\ PHILOSOPHICAL TRANSACTIONS. GIVING SOME ACCOUNT O F T H E Trefent Undertakings, Studies, and Labours OF THE INGENIOUS, IN MANY Confiderable Parts of the W orl d. Vol. XXXV. For July, Augnft, -September, Obfo- ber , November and ‘December 1717, and for the Year 1718. ~ f , L O N D O N: Printed for W. Innys, Printer to the Royal Society at the Weft End of St. Paul3%. « M.DCC.XX1X. * 1 i Numb. 401. PHILOSOPHICAL TRANSACTIONS For the Months of 'January , February , and March, 1728. The CONTENTS. I. The Anatomy of the Poifonous Apparatus of a Rattle-Snake, made by the Direction of Sir Hans Sloane, Bart. Praef. Soc. Reg. Sc Coll. Med. Together with an Account of the quid Effefis of its Poifon 5 by John Ranby, Effo Surgeon to his Majejlys Houjhold, and F. 5^. S'. II. A Letter from the peV. Vr . Samuel Clarke to Mr. Benjamin Hoadly, F- % S. occaftond by the prefent Contro'VerJy among Mathematicians , concerning the Proportion of Velocity and Force in Bodies in Motion. III. Aftronomical ObferVations made at Vera Cruz, by Mr. Jofeph Harris. (fierifed and communica- ted by Edm. Halley, LL.D. Aftron. Reg. Sc R. S. S. b b IV. A The CONTENTS. IV. A new Method for compojing a natural Hiftory o/Meteors communicated in a Letter to ©r.Jurin, R. S. Sc Coll. Med. Lond. Soc. By Mr . Ifaac Greenwood, Trofeffor of Mathematic h at Cam- bridge, New-England. V. Some ObferVations towards compojtng a natural Hiftory of Mines and Metals, communicated in a Letter: to Dr., Rutty; S. R. Seer. Sc Coll. Med. Lond. Soc. By Dr . Francis Nicholls, P rofeffor of Anatomy at Oxford. Vl« ObferVationes d fl-vonomic& balittc Ulyffipone, Anno 1726, a tfeV. P Joh. Baptifta Carbone. Soc. Jef Communicante Ifaaco Sequeyra Sa- muda, M. D. . 5. S. & Coll. Med. Lond. Lie . VII. Some Obj creations made in the DiffeElion of three Subjects 5 by Mr. Ranby, F. S. t I. The ( )77 ) I. The Anatomy of the Poifonous Apparatus of a Rattle-Snake, made by the J)ire£lion of Sir Hans Sloane, Bart, Pnef. Soc. Reg. &c Coll. Med. Together with an Account of the quid ^ Ejfetts of its Toifon 5 by John Ranby, Efq: $ Surgeon to his Majeftys Houfbold, and K (Zy. S'. TH I S Animal was fent from Virginia to an eminent Merchant, and having been by him prefented to Sir Hans Sloane , it whs plac’d in my Hands, on Purpofe to make fuch Experiments with it as might inform Mankind of the fatal Sym- ptoms which attend its Bite, and the Appearances in the dead Bodies of fuch Animals as have been bit by it. It is only by this Method, and a Number of Fads faithfully dated and compared with each other, that we may hope one Time or other to difeover the Man- ner of the Poifon’s operating, and perhaps ( a thing of the utmoft Confequence) to find out fome Remedies, internal or external, to relieve Perfons bit by it. The Anatomy of the Rattle-Snake having been fo accurate- ly deferibed by the late ingenious Dr. Tyfon , very little more can be added to his Account ; I fhall therefore only take Notice of th 0 Inftruments of its Poifon, fome of which are different from what that celebrated Anato- mift obferv’d. Removing then the common Integu- E e e ments ( 3 78 )' ments of the Head, the Mufcles that raife the poifon- ous Fangs appear • the firft of which arifes with a fhortr flefliy Beginning from the upper Edge of the lower Jaw, near the Articulation of one of thofe Bones which Dr. Tyfonc alls Maxillarum 'Dilatores (See Fig. i. A.) and fends a few carnous Fibres to the Side of the Cra- nium *, then becomes tendinous, and fo marches to its Infertion in the Outfide of the Bone which receives the poifonous Fang. ( See Fig. 2. ) Difplacing this Mufcle there appeared a Gland , (See Fig. 1. B.) about the Bignefs of a fmall Pea, which I take to be one of the Maxillary Glands, for the following Reafons: Firft , The Stru&ure of the Parts and its Diflance from the Fang make it unlikely to be defign’d for feparating the poifonous Fluid, but rather a Saliva to moiflen the Aliment, in order to make it pafs down the Oefo - phagus with Eafe, the Stomach of thofe Animals be- ing but fmall, and the Gullet confiderably larger • not without fome Analogy to the Ingluvies or Crop of Gra- nivorous Fowls, where the Food flops for fome time and is moiflened, before it is capable of defcending into the Stomach. Secondly , Thefe Parts are fo con- trived, that on opening the Mouth to receive the Prey (at which Time fuch a Fluid is mod wanted) the Mufcle above mentioned prefling on the Gland pro- motes the Difcharge of its Contents into the Mouth. The Fiuft of this Gland feems to open between the Upper Lip and the Jaw, but as the excretory Dudfs of fo fmall a Gland are rarely to be feen with Certain- ty, I won’t pretend exactly to determine its Aperture. Under this Gland lies another Mufcle fmaller than the former, which arifes and is inferted near it (See Fig. i„ G) thefe two Mufcles draw the Bone (. Fig . 1. D.) in which - ( 379 ;) which the poifonous Fang is fix’d a little outwards and upwards. Between the lafl defcribed Mufcle and Gland palVes a Nerve to the upper Part of the Bone which re- ceives theTooth(F/^.i.E.andJF;^.i.B.) and it is probable that this Nerve has been taken for the excretorfEucl of the Gland before mention’d. Opening the Mouth, two fmall Eminencies appear in the Fore-part on the Infide of the upper Jaw, being a Membrane , raifed by the Fangs and drawn over them like the Mouth of a Purfe (Fig, 3.A.B. Fig . z, C.) This Membrane is thick andftrong, and placed in a Microfcope, appears to have a Num- ber of Glands, fome of which are even vilible to the naked Eye. In a common Viper I obferved one on each Side the Fang. Thefe Membranes prevent the invo- luntary Difcharge of the Poifon out of the Fangs (which in my Opinion are the only Refofitories of that Fluid) into the Mouth, as alfo the killing with the Fangs lit- tle Animals on which they fometimes feed. Putting back this Membrane, the fatal Fangs appear, which on firft View feem’d to be only one on each Side, till fearching further there appeared four more ; the firft and largefl is fix’d in a Bone , which Bone is articula- ted to the fore Part of the upper Jaw (Fig. t. F.) The four others are fattened in and covered with ftrong ten- dinous Membranes, and lie as it were one over another (Fig.z, B. Fig . 3. C. and E.) Thefe Teeth are crooked and bent in this Form^efpecially the firft, and have each two T erf or at ions y the one on the upper Part, the other at the lower Part of its convex Side } which lafl comes quite to the Point, and refembles the Hoping Cut of a Pen. The upper Perforation (Fig. 4. A.) I imagine receives the Poifon, the other tranfmits it into the Wound (Fig. 4, B.) All thefe Fangs are tubular , the Ee e i largefl ( ) large# of which contained a finall Quantity of a tran - /parent Fluid of a light yellowifh Colour, which on putting the Snake into Spirit of Wine changed to a beautiful Red (the Fangs of the common Vipers I have examined had the lower Perforation nearer the Middle) Freeing the Mouth of the Membrane, a Muf- cle appears about the Size of the fir# defcribed above, which arifes from the Middle of the Maxillarum cDi- latores ( Fig . 3. D.D.) and is inferted on the under Side of the larged Tooth, for the Force required to pull down the Fang being lefs than to raife it, fewer Muf- cles are required. This Animal was in my Cudody about a Month, during which Time he bit three Dogs, and a Cat ^ the two fird were bit at the College ofFhy * Jicians^ and of thefe the fird died about two Minutes after the Bite, and the Moment he was bit he grew convulfed, and lodtheUfe of his Limbs. TheWounds were exceed- ingly finali, and between the pe&oral Mufcles. Upon opening the Dog, the Skin and Membrana Adipofa for the Breadth of a Crown were livid about the Wound, as if from a violent Blow. The fecond Dog bit at the College had tide fam£ Symptoms with the fird, but liv’d near a Quarter of an Hour, and had bloody Stools. Three Days after, I carried the Snake to bite another Dog and Cat. The Dog was larger than either of the two former, and having been bit at the Extremity of the Nofe he was immediately affe&ed, howled, fhook, fell down and foamed at the Mouth ; and in about ten Minutes difcharged his Excrements involuntarily, tinged with Blood : He died in about two Hours. The next Day I opened the Body arid obferv’d the Abdomi - nal Contents very much inflamed, efpecially the Sto- mach and lntedines> wjiich appeared nearly equal to ( 3 § i ) the fined Inje&ion ; opening the Stomach and Intedines they contained a mucous Matter, the greateft Part of which was Blood, and the fine villous Coat which is fo vifible in thefe Animals was entirely dedroyed. A- bout an Hour before he was bit he had a plentiful Meal of coarfe Beef, of which there was not the leaft Appearance. Opening the Thorax , the Fleura and other Membranes looked as if inje&ed } the Heart was turgid with Blood, as were alfo its Veflels. The VelTels of the Membranes of the Brain made a mod beautiful Figure from the Quantity of Blood .contained in them, as did likewife the Blood-Vdfels of the Nerves ^ there was a fmall Quantity of Water between the two Hemi- fpheres. The Blood contained in the Heart and its Veffels was an even Mafs about the Confidence of Cream. The Cat had upon opening nearly the fame Ap* pearances, and lived about five Hours. ’ f * . a" • ;v‘r V ; . . . • * > . r • — — 1 1 - ' ' V fc fc- v ( vy.; y, y •; -Sf £■**♦ ‘ II. ' A Letter from the (^ev. Dr. Samuel Clarke to Mr. Benjamin Hoadly, F. % S . occafiond by the pre/ent ControVerfy among Mathematicians , concerning the Proportion of Velocity and Force in Bodies in Motion. S 1% IT has often been obferved in general , that Learn- ing does not give Men Dnderjlanding ; and that the abfurdeft Things in the World have been afferted and maintained, by Perfons whofe Education and Stu- dies ( 3 82 ) dies fhould feera to have furnilh’d them with the greats eft Extent of Science. That Knowledge in many Languages and Terms of Art , and in the Hiftory of Opinions and Romantick Hypothefes of Philofophers, ftiouid fometimes be of no Efted in correding Mens Judgment , is not fo much to be wonder’d at. But that in Mathematic ks them- felves, which are a real Science , and founded in the necejfary Nature of Things } men of very great Abi- lities in abftrabl Computations, when they come to ap~ ply thofe Computations to the Nature of Things, ftiouid perfift in maintaining the moft palpable Abfurdities , and in refuting to fee fome of the moft evident and ob- vious Truths , is very ftrange. An extraordinary Inftance of this, we have had of late Years in very eminent Mathematicians, Mr. Leib- nitz, Mr. Herman , Mr. 