenient 
 Figure, it matters not much. Make this float as heavy as 
 you can at the bottom, and as light-as may be at thetop, 
 but yet of fuch weight as may well float upon the 1 top of 
 the Oyl, &c. Let one end of this be faftned by a wire or 
 firing, fo as that end thereof may always touch r that 
 point of "the Concave of the Veflel to which his tied, 
 and that the reft thereof may turn and follow the link¬ 
 ing of the Oyl; and through the end of it,: near th&place 
 where it is faftned, let a Pipe go through it to receive the' 
 Wick, which Pipe hath no communication with the. Ca¬ 
 vity of the hollow float. This done, fill the Veflel as full 
 as convenient with Oyl, and light the Wick, and you 
 fhall find that as the fire confumeththeOyl, the Veflel 
 will turn upon its Poles and keep the Superficies of the 
 Oyl always at the fame diftance from the flame that it was 
 put at at fir ft till the whole be confirmed. 
 
 This will be made more conceivable by a figure and. 
 explanation thereofj which therefore take as follows 
 in the fifth figure. 
 
 A C B B reprefents a hollow Veflel, the Cavity where¬ 
 of is very exaftly turned upon an Axis whole Poles are in 
 P, the fpace between A and B in the fide thereof is left 
 open into the Cavity of it. This Veflel .is. fiilpended 
 D upon 
 
upon its Poles at P, fo as to be free to move round upon 
 them, and exactly poifed as ho one fide thereof be hea¬ 
 vier than another. To the hollow of this Veflel is fitted 
 a. float D of Brafs, Latton, Silver, Lead,e^c. whofe under- 
 fide is made of a Convexity juft fit for the; Concavity of' 
 the.Veflfcl, as may be feen at K D I, and thd upper ftraight 
 or Plain- Let this float be made fomewhat lighter than, 
 the Oyl or Liquor on which it is to fwim, fo that a part 
 thereof may'float above the Superficies thereof Let one 
 end;thereof-.E be'faftnedto the fide of theVefleJ alittle 
 below 'the Brim B ; through the end of this float is put a 
 Pipe and.Wick h, for the flame i, then pouring in Oyl 
 by the open fide A QB, fill the lame till it carry the float 
 up to touch the hollow of the Veflel 5 then light the 
 Wick, and.you will' find that the Lamp will confume the 
 Q.y],-and this contrivance will continually fupply it till 
 the whole be .conliimed, and the Poile be moved to 
 touch the Concave of the aforefaid Veflel ; for when the; 
 Veflel is filled up to f g, the float D will touch at O and 
 E, and the Cavity above f g being empty, the Veflel will 
 be as is defcribed in the Figure, the open part A B being 
 upwards; And as the flame conlumeth the Oyl, the fide . 
 of the-Veflel B will defcend downward towards B 15 
 audio by B 1, 1 B 2, Bg, toB 4, where the whole quanti¬ 
 ty of Oyl will beconiumed-, and the bottom of the float - 
 Will touch the hollow fide of the Veflel; in all which 
 gradual wafting of the Oyl the Superficies' thereof will lie 
 atthe fame diftance below the upper fide of the float D 
 that it had atfirft, and confequently at the fame diftance , 
 from the bottom of the flame. The reafon of all which 
 willbe very eafieto .be underftood by any one that fhall 
 ferioufly bn this Delineation confider that the float D muft 
 neceffitate; the Veflel! A G B -to move oh-its Axis B ac- - 
 cording as its Oyl wafts,becaufe one end- thereof E being 
 faftned to thebrim of the Veflel B, the other end O be- 
 ing loofe will as the Oyl wafts defcend towardsN, whence 
 the end E muft.hang heavier on the brim B, and confe- . 
 ^uently muft'move it! down towards B, till the upper 
 A ' ■ fide ; 
 
C19) 
 
 fide fg of the. float be reduced to aParaflelifinwith.tfie 
 Superficies of the remaining Oyl, and the end E have no 
 gravitation on the brim B, which motion will be continu- 
 ed as the Oyl wafts, and the brim B will be moved down¬ 
 wards by the points B 1, B2, Bg, toB 4. I {half not 
 therefore fpend any more time in the Geometrical demon- 
 ftration thereof, but proceed to explain a fourth way by 
 which the Flame and Superficies of the Oyl keep always 
 .at the diftance they were firft put at. 
 
 The Fourth way then is, the making the Socket of the 
 Wick to fwim upon the top of the Oyl, fo that the 
 Socket may fink as well as the Oyl, by reafon it is fiiftai- 
 nedbythat, and by that only. The Veffel or Receptacle 
 is generally made of Glafs, and it is beft of a Hemifphe- 
 rical Figure, the light calling it felf through the body of 
 the Oyl as well as of the Glafs. This is fo plain and obvi¬ 
 ous, andfo commonly ufed and pra&ifed, that I need not 
 fpend more time in the explanation or demonftration 
 thereof, but proceed to defcribeaFifthway. 
 
 The Fifth way then is much upon the fame principle 
 with the Fourth, but avoids feveral inconveniences to 
 which that is fubjeft: For whereas the Flame in thcp 
 Fourth is neceffitated to be within the capacity or the 
 Receptacle in this Fifth, it may be at any diftance, and 
 fo is made much more convenient to be come at, and to 
 be drefled and trimmed. Take then a Vefiel of Glafs, Cy¬ 
 lindrical is beft,as a Glafs Bottle,and fit to it a Siphon,long 
 enough to draw the Oyl from the bottom of the faid Vef- 
 fel make the one end of this Siphon extend at what di¬ 
 ftance you think convenient for the placing the flame of 
 the Lamp, and fo order it that it may always draw from 
 the Receptacle by its arms to feed the flame, which it 
 will do if the end of the Siphon be made where the 
 Socket of the Lamp is placed to return or bend upwards 
 again. So that the'Plain of the upper Superficies of the 
 Oyl njay cut that end of the Siphon where the flame is 
 Da between 
 
( 20 ) 
 
 between the top of the mouth of it next the Socket and' 
 the return thereof upwards 5 then by a counterpoife fo 
 fufpend this Siphon that it may follow the Oyl as it wafts, 
 and fit into the return of the Siphon a Socket and Wick 
 for the flame to be continued^ A contrivance fomewhat 
 of this kind you have in divers Authors, and therefore I 
 fliall lpend lefs time in the defeription thereof. Let 
 A AAA in theSixthFigure then reprefentalarge Cylin¬ 
 drical Viol of Glafs through the mouth B of which the 
 Cavity thereof may be filled with Oyl, and allb the end D 
 and float C of a convenient Siphon may be put in. ’This 
 Siphon D.DDPG muft Be made long enough-that the 
 float G may reach the bottom of the Veflel when the 
 Oyl is fpent, and the other end thereofmuft be fo curved 
 that the knee of the Siphon P may be below the Super- 
 ficies of, the Oyl E F, and yet that the Socket H made for 
 holding the. Wick for the flamel may be fomewhat above 
 it, this Siphon DD D P G with its .Socket and float 
 Should befo counterpoifed with a- weight M, hung over 
 a Pulley K, by a firing L, that the float may not fink deep, 
 into the Surface of the Liquor, but fwim as it were at. 
 the top. This done, , if.the W-ick I be lighted, the Surface 
 of the Oyhvi'lbe kept always atthe lame.diftancebelow 
 the flame that it was firft put at. 
 
 In the firft,-third, fourth, and fifth W3ys-the flame of' 
 the Lamp defcends equal fpaces with-the Superficies of 
 the Oyl in the Veflel, and therefore though for fome ufes-, 
 it be very convenient, as in annealings, where things are 
 to be cooled by degrees,, yet for many other it is not-5 
 Especially in Lamp Furnaces, where the fame heat is to be 
 continued, and in fome. cafes gradually increafed.' For 
 fuch cafes therefore the. firft and fecond ways will be 
 very convenient. In fome other cafes the fixth and leventh. 
 ways, which- domuch the fame thing.. 
 
 The fixthway then-is this; -.Through an arm or Siphon. 
 (like the Branch of a Lamp hung againfta Wall) fixed 
 many convenient place, the Oyl from the Receptacle is, 
 continually/ 
 
(=0 
 
 continually and equally fupplied to the flame of the 
 Lamp by the railing of the Receptacle as faft as the Oyl 
 wafts, fo asto keep the Superficies of the Oyl ahvay in 
 the fame Horizontal Plain. The Receptacle is. raifed by a 
 Counterpoife hung upon a Fufey, which Fufey is a part 
 of an Archimedean Spiral. 
 
 Let C C then in the feventh Figure reprefent the Recep¬ 
 tacle for the Oyl, being a Cylindrical or Prifmatical 
 Veflel, of what Bignefs or Length you pleafe} to this 
 by two Ears at L L fallen two Lines or Ropes R K, the 
 ends of both which are faftned to the Wheel or Pulley G, 
 though one of them do run oyer the Pulley F. Fit into 
 this Receptacle is made a Cylindrical or Prifmatical 
 Plug A A,, which is fixed in fomeconvenient place, foas 
 not to rife or fink, and through , the middle thereof pa ft 
 feth a Siphon BBB, the one end;whereof extendedlike 
 the branch of a Candle or Lamp fuftains the Socket D 
 for the Flame E, which is fed with Oyl through the Si¬ 
 phon B B B by the rifing Receptacle C C. 
 
 To the fide of the Pulley G is faftned a'Fufey H, 
 made with very great care of one Revolution of an 
 Archimedean Spiral, not beginning from the Center, but 
 from fome convenient diftance from it, where the. 
 weight I hanging,- may juft counterpoife the Receptacle 
 CG, whenquite empty of Oyl,. the other hanging coun¬ 
 terpoife (Tan gent to the largeft part of: this Spiral) muft 
 be fo far diftant from the Center of the Wheel G, that 
 the fame weight I may juft;counterpoife the faid Re¬ 
 ceptacle filled top-full of Oyl, and the. Fufey muft be 
 filed true to a Spiral,. drawn with great care of one 
 Revolution between>thofe two points. I fay hereof 
 one Revolution, becaufe I have fuppofed. the..'Wheel : 
 or Pulley G big enough, by one Revolution of it to 
 draw up the Receptacle the whole fpace. it is to be rai- 
 fed 5 for ifthe faid Pulley be fofmalL as to. require two, 
 three, four,- or more Revolutions, then muft the. piece - 
 of the Spiral .between thofc points be*.drawn of two,. 
 three, four, or more Revolutions proportionably, which. 
 
 beingj 
 
c=o 
 
 being very Artificially and Mechanically performed, the 
 Receptacle C C will be railed by the lame Degrees by 
 which the Oyl is confumed at E, and the upper Super¬ 
 ficies thereof lhall always be in the fame Horizontal 
 Line MM. The Geometrical and Mechanical Realbn 
 of which being fo very plain, I hope I lhall not need to 
 fpend any more time in the explication thereof than only 
 to lay, that by means of the Archimedean Spiral-Fufey- 
 the Power of the weight 1 upon the Pulley G decreafeth 
 in the lame proportion as the weight of the Oyl in the 
 Receptacle C Cis diminilhedbyitsconlumption. 
 