'sGravefande , and Mr. Ber- noulli ; who (in order to raife a Huft of Oppofition a- gainft Sir Ifaac Newton's Philofophy, the Glory of which is the Application of abflraEl Mathematicks to the real Thcenomena of Nature,') have for fome Years infilled with great Eagernefs, upon a Principle which fubverts all Science, and which may eafily be made appear (even to an ordinary Capacity) to be contrary to the necejfary and ejfential Nature of Things. What they contend for, is, That the Force of any Body in Motion , is proportional, not to its Velocity , but to the Square of its Velocity „ The Abfurdity of which Notion, I fhall firft make appear, and then (hew what it is that has led thefe 'Gentlemen into Errour. In the Nature of Things, ’tis evident, every Ejfe6l mull neceffarily be proportionate to the Caufe of that Effed; ( 383 ) Effed ; that is, to the Att'ton of the Caufe, or the \ Tower exerted at the Time when the EfFed is pro- duced. Tofuppofeany EjfeEt proportional to th t Square or Cube of its Caufe , is to fuppofe that an EjfeEl arifes partly from its Caufe , and partly from * Nothing . In a Body in Motion , there may be conlidered di- ftindly, the Quantity of the Matter , and the Velo- city of the Motion. The Force ariling from the Quan- tity of the Matter as its Caufe , muff necelTariiy be proportional to the Quantity of the Matter : And the Force ariling from the Velocity of the Motion as its Caufe , muft necelTariiy be proportional to the Velocity of the Motion. The whole Force therefore ariling from thefe two Caufe s, muft necelTariiy be proportio- nal to thefe two Caufes taken together. And there- fore in Bodies of equal Bignefs andfDenfty , or in one and the fame Body , the Quantity of Matter continu- ing always the fame, the Force muft necelTariiy be always proportional to the Velocity of the Motion. If the Force were as the Square of the Velocity, all that Bart of the Force , which was above the Broportion* of the Velocity , would arife either out of Nothing , or (according to Mr. Leibnitz! s Philofophy) out of fome * Which is juft like the Suppofition made by thofe Mathematicians, who have taken it for granted, that | is equal to Infinite-, that is, that as o to 1, fo 1 is to Infinite that is, that Infinite multiplied by o, is equal to 1, or an infinite Number of Nothings equal to Something ; which is pal- pably falfe. The true Proportion is, not as o to 1, fo 1 to Infinite ; but as an lnfinitefimal is to 1, fo is 1 to Infinite. And as the Infinitefimal of an Infinitefimal (that is, a fecond Fluxion, or the fecond Power of Infinitefimal) is. to 1, fo is 1 to Infinity of Infinites, or the fecond Power of Infinite that is, (for Inftance) *tis as a finite [phyfical] Line to an Infinite Surface, or as a finite [ phyfical ] Surface to an infinite Solid. And as o (which is beyond alt Proportion lower than the Infinit'th Power of an Infinitefimal ) is to 1, fo is 1 to that which is beyond all Proportion higher than the Infinit'th Power of Infinite. Which clearly removes the Foundation of all the ridiculous Confequences, which have been drawn from the Suppofition of the fore-mention’d falfe Proportion, ( 3^4 ) living Soul effentially belonging to every *P article of Matter . Whenever any Effect whatfoever, is in a duplicate \ Proportion , or as the Square of any Caufe ^ his al- ways either becaufe there are two Qaufes acting at the fame Time , or that fame Caufe continues to aft for a double Quantity of Time. The Reflftence made to a Body moving in any fluid Medium , is in a duplicate Proportion to the Velocity of its Motion * becaufe, in Proportion to its Velocity, it is refilled by a greater Number of T articles in the fame Time \ and again, in Proportion to its Velocity. , his refitted by the fame T articles fingly with a great - _er Force , as being to be moved out of their Places with greater Velocity. Light decreafes in a duplicate Propartion of its Di- ftance from the Sun ; becaufe the Rays divaricate ac- cording to two Dimenfions ^ according to the Dimen- (ion upwards or downwards , and according to the Di- menfion flde-ways. But according to the third Dimen* (ion forwards from the Sun, a Ray of Light undergoes no Alteration ; becaufe the Particles, of which it con- (itts, being emitted all of them with an equal Velocity, continue every where at an equal Diftance from each other. One and the fame Caufe, afting in a double Quan- tity of Time, produces the fame Effeft, as two equal Caufes afting in a Jingle Quantity of Time. One and the fame Force , in two Parts of Time, will caufe a Body in Motion to defcribe the fame Space , as double the Force would do in one Part of Time. The Space defcribed therefore by a Body in Motion , is not as the force ; but as the Force and the Time taken together. ~ A if 3 85 ) A Body, with any the leaf l ajjignable Force, will move through infinite Space , if it meets with no Reftftence, in an infinite Time . And in Spaces where there is an uni - form Reftftence to Motion, the Space defcribed before the Motion ceafe?,muft needs be as the Force and as the Time together: Becaufe a double Force will carry a Body twice as far in the fame Time , and will alfo caufe the Motion to be twice as long Time in defray- ing by an uniform Reftftence. The Space defcribed therefore before the Motion ceafes, is in this Cafe de- monftrably as the Square of the Force. A Body thrown upwards with double Force , will be carried four Times as high, before its Motion be flopp’d by the uniform Reftftence of Gravity ; becaufe the double Force will carry it twice as high in the fame Time , and moreover require twice the Time for the uniform Reftftence to deftroy the Motion. The Cafe is the fame in accelerated Motion, in Bodies acceleratedby a Succeflion of elaftick Impreflions, or falling with a Motion accelerated by the uniform Power of Gravity, or by any other uniform Power whatfoever. The Space defcribed muft needs be as the Force , and as the Time wherein the Force operates. What 1 have thus demonftrated concerning any Force , conftdered as the Caufe producing an Effed-, and con- cerning the Time , during which the Force operates; is on all Hands acknowledged to be true concerning Velocity . And therefore V elocity and Force , in this Cafe, are one and the fame Thing. So that to affirm Force to be as the Square of the Velocity , is to affirm that the Force is equal to the Square of it felf. Now from hence appears very clearly the Ground of the Errour thefe Gentlemen have fallen into, and F f f of f *8 6. ) of their Mi fabrication of the Experiments they build upon. The Effect of a Force itnprefs’d on a moveable Body, is the Motion of that Body from cne Place to another. Now forafmuch as the Effeffi cannot but be proportional to its Caufe , hence Mr. Leibnitz (whom the other Gentlemen have follow’d) contends that the Space deferih'd by a Body in falling, is proportional to the Force by which it is impell’d during its Fall , and that the Force acquir’d by a Body in falling, is proportional to the Space it has deferibed in its Fall. Which Space being agreed to be as the Square of the Velocity (as being proportional to the Velocity and to the Time taken together ) hence they infer that the Force likewife is as th t Square of the Velocity. But from what has been faid, ttis plain, that the Space deferibed in thefe and all other the like Cafes, is not as the Force only, but as the Force and as the Time wherein the Force ads ; that is to fay, as the Square of the Force. For the Caufe of the Quantity of the Space deferibed , is not barely the Quantity of the Force , but alfo the Continuance of the Time wherein the Force ads. The Force therefore and the Time taken together , being necettarily as the Space deferibed } as the Velocity and the Time taken toge- ther, are on all Hands acknowledg’d to be ^ it follows that the Velocity and the Force are equal, and not the Force as the Square of the V zlocity. When two unequal Bodies fattened at the Ends of the Arms of a Balance of unequal Length , counter- poife each other, and vibrate in equal Times ^ as they mutt necelfarily do, being fafened to the Arms of the fame Balance : which is an Obfervation Mr. Leibnitz lays great Strefs upon : In That Cafe indeed the Forces ? will ( j8r ) ‘ will be as the Spaces defer ibed. But not therefore as the Squares of the Velocities . For in That Cafe, the Velocities themfelves are as the Spaces deferibed \ becaule the Times are equal. When a Body projected with a double Velocity , en- ters deeper into Snow or foft Clay , or into a Heap of fpringy or elaflick Parts, than in Proportion to its V locity ^ ’tis not becaufe the Force is more than pro- portional to the Velocity ^ but becaufe the "Depth it penetrates into a foft Medium, arifes partly from the Degree of the Force or Velocity, and partly from the Time wherein the Force operates before it be fpent. In the Colhfion of hard Bodies, his (1 think) agreed on all Hands, that ’tis demonft rated by Reafbn 9 and confirmed by Experience ; that when a perfectly hard Ball, moved with whatever Degree of Velocity , flrikes full upon another hard Ball, equal in Bignefs and Weight, and without any Motion in it *5 if the Balls be unelaftick , they will both go on together the fame Way, dividing the Motion equally between them, with half the Velocity the nr ft Bali had originally : But if they be perfe&ly elaflick , the moving Ball will com- municate its whole Motion and Velocity to the quie- feent Ball, and it felf lie f ill in the others Place. Were it true now, that the Force of the moving Ball was as the Square of its Velocity ^ thefe Experiments would then lhew (which is infinitely abfurd) that the Force or vis inertia in the quiefeent Ball, the dead Force, was always proportional to the Square of the Velocity (which thefe Gentlemen affect fantaftically to call the living Force) of the moving Ball, whatever its Velocity were. Or the Force in Both might juft as reafonably be fuppofed to be as the Cube , or the qua - drato-quadrate, or any other Tower of the Velocity of the moving Ball, Which is turning the Nature Fffx of % ( 3g8 ) of Things into Ridicule. Mr. Leibnitz , in Tome Let- ters which he wrote into England , intimated' that he had a Profped of a perpetual Motion , founded cn> the Notion of a Vital Principle , or active Tower in Matter. But from the Experiments now mention- ed, ’tis evident that if the Force of Bodies in Motion could be exalted even to the infinifth Tower of their Velocity ; yet fince, to anfwer the Phoenomena of Na- ture with Regard to Action and Re-affion, the fame Force mud neceifarily be allowed to all quiefcent Bo- dies likewife , it could be of No Effect. III. Agronomical ObferVations made at Vera Cruz, by Mr. Joieph Harris. TpVifcd and communica- ted by Edm. Halley, L. L. D. Aftron. Reg, ! & R. S. S. THE Latitude of this Place I found (by feveral didant Obfervations made by a Quadrant of four Feet Radius) to be 19° it! N. On March 11, 172,7. O. S. there happen’d here a confiderable Eclipfe of the Sun, the greated Obfcura- tion being about 10 f Digits ^ and having that Morning carefully adjuded the Pendulum Clock, and fixed a Telefcope to the Index of the forefaid Quadrant, I ob* ferved it to begin in or about the $ . E. by S. Part of the Sun’s Disk at 49 f Minutes after Noon apparent Time ; the Altitude of the Sun’s Center then ,was 67® 53'. We could not determine exa&Jy the Middle of this Eclipfe, but as near as we could judge, it happen’d about zh 3om P. M, The ( t*9 ) The Eclipfe ended in or about the A7", N.E, Part of the Solar Disk, at 3h 5*9'* P. M. at which Time the Sun’s Altitude was 2,8° 34'. By comparing thefe Obfervations with a Calculation which I made from Mr. Flamflead’ s Tables, I judg’d Vera Cruz to lie 970 30' to the Weftward of the Me- ridian of the fa id Tables. We had here alfo a Lunar Eclipfe September zqc 1 716, O. A. b ut it happen’d to be a little cloudy about the Time of its Beginning and Ending, fo that we could not get a juft Obfervation. In the Years 1 726, and 17x7, I obferved here the Magnet ick Variation feveral Times,. and found it to be about z\ Degrees Eafterly. We alfo obferv’d the Variation feveral Times on our Voyage from England towards Vera Cruz ; (having on Board a good Azimuth Compafs)but I always found that the beft Obfervations we could make, when compared together, differ’d fo much, that we could not depend upon them, to much lefs than three or four Degrees,, or fometimes half a Point of the Compafs. IV. A \ C 390 ) IVf A new Method for compofing a natural Hijlory of Meteors communicated in a Letter to Dr.Jurin, R. S. & Coll. Med. Lond, Soc. By Mr. Ifaac Greenwood^ Brofeffor of Mathematic kyat Cam- bridge, New-England, Honoured Sir > TH I S Method in general is, that in Addition to fuch Obfervations as fhould be made on Land, there might be fome Account taken of thofe alfo that were made at Sea j which already are by far more nu- merous than what were ever made afhore, or indeed what can be expe&ed thence for fome Ages dill to come. This Method occurcd to me, as I was looking over va- rious Journals of Voyages in my Paffage from Eng- land^ in which 1 was not a little furpriz’d to find tne following Particulars conftantly obferv’d. Firfi1 There was a general Account of the Weather for every Day, during the Paffage of the Ship on the Voyage, which tho’ not quite fo exad as the Obferva- tions of the fame Kind that have been made on Land, particularly what were publifh’d by the Rev. Mr. 2Vr- ham , yet for all that I know, are fufficient for the De- fign. However, if there is any Defed in this Article, it is abundantly made up in another Column • which is a far more exaft Regifler of ih z'Dire Elion of the Winds than was ever kept afhore , being an Account thereof to every two Hours in the Day, This Article may per* ( ) haps be of very great Importance ; fince, as you obferve, Compertum habemusy ut quod maxime , fubitas tem- po fiat um commut at tones Vends pracipu'e accept as ejTe refer endas. As for the ‘Degree or Strength of the Wind there are alfo fuffi'cient Data in all Sea- Journals to de- termine it3 as I fhall particularly fhew in the Sequel of this Letter. Laftly, there is a daily Account inferred of the Latitude and Longitude of the Ship, that there will be no Difficulty in computing what Part of the Globe each Obfervation belongs to. And now fince there is in the World a great Variety of thefe Marine Obfervations already made, (for in all Voyages what foe ver that have been perform’d for many Years pad, it has been cudomary to keep an exad Jour- nal of the aforefaid Articles,) I thought it might be no difficult Matter to colled therefrom the Hiflory of the Winds, and Weather in mod Parts of the Ocean. In order to this, I imagin’d that if the Royal Socie- ties of London and Daris fhould encourage fuch a De- fign, they might eafily procure Extracts from mod of the Journals kept in their refpedive Nations : For cer- tainly fuch Gentlemen as would be at the Pains to keep a condant Diary of the Weather, would not fail alfo to communicate fuch Marine Obfervations , as they fhould be able to obtain. The Seamen likewife themfelves, (among whom there are a confide rable Number of fuch as have a 'Fade for phyfical Knowledge) as they are under a Kind of Neceflity to obferve exadly the Winds , &c. would not be backward in tranfmitting their Obfervations ; efpe- cially when they were informed of what Importance and Advantage it might be to themfelves, and the Caufe of Navigation ♦ I pro- I < 3 9i ) I proceeded further to think, that if the aforefaid Societies fhould judge it improper to be at fo great an Expence as would be requifite in printing fo many Ex- tracts from fuch Journals as fhould be fent to them; that they might notwithftanding keep in Manufcript a Book of Tables of fuch Marine Obfervations , as they fhould think, fit to colled: therefrom ; and that the Secretaries of the Society (who for the mofl Part are fuch Gentle- men as have in a particular Manner difcover’d a gene- ‘ rous Principle of promoting Natural Knowledge) fhould take Care, that all fuch Obfervations were transcribed in their proper Places. The Form of thefe Tables I thought might be in the following Manner. January the Firjt , 1726. Longitude. 20. | 21. 1 , 22. r po H. W. D Weather. W. D. Weather. ! W. D. Weather. r—f ►— * • 12. N. 2. Fair. P a- 6. (D 12. NbE 3. Fair. • . 30. 6. — . — 12* SbE 2. Cloudy. 6> 2. Rain. 12. S 3. Stm.ofRain. 31. 