 The feventh way then is, by a Cylindrical or Prifma- 
 tical Plug fitted into a Cylindrical or Prifmatical Re¬ 
 ceptacle, and let down into it by a Counterpoife, hung 
 upon a Spiral Fufey, the Oyl is fo raifed in that Recepta¬ 
 cle as always to Hand Brimful], or to the lame Horizon¬ 
 tal height till the whole Oyl be confumed. 
 
 The contrivance of this way will be very eafily under- 
 ftood by any one that lhall perufe the Delineationin the 
 eighth Figure, and examine it by this following defcri- 
 ption. 
 
 Let A A in the eighth Figure then reprefent a Cylin¬ 
 drical or Prifmatical Receptacle, Handing fixt upon a 
 Table or Pedeftal, from the fide of which iflues a hol¬ 
 low Arm or Branch BB, bearing the Socket for the 
 WickC, where the flame Discontinued. Into the Ca¬ 
 vity of this Receptacle is fitted a Cylindrical or Prifma¬ 
 tical Plug E E, big enough to fill the whole capacity 
 thereof, and yet not fo clofe but that it may freely flip up 
 and down the Cavity of the faid Receptacle without 
 finking. Let this Plug be made confiderably heavier than 
 the Oyl of the Receptacle; that is, let the Counterpoife 
 L, hangingupon the little Wheel M juft reduce its gra¬ 
 vity to be equal to that of the Oyl; then let the point I, 
 where the Perpendicular toucheth the Spiral, be fb far 
 removed; from the Center of the Wheel H, that the coun- 
 ’ terpoife 
 
( 23 ) 
 
 terpoife L may juft take off its whole gravity;, and fuffer 
 it to have no degree of gravity or preffure downwards. 
 Then draw the Spiral nop according to the direction I 
 gave in the former way, and the effeft will be produced. 
 The Geometrical and Mechanical Demonftratiom of 
 which is very plain to any one thatfhallconfider,that,As 
 the Plug EE by finking into the Receptacle A A fofar 
 as to rail’e the Oyl to the Horizontal Superficies M M 
 will lofe its gravity by the fame Degrees by whichit 
 finketh into the Receptacle, and that is alway propor¬ 
 tionable to the diminithing of the Oyl in the Receptacle 
 ' by the flame: So the weight L will lofe its power upon 
 the Wheel H, by the fame degrees by which the Plug de- 
 fcendeth, by reafon the Line by which it is fufpended 
 becomes a Tangent to a proportionately ihorter Radius 
 of the Spiral, of the Rays of the Spiral. 
 
 I know indeed that both in this and the former Fufey 
 there lies an objection againft the true form of the Spiral, 
 becaufe the Line K K of the weight L doth not touch the 
 Spiral i.n a point level with the Center, but in one fome- 
 what above it, and in this latter fomewhat beneath it j 
 but though that be a feeming material one, yet as to 
 pra&iceit fignifies very little. For firft, it will not be 
 difficult So prove that this may be Mechanically drawn 
 true enough,that there (hall be no fenfible error,and ifthe 
 errorbe not fenfible,it is no error.in practical Mechanicks. 
 
 . Next, were it the true Spiral, yet it would not be more 
 Geometrically Delineated than this which is .here requi¬ 
 ted, and .- at bed it would prove but a Mechanical ap¬ 
 proach, which is lufficient for the effeft to be produced 
 ’ by it. 
 
 Thefe two laft contrivances do keep the flame of the 
 Lamp always in the fame place, and of the fame ftrength. 
 and fulnefs. But the fucceeding ways, though they 
 maintain the flame in the fame degreeof ftrength and. 
 nourilhment, yet by their motion upwards they may be 
 made to increafe, and intend the heat produced by them 
 in the bodies ppfited above them, which is of great 
 
life in many Chymical and Philofophical Experi¬ 
 ments. 
 
 The eighth way then is this: Make a Cylindrical or 
 Prifinatical Receptacle for the Oyl exa&ly like the for¬ 
 mer, with its Arm, Socket, Wick, &c. ana lit into it a 
 Cylindrical or Prifmatical Plug, as in the former, that 
 may be able to fill the laid Receptacle. Fix this Plug foil 
 intolbme WallorStandard, lb that it (hall not be able to 
 ftir 5 Then by the help of two Lines faftned to a Coun- 
 terpoife at one end, and, the other to the Ears of the Re¬ 
 ceptacle, fo counterpoife the faid Receptacle that it (hall 
 have no weight or gravity downwards, but hang in a 
 perfect equilibrium; I fay, whatever quantity-of Oyl 
 there be in the laid Veflel, the Superficies thereof {hall 
 always be in the Plain which is equal to the top of the 
 Oyl when the Veffel isfilled as high as isdefired, which 
 will very plainly appear to any one that {hall examine 
 and confider well this following defeription, and com¬ 
 pare it with the Delineation of the Inftrument in the 
 ninth Figure, where A A reprefents a Receptacle for the. 
 Oyl of any convenient capacity, made Cylindrical or 
 Prifinatical, to which is fanned a hollow Neck or Arm 
 B B for bearing the Socket C, to which through .its Ca¬ 
 vity ( being made hollow ) is conveyed the Oyl or Pa¬ 
 bulum for the continuance of the Flame D; into this Re¬ 
 ceptacle fit a Cylindrical or Prifinatical Plug, fo as it may 
 pretty .equally fill the laid Cavity of the Receptacle, 
 yet not fo as any -ways to hinder the Aiding on upon it of 
 the Receptacle. Let this Plug then be fixt by the top in 
 any convenient place Perpendicularly, and fetting the 
 Receptacle underneath it, Counterpoise the lame when 
 filled up with Oyl by a Counterpoifo I, which is faftned 
 to the two firings F F F F, by which the Receptacle is 
 to hang, which two firings for their more eafie Aiding to 
 and fro move upon the two Pulleys orTruckles GG, 
 that are fixed to the {ame frame to which the Plug E E 
 is fixed; which being fo adjufted, as faft as the flame D 
 confumeth the Oyl out of the Receptacle A A, the. 
 
 Counter- 
 
( 25 ) 
 
 Counterpoife I raifeth the laid Receptacle on upon the 
 Plug fo far till the top of theOyl be equal to the height 
 it was at firft counterpoifed at, to which height it always 
 keeps it till the whole be confumed. 
 
 This.Iaff way of poifing the Liquor or Oyldoth make 
 the Superficies thereof run higher and higher as the 
 auantity t hereof is more and more confumed, which 
 for divers Expedients in Mechanicks,Natural Philolbphy, 
 and Chymiftry is of excellent u(e, as I may hereafter 
 have opportunity to manifeft upon many occafions 
 where I lhall make ufe of them; and it would be,I fear,too 
 tedious to the Reader to have them here enumerated. 
 
 Butbecaufeit may not pofiibly be ungrateful to him 
 to have fome ufes of this Principle here hinted, I lhall 
 now fpecifie a few, and hereafter add many more, toge¬ 
 ther with a great number of other Poifes for Liquors 
 which ferve for very differing effefts in their kinds, 
 not lefs confiderable, but rather fomewhat more ftrange, 
 as being yet farther removed from the common practices 
 and dilcourfes ofHydraulicks. 
 
 . The firft ufe then that I lhall mention of this Liquor- 
 poife lhall beiiiHydraulicks, viz. to make a Ciftern of 
 whatever bignefs and depth is required to deliver all 
 its water at the top, or fo near unto it as it lhall be de- 
 fired : By which means nothing of theDefcent of the 
 water falling into the Ciftern is loft, but without any la¬ 
 bour or trouble the whole quantity of water that is de¬ 
 livered at the top into the Ciftern is re-delivered again, 
 out of the Ciftern at the top. This may be done by the 
 firft, fecond, andleventhwaysof poifing Liquors; this, ' 
 that, or the other, of which may be more convenient 
 to this, that, or another effeft or operation to be per¬ 
 formed by it, which mull: be cholen and applied with ■ 
 judgment, according to the occafion, and the circum- 
 ftances of it. Every of the three, though they all agree 
 together in the producing, the effeft of keeping the Su¬ 
 fi perficies 
 
w- 
 
 perficiesof the water to the lame Level, and there de¬ 
 livering it, have yet each of them their feveral proprie¬ 
 ties, which maketh fome one of the three more proper 
 and adapted to one defign.than either of the other two, 
 and each of the other two in fome other effefts and ap¬ 
 plications may be much more ufefully applied than the 
 firft. By this means the whole depth of the Ciftern is 
 gained, and all that water that was ufed to be delivered 
 at the bottom is now delivered at the top, and confe- 
 quently gains the advantage of the Perpendicular height 
 of the Ciftern to be imployed, for any ufe, for turning an 
 Automaton, or conveying the Stream farther, or to a 
 higher level. 
 
 A fecond effe£t performable by thefe Poifes may be 
 for delivering any quantity of water with an equal de¬ 
 gree of fwiftnefs, (o as to continue an equal fupply of 
 water till the whole Ciftern or Receptacle be emptied, 
 the fpending of the water in the Ciftern not at all 
 abating the ftream without, the Counterpoife always 
 keeping the Ciftern full, and maintaining the current till 
 the lqft. This may be ufeful for (awing or grinding 
 (tonesby an Engine; for gauging of Gla(s Tools, or 
 grinding glades by an Automaton, in all which cafes 
 there is need of aconftant and equal fupply of water 
 and fand; asalfo for walking and Fulling of Cloth; it 
 may alfo ferve for various forts of Clepfydras, or mea- 
 foring the quantity of time by the quantity of the cur¬ 
 rent of water, as I (hall by and by (hew. And thirdly, 
 for maintaining any flow and conftant motion, as that 
 of a Jack, or Clock; an Engine for continually ftirring 
 of a liquid body, or (haking, tumbling, and turning of 
 dry Solids and powders,, of which fort there are a 
 great number of ufes in Chymiftry for the operations of 
 Digeftion, Calcination, Pounding, Grinding, Trituration,. 
 Searring, and the like; which operations being certainly, 
 evenly, and conftantly performed by an Engine fupplied 
 by fuch a ftream of water will.fav exceed, the (ame kind 
 of 
 
( 27 ) 
 
 of work done by the hands of men, efpecially in fudh 
 operations where the Labour and Diligence is to laft 
 divers days and nights together without any intermiffion, 
 which are Requifites not at all ftrange to Chymiftry, and 
 which will weary the diligence of the belt Laborant and 
 his Attendants. . 
 