6. SbE 2. Rain. In which the Title fhews the Tear , Months and T)ay^ the horizontal Space juft below it, the Longi- tudes^ the vertical Space without the double Lines, the Latitudes ^ that within the double Lines , the Hour of the Day } and the horizontal fpaces under the Longi- tudes, ( 39? ) tuclc?, the Wind , its 'Degree , or Strength , and the Weather , which are accordingly mark’d with W. D. Weather. In this Specimen 1 have noted every Degree of Lati- tude and' Longitude, that the Work might be the more perfect. I have only taken Notice of Four Hours in the Day, viz. 12 at Noon, 6 in the Afternoon, n at Night, and 6 in the Morning. However, if there be requir’d a greater Exa&nefs in this Article, it will be eafy enough to frame Tables accordingly. I be- gan the Hours with 12 at Noon, becaufe all Journals are kept from that Period, the Marine Day being al- ways counted from Noon to Noon. There may be other Columns inferted, as I fhall mention in theClofe of this Letter, tho’ what I have already taken Notice of is fufficient to our prefent Defign. Of thefe Sort of Tables there mud be at leaffc Four Volumes-, One for the Atlantick Ocean , which will be by far the larged of them ail, and perhaps the mod: profitable, as mod of the Trade of the World lies there- on j the fecond for the Mediterranean ^ and the others for the German Sea and Baltic k. In Procefs of Time alfo, it may perhaps be thought worth the while to pre- ferve fuch Obfervations as are made on the Indian Sea , and the Bacific Ocean . I mufl acknowledge my felf incapable of making a juft Comparifon between the Advantages and Inconve- niences attending fuch a tabular Regifier of the Winds and Weather, as 1 have propofed } however, I will take the Liberty to mention one or two Things, by which you will fee how the Matter appears unto me. It mud be confefs’d, that the Work will be very much protra&ed, and require fome confiderable Appli- G g g cation I ( 3?4 ) cation and Care in extrading fuch Obfervations, as fhall be of Ufe, from Journals. There will alfo be fome Dif- ficulty in procuring any confiderable Number of fuch Journals \ and laftly, there is but a very frnall Num- ber of Obfervations made, in Comparifon to the Spaces that muft be allow’d in the Tables for them, by which Means there muft neceffarily be a great Wade. In x^nfwer to thefe Objedions, it may be faid in ge- neral, that there will be much lefs Application and Care requir’d than in keeping a ‘Diary of the Weather, &c. on the Land. By this Means alfo, there may be more Obfer- vations colleded in a few Years, than can be expeded from the other Method in fome Ages j and one Man may be able in a few Months, hereby to compile a lar- ger Hiflory of the Weather, than what has hitherto been done by the united Obfervation of all fuch, as have undertaken this Province. Tho’ there might bg fome Difficulty as to f articular i Verfons in procuring a great Number of Journals, it cannot be fuppos’d, that fo illuftrious a Body of Men as the Royal Societies at London and Baris, ffiould meet with the fame. It is obfervable alfo, that in the Royal Navy of Great-Britain , the Mailers of the Mathema- ticks are oblig’d to keep fuch a Journal by an Ad in the late Reign, on Board every Ship, which without Doubt might be eafily obtained on this Occation : Nor can we imagine any in the trading Intereft would re- fufe a Thing, that tended fo much to their own Advan- tage and Benefit. It is true, there can be no Remedy for- the many em- pty Spaces in the Tables, ( if that Method be follow’d which I have propos’d ; ) however this will be look’d upon as a trifling Objedion, by fuch as confult the Im- provement ( 395 ) provement of Natural Knowledge , rather than the Wafte of Paper. I (hall conclude thefe general Remarks, by obferving, that as the Hiftory of the Winds and Weather is capa- ble of a more fpeedy and expeditious Improvement from Marine Obfervations than from Diaries from the Land> fo alfo it is capable hereby of a more large and exten- five Improvement. Without Doubt it will require ma- ny Years before Obfervatories of the Weather, &c. will be ereded at all the ‘Cniverftties and Capital Towns of the *P r ovine es, Shires , die. in Europe , (if ever fuch fhould be,) not to mention Africa , Aft a, and America , from which little can be expeded in this Affair-, and yet upon that Suppofition, how few would the Diaries be, in Comparifon of the great Number of Journals that are annually kept at Sea ? belides many Thoufands that might perhaps be obtain’d, relating to the Courfe of the Winds and Weather, fucceflively for many Years laft paid. It is beyond my Abilities, in- deed, to calculate with any Exadnefs, how many Vef- fels there may be upon the Seas which I have named, in the Space of one Year, and confequently how many diftind Journals there are annually kept } however, if I may judge from the Trade of the little Town, where this Letter is dated, there mull be many Thoufands : For there are feldom lefs than eight or nine Hundred Voy- ages made to and from this Port in a Year. I fhall only add in this Place, that the Method here propos’d feems to have the Advantage of the common Method hereto- fore ufed in compoling the Natural Hiftory of Mete- ors ; inafmuch as that requires a particular Applica- tion and Attention without any other Views and Advan- tages ; whereas in our Cafe there is a Kind of Neceflity G g g a of ( 396 ) % of making fuch Obfervations, in order to condud a Ship fafely thro* the Ocean, whether the philofophical Part of Mankind (hall think fit to improve them in their In- tereff, or no : However, I would not be underflood, by any Thing that has been faid upon this Head, to dero- gate from the Defign of obferving on Land , for that likewife has many Advantages, that we can by no Means pretend to in the New Method. I fhould protract my Letter to anunreafonable Length* did I enter profeffedly upon the particular Advantages and Benefits, that may accrue from fuch a Tabular Re- gifter of Marine Obfervations , as I have propofed. I lhall mention therefore only two Things. Firfty We may be able from this Method to define with a great deal of Exadnefs, the Bounds and Limits of all confiderable Winds j for as there are at all Times in the Year fome Hundreds of VefTels at Sea, it is of the fame Importance in our Cafe, as tho’ there were fo many diflant Cbfervatories there j and that the Know- ledge of thefe more extenftvem& general IVinds would be of confiderable Ufe, none will deny, that fhall at- tentively confider it ; for hereby we may be able to judge, in what Place fuch a Wind has its Origin, how long a Time it continues, with what Velocity it moves, where its greatefl Strength is, and how great a Part of the Earth it paffes over. Perhaps alfo, in Procefs of Time, by this Means, we may arrive to fo much Skill, as to judge with fome confiderable Certainty, from the Rife or Beginning of a Wind, what its Effed and blue lhall be \ which will be of as great Importance in Navi- gation,, as any Thing flill wanting. Again, from fuch Marine Obfervations of the more extenfive and lading Winds, it is not impoflible, that we fhould be able to. make C 3 97 ) make a probable Judgment of the Effed and Influence of the Wind upon the Weather ; which, for what Caufe I know not, I have frequently obferved at Sea, to change and alter, according as that doth. Secondly , From collecting all fuch Meteorological Obfervations as are made at Sea, we may reafonably expect to come to the Knowledge of fuch Winds, as pre- vail moft in particular Latitudes. Tho’ the Wind is a very uncertain Meteor, there is no Doubt, but rhat in fome Places, it has a very different Courfe from what it has in others. If I miftake not alfo, it has been fre- quently obferved, in fome particular Places, that the Courfe of the Wind in one Year has been much the fame as in others and tho’ there has been no particu- lar Order or Exadnefs yet difcover’d, yet the prevalent Winds, ox the greater Number of Winds have been, in both Cafes, according to the fame Diredion : In thefe Parts of the World it is remarkably fo. We can’t, in- deed, exped to difcover the Reigning or Prevalent Winds of fuch Latitudes , as are very diffant from the Tropic ks, by as eafy an Obfervation, as the Trade- Winds and Mon/dons , which are in the Torrid Zone , were firft found out. However as it has been after many Obfervations, that the Courfe of tho Fix'd Winds was determin’d, we may alfo hope, that Time and In- duftry may bring us to a much better Knowledge than what we have at prefent, of thefe which are more Va- riable. I need not fay of how much Importance it would be to the Trading Part of the World, were we able to define the more frequent and reigning Winds of every Climate ; for as -the Probability of Voyages might then be calculated in the fame Manner as that of other Chances, the Sailor might then better know ( 398 ) know how to order his Courfe fo, as to arrive with the moft probable Difpatch to his Port. It may not be impoflible alfo, from a protracted Series of Sea Obfervations , not only to know the general Courfe of the Winds in every Climate in the whole Year, but alfo to make a very probable Judgment of the reigning Winds of the feveral Seafons of the Tear , and perhaps of every Month too : Which if it could once be obtained, we (hould have nothing more uncertain in Navigation , than that it was a TOodirine of Chances , which might be mathematically calculated. I lhall mention under this Head but one thing more, which we may with all the Probability imaginable ex- pe& to arrive to, viz. the particular Seafons, Signs, and Places of the Tornados and Hurricanes . The EffeCt of thefe are in many Cafes fo fatal, that they call for all our Skill and Obfervation : And could the Hiftory hereof be fo fucceffively known, as that we might be able to draw any certain Conclusions from it relating hereunto, it might perhaps be a fufheient Recompence for all the Care, that is requir’d, in the whole Collection of Marine Obfervations. I might add in common to the two foregoing Heads, that the Marine Obfervations have much the Advan- tage of fuch as are made on Land , (which notwithftand- ing are of very great Service,) inafmuch as they are not obnoxious to any external Accidents, as thefe are ; the Winds afhore being frequently interrupted in their Courfe, and often diverted therefrom, by intervening Mountains, Valliesor Promontories. Were I allowed to reckon among the Advantages of this New Method of obferving on the Winds and Wea- ther, thofe incidental Obfervations, that might be found ( 199 > in Journals , of general Benefit to Mankind, they are perhaps alone diffident to engage us in the Work. I (hall only hint here, that if it (hould be thought pro- per to pra&ice our Defign, it may perhaps be worth the while to infert into the Meteorological Tables , fuch Observations as relate to the Variation of the Compafs and Currents ; the true Knowledge of which would be of no inconfiderable Service to Navigation . If likewife there was a Column left for fuch remark- able Accidents as did occur, it might not be amifs \ par- ticularly, any uncommon Difcoveries of Lands, Rocks, or Soundings ; excefiive Thunder and Lightning, &c. Luminous Appearances in the Sky j what Remarks may be found relating to the Water-Spout, which tho’ per- haps one of the mod curious Phenomena of Nature, is as little known as any whatfoever* Submarine Hiatus or Wirlpools, if any fuch there be:, and laflly, any ex- traordinary Rendezvous of Fifh, &c. that are ufed in the Affairs of Life, not to mention fuch Descriptions, as may relate to Matters of meer Speculation and Curiofity. But thefe Sort of accidental Advantages, in fuch a Colle&ion of Journals of Voyages, as is necelfary to our Defign, are too numerous to be infilled on : I (hall therefore only add one more, which is the great Im- provement there would hereby be given to Geography , a Science of the greateft Ufe and Importance in the Af- fairs of Life. Not only all Hydrographical Charts might be by this Means corrected, and brought to the Truth, which is of fo much Concern, that the Lives of a great Part of fuch as go to Sea depend upon it ; but alfo, the Diftances and Situation of all Sea-Torts, and many other Things, which are uncertain, or wanting in that Science, determin’d with the greatefl Exa&nefs. 1 ' In ( 4°° ) In a Word, Geography may, by fuch an Expedient, ar- rive, in a very expeditious Manner, to as great a Degree of Perfection, as it is capable of. I fhali have finifh’d my Defign in this Letter, when I have taken Notice of the Method of determining the Degree and Strength of the Wind, from fuch ‘Data re- lating thereunto, as are to be found in Sea-Journals * which in general is, from obferving how many Knots the Veffel goes at the Time of Observation ; which is always inferted in the Day-Book or Journal , or, in other Words, what Velocity the then has; for the Strength of the Wind may, with Exadnefs enough, in this Affair, be judg’d of from the Effed it produces, or the Motion it communicates to the Ship. It is true, there will be fome confiderable Difference in this Re- fped, arifing from the Shape and Burthen of the Vef- fel : However, as we do not exped a mathematical Ex- adnefs in this Article, after a little Ufe and Experience, together with comparing the greateft Velocities of dif- ferent Ships together, a Perfon may feldom fail of judg- ing of the Strength of the Wind, at lead to a fourth Part ; that is, if according to the Method you propofe in your Invitatio ad Obfervationes Meteorologicas , the greateft Winds be exprefs’d by 4, and the lighted by Dnity. In Oblique Winds , the Strength or Degree thereof will not be diredly proportional to the Velocity of the Veffel, but mud be correded a little ^ however, there will be no Difficulty in this Matter. For fuch as are acquainted with the Method of refolving Oblique * Towers into Dire 61 ones , may eafily compofe a Table of ‘Proportional Parts fuited thereunto. I did intend to have inferted fuch a Table ; but I am afraid I have ( 401 > already trefpafs’d in the Length of this Epiftle, and {hall therefore only add, at prefent, that I am, J I i ‘ ' • 1 ? * - f With the utmoft Sincerity and Refpeft, r ' I { ; * . . ^ „ r V V Tour moft obedient , and i devoted humble Servant , Ifaac Greenwood. * J i 1 V .* ' ‘ * [ W r -» • ' ' * f POSTSCRIPT. SINCE my writing the foregoing, I have thought on a Method of keeping the Meteorological Tables therein propofed, whereby the Work will be very much contra&ed. This is, inftead of conftru&ing the Tables according to the Oceans whereon the moft confiderable Trade of the World lies, to frame them only according to the Route of the moft common Voyages on thofe Seas. Thus, may one of the Tables be contin’d to that Part of the Atlantic k Oceany which fuch Ships gene- rally pafs over, that Trade between Great -Britain and the Weft Indies •, another Table for thofe Parts of the Ocean , that lie in the Paffage of fuch Ships as are enga- ged in the Mediterranean , or Turkey Trade , to which may be added a Table for the African , and India Commerce. Another Table may be framed to that Part of the Ocean , that lies between the Northern Pro- vinces in America and the Weft Indies \ as alfo one for the Ships that pafs between New-England , and H h h New • C 4° ^ New- Tor k and Britain , which on the Northern Part may be made fo wide as to take in the Newfoundland Trade, &c. But l (hall mention no more Particulars j for in the fame Manner it will be eafy to confftud Ta- bles to all thofe confiderable Parts of the World, to which Voyages are perform’d. V. Some ObferVations towards compojing a Natural Hiftory of Mines and Metals, conwiunicated in a Letter to Dr. Rutty, S. R. Seer. Coll. Med. Lond. Soc. By Vr. Frank Nicholls, Profeffor of Anatomy at Oxford. Dear Sir3 IN Obedience to your Commands, I here fend you the Particulars of what I obferv’d during a Year’s Stay in the Weftern Part of Cornwall , concerning Mines , die. Mines in general are Veins or Cavities within the Earth, whole Sides receding from, or approaching nearer to each other, make them of unequal Breadths in different Places ^ fometimes forming large Spaces, which are call’d Holes. They are fill’d with Sub- ffances, which, whether metallic!*, or of any other Na- ture, are term’d the Loads. When the Subftances form- ing thefe Loads are reducible to Metal, the Loads are by the Miners faid to be alive ; otherwife they are term’d dead Loads . In ( 40? ) In Cornwall and ^Devon the Loads always hold their Courfe from Eaftward to Weflward ^ tho’ in other Parts of England they frequently run from North to South. The Miners report, that the Sides of the Load never bear in a Perpendicular, but conflantly underlay either to the North or South. The Mines feem to be, or to have been, the Channels thro* which the Waters pafs within the Earth j and, like Rivers, have their fmall Branches opening into them in all Directions ; which are by the Miners term’d, the Feeders of the Load. Moft Mines have Streams of Water running thro* them, and when they are found dry, it feems to be owing to the Waters having changed their Courfe, as compell’d to it, either becaufe the Load had flopp’d up the antient Paffages, or that fome new and more cafy ones are made. The Load is frequently intercepted by the crofting of a Vein of Earth, or Stone, or fome different metallick Subfiance. In which Cafe it generally happens, that one Part of the Load is moved a conftderable Diflance to one Side. This tranfient Load is by the Miners term’d a Flooking ^ and the Part of the Load which is moved, is, in their Terms, faid to be heaved. This heaving the Load would be an inexpreflible Lofs to the Miner, did not Experience teach him, that, as the Loads always run on the Sides of the Hills, fo the Part heaved is always moved towards the Defcent of the Hill. So that the Miner working towards the Afcent of the Hill, and meeting a F lookings confiders himfelf as working in the Part heaved ^ wherefore cutting thro' the Flooking , he works upon its Back towards the Afcent of the Hill, till he recovers the Load, and vice versa. H h hi Thus ( 4°4 ) Thus in Figure the firfl, A D (hews a Load running in the Side of a Hill, B the Feeders , C the Flook * D is the Part heaved . Sometimes, tho’ not conftantly, the Mine is lined with an intermediate Subftance between the Load and it felf. This is (properly fpeaking) the Wail of the Load: Though, in the common Acceptation of that Term, it fignifies either fuch intermediate Subftance, or the Side of the Mine, where the Load immediately unites it felf to it. Thus in Figure the fecond , A is the Side of the Mine, B the intermediate Wall of white Mundick, C the Load of Copper. And in Fi- gure the third , A B the two Walls of Spar-Stone , C a fmall Vein of Fin Oar . The Springs in thefe Parts are always hard, as a - bounding very much, either in ftony, or fulphureo - f aline Particles. From this Water thus faturated with ftony Par- ticles, we frequently find the Paffagesof the*W ater un- der Ground, either partly, or totally flopp’d up \ the ftony Matter gradually concreting round the Sides of the Mine, and forming thereby a confufed Load of Spar-Stone. At other Times this ftony Matter concretes more diftin&ly : In which Cafe the ftony Matter feems to be govern’d in its Concretion by a Flaftick Power. N. B. When I fpeak of a Flaftick Power, I would be underftood as meaning only a Modus of Attra6lion , by which the attracted Particles are rang’d in this or that determin’d Form. This