 A third effect performable by thefe Poifesis the ma- 
 kinga perpetual and conftant ftreamin imitation of that 
 of a natural Spring or Fountain in the Earth. This may 
 be done if the Cittern be once in twenty four hours re- 
 cruted and fupplied with a new accefs of water from 
 fome Pipes, which is ufual enough here in London, and 
 ellev/here, where there are Waterworks and Convey¬ 
 ances of water. For as the wafting of the water in the 
 Cittern does no ways abate or diminifh the ftream of the 
 water from the Cittern, fo the new accefs of other wa¬ 
 ter for a fupply to refill the Cittern does not at all accele¬ 
 rate it, but the ftream remains equal; And hence, con- 
 fequently conftant, and, as it were, perpetual. 
 
 A fourth effeft is, the delivering any quantity of wa¬ 
 ter to any degree of fwiftnefs, and the whole quantity 
 of the water by the fame degree. This is performed by 
 tapping the Cittern at any part of the depth thereof, for 
 according as the Veflel is tapp’d lower Under the Sur¬ 
 face, fo will the motion of the water be fwifter; and 
 here the depths mutt be in a duplicate proportion to the 
 Velocity defired: Asfbrinftance, the Cittern being tap¬ 
 ped with a hole of a quarter of an Inch bore, at the 
 depth of an Inch below the Surface, is found to de¬ 
 liver a certain quantity of water in a minute; if it be 
 defired that through a Tap of the fame bore there fhould 
 be delivered twice that quantity, the Cittern mutt be 
 tapp’d at four Inches deep; and if thrice that quantity in 
 the fame time, it mutt be tapp’d at nine Inches deep; and 
 fo forwards, as is already demonftrated by Merfemm , 
 and other Authors. For fince the preffure of Fluids 
 upon the parts thereof increafe, in the fame proportion 
 E 2 with 
 
( 2 8 ) 
 
 with the depth below the Surface. And fince the forces 
 requifite to accelerate motions muff always be in du¬ 
 plicate proportion to the Accelerations, it follows, that 
 the perpendicular depths of the Tap under the Super¬ 
 ficies of the water muff be-always in duplicate proportion 
 to the Velocities required. 
 
 The plainnefs and certainty of this truth in Hydro- 
 ftaticks, long fince fo fully and excellently demonftrated 
 by S twin ns of all Fluids, and fb highly improved of 
 late in the particular applications thereof by many more 
 modern Authors, who have writ moft learnedly and 
 clearly thereof, as well as experimentally and prattically, 
 makes me much admire at the learned Dottor More, 
 who in his Enchiridion Metuphyficim , in the n, 12, and 
 19 Chapters, and in a Book, newly piibliftied, called, 
 Remarks upon two lute ingenious difeourfes , &c. does not 
 only deny this Gravitation in the parts of Air, but of 
 Water, quickfilver, and other Liquors. And inftead 
 thereof, to fblve the Phenomena, would introduce into 
 the World a Principle, which he terms an Hjlarchii\ 
 Spirit^ which at command afts 'and performs whatfoever is 
 neceflary to folve all the Phenomena of Mechanical, Hy- 
 droftatical,and,ina word,all Phyfical motionsand effefts. 
 
 In anfwer to whofe Doctrine about Hydroftaticks I 
 [hall only urge this one Experiment of the Velocity of 
 the current of Fluids, tapp’d and running at feveral 
 depths under the Superficies of that Fluid,which can no 
 ways be folved by the Hylarchick Spirit, and we muff be 
 fain to come to the Mechanical, andplain Rules of moti- 
 , on, and to allow every particular of that Fluid to prels 
 with its own gravity where ever placed. And this I will 
 prove from his own words in his Enchiridion Metapky- 
 jicutn, pag.119. where explaining Very ingenioufly the 
 Hypothecs of Gravitation of the parts of Fluids one 
 upon another by the fimilitudeof fix menftanding in a 
 Line, and preffing againft a Wall, (which men .he marks 
 with A B C D E F, and the Wall with G) He fays, that 
 A.the filft man cannot prefs. F.the Jaff .againft- the Wall 
 G, 
 
- ( a 9) 
 
 G, but by preffing B againft C, and C againft D, and D 
 againftE, and E againft F; nor can A prefs B againft C, 
 nor Cprefs D againftE, nor E prefs Fagainft the"Wall 
 G, but at the fame time it muft be underftood that B 
 prefles D towards F, and D prefles F towards the 
 Wall G,for A C and E,fays he,are here put for Des Cartes 
 Materia Coslejik , prefling the parts of the water within 
 the pores, and B D and F for thofe parts of the water 
 prefling the bottom of the Vefl'el. But, fays he, that B 
 prefles D, and D prefles F appears from this, that calling 
 out E and F, D doth run to the Wall G, and calling out 
 C D E and F, B alfo will run to the laid Wall. And lo, 
 fays he, the Hate of the matter would be if Gravity did 
 proceed from the meer Mechanical motion imparted to 
 theTerreftrial partsof the Fluid by the MateriaCelejlit ,. 
 of Des Cartes, to wit,the Elements would actually gravi¬ 
 tate in their proper places. But fincc there is nofucli 
 thing, it is a lure fign that Gravity doth, arife from 4 
 higher caufe, which higher caufe he elfewhere flippofes 
 to be an Hylarehick Spirit. This from fo plain, reailbning 
 is a ftrange Conclufion, and contrary to all experience.. 
 
 Now though, I conlels, I fuppofe Gravity, to be other- 
 wile performed than as Des Cartes has fuppofed, yet do 
 I believe his Suppofitions fo flational and Ingenious, and 
 fo much above the Objections brought againft them, and 
 fo much better than any other I have yet met with, as no 
 wile to deferve to be efteemed facia dehria, . as thelear- 
 ned Doctor is p leafed to term therrpp^. 125. 
 
 It lhall not be my bufinefs to defend Des Cartes .Prin¬ 
 ciples at the prefent, nor to-fet up any new . Hypothe- 
 fis inftead thereof, but only tourge this Experiment of 
 tire running of a Liquor fwifter.and fwifter, .according 
 as the hole through which it runs is deeper and deeper 
 placed-below the Surface of the faid - Liquor or Fluid, 
 and that.the Velocities of.thole ftreams.are always in'a ; 
 lubduple proportion to the Altitude,of. the Fluid above • 
 thofe holes 3 whence it is evident,, that , the force, that 
 makes that.Fluid run is always in.the.lame proportion • 
 
 ’ wit&s 
 
'■with the Altitude of the fluid parts above thole holes 5 
 arid confequently, that the motion of them is exa&ly 
 accordingto the plain and obvious Rules of Mechanical 
 motions. And confequently for the folving all the Phe¬ 
 nomena of Hydroftaticks there is no need of any other 
 Principles than the plain Mechanical Principles, which 
 fiippofeth every Terreftrial Body to have a Gravity in it, 
 which is always the lame, and always communicates its 
 Gravity to'the Terreftrial Bodies fubjeded under it, 
 and not only its own, but the Gravity of all other Bo- 
 dtesabove.it, which have communicated their Gravity 
 tbit, ard“that this Gravitation is always the lame, and 
 adeth 'continually by continual repetitions indefinitely 
 iwift. And that this gravitating or communicating of 
 its weight, together with the weight of all other Bodies 
 communicated to it, is no ways differing from all other 
 communications or propagations of motion, which the 
 Doftor muft confels to be meeiiy Mechanical, if at leaft 
 he will admit of any luch thing as Mechanical motion. 
 For I cannot conceive any Reaion why the Doftor 
 Ihould not allow for inftance the parts of a Cylinder of 
 . Lead to prefs upon one another as much when they are 
 kept melted in an Iron Cylinder into a Cylindrical form 
 part over part as when the Lead is cold and divided 
 into feveral parts, and laid one over another in the 
 fame form that they were kept in by the incompaffing 
 Iron Cylinder. Since if the Iron Cylinder and melted 
 Lead, and the Iron Cylinder and cold Lead be weighed, 
 it will be found that they have both the lame weight 
 or gravity downwards, and do communicate continu* 
 ally the fame force,preffure,indeavour, impetus, ftrengtb, 
 gravity, power, motion, .or whatever elfe you will 
 call it to the Scale. And I luppofe the Doftor will grant, 
 that if the cold Cylinder of Lead, weighing tenpounds, 
 be divided into ten {hotter Cylinders, that are each a 
 tenth part of the whole, and do each weigh a pound 
 alone, every one of the upper (hall gravitateupon every 
 one ofthe lower; and that the tenth, with the other nine 
 
('. 3-0 
 
 upon it, (ball prefs the Scale with' ten pound Weight;. 
 and confequently, that the. tenth doth not only commu¬ 
 nicate its own gravity of one pound, but. the gravity of; 
 all the other nine above it, which is nine pounds, and, 
 if the tenth be taken away, and the ninth be put to 
 touch the Scale, with the other eight upon it, it is certain’: 
 that the ninth will not only communicate its motion, or 
 prefsthe Scale with its own weightof a pound,, but will; 
 communicate the motion to, or prefs the Scale with the- 
 weight of eight pounds more, or of all the eight Gy- • 
 linders fuperincumbent, and the like Ratiocination may 
 be upon the eighth, feventh, fixth, fifth, fourtb,and ; 
 fecond, but the Iaft will only prefs the Scale with its own i 
 weight, unlefswetakeinthe confideration of the weight ; 
 of the Air, which in this Ratiocination is not neceR.- 
 lary. Since then I think it cannot be denied but that the 
 whole ten (landing in. a Cy linder one over another,; the : 
 tenth is prefled by nine, and prefles with ten pound; 
 weight 5 the ninth prefles with nine, and is prefled with , 
 eight; the eighth is prefled with feven, and prefles with 
 eight, and fo onwards, and that the preflure of the 
 lowed downward is always proportionable to the height : 
 of this Cylinder. Suppofing thefe to be all melted. in am 
 Iron Cylinder, but kept in the lame pofition and fitua? - 
 tion, and finding the whole to keep the fame weight,:, 
 why (hould we not believe that each of thofe. parts will: 
 exert the feme effefls, as to gravity, on thofe be¬ 
 neath it as the fame parts-;Cold, and in the fame, pofture; 
 did 5 fince if the Cylinder of . the Fluid be (hortned .by: 
 i, 2,3, or 4, tenths of its height,sthefame abatement oft 
 weight or gravity will appear. Having, (erioufly perufed: 
 all the Ratiocination that the Doftor hath produced,. , 
 both in this lateB’ook, and. in . his Enchiridion Metaphyfi- - 
 rum^ I cannot find any convincing . reafon againftit, ,b.ut. 
 what feems grounded upon (ome pre-conceived Notions , 
 and Hypothefes which I cannot underftand$ and I can- - 
 not fee how he can avoid acknowledging this to. be a 
 