Power then fo exerts its Ac- tion, as to range the concreting Matter into the Form of an hexagonal Trifm , whole Head goes off in an * hexagonal ( 4®5 )• hexagonal Fyr amid. Where this plaftick Power hap- pens to be (ingle and uncontroul’d, itpreferves the Form of the Criftal to very conliderable Magnitudes. In thefe (ingle Criftals we may obferve, that they are of different Tranfparencies and Colours, as the (tony Matter is more or iefs difengaged from other Subftan- ces ,or as thofe other Subftances are capable of impart- ing different Tinctures to them. And that they feem form’d laminatim \ tho’ the Lamina are only diftin- guifhable, when the Matters from whence the Criftal is fucceilively form’d, happens to differ in Purity. Thus in Figure the fourth , the Criftal was at firfl form’d from Matter intangled with a foul yellow Subftance^ after which, a pure Matter advening, the Criftal was in its future Lamination form’d more pure and tranfparent. But where the plaftick Particles are more numerous, there feems Reafon to believe, that thefe very Flaftick F articles, before they are fix’d, are fubjed to the Controul and Direction of any fix’d plaftick F article, within the Verge of whofe Adivity they happen to move: notwithftanding which, after they are once fix’d, they exert their own plaftick Fowers , and, in Conjundion with the firft plaftick Farticle , govern the future Concretion, in luch Manner as to form a feemingly irregular Criftal, tho’ compofed of two or more regular Criftals. Thus in Figure the fifth and fixth A and C feem to have attraded amongft the ftony Particles, two plaftick Particles, which afterwards ex- erting their own Powers, form the additional Criftals B and D. There are many Phenomena obfervable in thefe Criftals, which, at prefent, 1 may pafs over, as lefs re- lating ( 4°6 ) lating to the Affair of Metals j wherefore I (hall only add, that thefe criftalline Concretions exert a flrong Attraction on many metallick Subftances. As in Fig . 7. A the Spar has attracted the three Portions of Lead B. and in Fig, 8. the Criftals C have attracted the Copper D, and are attracted by the Lead E. The fulfhureo-faline Particles, with which, as I obferved, the Waters are frequently faturated, are found to be either of a1 vitriol ick or an arfenical Nature : The firfl conflantly, if pure, concreting into white Cubes re- fembling Grains of Silver, while the arfenical Sulphur concretes into yellow Cubes like Grains of pure Gold. Both thefe are' by the Miners term’d Mundick. Thefe fulphureo-f aline Subfiances feem directed in their Concretions by a plaftick Particle, in the fame Manner as the Criftals above-mention’d ; and, like them, upon the fame Principles, are found fimple or compound. In their Sides you may obferve the Concretion forms it felf like Threads, which in three Sides run in different Directions, but are always fimilar in the oppofite Sides. Fig. 9. fhews one of thefe Cubes, A the parallel Threads. Fig. ic. {hews another of thefe Cubes, from whofe Sides arife fmall Segments of Cubes C. But this plaftick Tower feems to be weaken’d or deftroy’d, in Proportion, as this fulphureous Matter is more or lefs intangled with metallick Subftances. Thus in Fig . 11. the plaftick Particle feems for a while to have exerted its Power in the ufual Manner, till the advening Matter grew intangled with a fmall Quantity of Copper, after which it feems only to have exerted its attraffive but not its plaftick Tower . And C 407 ) And in Fig. n. the white Mundick being infe&ed with Iron, feems fo far from being affe&ed by a ftick Tower , that it concreted in the Form of Icicles from the Fluid which tranfuded thro’ the Top of the Mine. Fig . 1 3 . reprefents fome fmall Cubes of white or vi- triolick Mundick. But to return to the Mines : They are found to con- tain Tin, Lead, Copper, Iron, and a pfeudometallick Subftance, by the Miners term’d Glijl : For the Par- ticulars of all which, as they would vaftly fwell the Bulk of one Letter, I muft refer you to my next. I am , With the utmoji Refj>e£t% Tour obliged Friend , ( ' Fran. Nicholls. s' ( 4°8 ) * VI. Obferyationes AftronomicA habit Ulyflipone, Anno 172 6. d (%ev. ^P.Joh. Bapcifta Carbone, Soc. Jef. Communicante Ifaaco Secjueyra Sa- mud a, M. D. 5^. S. 5. & Coll . Med. Lond. Lie . Immerfiones & Emerfiones Trimi Jovis Satellitis a Maii 23®. ad finem Aunt 1726. Maii 2,3. Debilitatio lucis Totalis Immerlio JuL i. Debilitatio lucis Immerlio totalis 8. Debilitatio lucis Immerlio totalis 17. Debilitatio lucis Totalis Immerlio Aug. 9. Immerlio totalis 16. Attenuatio luminis Totalis Obfcuratio 23. Attenuatio lucis Immerlio totalis 2f. Debilitatio luminis Totalis Obfcuratio Sept. 1. Attenuatio lucis Totalis Immerlio 10. Debilitatio lucis Totalis Obfcuratio 15. Immerlio in Umbra m 17. Attenuatio luminis Totalis Immerlio 24. Debilitatio lucis Totalis Obfcuratio. T)ubia. 12 47 ^ Odob. 10. Immerlio dubia, 1 1 8 34 Emer - h ' a - 1 f 2 4^0 - 15- 24 40 * 13 46 29 13 47 47 * if 40 30 if 41 40 12 o 4f * 12 1 f 2 12 13 30 14 7 33 * 14 8 4 6 * 1 6 3 10 * 1 6 4 23 - 10 31 40 10 32 f 7 12 27 f7 - 12 29 29 8 53 47 8 S 4 * 1 6 zi 3x * 10 fo 12 10 fl 39 12 4 6 38 ( 4 °? ) Emerfiones. H. * // 0le 3 . Mail. Altitude) Meridiana limbi fuper. Solis Quadrant e Mttrali quinque pedum Corre&io additiva Quadrantis Altitudo apparens ejufdem limbi Refratftio - Altitudo corre&a, Sc vera limbi fupe rioris Semidiameter Solis apparens Altitudo vera centri Declinatio Borealis Altitudo iEquatoris Elevatio poli. • - , I i i 67 5* *£ 10 1^ 67 Jf 40 2 3 67 14 17 IS 56 66 58 21 IS 40 36 17 45 3B 41 1 S ie xx. Junii. Altitudo Meridiana limbi iuper. Solis ; Quadrant e aftronomico trium pedum Corre&io Quadrantis fubtrahenda Altitudo apparens prasdi&i limbi Refra&io - - Altitudo vera limbi fuperioris Semidiameter Solis apparens Altitudo vera centri Solis Ejufdem Declinatio Bor. Altitudo iEquatoris Elevatio Poli 2)/> ii. Align fli. Altitudo Meridiana Lucidas Lyras, Qua- drant e Mur ali quinque pedum Corre&io Quadrantis, addit. Altitudo vera fideris Declinatio Borealis, ex tabulis Cl. V. Joannis Flamfteadi - Altitudo iEquatoris Elevatio Poli SDie 14. Augufli. Altitudo Meridiana limbi fup. Solis, eodem Quadrante Mur alt - Corre&io Quadr. add. Altitudo apparens ejufdem limbi Refra&io Altitudo vera limbi fnperioris Semidiameter apparens Solis Altitudo vera centri- Declinatio Bor. Altitudo iEquatoris - -> Elevatio Poli * * • Gr. ' " IS 5 10 x 37 IS 2 43 1 S IS 2 ^ lS S3 74 4^ 3 S 23 28 50 S* 1 7 4 S 3% 42 1$ 89 40 1 y 10 iy 89 90 30 38 3z SS fi 1 7 3 S 38 42 25- 6s 49 13 10 1 S 6s S9 2§ 24 6S S9 4 1S S3 &S 43 11 14 25* 30 5 1 17 41' 38 42 19 \ Die ( 4H ) cDie 25*. Septembris. ^r>tUC^/ ^Gr^ana iirnbi fup. Solis , ^uadrante aftronomico trium pedum Correftio Qpadrantis fubtr. - Altitudo apparens ejufdem limbi Kefra&io Altitudo apparens corre&a ParaJlaxis Altitudo vera limbi luperioris Semidiameter Solis apparens . Altitudo vera centri Solis Ejufdem Declinatio Auftralis ' Altitudo iEquatoris Elevatio Po li 27. Ofiobris. Gt. 1 " 47 n a 37 5° 44 34 44 43 50 2 5*2r 4 5*° V 48 f0 43 1 6 50 12 S* 18 o 38^2 5 ^^5W° ^eri^iana Embi Pup. Soli; Corre&io Inftrumentiadditiva Altitudo apparens ejufdem limbi Kefra&io Altitudo limbi luperioris corr. Parallaxis Altitudo vera ejufdem limbi Semidiameter iolis apparens Altitudo vera centri Ejufdem Declinatio Auftralis Altitudo iEquatoris Elevatio Poli ; li i z 38 40 ij 6 S' 38 4 6 20 1 6 38 45 14 38 45 ly *6 12 38 29 ^ Ix 48 34 5* *7 jg 38 42 xt. Eodem ( 4’2 ) Eodem die zj. OElobris. Altitudo Meridiana Fomahantis Aquarii feu Lucids in ore Pifcis Auftritn, eodem Sextante Corredio Inftrumenti additiva Altitudo apparens • - • Refradio - - -<• ■ « Altitudo vera lideris Declinatio Auftralis ex De La Hire Altitudo ihquatoris Elevatio Poli ?Gr. ' " >2o 9 55“ 6 $ ■ 20 I 6 o ./ 2 z$ ■ '20 13 34 3 1 3 59 “ T7 33 • 38 42- 17 Ex hi?, aliifque Obfervationibus inferre hadenus licet, lyjjipon enfem Latitudinem in ObfervatorioRegii Palatii, non excedere grad. 38° 43', nec minorem effe grad. 38° 42'. Cseterum, ad minuta fecunda quod attinet, nihil audeo certi definire ncque enitn hujufrnodi Ob- fervationes ad id praeftandum fatis effe arbitror ; qua3 fcilicet, vel Inftrumentomm defedu, utcunque exiguo, vel refradionum inconftantia ab aeris inasqualitate, vel Aftronomorum diflidio in Declinationibus (iderum fta- tuendis, vix aliquando contingat, ut Omni prorfus ca- reant errore j nec li aliquando careant, id ullo poterit indicio deprehendi. Ex prasdiftis tamen Obfervationi- bus, non imprudenter flatui poteft latitudoObferva- tdrii Regii in aula 38° 42' zo°, nofiri verb Collegii 5D. Antonii Magni, 38° 42' 3 o''. Quatiiquam tec ipfa fecunda prudens neglexi in nonnullis fupputationibus, in quibus Elevatione Poli fuit utendum ; turn quod nullum negleda, aut nullius momenti errorem inducere poifent; turn etiam quod aliarum Obfervationum indi- cio ( ) cio pauciora, aut pene nulla ea effe viderentur. Mox tarnen novis, variifque Obfcrvationibus inftituendis, ac praefertim magni Gnomonis ope, Auguftifftmi noftri Regis juftu erigendi, fore fpero, ut fecundorum nume- rum congruentius aflequarmir. Quas hfc obfervavi Solis, Lunteque Eclipfes, obfer- vavit R. P. 'Dominions Cap affns, Conimbrica ?, quo, a menfe Junio anni proxime i'uperioris 1716. balneorum causa feceilerat^ ibique nonnullas ctiam inftituit Ob- fervationes circa Poli Elevationem^ ac circa Intimi Sa- tellites Immerliones, atque Emerfiones 3 quas omnes feorfim exhibebir, una cum reliquis ab ipfo mox ha* bcndis in variis hujufce Regni locis ad Boream fitis. Deinceps in aliis etiam opportunity inftituentur. VII. Some OlferVations made in the Dijfettion of three Subjects 3 hy Mr, Ran by, THE Fir ft, a Man aged 70 Years, who died of a Suppreflion of Urine, occafion’d by a Stone flop- ping in the Urethra , juft within the Gians , of the Bignefs of a Horfe-Bean. This Appearance, with the Symptoms that had attended this miferable Man, gave me Reafon to exped fomething remarkable in the uri- nary Paftages. The Ureters and Uelvis were very much diftended} which is common where great Num- bers cf Stones have defcended down them, from the Kidneys to the Bladder. The Bladder contained about fixty Stones , the largeft of which was about the Size of a Walnut, the others (mailer 3 and juft within the iNeck, was a hard 'Tumour , as big as a Nutmeg, which . almofl ( 4'4 ) almofl: clofed the Orifice: and. indeed the Situation of this Tumour was fuch, that it not only made the paf- fingthe Catheter very difficult, and hinder’d our feeling the Stones, by direding the Inflrument upwards } but likewife would alone produce the Symptoms of the Stone in the Bladder, by obftruding the free Difcharge of Urine through the 'Urethra \ the inner Membrane of which appeared as if lacerated in feveral Places, and the Tube fill’d with a glutinous Matter tinged with Blood. Cn the back Part of the Vejicula Seminales , near the 'Pro fiat a , were feveral Stones , as large as Peas, which clofely adhered to the adjacent Mem- branes. The Second , a Boy aged 10 Years, kill’d by a Blow on the Skull} whole' Spleen weigh’d two Pounds, and pofleffed almofl all the left Side of the abdominal Ca- vity. The Bladder, when diftended to its greateft Ca- pacity, would not contain an Ounce. The Third , a Man aged 25, who died of a Pocky Hectick, and fome Days before complained of a pain- ful Swelling in the Tefticle, which he faid came the Night before. I examin’d it, and found it to be a Hernia Aquofa , and would have pundur’d it, if I had not felt (befides the Water) a hard Body, which I could by no Means reduce. In a few Days he died, which gave me an Opportunity of being fatisfied. Opening the Scrotum , and feparating the common Membranes to the Procejjus Vaginalis , it contained about four Ounces of Water, befides a great Part of the Omentum ; fome Portion of which adhered to the Bot- tom of the Cavity, and the Albuginea that immediate- ly covers the Tefticle. F I N I S. 4* * *4 M i i t w.„ ? "iC * . i i 4*. / . Numb. 401.' PHILOSOPHICAL transactions Tor the Months of April, May and June, 1718. The CONTENTS. I. ObferVations of the Eclipfes o/Jupiterh Satellites, from 1 7 o o , to the Tear 1 7 2 7 . % the Reread w! Derham,MA Canon of Wind for and F. and was couch'd between i 3 and 1 4 Tears of Age. By Mr. W. Cheffelden, F. Surgeon to Her Majefty, dW SL Thomas’* Hofpital. VIII. Explication of the Inftruments ufed in a new Operation on the Eyes , £j/ f/;e Same. IX. An Account of feVer al Stones found in the Rod- neys of a Berfon opened by Mr. John Dobyns, Surgeon and Litbotomifl to St. Bartholomew'* Hofpital and F. Be S. X. Extratt of feVeral Letters , See. from different Barts 0/Europe, relating to the Aurora Borea- lis, Jeen Q£t. Ip. N. 5. 1 716. I. Ob- [ 4 if ] I. Obfervations of the Eclipfes of Jupiter\r Satellites, from 1700, to the Tear 17x7. By the Reverend W. Derham, M. A Canon of Windfor and F. R. S. Communicated by Sr. Hans Sloane, Bart. Brefident of the College . of Phyficians and Royal Society, &c. Eclipfes Prim Satellite. Dies Tempus Tempus Per Tab. Qua- Locus Menfis. squale. apparens. Flamft. & lis E- Jovis > Caflini. clipfis. Helioc. 1 H. M. S. | H. M. S. I Min. Sec. 1 | Grad. I Anno Domini 1700 Aug. 13 10. 59. 4 IO. 57. 10 59- FI Em. £7 15 Telefcopio 6. pedali. Dec. 1 — — — S 5. 1. 8 c — 1. 38 4h- 55'l C. 4- 58 FI. E. £7 10 Telefc. 16. pedali. Omnes fequentes E- clipfes 'Fubo 1 6. pedali obfervata; fuere, nifi cum 1 v a liter notatur. Anno Domini 1701. Jun. 15 — — — 5 13. 23. 0 c — 24. 50 13. 21 FI. 13. 26 C. Im. -vvv 'y “7 AW 2 / » 13. 28 FI. I. Jul. 8 — — . — 13. 30. 0 13. 34 C. £? 29 r 5- 54. 9 5. 59 c. K 8 Oft . 1 z — — < — 54- 1 9 k— 54- 49 E. Bona Obfervatio. — 19 — — — S 7- 48. 5 7 l— 49- 47 7. 55 C. E. X 9 Bona. Dec. 20 — — — 6. 25. 0 6. 28 FI. E. ^ 14 Dubia. Anno Domini 1702. 0£L 15 — — — C p. 22. 0 < — 22. 15 C 22. 45 p. 23 FI. p* 26^ Gi E. T 11? Optima. > — 24 f 5* 44- 5 7 5 8J Dubia ob Nebulas. 24 J 13* 43- 4 < •— 43- 35 13. 38 F. 13. 45 C. I. £5 10 Bona. Sep. 2 10. 8. 20 10. 4 F. I. 0 11 Nebulofum Ccelum. Nov. 2.8 5. 37* 40 5. 44. 52 5. 43 F. E. 19 Non mala. Anno Domini 1704. Aug. 2 6 17. 7* 43 IT* 9- 5 3 S 11. 38. 18 ?— 39. 3 17. 8 F. I. tl 12* Nimia lux, fed non malac 2,8 11. 36. 16 11. 37 F. I. LL 13 Bona. Sept. 4 13. 29. 14 Ji3* 33- 5 ' — 34- 25 13. 23 F. I. n 134 Bona. Oft. 6 10. 2. 40 J IO. I <5. 40 ( — 17. I O 10. 13 F. I. II 1 6 Nebulofa, fed non malae Nov. 3 IT* 39* 54 17- 54- 55 17. 48 F. I. n 18 l Nebulofum. Dec. 9 5. 31. 00 E. H 21 | Dubia. 23 9. 14. 43 9. 9. 17 9. 10. C. E. n 23 Bona. Anno Domini 1705". f 9. 4*. 3 Mart. 2. — — “n — 4 6. 40 ^ — 47. 0 9. 47 F. E. TL 29 Bona. 25 10. 9. 58 10. 7. 18 — 7- 52 10. 10 F. E. S of Bona. v- 10. 11. 5 — 8. 25 Sept. 7 J itf* 39* *5 1 — 40. 15 1(5. 45. 26 — 46”. 2(5 1 6. 52 F. I. 2o 15 Bona. O O r 18. 54. 50 i — 55. 20 19. 10. 19 — 10. 49 19. 10 C. I. $ 19 Nimia lux, ideo dubia. Nov, 22 19. 4. 50 19. 13. 59 I. $ 21 r- /'■Dominos Gray banc Dec. 15 19. 15. 0 19. 13. 20 19. 11 F. I. $ 22J 9 immerfionem Cantua- Crije i9h. 15' obfervavit. Anno Domini 1706. Mart. 7 — — — 7. 27. 0 7. 2 6 F. E. 2o 29 T Emerfum inveni. 3c J 7- 4*- 4C « — 47- 37 7. 45* 25 — 4(5. 20 7. 48 F. E. SI 3 Bona. Apr. 29 9. 59- 2 10. 3. 5 10. 3 F. E. a 3i Nebulofum. /■ Dies Eclipfis Trimi Sate Hit is, 417 Dies Menfis. Tempus aequale. \ Tempus apparens. 1 Per Tab. "lamfteed. k Caffini. Qua- lis E- :lipf. Locus fovis. I H. M. S. | H. M. S. IH. Min. | Grad. | Feb. 15 * 24 Mar. 26 Maii 11 10. 17. 52. 5 6. 39. 52 < — 4i. 32 i 8. 47. 53 J — 48. 6 J 9- 14. 43 « — 1 <5. 7 Anno Domini 1707 E. E. E. E. cSb + eSl 274 ^9-4 Bona. j Ventus fortis tubum ( motitavit. Bona. 10. 4. 43 6. 28. 20 — 30. 0 8. 45. 3 <5 — 45* 49 9. 18. 431 20. 7! 10. 3 F. <5. 28 F. 8. 4 6 F. 9. 20 F. Jan. 51 Anno Domini 1708. I. ♦ 23! Immerfus fuit ante. 17. 35. o| Maii 18 Jun. 10 C 9. 7. 2(5 £ 1 8. 2(5 $ 9. 22. 21 7 24. O Anno Domini 1709. E. E. T i 1 4 - 3, Non mala. Bona. 9. 10. 47 — 11. 47 9. 21. 9 — 23. 8 9. 18 F. 8. 59 C. 9. 27 F. 9. 12 C. Maii 14 Jul. 15 Aug. 23 10. (5. 57 7. 22. 2 Anno Domini 1710. E. E. E. in. 25 2 / 5 , [mmerfum vidi. Non mala. .10. 10. 2 <5 8. 4<5. 0 7. 22. 50 10. 14 E. 8. 49 F. 7. 28 C. Aug. 1 9 f (Anno Domini 1711. E. VS 4 Bona. r 8. 23. 40 K — 24. 30 1 1 25. 00 8. 32 F. 8. 30 C. Oft. 27 Dec. 28 8. 10. 28 7. 4. 18 Anno Domini 1713. E. E. X 14 K 19? Bona. Bona. 8. 2(5. 19 (5. 5(5. 30 8. 35 F. J 7* -5 F- 1 7. 1 c. Oft. a3 Nov. 1 9. 59. 0 Anno Domini 1714 E. E. T 17 V 18 Dubia, fNubilum ideo dubia \ licet tubo 34 pedal ' obfervationem feci. 10. 1. 1 6. 20. 0 10. 5 F. <5. 28 F. 4 K k k a Dies Eclifjls Secundi Sate Hit is. Dies Mends. 1 empus asquale. 1 empus apparens. Per Tab. Flamft. & Caffini. Qua- lls E- clipf. Locus Jovis. |U. M. o.|h. M. S.l H. M. | | Grad. Feb. 1 — — 8 c 6- 25. 3 X 2 (S'. 18 C • — ad. 48 c 8. 21. 21 X — 21. 51 / — 22. 21 Anno Domini 1717. E. E. <3 1 $ i* Bona. Bona. C. 10. 15 — 11. 30 — 12. 00 8. 7. 0 ~ 7- 3° * — 8. 0 d. 14 F. 14 C. 8. 9 F. 8. 12 C. Hov. 27 — Anno Domini 1725-. : K 22 Sequentes Obfervatio- nes Telefcopio 12 f pe- dali optimo fa<3a; fuere. Windeforije, dubia. j 9. 8. 3d ( — 9. 0 Per Tabul. D. Bradley. 9. d. B. Anno Domini 1726. Jan. 5 Aug. 5 Sep. i 5 oa. ! 8 17 Dec. a 25 l 7. 40. 19 — 41. o — 41. 30 14. 50. 17 “ 51- 7 7- 44- 17 ~ 45- 37 — 4tf. 7 7. ia. 57 — 13-57 7. 29. 49 — 30. o — 31. o 14. 45.. 28 — 47. 18 7- 5 3- 10 — 54. 30 — 55. o 10. 25. o 6. 4 6. 30 >7. 2. o - — 3- o 7. 7. o — 8. o 7. 31 B. 14. 47 B„ 7. 53 B. 10. 7 B. 6. 4* B. 7. 5 B. 7- 9 B. — E. I. I. E. E. E. E. K 25 Y 15 Y 19 Y 21 Y 21 f r 25 Y 28 Bona, Upminflro. Bona. Bona. Obfervatio incerta propter vicinitatem« ft V. Windeforise, dubia. Upminftri bona- ObferVat tones Eclip/ium Secundi SateHitis JoVis. Anno Domini 1700. ■ rSequentes Obfervatio- nesTelefcop. id peda- E. li faita iuere. Oil 27 8. 24^ 0 8. 23 /Ci. A%V O | i < D ubi a propter vapo - Ires. D. Flamfteedii Minifter obfervavit cir- ^ca 8h. id'. p. m. 2 Dies Eclipjis Secundi Sate Hit is . 419 Aug. 26 Sep. 9 Oft. 15 22 Dies Menfis. Tempus aequale. Tempus apparens. Calculatio Flamftee- dii. Qua- lis E- clipf. Locus Jovis Helioc. J H. M. S.|H. M. S.\ H. M. | 1 Grad. | Anno Domini 1701. Jun. 29 — — — 10. 50. 0 10. 52 I. xs 28 7 Dubia ob vapores. Jul. 31 Inter S 9- 43- 0 ( 10. 3. 0 10. 33 I. X 1 Nubilofum. 061. 2 1 — — — C 7- 39- 35 < — 40. 0 C — 41. 0 7- 5i E. H 8| Bona. 2,8 — — — < ^ 10. 18. 2 £ • — 20. 0 10. 29 E. X 9 Bona. Nov. 22 — -- — c 7. 26. 18 ? — 27. 0 7- 34 E. X 117 Bona. Anno Domini 1701 1 9. 4 6. o 15. o. 51 — 1. 51 7- 5 — 6 7 9. 40. 38 — 41. o — 42. 13 21 22 22 10. 17 15- 35 7- 30 10. 8 I. I. E. E. T 8 Y 11 7 Bona. Immerfum inveni. Bona. Y 12 Bona.. Aug. 20 oa, 5 Dec. 19 8. 41. 