O) 
 
 chanical motion at all, fince it doth fo perfe&ly, and in 
 alleircumftances foexaftly conform and agree with the 
 Laws of Mechanical motion, that I do not know any 
 difference, nor any one Phenomenon of Hydroftaticks or 
 Gravity but what may be clearly folved by the common 
 Rules of Mechanicks: 
 
 But to pals by "all other Mediurhs to prove this Gra¬ 
 vitation or preflure of the parts of Fluids one upon 
 another, I {half only infill: upon this one Experiment of 
 the Velocity of Fluids, vented or running at leveral 
 depths below the Superficies of that Fluid. In which it 
 iS’obfervable, that the quantity of water running with- 
 ina certain fpace of time is always in a Subduple propor¬ 
 tion to the height of the preffing Fluid above the hole. 
 That is, the quantities of water are in proportion to 
 •one another as the • fquare Roots of the feveral Alti¬ 
 tudes: As for mltance, itistheoblervationof Merfennus 
 in his Hydiaulicks, that a Tap of an Inch bore, four 
 foot under the Superficies of the water will yield a 
 •pound or pint of water in 13 Seconds of time, now, if 
 itbedefiredtomakethe water run through a Tap of the 
 lame bore-twiceas fall, that is, to yeild a quart or two 
 pounds of Water.. This new Altitude mull: be made to 
 the former-Altitude, as the fquare of two to the fquare 
 of ope,that is, as four toone; whence it will follow, that 
 the Altitude of the water above the Tap mull: be made 
 fixteen foot to make the Tap run a quart of water in 13 
 Seconds of time. And if it bedefired to have the Tap run a 
 Gallon or^eight pints in-13 Seconds, the proportion of 
 the new Altitude to the-firft mult be as the Iquare of 
 eight to the fquare of one, that is, as 64 to 1, whence 
 the Altitude of the water muftbe 256 foot, and the like 
 for any other-quantity or Velocity defired. As if 'itbe 
 deified that the Tap lhould only run half a- pint in 13 
 Seconds, theTap muftbe placed at one-foot under the 
 Superficies,; which is a quarter of the former Alti¬ 
 tude.' Now. this is exaftly according to the General 
 Rule of Mechanicks. Which is, that the proportion of 
 - . the 
 
( 33 ) 
 
 the ftrength or power of moving any Body is always 
 in a duplicate proportion of the Velocity it receives 
 from it 5 that is, if any Body whatfoever be moved 
 with one degree of Velocity, by a determinate quantity 
 of ftrength, that body will require four times that 
 ftrength to be moved twice as fall:, and nine times the 
 ftrength to be moved thrice as faft, and fixteen titties the 
 ftrength to be moved four times as faft, and lo forwards. 
 This ismoft certainly true in the motion of Bullets (hot 
 out of Cannons, Muskets, Piftols, Wind-guns, Croft- 
 bows, Spitting-Trunks, and the like ; as likewife in the 
 motion of Arrows {hot with Bows or Ballift® ; of Stones 
 thrown by the hand, or with Slings 5 of Pendulums mo¬ 
 ved by Gravity or Weights; of Mufical Strings; of 
 Springs, and all other vibrating Bodies; of the motion 
 of Wheels, Flies, &c. drawn and turned by Weights 
 or Springs; of the motion of Perpendicularly or Ob¬ 
 liquely falling Bodies; and in a word, of all other Me¬ 
 chanical and Local motions, allowance only being made 
 for the impediment of the Air or other Fluid Medium, 
 through which the Body is moved. Now if the 
 Doftor will contend for an Hylarchick Spirit to perfbrfti 
 all thefe, he may plaufibly enough contend for it alfo in 
 the Experiment of the Gravitation of the parts of,Fluids 
 one upon another. _ . ' . 
 
 We fee then how needleftitisto havereeourfeto an 
 Hylarchick Spirit to perform all thofe things Which are 
 plainly and clearly performed by the common and known 
 Rules of Mechanicks, which are eafily to be underftood 
 and imagined, and are moft obvious and clear to fenfe, 
 and do not perplex our minds with unintelligible Ideas 
 of things, which do no ways tend to knowledge and 
 practice, but end in amazement and confiifion. ’ 
 
 For fuppofing the Doftor had proved there were fuch 
 .an Hylarchick Spirit, what were we the better or the 
 wifer unlefs we alio know how to rule and govern this 
 Spirit? And that we could, like Conjurers, command this 
 Spirit, andfet it at work upon whatever we had occa- 
 F fion 
 
. ( 34 ) 
 
 (Ion for it to dp. If it were a Spirit that Regulated the 
 motion of the water in its running falter or flower, I,am 
 yet .to learn by what Charm or Incantation I Ihould be 
 able to incite the Spirit to be left or more active, infuch 
 proportion as I had occafioh for,and defired 5. how Ihould 
 I fignifie to it that I had occafion for a current of water 
 that Ihould run eight Gallons in. a minute through a hole 
 of an Inch bore ? If the Doftor Ihould tell me, that I mull 
 make the Tap at luch a depth, under the Superficies of 
 the water, and then theHylarchick Spirit will make the 
 water run as I defire, I would then inquire how he 
 comes, to call that an Hylarchick, or matter-governing 
 Spirit, which is rather commanded by iriatter, and fub- 
 jefted to its Laws, and is necefiitated to aft exaftly ac¬ 
 cording to the quantity and pofition of matter, by what 
 means foever it be lb placed ? This . Principle therefore 
 at belt tends to nothing but the difcouraging Induftry 
 from learching into, .and finding out the true caufes of 
 the Phenomena, of Nature; And incourages Ignorance 
 and. Superftition by. perfwading nothing more can be 
 known, and that the-Spirit will do what it pleafes. For 
 if all things be done by; an Hylarchick Spirit, that is, I 
 know, not what, and to be found l know not when or 
 where, andaftsall things I know not how, what Ihould 
 Ihould I trouble my felf to enquire .into that which is 
 never tobeunderftood, and is beyond the reach of my 
 Faculties to comprehend ? Whereas on the other fide, 
 if Iunderftand or am.informed, that thefe Phenomena 
 do proceed from the quantity of matter and ifiotionyarid 
 that the regulating and ordering of them is dearly with¬ 
 in the power and reach of mans Induftry and Invention,. 
 I have incouragement to be ftirring and aftive in this in¬ 
 quiry and fcrutiny, as where I have to do with matter 
 and motion that fall under the reach of roy fenfes, and 
 Save no need of filch Ratified Notions as do exceed 
 Pagination and the plain deduftions of Reafcns therc- 
 - Sqm . • 
 
 Tpi what is clearer, to: be leen and', tried by Experi¬ 
 ment, 
 
( 35 ) 
 
 ment, and what more eaGe to be imagined arid under- 
 Good than that a Cylinder of water, or any other Ho¬ 
 mogeneous fubftance of twice the height. ihould have 
 twice the gravity or prellure: of thrice the height, thrice 
 the preflure: of ten times the height, ten times the p ref¬ 
 ill re : of ioo times the height, ioo times the prellure, 
 and confequently,toimaginethatasinall other Mechani¬ 
 cal motion, four times the preflure will double the Velo¬ 
 city, nine rimes the preflure will treble it, ■ fixtec-n times 
 will quadruple it, and ioo times will decuple it, and ifo 
 forward; So in this Experiment the fame preflure 1 will 
 perform the lame effeft, and a proportionate preflure a 
 proportionate effeft. And fince we find that the effeft 
 docs mod exactly anfwerthe Theory ( as moft certainly, 
 evidently, and undeniably it doth), why Ihould We 
 doubt of the caufe which is fo certain and Regular a Con¬ 
 comitant, that it is always prefent. tbhen i the effeft is 
 performed? And where-ever it is prefent,it other 
 Circumftances hinder not) the effeft certainly follows. 
 I could have gone over all the other Ratiocinations Of 
 the Doftor for an Hylarchick Spirit, tot perfoimn the 
 effefts. which do clearly bdlong .to Mechanical motions 
 and powers, ;and are; performed and regulafodi daftly 
 according.to. the 'quantity ahd quality of matter, and ad- 
 cording to the general and uniyerlai Laws of motion, 
 and riot otherwise. But that is not my prefent bufineff, 
 but rather to.explain-how this contrivance of Poife 
 doth fern: td make a Ciftern or Vefleltd run any quan¬ 
 tity of-water required in anyfpaceof time;-And'that to 
 run the whole quantity either with un equal Velocity or 
 Itream, or by any deiired degrees- to be accelerated or 
 retarded from the beginning to the end, which for- foirie 
 occafions. in Mechanicks is of great ufe, and hath not 
 been explained: by any Writer of Hydraulicks hi¬ 
 therto. i.i ! i f: 
 
 I fliould have here left this Digrefiion, but that I find 
 a little further in the aforefaid Doftors Enchirtdm^ to 
 wit. in thc,ninereenth Ghapter,in the’fifth; fixth/feVinth, 
 F 3 and 
 
(30 
 
 aad eighth Sections,. continued from the 2 46. to the ij 6 . 
 Page, fome Animadverfions upon an Explication of Co¬ 
 lours which I did formerly publifh in my Micrography 
 from the confutation of which he endeavours to a fieri - 
 tjhis Hylarchick^Spirit. But in this he doth Canere trinm- 
 p}mm ante vtftoriam, andfeems to make very flight of that 
 which he neither hath hitherto by all he hath laid in his 
 'Enchiridion Metaphyficum, nor can by all other Argu¬ 
 ments he can produce anfvver. For if the Doftor had; 
 plealed to have confidered the Objections I made againft 
 the Hypotheflsof the Rotation of the Cartefan Gwbul/, 
 with , a little more lerioulhels and deliberation, he would 
 not, I conceive, have believed that one that underftood 
 the Objection would befatisfied with lb flight and infig- 
 nificant anfwers, as he is pleafed to make ta them.^ His 
 Anfwer then tb the firft Objection which I brought 
 againft.thisHypothefis, which .was railed from Experi¬ 
 ments made with; thin plated'bodies, producing colours, 
 though the refrafting Superficies were parallel, is no . 
 more but this :..That it is riot everyfecond Refra&ionof 
 the Rayima Parallelipiped that doth .deftroy- the Rota- . 
 tion generated by the firft, but only that which entring 
 at-one fide, pafleth through, and goeth out again with 
 the fame reftafltion it entered. In which cafe only, lays 
 he, the Rotation of the Globulin generated. in the firft 
 Superficies, is deftroyed in the fecond. But, lays he, a 
 Ray falling upon a Parallelipiped,' and being reflected 
 from the fecond Superficies, fullers- a double Refraftion 
 in the fame Superficies, the one at entring, and the-other 
 at goingiout again; both which Reflations, lays he, do 
 promote the: Rotation of the Globuli the lame way. 
 This, he lays very. pofitiyely, bur gives no realbn. for it; 
 Nor -indeed, could he, fince it is exprefly contrary to 
 D^s Cartys Principles, and to all the Phenomena of fuch 
 Parallel fided bodies until they come to a certain degree 
 of thinnefs : For. ifhis Affirmation were true, then mull 
 all Refle&iqnsifrom the^ickfifrer, ..or foil of Looking- 
 glafifes, elpeeiajly ,ii£ a littleeblique, make' the Object 
 . : 1 fpread, 
 
( 37 ) 
 
 fpread, and become coloured in the fame manner ssOb- 
 jeXs do which are look’d at through Prifmes. But this 
 is contrary both to Experience, and the Laws of Reflexi¬ 
 on; for the RefraXions in the Parallelipiped Bare the 
 very fame with the RefraXions; in the Parallelipiped A, 
 the RefleXion at Dmaking the Ray to be refraXed at F* 
 in the fame manner as.if it were refraXed at C by G H, 
 and the Parallelipiped were twice as thick, and conse¬ 
 quently the:colour generated in E muft be deftroyed in 
 Pi, andconfequently produce no colours, as really it doth 
 not inplates beyond fuch a thicknefs; whereas-if the 
 RefraXion at F did promote the Rotation, as he. affirms, 
 then muft the refleXed Superficies IK not. be.ParaIleIto 
 EF, butinclined to it with an Angle atLM..Then,GN 
 , would - reprefent F O, which is impoffible, and conr 
 trary to the Laws of all refleXion,. as he., might, have 
 underftood ; if he had confidered. my Demonftration 
 about the RefleXions of a Globe. Nor will the DoXors 
 adding,,- Seel dehac prima obje&ione non efiqmdjttmus adeo • 
 foliciti, cum (it in materia , tnagis. incerta ac. inemali cujus. 
 interna conUxtnra videatur.GlobulormmotUi variit modk 
 pojje mtari. For fince all tranlparent bodies, whatfbever. 
 
 d uce the fame effeX, that Subterfuge of.fuppofing 
 ftrange invifible texture in the. body of Mnfiovy .. 
 Gldfe, differing from that of-other, tranlparent- bodies, 
 will prove but a lame, help, for . this interna tontexltirn 
 muft be common to all tranlparent Bodies', And why, it 
 Ihould do it at one time, andnot,at another, the DoXof. 
 doth no where lhew, nor feems to underftand.. 
 
 Next, whereas in the,leventhSeXionof the laid iiinet 
 teenth Chapter he &ys,.-Ferum.in materia ilia idonea . 
 Gntta Jcilicet Plnvia, S nttllus Demonjlrationk. Scopo fibjip 
 error, aUum eftdeGlobulk Cartefiank.. Sed videtur (lays . 
 he )’ ingemofiis demonfiratar.-mn Jatis. intellexiffejcopim 
 quo collintieare debeat ipjitts Demonfiratio. To whichl ari- 
 fwerj that I perceive by. the Learned DoXors endea- - 
 vour$>to. refute it, that he neither underlined dthat, 
 nor the ; Laws of .RefleXion. and RefraXion. according; - 
 
( 38 ) . 
 
 to fret Cartes Hypothefis. Neque enim fatis erat probare 
 ( quod agnofco cum fecijfe fiife & eleganter ) Rcfratfiones in 
 gulta phvia it a fieri, ut fi in duobus pcllucidi Parallelipipedi 
 Lateribut oppofitis, fitfie ejferit, fid oportebat prtterea. evi - 
 cijje quod eodem modo refringatur radius in utrifque Leers 
 quo in Parallelipipedo A refringitur,hoc efi ut Radius B C 
 quamvis oblique, perpetuo tamen enrrat verfus candem ex- 
 tremitatem tarn in F qnam inD ParaUepipcdi A put a -verfus 
 extremitatem E, nam in hoc cafu Rotatio ad D dijfolvitnr 
 iterum ad F. ut firpra diffum efi ; fed Demonjiratio luge - 
 niofi Micrograph} hue non attingit j fid probat fecundamre- 
 fraBionem in oppofito Latere fieri ad modnm refiaBionrs in 
 'Parallelipipedo Cubi Radius B N primo refringitur in D 
 & promrrens verfus extremitatem E ibique infiexus pergit 
 pofiea verfus alteram extremitatem G & Refringitur in F, 
 qn<£ refraBio non dilnit Rotatiorient prioris refraiticnis in D, 
 qnippe quod fendentia Radii fit in partem oppoftam. If 
 the Learned Doftor had better corifulted ‘Lies Cartes 
 Do&rine, or the common Laws of Reflexion and Re- 
 fra&ion, he would have been, of quite another mind, and 
 would not fo pofitively have aflerted a Propofition fo 
 pofitively contrary to the Principles of Des Cartes , and 
 all Experiments. For if vvhat he affirms were fo, then 
 (as Purged before) according to Des Cartes Do&rine^ 
 and the Do&rine he would defend, the Image from a 
 Looking-glafs' muft be returned coloured, and the dame 
 alfo from a plain fided Prifine, where the refra&ing fides 
 are Perpendicular or equally-inclined^ but contrary vvays 
 to the Refle&irig- Superhcie?. . But this 'is : contrary to 
 Experiment, hemulV therefore once again eonfider how 
 to find out a Reafon why there is no colour generated, 
 where, according to his. Affertiqn; 'there is fo great a re-* 
 fra&ion, and a' doubly promoted Rotation made in both 
 the refra&ing, Superficies the Fame'way, arid-bbth’jb 
 much promoting the fold Rotation of the Clobuli. He 
 migh t therefore, if he had pfoafed, have fufpended his 
 Conclufiqri. ’ Adco ut. DoBrin'a Carte(iand d/Globulrs eo~ 
 runique -Rotationibus'nihil perkliietnr ab' hap Demohftra• 
 ' 1 • tione 
 
tione qu£ quamvis fatk eUgansfit & cornmrn, debitim U- 
 mcn jcoptm no?t omnino attingit , until he had a little far¬ 
 ther confidered the nature of Reflection and Refradion. 
 Now, becaufe I find that the Learned Dodor is not the - 
 only perfon that hath not rightly apprehended this 
 Theory, give me leave to explain a little more particu¬ 
 larly the manner thereof: Suppofe we then in the three 
 Figures D E and F, that the (pace between the two 
 Parallel Lines a c and b d doth reprefent a Ray or Radia¬ 
 tion of light 5 Not a Mathematical Line, but a Phyfical 
 one of forae Latitude, between which Lines is propa¬ 
 gated a motion, or fbmething equivalent thereunto, 
 which ferves to produce the effed of light. This motion 
 wefuppofe to be propagated by aPulfeor Wave in all 
 uncoloured Rays at Right Angles with the Line of Di- 
 redion, but in coloured Rays more or lefs obliquely ac¬ 
 cording to the greater or lefs refradion. Wewillfup- 
 pofe the ftroke of thePulfe to be the length of the (pace 
 between i and 2, or 2 and 3, or 3 and 4, &c. andcon- 
 fcquently, in a uniform medium the pulfe will continue • 
 the fame, and the expanfion of it will be Perpcndicular 
 to the Line of Diredion or progrefs; but when it comes 
 tothe Refrading Superficies c a, Obliquely the fide of 
 the Pulfe c touches the refrading Superficies firft,and be- • 
 ing propagated into the refrading medium by a longer 
 and quicker Pulfe, it is propagated to 4 below c before - 
 the other fide of thePulfe touches the Superficies at d, 
 the Pulfe therefore 44,5 5, 6 6, &c. becomes Oblique, 
 to the tendency of the Radiation 5 and by the Superfi- • 
 cies e fit is refleded by 7 7, 77,7 7, till it touches the - 
 fecond refrading Superficies g h} where it is obfcrvable,, 
 that the fame fide of the Ray that entred firft the Super¬ 
 ficies c d enters firft into the Superficies g h, ; in the- fame 
 manner as if it had proceeded on by the ftraightLines f m 
 el till it met with a Parallel Superficies 1 m to the firft. 
 c d 5. for the Ray between the two Parallel Lines f hy e g, 
 hath the fame inclination and refped tp the Refrading 
 Superficies-hg, that the Ray between, fm and.el would 
 have 
 
have to the Superficies m 1 , fiippofingthefeweretioRe- 
 flefting Superficies at ef. I (hall not need, I hope, more 
 particularly todemonftrate- every part of this Explana¬ 
 tion, the very obferving the Delineation of the Scheme 
 being enough to make it plain to any one never fo little 
 verfed in Geometry, from which he will plainly per¬ 
 ceive that what I endeavour to demonftrate was really 
 Co, and that I did underftand what feope my De- 
 monftration aimed at, fo far as to hit the Mark, which 
 was to (hew that Colours were generated, where, ac¬ 
 cording to DesCartes own Principles, there could be no 
 Rotation of the Globuli. Now, though the Learned 
 DoftOr'Would not admit of this Demonftration to be 
 fijffieient to dothework, yet he fays, Pag.2^2, Verttn- 
 tanten diftimulandum non eft, non pauca me meapte open 
 excogitafie quibus pro perfmftjftmo kabeo eorttm mot us & 
 retationet modts pure mechanics femper fieri non pojfe. And 
 in' profeeution of the deftruftion of this Rotation of the 
 Globuli, which he hath hitherto feemed to defend, he 
 adds four feveral Arguments, I (hall not now flay to re¬ 
 peat them. But wholbever will pleafe to read what the 
 Learned Doftor hath ftiapte opera excogitated againft the 
 Carteftan Hypothefis, and fet down in the 252,253, 254, 
 and 255. pages. And compare them with what I have 
 laid in the forementioned place, to wit, at the latter end 
 of the 60. and the beginning of the 61. pages of my 
 Micrographia, may plainly find the Arguments brought 
 . by the Doftor do very little, if at all, differ from thofe 
 Ithere publifhed. 
 
 f could heartily therefore have wifhed that the Lear¬ 
 ned Doftor had made ufe of fome other Mediums to 
 prove the Exiftence of an Hylarchick Spirit, and not 
 have medled with Arguments draws either from Me- 
 chanicks or Opticks5 for I doubt, that fitch as underftand 
 thofe fubje&s well, will plainly fee that there is no need 
 of any fuch Hylarchick Spirit 5 and if there be no need 
 of it, but that all the Phenomena may be done with¬ 
 out it, then it is probable that there is none there, for 
 
(4i) 
 
 Ndtun nihil agit frttjlra. It had been much cadet to have 
 proved the exiftence of it by Arguments drawn from fub- 
 jefts we lcfs perfe&ly underftand, as from the generati¬ 
 on,nutrition, vegetation, and propagating of Vegetables, 
 and animal fubftances; for there the manner of the progrels 
 of Nature being infinitely more curious and abftrufe, and 
 further removed beyond the reach of our fenfes and un- 
 derftandings, one may more boldly aflert ftrange things 
 of this Hylarchick Spirit without fear of controul or 
 contradiftion, and from whence poffibly it may never lie 
 within the power of Reafoning to banifli him. 
 
 But to leave this Digreffion, and return totheufeof 
 thefe water-poifes. 
 
 A fifth effeft may be for walking and refining of 
 Earth, Clays, Powders, and the like; the clear Water by 
 thefe contrivances being made to run over gently at the 
 top, and fo leaving all the fettlement from the water at 
 the bottom. 
 
 By any one of thefe, with a receptacle Ciftern added 
 to it, the ftream of water from that Ciftern may beacce- 
 lerated or retarded by any degrees defirable.This doth de¬ 
 pend partly fromtheproportionoftheTap oftheRecep- 
 tacle Cifterntothe Tap of thecounterpoifed Ciftern, and 
 partly from the fhape and make of the Receptacle Ciftern, 
 by-the proportion and lhape of which the ftream ofLi- 
 . quor through the Tap ofthe Receptacle Ciftern may be 
 modulated at pleafure, as any one, a little verfed in Hy- 
 droftaticks, willeafily perceive and demonftrate. 
 
 A fixth effeft may be for governing- the heat of Lamps £ 
 
 for Diftillations, Digeftions, Fermentations, Putrefa&i- 
 ons, Diflolutions, hatching the- Eggs of Birds of Infefts ; 
 accelerating, and feafoning, or timing the growth of 
 Plants; nealing of Glafiesand Metals by the gradual ac- 
 cefs of the heat, fp as to make:, them fit forftrorigex 
 ‘ ' G. degrees. 
 
degrees, or by the gradual recefsto Bring them out of the 
 greater degrees to make them, tough and capable to. re¬ 
 ceive the,cold of the Air-. 
 
 It would be too long to give inftances of contrivances 
 for every of thefe operations but the skilful Mechanifi, 
 Philofopher or Chymift will eafily lupplyhis own defires 
 by feme one of thefe Ihaveinftancedin, or at lead by a 
 compofition of them. I {hall therefore only add a defcri- 
 ptionof a Clepfydra or time-keeper or two, and fo leave 
 this fubjeft for the prefeht. 
 
 A defcriptiw of a new fort of Cleffydra. 
 
 '“"■/''His contrivance is nothing elfe than that Two of the • 
 X : fecond.fort of VelTels are io contrived as to run ; 
 into each other and-to empty themfelves and be filled al¬ 
 ternately, and their bignefs or capacity and the hole 
 through which the Liquor is vented are fo proporti-, 
 onedas to be emptying the fpace of an hour, which is 
 eafie enough,, andmaybeadjufted to what accuratenels 
 isdeiired. Then the convex Superficies of the Cylin¬ 
 drical, poife is divided into fixty equal parts by ftraight 
 Lines drawn upon its Surface Parallel to the Axis, andto 
 each other,; thefe lines by the finking of turning of .the 
 laid poife denote the minutes, and if ImaHer Divifions. 
 of time be defired, the Ipaces between them may be di- 
 videdby other fmaller Parallel Lines denoting the parts, 
 of. each minute to-what niceiiefs is defired. One of thefe 
 Cylindrical Receptacles may be fixt, and the other by an., 
 eafie apparatus may be made tb fife a little when it is top¬ 
 full and fall a. little when quite enipty below the Level 
 of the other that is .fixt t The Chanel between'them, 
 through which the water is to run out of the one into the 
 other, may be a finall pipe with a hole in it of .a .bignefs 
 proportioned,, as.I faid above, to let the Liquor runout 
 
( 43 ) 
 
 .of one into the other in the time defired, and its ends 
 maybefaftned to the two .Receptacles by a part of the 
 neck of a bladder or gut, fo. that it may be limber, and 
 may always have a Declivity into the Veffel that is to be 
 filled;, the Dedivity need not be above half an Inch. 
 The.Liquor ufed in it may be Water, Oyl, or any other 
 Liquor that doth not eafily evaporate: But the beft of 
 all isQuickfilver, becaufe it doth not with keeping.eva¬ 
 porate at all fenfibly, which I have" carefully oblerved 
 for thefe fifteen years laftpaft. Nor doth it grow thick 
 or foul by the alteration of the Air, nor do I find it feri- 
 fibly alterby the heat and cold, at left hot comparable to 
 the great changes which other Liquors fiiffer by thealte- 
 rations'of thofe qualities. It is an excellent material for 
 mealuring time in a ftanding Machine; and there may be 
 hundred of ways contrived to make it meafure the. Ipace 
 thereof as accurately, as a Pendulum; and Ihave many 
 times admired that Tycho Brahe, who was otherwife to 
 curious and exaft in the contrivance and make of his En¬ 
 gines and Inftruments, was yet fo defeftive in his con¬ 
 trivances of meafuring time by Quickfilver,when there 
 werefo many obvious and. eafie-ways Q.f doijng it, as he 
 Teems to complain in Ws works. I have made trial of 
 feveral with very goodfuecefs, and found Tome of them 
 even beyond expectation certain, of which I may here¬ 
 after upon an other occafion add the ddcriptions, when 
 I publifh the yarious .ways of making exaft Tirne-keepers 
 or Watched Trt' the mean- time; being'hOW : Q)eaking of 
 Time-keepers, for variety fake I (hall mention. 
 
 A^w'frhici^U'foK W4ti}e^ ‘",'!' 
 
 T His is a way ofregulating both ftanding Watches,and 
 movable Watches,either for the SeT'or the Pocket, 
 whichfometenoftwelve years finceT fhewed thsRoyal 
 &«cty,whenlftiewedthemjny contrivances of the Sircu- 
 
( 44 ) . 
 
 &r Pendulum, which isfince publilhedby Monfieur Huge- 
 tiiusy which is alfo mentioned in the Hiftory of the laid So- 
 ae/>’,p.247.1in.Qo.Thiswas by a fly moving Circularly in- 
 ftead ofaballance,whofe motion was regulated by weights,, 
 flying further and further from the Center according as 
 the. ftrength of the Spring of the Watch had more and 
 more force upon its Arbor. The Weights were regulated, 
 from flying out further than they ought to do by the con¬ 
 trivance of a Spiral Spring,drawing both the faidWeights. 
 to the Center of the motion, or fly, in the fame proportion. 
 asl.then demonftraited Gravity to attr-adf the weight of a. 
 Circular Pendulum, moved- in a Parabolical Superficies, 
 towardsthe Center or Axis- of its motion. The Weights. 
 were lo contrived as. always to counterpoife each other. 
 The Skeleton of this fly you have reprefented -in -the 
 Figure. The particular explanation of the parts, and 
 the. Geometrical Demonftiration. of the-P-rineiple both of 
 the Springs, and of the flying from the Center, I 
 fhall explain in the, Theory of Springs, and in-the de- 
 ' fcription . of - Time-keepers and Watches.. 
 
 - Ol &ijMovpyit ■x.u.'mjm&ia.Qiim opy^vov 'rnv dp%lu} 9 
 
 OTrdsti tv< pctve£pv' fjyroii'to <rl 
 
 <T’ ttjrior, a&iAay, Ariji. £>u<eft. Meehan. 
 
 . JnM^yatm4hout,tkSeed,of : Mf^ '• 
 
 S ince the publifhifig. of my Micrography, I have met 
 
 with an Obfervatiori,which thoughitbeofone.of the 
 
 fmalleft compound bodies I have hitherto taken notice of, 
 yet does it'afford a hint ofvery -great concern in Natural 
 Philofophy; And it does feem to make clear the caufe of 
 a .Phenomenon, that hath; appeared dubious,not only to 
 hk?, buttomany othemoreknowing Naluralifts. I have 
 often doubted, I confels, whether Mofs,Mufhroms 5 andli- 
 ^eralother.finall Plants^ which the. EsrthTeems.to.pror 
 
( 45 ) 
 
 duce auTB/^ros)' were the off-fpring of a Seed or Grain; 
 and I have been apt to believe, that they were rather a 
 fecondary ptodu&ion of Nature; being foraewhat the 
 more inclined to that opinion* becaufe having formerly 
 examined the fmall knots or Seed-cods of Mofs-with a- 
 Angle Microfcope, I could not perceive any, thing in them 
 that I could imagine to beSeed,at lead not- fb great a quan-i 
 tity as feemed neceflaryto maintain (o numerous a Pro-. 
 geny, as was every where to be found of it-; that, which ; 
 then came out of them* feemingtobe rather a pulp -or- 
 pith, than any thing like the Seedsdnother fimilar Cods. 
 But-being fince fomewhat more inquifitive, I did exa¬ 
 mine feveralofthe above-mentioned Knobs orSeed-veP 
 fels, and found that there, were feeds in them,, no kCs, 
 wonderful. for. the. greatnefs of number, than -the final-, 
 nefsof bulk, .Taking then fome of the ripe and brown 
 orreddifh ones of them, and preffing them pretty hard, 
 Ifound, that there was a fmall; duft went opt of them, 
 which feemed to vanilhinto the Air, PreffingandTquee- . 
 zing others! of. thgfe, uporha black-plate, and .-examining 
 the powder; with: a Microfcope, I found it to be a great 
 heap of exceeding'.fmall ; Seeds, Globular, and, pretty 
 tranlparent. Itis.the finall.eft, I con.fefs, I have yet feen, 
 and, jtmay be; that'hashithertobeen difeovered.- And, 
 unlefs that be a:.-plant, which I difeovered growing ori ;■ 
 the blighted leaves of Rofes,.and that t hole, fmall bodies . 
 be fecd velfels; or, unlefs thofeKnobs, J have difeovered 
 on-the top of;,mould, -.be.,thq like; f-cannot prefently 
 -imaginp.where th'ere flioulil be found;a finaller. • For,- I 
 find, that there.will need no lefs'than; thirty fix hundred 
 of them to belaid one by/another; in a line,to make the 
 iengthofan inch; and,;to coyer,the,;Superficies of-an . 
 Inch-fquare, there will .need no lefsithan-nipo hundred 
 andthreefcorethoufandsj-befidestwelye millions, of Ca¬ 
 gle Seeds if.latd quadrangular^-, hut-if laidtriangularly, 
 there will need no lefs. than two hundred- and. fburfeore 
 thpufand, befides feventeen.Millions.. ofTngle .grains. 
 And the number in a grain weight of them cannot be 
 slefs 
 
w 
 
 Iefs'than onethoufand three hundred eighty two Millions 
 and four hundred thoufand fihgle grains, about eighty 
 of thefc fquafe Su'perficies of Seeds being laid one upon 
 another in the Trigonal order, making, as near as I can 
 guefs, the thicknefs ofu piece of fine Paper, a fquare 
 Inch of which weigheth a grain. And though this 
 may ,leem a moft ; incredible .narration 5 yet I would 
 defirefuch as aire apt to be too cenforious, to take the 
 pains to gather a feW of thefe Seed-veffels, and examine 
 theni as I have done, and then fpeak what they find, and 
 believe no - more than their owny fenfe and reafbn will 
 inform them, and they may eafily fee, that, .what I have 
 afleitedi will be rather^ fllOit of than exceed the real num¬ 
 bers. Now if this Shell of the Seed be thus fmall, how 
 much Imaller muft needs be' the rudiment of the Plant 
 that lies eiiclofed Within it ? And how eafily may fuch 
 Seeds be drAWn upiritothe Air,: and carried from place 
 arid place,"'even to the topsof the higheft Towers,- or to 
 places moft remote, arid befoWed’by the paffing Air,’or 
 falling drops of Rain, -on the boughs or branches of 
 Trees, fides and tops of WallspiHoufes, - or Steeples? 
 Ahd itisnotiri the Art of man to leave Earth expofed.to 
 ' the.common Air, arid to excludethe entrance,:or.prevent 
 the fowing of'thefe imperceptibleSeeds 5 and therefore 
 it is notto be wondred at,’ that, if any .earth, though 
 neverfopure, be expofed to the Air and Rain, though 
 at the top of a Steeple, it will produceMofs:. . : . 
 
 ; ' Tuith'er inq uiry may poffibiy iriftruft us,, that there 
 may be Seeds of Muftiromsj! Mould and other Vegetables 
 of -asTniSl], if ndtfinaller, bulk, which.may be' diver¬ 
 ted and mingled'With the: Air, and carried to and fro 
 -with it, till wafhed down by the falling drops of Dews 
 -or-Rains j Which,J if- they chance to lightoma conVeni- 
 entfoy], do there -Vegetate and ! fpring upbut. dye and 
 perilh, if theground, they light on, bemotuaturaland 
 agreeable. ; But-whetherthis conjefture hit right,furthcr 
 obfervation muftdetermine. 
 
( 47 ) 
 
 This difcovery I made the year after the late Fire of 
 London ,. tb wit, - in the.-year, i66j. there being then vaft 
 quantities of it to be found every where dilperfed among 
 the Ruines left by that Fire, which made me, I confefs, 
 very much wbnderat tirfthoW fuch. vaft.quantities fhould 
 come toi be thehfo fuddenly rooted, and was theoccafi- 
 on of rnymore ftrift examination bf it. ; Thislprefently 
 {hewed to many of my Acquaintants, and the next 
 year 1668. upon the eleventh of Jiw l brought an ac- 
 count of it into the Royal Society, where I fuppofe it may 
 yet remain upon fheir Regifter5 and it .was not a little 
 jurprifihg- to all that law it, when theyconfidered how • 
 exceedingly fmall’ each particular Seed was,' and yet how 
 infinitely vaft the number of them was produced by each 
 Plant. How prodigioufiy (mail the firft beginning and 
 rudiment of that Plant muft be thatwas produced by it 3 
 now, though indeed the Plant it.felfbe one.of. the fmal- 
 left, yet this Seed of it was much fmaller in .comparifon 
 to the Plant than the Seeds of moft other Plants compa¬ 
 red with theirs. But about two years-after this I re-t 
 ceived from a very good friend of mine at Brifhol, the 
 Ingenious and Inquifitive Mr. W-C. a Relation-of fbme 
 later difcoveries of his, which feemed much to outftrip 
 even this, whether the comparative magnitude, of the 
 Plant,-and of the Seeds, or the number of the Seeds, or 
 the curiofity. of the Seed-boxes, or,the. ftrange way of 
 fowing and difperfing, or the place and manner of the 
 Seeds production be confidered. As -they were lent to . 
 me by him in a Letter 1 from Brijlol,. dated September 30. 
 1669; take them in his own worcls.and defcription. 
 
 J^Qtmithfianding. myfmny othm Avocations, variety, cf 
 do almofi'chjcry day inhrge. my experience 3 
 but more especially tbklajl Weef I . re as, vtryhappy in the 
 det elding of that-TchichaU. the'Philofophers and Pbyficians 
 of former Ages,have hem, ignorant of, as,.. Tcemay.veeVma- - 
 ginefrom xohut rcmmvs'wAavcofthem.; My Difcovery in. 
 fort Tvasjhk, that _ all the kinds orjpecie; of Ferns together. 
 
'C4*') 
 
 with all thelike Capillary Plantstheir Congeners are (though 
 generally denied to have any at ad) moire abundantly prolifecal 
 in Seeds than any other Plant befide, especially the common 
 Female -Ferns or Brakes, and thofe more elegantly formed 
 (Imeanchiefly inthe little Feficlescontenting the Seed) than 
 many others, among the hundreds Ihave dbferved. To make 
 it deimenfirable . to you, I have novo fent ymi both the Plants 
 with the Seeds on them, and the Seeds of the'fame Plants 
 apart in Papers by thcmfelves, which 1 took, off from other 
 Plants of the fame kind, having plentiful parcels of each 
 (exeeptingof what Ihave not fent you) thh being the feafon 
 ofperfe&ing. their Seeds. I thought, to have fent you draughts 
 of the Seed Veffels, as they appearedprefcntly after gathering, 
 but could not, Iprefume fame of the Feficles or little boxes 
 may remain, whole, fo that by your Microfeepc you may fee 
 their true figures and: dijlinftions, feme of them being more 
 flitted an each fide the little ring or emboffed girdle mcom- 
 pajfing them, others more fweding. 
 
 Alfo thofe little rings or bands encompajpng the boxes are 
 different, in feme of the kinds broader andflatter, in others 
 rounder, and.funding-up bigher, yet all agreeing in the 
 principal parts of their farm. Ipurpofe to draw the figures of 
 t hem all. as. they appear by the Microfcope, together with their 
 Seeds, and Jo add deferiptions of all circumflanccs confide- 
 rable, and joyn them to the reflof my draughts of that kind. 
 Some particulars mejl cot/fiderable I now give you inthe fol- 
 r following account. 
 
 I. The little 'boxes containing the Seeds are in tsrofi of 
 thefe Plantsnot half and in feme not above. one third, or one 
 quarter as big as a very [mail grain of common white fand$ 
 appearing like little bladders infolded with rings or band's, 
 feapcdlilg certain littleworms lhaycmet with, which maybe 
 rcfemdto thcTercdds-and Fntca’s. 
 
 a. As near at I could compute, feme -of thefe bladders con- 
 tainedabout 100 Seeds, which -were, fo exceeding fmall, as to 
 Le wholly anvifible tot he mkcdeyc,,andindifecvcrablc without 
 aMicrofeope. 
 
.(49) 
 
 g. The Leaves of both the Ferns, ejpecially the, common 
 Female Fern, (which is more abundantly fioredwith Seed 
 than any of the refij and the other Inowfend you, being kept 
 clofe without bruijing, and foonafter gathering expofedtothe 
 Sun, or dry Air, the bands ;of as many of them as are ripe, 
 willcontraff themfelves and break,, and ding their Seeds aU 
 about, after the fame manner as fome other'[mail Plants,fitch 
 as ffePerficaria Siliquata, and feme of the Cardaminas are 
 obferved to do. This I have obferved with a Jingle convex 
 glafsas well as with the Microfcope, but with the latter only 
 I could difcdver the filling of the Seed.' And a pretty quantity 
 of the Seed 'being nibbed or brufied ojffrom the . Leave's upon 
 a fine piece of Paper or Parchment, andJbeeped together into 
 aheap, many of 'thofe boxes breaking together., and jufiling 
 one another would make the heap' feem,.as it werefullofMites 
 or living Creatures,' even lot he pah eye j yndfifthe place be 
 fee frdninoife, \and the Far be'clojeapplied, the \crdckjing of 
 them 'Upon" breaking ‘ map daftly'-enough fie heard, 'and upon 
 running over the Paper with a Microfcope the Seeds will be 
 found dijperfed, and thrown at a great difiance. 
 
 ■4. Thefigures of the'SeedfiJeJfels, asalfopfiFeSeedsofad 
 theFernsdnd'tVofe their Congeries, cafied Capillary. Plants., 
 are very liedt 1 ofih,efdme'feapedh.d fize, n’otmthflandingihe 
 vaji dijpropOrtion between them, asparticular common Fern, 
 Wad-Rue, .HartsTongue, and Ofmond Royal, the firft three 
 df bhic'h'-ireingfierp yemarkfelefof their, unlikenefsfeo., each 
 dtherfi'dndthe’lajl-chiefiyfor its excelling fo mahythofifancl 
 times in magnitude that of Wall Rue. Which obferyatjonfmay 
 feeni to 'coifirm'the opinions of fome learned Boianifis that 
 the dfffiity of ' Plunts are to be judged by the figures 'of their 
 
 v 5) ThdiOfinnndRtoyal, which excellethaU thepihe^F'ems 
 bothpin,'gredti)efs,;cemltnefs, and yertues, and. .wfadti -faath 
 been demounted barren', with thi rfifyth 'Veffelsand Seedsff 
 the fame figure -with ■ the other, ■ and very near of, the fame 
 (iZe,the extremeJmklnefs of which, ‘ evehto invifilfility, anif 
 'the grehttiefs of ihe] Plant, %he ropi whereof ,. with'qjl.. the 
 growth out of it, LkaVe fomid weighing ten pounds and bet* 
 H i ter , 
 
ter,isfurpajjtngly mm wonderful than that ofMofs Seeds ; of 
 which I have fome kinds of them bearing Seeds,, that a great 
 number of them, with their Roots, Stalks, Leaves, and Seeds 
 do not weigh a Grain. Befides, I havefound of the common 
 Female Fern feme which fove been from the Roots to- the nt- 
 moft top. of the Leaf nine foot high, and within thefe three 
 days meafured the common broad-leaved Male Fern fix foot 
 and an half long-, fome. of the Leaves, of which are Jong 
 thoje lnowjendyou. 
 
 6. But that which appeared mofi admirable, both to me 
 fnd fome other Gentlemen that were witness , of it with me, 
 ^ an fd } fftringkindsoffmalllivingCreatures,whoIly 
 mvjjibleto the nakgdeye, and even through largely magnify. 
 ingMacles, thoughfome of them were to be Jeen through a 
 deep Convexglafs ; but with a Microfcope, when the Plant 
 was newly gathered, they might befeen nimbly runningup and 
 down among the Seed-vefels,. and fame of them were fo 
 iTlZr *° k , a r 0Ve tivice * the fmall Seeds in 
 
 tndrn 5 * de ^ tion ‘ °ff me °f which tmy hereafter 
 
 Ihave.infibfed’ in tkeboxfent youtwelhe forts of Plants 
 of thss frrbe, being the greateft part of the number, ind only 
 fevenforts of thp Seeds 5 thofewanting are the Cetrach, Wail 
 Rue, Maiden-hair, and Polypody, of which, notwithfland- 
 sng you may fain fie your felf in the mean time tiJl can 
 fend them green by. thofe fmall parcels of the Plants which 
 
 wKfedf am ° n?fi ^ °’ igh y: ^ ™ 
 
 The Seeds of the Ferns through a very excellent Micro¬ 
 be appeared of the bighefs op a fmall Vetch or Seed of Len- 
 tsles to the naked eye, and fome of them (brink like thrfiZ 
 of white. Peafe-, pith fmall regular knobs, and hollows. Thofe 
 of Polypody are differing in colour and jhape being yellowil 
 
 ?h f l/ k V7 r T’ red > af!d formed life the Seeds of 
 thefmafier Medicos that hofa Kidney fi M pe. All. theJi 
 I found very near af the fame form. ' I cannot omitfihatl 
 offer ved in Cetrach, which'Plant I have heMo fore'often com. 
 fidered, and wondred at the illfivouiQroughnefi on the m- 
 
(50 
 
 der Jide of the Leaf, appearing like the fiejhy fide oftann'd 
 Leather, being wholly ignorant what Nature meant in it, but 
 now by myMicrofcope L find it a very plcafant objelt differ¬ 
 ing fiomall the ref, wherein the curioftty of Nature ( in a 
 Plant fo abjeU as that appears ) is fiewn beyond imaginati¬ 
 on. This, when fief) gathered, and not bruifed, appears 
 through the Microfcope like fine thin Membranes, fuch as the 
 Wings of Flies, chequered with figures after the manner of 
 Honeycombs when the cells are full of honey, and clofedwith 
 Membranes, amongflwhick,asin fo many Cells, lietheSeed- 
 veffels, f japed as before is mentioned. I doubt not but you 
 have read the firange Jlories and fabulous conceits of Ait: 
 thors about Fern Seeds. But Parkinfon is more Orthodox in 
 feme things than any of them: For he pofltively concludes 
 ffrom Gen.i.il, 12. that all Plants have their Seeds, and 
 confequently Fern I, where if he had Jlaid, he had afferted a 
 general truth : But in coming to particulars, he affirms as 
 great an untruth, in faying, fol. 1036, and 1037. that the 
 Seed is ripe at Midfummer, according to the old traditional 
 Fable, and tells how it may be gathered $ whereas now is the 
 very feafon of their feeding, and at Midfummer this and the 
 rejl are not come to their fill growth, before which no Plant 
 feeds. That dufinefs which he fieaks of, and calls the Seed, is 
 no other than what is found on divers other Plants, being an 
 irregular Dujl, and is not found on the borders of the dents 
 of the Leaves on the under fide, on which the Seed grows, 
 but all over firinkled on both fides, and not found when it is 
 fully grown. This he affirms of the Male Ferns, which are all 
 differing very notably fiom the common Female Fern, con¬ 
 cerning which the fabulous tradition is held. But after in 
 the following Chapter of the Ferns and their Relatives now 
 fentyou, he feemstogivL over his Scripture Propofition, and, 
 Jpeaking of the Seeds, fays no more but that they have fpots, 
 dajhes, feales, or marks on their backsides. And of the Of- 
 mmd Royal (Jpealqng of the bujh at'the top of the Plant) 
 fays it is accounted as the Flower and Seeds. And of the Lo- 
 chitisafpera fays plainly they have'none at all. Of thislafi 
 I am yet to enquire, but doubt not I jhall find that it hath 
 Ha Seed 
 
(sO' 
 
 Seed life the reft. Of all which Gerrard and Johnfon his 
 Corrigitor gravely concludes ( having indeed no demonftra- 
 hlegroundto the contrary ) that fame have been too raft in 
 affirming Ferns to have Seed. I intend next Summer to ob- 
 jerve whether thefe hitherto unhjiown Seeding Plants have 
 Flowers. In the mean time' I am, &c. 
 
 Eriftol. Septem- 
 to-30. 1 66$. 
 
 tr.c. 
 
 Macula in Sole. 
 
 D Uring this laftgreat heat of weather in June I obfer- 
 ved a very conspicuous Macula with its immediatly 
 incompafling Nubecula, and fome other lefs conlpicuous 
 Spots at a further diftance pafs over the Disk of the Sun, 
 and found that it was neareh the middle when the heat 
 was greateft, that the heat increafed as it came nearer the 
 middle, and decreafed as it departed from it. It may be 
 therefore worth obiter ving for the future whether the like 
 weather do not happen upon the next appearance of the 
 like Macula, finceit feems not very improbable to fuppofe 
 that the body of the Sun it felf may be much hotter when 
 luch eruptions appear, thofe Macukoften times ending.in 
 Fa:cute. And the rather becauie lam informed that this 
 extraordinary heat hath not been peculiar only to Eng¬ 
 land, , but very general to Europe ; what it hath been to 
 other parts of theworld further intelligence will inform us. 
 
 ..Upon a fecond appearance of ; Spots in the Disk of 
 the Sun at the latter end of July and the beginning of 
 Auguft, when atone time, to wit, July 2 9. there appeared 
 about fix greater and finaller in one knot with their proper 
 Nubecules or Umbra's, the, heat of the weather again 
 increafed to a very great degree, and abated as they drew 
 toward the Limb, and grew fainter. But it hath now 
 fince the dilappearing, viz. on the fourth of Augttft, been 
 exceeding hot alfo, though I do not find any Spots this 
 feventhof Augufty, it may thereforepoflibly be'thatother 
 part's of the. body of the Sun may have an extraordinary 
 inflammation 
 
( 53 ) 
 
 inflammation which may caufe fo fervent and lading heats 
 as have hapned this Summer. At lead this Hint may 
 deferve fome farther Inquiry, for though probably it 
 may not be attained to preditt the appearances of thole 
 Spots, yet poffibly the appearances of the Spots may 
 ferveto predift the future conftitution of the weather. 
 At leaft it feems worthy remarking that the greateft heat 
 that hath beenin the Air this year was onthatdayofjfrae 
 when the firft Spot Was near the middle of the Sun. 
 
 PcTsT SCR IP T. 
 
 T He Publifher of Tranfa&ions in that of OUoler 
 1675. indeavours to cover former injuries done 
 me by accumulating new ones, and this with fo much 
 paffion as with integrity to lay by difcretion; otherwife 
 he would not have affirmed, that it was as certain that 
 none of my Watches fucceeded, as it was that I had made 
 themfeveral years ago : For how could hebefure of a 
 Negative? Whom I have not acquainted with my Inven¬ 
 tions, fince I looked on him as one that made a trade of - 
 Intelligence. . 
 
 . Next whereashe lay s I made them without publifhing 
 them to the world in Prints he prevaricates, and would . 
 have it believed that they were notpublifhed to the 
 world, though they were , publickly read of in Sir John 
 Cutlers Leisures before great numbers at feveral times, and 
 though they were made and (hewn to thoufands both 
 Englifti andForeiners, and writ of to feveral perfons ab- 
 fent, and though they were in the year 1665. in'.the Hi¬ 
 story of the Royal Society publilhed to the world in 
 Print, becaufe, forfooth, they were not printed in his . 
 Tranfaftions. 
 
 Thirdly, whereas the Publifher of Tranfacfions makes 
 along dory of my feeing his Journal Defcavans^ and my 
 defiring to tranfcribe that part of it Which concerned . 
 this matter, as if I had requefted fome Angular, favour . 
 thereby. I anfwer, 
 
 Firft, 
 
( 54 ) 
 
 Firft, that he knew Idefigned prefentlyto have printed 
 it with Animadverfions, but he endeavoured to prevent 
 me, defigning firft clancularly to get a Patent of it for 
 himfelf, and thereby to defraud me. 
 
 Next, I fay, I had a right without his favour to have 
 feen,perufed,and copied it, as I was one of the Royal Sock, 
 ty , theintelligence he there brings in being the Societies. 
 
 Then it is denied that the Defcriber of Heliofcopes 
 well knew that theTranferiber of Intelligence would pub- 
 lifti it in hisTranfa&ions, though it was believed if the 
 publilhing it would injure me it would not be long con¬ 
 cealed 5 which was the foie reafbn of Printing in the fame 
 Tranfattions, viz. 112. a Letter' which he had feveral 
 years before. 
 
 Thirdly, Whereaj heaflerts that feveral difcoveries of 
 the Accufer had been vindicated from the ufurpation of 
 others. Itis anfwered, the clean contrary is upon good 
 grounds-fufpe&ed from the Publication of a Book about 
 Earthquakes, Petrifaftions,e^c. Tranflated and Printed 
 by H. O. the manner of doing which is too long for this 
 place. Such ways this mif-informer hath of vindicating 
 difcoveries from the ufurpation ofothers. 
 
 To his upbraiding me with his having publifhed fome 
 things of Mine; I anfwer,he hath fo,butnot fo much with 
 mine as with his own defire, and if he fend me what I 
 think worth publifhingl willdoas much for him, and re¬ 
 pay him in his own coyn. 
 
 Laftly, Whereas he makes ufe of We and Us ambigu- 
 oufly, it is defired he would explain whether he means 
 the Royal Society, or the Pluralities of himfelf If the 
 former, itis not fo, as I can prove by many Witneffes; if 
 the later, I neither know what he is acquainted with, or 
 what has been imparted or explained to him. 
 
 So not defigning to trouble my felf any further with 
 Him, unlefs he gives me occafion, I difmifs him with his 
 
 -- Speque mtaqtte 
 
 Prdcul hificpreciil ito. Ho. 
 
 FINIS.