9 Anno Domini 1703. I. I. E. 9$ X5 24 X5 20i Immerfum inveni. Immerfus ante. Bona. 9. 50. 0 15. 3. 0 8. 38. 7 10. 11 15. 19 9. <5 Aug. 20 oa. 5 1 6 12. 15. 29 Anno Domini 1704. I. I. I. XT 12 It 1 6 rt 10 Bona. Bona. Haud mala. 12. 15. 34 ST 7. 10. 44 c — 11. 14 9. 2. 19 12. 32 17. 32 9. 26 Die? 4^0 Eclipfes Secundl Sate Ills. Dies Menfis. Tempus aquale. Tempus apparens. Calculatio jQua- Flamftee- jlis E- dii. [clipf. Locus Jovis Helioc. I H. M. S H. M. S | H. M. | | Grad. | Jan. 15 20 Feb. 14 Mar. 25 Apr. 2 8 Sep. 29 Oft. 31 $10. 30. 23 3r. 14 7- 45- 3i S IO. 15. 10 £ — 1 5. 5 S 18. 28. 11 o — 28. 26 Si5- 5 5- 201 — 58. 26 Dec. 2c| % 9* 49* 3° • t' — 50. ro Anno Domini 1 705" 7* 47* o_ 10. 18. 9 17- o! 7. 32. o 10. 12. 30 — 13- 2 5 10. 4. o 18. 39. 11 — 39. 26 18. 10. 52 — 11. 49 9. 45. 38 — 46. 1 8 8. 14 10. 50 8. 1 10. 36 10. 29 18. 48 15. 27 10. 11 E. E. E. E. E. I. I. L E 24] * 25h H 17* S3 o 95 3 » S 1 5 | S 19 ® 2 3 Emerfio ante. Bona. Vaporofus aer : dub, S Incerta propter vicini- f tavern primi Sat. VaporofusHorizon : dub. Bona. Bona. Bona. Ap. 20 Anno Domini 1706. 8. 58. 30 1 9 31 E. SI 3 Fuerat emerfus. Mar. 13 20 Ap. 14 - — 21 10. 28. 14 7- 33- 17 5 10. 9- 33 d — 10. 59 Anno Don 7. 59. 0 • 10. 23. 54 7* 35- 39 10. 12. 51 — 14. *7 rini 1707. 8. 18 11. 5 8. 9 10. 45 E. E. E. E. eft 284 SI 29 •Kx * Emerfit ante. Dubia. Dub. propter nim. lucem Bona. Mar. 4 • 1 "lr " Anno Domini 1710. 17. 5. oj I. ^ 21 1 Nubilum, & incerta. Jul. 15 % Anno Domini 1711. E. VS 1 1 Nebulofum & dub. 9. i5. 0 1 9. 5 061. 12 7. 35. * |S _ Anno Dom 7. 50. 30 S — 51* I5 d— 52. 30 lini 1712. 7. 58 E. ^ 10 Bona. Nov. 1 Dec. 3 — — Anno Dor 5. '34* 7 C 5. 14- 26 2— 15. 0 nini 1714. 8. 55 8. 34 E. E. T* 18 V- 21*- Incerta ob nubes. Bona. Dec. 22 Anno Domini 1716. 4. 55. 0 — E. n 27 ; Emerfio ante fuit. Dies Eclipfes Tertii Satellites. 421 Dies Menfis. l empus jequale. Tempus apparens. Calculatio Flamft. & Molyn. Qua- lis E- clipf. Locus Jovis Helioc. | H. M. S | H. M. S | H. M | Grad. | Jan. 30 Anno Domini 1717. E. 25. 1 Emerfum inveni. 7. 24. o| 7. 46 061. 30 — — — Anno Domini 1 7x5. E. H 19 Bona obfervatio Tele- fcopio 12 ^pefdali opt. 9. 1 6. 23 17. 0 — 17. 18 8. 4 6 M. Aug. a 8 061. 17 Nov. 25 S 8. 52. 25 c— 53- 55 Anno Domini 1726. I. E. E. y 17 Y ail r 25 Bona. Dubia. Non mala, Windeforiae. 8. 54. 52 — • 56". 22 6. 12. 0 c 8. 27. 15 — 28. 0 8. 58 M. 5. 53 M. 8. itfT ObferVationes Eclipfium Tertii Satellites JoVis. Anno Domini 1700. 061. 19 — — — 6. 23. 15 1 6. 13 I. ^ fZ AW O Jul. 11 Sep. 28 — Anno Domini 1701. I. E. K 6\ Dubia. 1 Bona. 10. 18. 0 Cio. 25. 27 < — 2 6. 0 C. z6: 42 10. 11 10. 12 Jul. 2 6 Aug. 2 Inter Anno Domini 1702.. E. I. r . 4 Y. 5 Dubia. Nubes interrumpebant. 10. 51. 13 cii. 55. 0 ^ 12. 5. 0 [10. 33 11. 35 Dies 4 2.x Ec It fifes Tertii Sate Hit is. Dies Menfis. Tempus Tempus Calculatio Qua- Locus aequale. apparens. Flamftee- lis E- Jovis dii. clipfis. Helioc: H. M. S | H. M. S | H. M. [ j Grad. Anno Domini 1703. 12 — — . — 14. 45. C 15. 32 1. 0> 6 C 1 3* 43- 2° ? 24 it t .. _ ) — • 44. 20 ?r3- 4 1. p )— 44- 5i 3 <3 10 v 1 6. 6. 3 6 M x-/l •r* 0 E. 3 22 — — — — — 8. 9. 53 7. 50 E. 12 * C 9- 57- 44 9. 17 E ") 2 9 — 58- 5 ( 0 13 C12. 8. 17 11. 52 E. J q-13. 4G 13 14. 0. 30 6 47. 55 — • 1. 50 13. 19 I. X5 14 /— 48. 33 — 2. 50 - ■ ■ Fuit Immerfus. / Optima obfervatio Im- J merfionis : at fomno j invadente, nimis fero CEmerfionem vidi. 5Immerfio accurate vl- fa, fed Emerfio du- 4 bia propter vicinitatem C Jovis. Bona. In Obfervationibus Aug. 24, Sep. 22, 251, Sc 0<5t. 6. notandum eft, Latitudinem tertii Satellitis majorem fuiffe quam C. Flamsteedius, aut Gassinus conjeftarunt. Nam ifte Satelles ufq3 ad extremum Poli Jovis marginem evagatus eft, & (antequam in e jus umbram prorfus immerfus eft ) diu in ejus penumbra latuit: & in eadem umbra non ultra duas horas permanfiffe autumo, quamvis poft Obfervationes Aug. 24, & Sep. ■29, moram diuturniorem fuiffe videatur. Sed in priore obfervatione, veram non vidf Emerfionem : Sc in pofteriore cum *02 j. fuerit) Emerfio Jovis limbo tam propin- qua fuit, ut difficile fuerit earn cum Teiefcopio 16 pedali vere obfervare. Anno Domini 1704 Sep. 14 Inter Si 6. 2 17- 58. 10. 0 0 £<5. 32 E. H 14 J- oa. 10. 28. 4° 9- 48 I. m 17 20 10. 14. 34 3°. 33 I. Nov. 3 18. 12. 16 i8T 27. 17 17- 45 IE 187 Anno Domini 1705. Jan. 14 ^ 10. 7. 5 4 9- 5 3- 55- 57 56 — ■ — — I. 2X 24 i . — - - — 9* 58. 7 281 Feb. 2 6 10. 9. 32 58. 42 — — ■ — I. n Inter S i'7« 18. 0 — . __ E. 17 oa. 6 27. 0 Nov. 25 — — 7- 41. 0 i I. 03 21 Nubilum coelum. Bona. Bona, licet aer nebulos. Bona. Bona. SIncerta per Nebulas ? denfas. Dies Jbclipjes i ertu date Hitts. Pec. z6 6. 38. 30 6 . 32. o) 6. 46- Sep. 17, 8. 26’. 56 — 28. 5 6 7. 22. o Oft. 23^ — 23. o — 25. o Anno Domini 1714 8. 3pedali. Bona. 6. 30. 40 — 32. O 7. 12. 17 — 13. 30 ^ 7. 21 M. Obferyationes Eclipjtum Quarti Satellitis. Jun. 11 Sep. 3 — Anno Domini 1701. I. E. /VW •_ AW 2/ X 4 4 m Immerfum inveni. Idem per nebulas. 14. 20. 0 13. 59. 0 14- 35 . 14. 21 Sep. 30 Dec. 6 Anno Domini 1704. E. E. re 15 4 n 21 1 Nebulofum, ideo dubia. r Dubia ob proximita- < tem Jovis, & parvita- ( tem Satel. 9. 21. 42 9. 52. 44 9. 40 Feb. 11 8. 38. 5 Anno Domini 1705'. I. rr 27 Non mala. 8. 24. 8J 8. 23 Mar. 20 Sep. 20 9. 3. 2 Anno Domini 1706. I. I- , 0 ^ <51 15 Non mala. Immerfum inveni. 8. 58. 40 1 6. 24. 0 9. 3 6 16. 11 Aug. 23 Inter. Anno Domini 1712. I. E. AW - AW 5 4 AW -* AW / Bona. 5 8. 29. 0 3— 39. 0 7. 43- 0 — 44. 0 — 45- 0 10. II ^ 9- 20 ( 42? ) (Remarks on the foregoing T A B L E S. < AS exaft Tables to calculate the Eclipfes of the Circumjovials , would be of very great Service to find the Longitude of ‘Places *, fo I have fome Hopes that thefe Obfervations of fome of them, in more Revo- lutions than one of Jupiter in his Orb, may be of Ufe to corred, or make fuch Tables. 1 wi(h that I could have made them more compleat (and in my younger, and more leifurely Days, I endea- voured to do it, by rifing at unfeafonable Hours, &c.) but befides cloudy and bad Weather, one great Hin- drance was the Want of Tables, to enable me to calcu- late the Eclipfes my felf, and the frequent Difappoint- ments of my Friends, that furnifhed me with Catalo- gues of them. And moreover, many times Company, and Bufinefs, and (to tell the Truth) fometimes Forget- fulnefs, have hindred the Conftancy of my Obfervati- ons : But the greatefl Chafms in them were caufed by fome dangerous Fits of Sicknefs, which fo impared me, that 1 have not dared, ever fince, to venture upon Obfervations at unfeafonable Hours of the Night. As to my Manner of obferving, it was (for the moft Part) with a 16 Foot Telefcope, and afterwards with an excellent one (not inferior to it) of 12 I Feet, that, at Jupiter's Light, bears an Aperture of 2 \ In- ches, and a Charge of about % Inches. And as to the Time ; I made ufe of an excellent and well-ad jufted Clock , corre&ed at Noon, by the Meri- L 1 1 2 dional ( 41 6 ) dional Tranfits of the Sun, obferved with the Inftru - merit defcribed in the Fhilof Tranfaff. N° 291, which fhews the Noon-time to one or two Seconds. This' Way fome of my fkilful Friends (particularly Mr. Flamfteed ) fufpeded to be fallacious, and not compa- rable to taking the Time by Altitudes of the Sun, or fix’d Stars. For a Trial therefore, I gave him a Chal- lenge, of obferving fome Eclipfes that we agreed on ; which when we compared, we found fo nicely to agree, as to Ihew to a Second of Time, or very nearly fo, the Difference of the Meridian of the Obfervatory , and that of Ufminfler. But becaufe the Credit of my Obfervations depends upon the Stridnefs of the Time, give me Leave to compare my Inftrument with a Quadrant. And here I will prefume to affirm, that my Inftrument is no more liable to Errors than a Quadrant . 1. It is lefs fo, in regard of its Structure : For a little Error in the Divifion of a Quadrant’s Limb, or in fixing its Sights (whether Telefcopick or Plain) fpoils all. But no great Curiofity, or Nicenefs is required in my Meridi- an-Inftrument, 2. In point of Obfervation, as much Care and Exadnefs is neceffary to guard againft Wind, and to take a true Altitude by the Quadrant, as is ne- celTary to take a true Azimuth by my Inftrument . For if we are fare that the Inftrument is exadly in the Meridian (the Manner of which is ffiewn in the fore-cited TranfaElion) we can be as fure, and that to as few Moments of Time, as any the beft Quadrant can ffiew it. And although I cannot fay, that every Day, or every Week, I examined the Polition of my In- ftrument, yet I did it fo often, as to be fatisfied, that not ( 4*7 ) not many, or great Errors, could be in my Obferva* tions. The greateft Part of the EcIipTes, that were the mod accurately made, may eafily be diftinguifhed by the two, or more Numbers of the Time of Obfervation : The hrft of which fhews the Moment of the Begin- ning of the Eclipfe • the following, the Times when farther advanced : As in anEmerfion, the firft Number {hews the Time, when the Satellite appears like a fmall obfcure Spot:, the following Numbers, when brighter, or quite emerged out of Jupiter' s Shadow } and fo contrariwife in an fmmerfion. But altho* this might have fufhced, yet for greater' Certainty and Satisfaction, I have noted which Obfer- vations were good, which doubtful, or bad : Even the latter of which may be of Ufe in fome Cafes, where better are wanting. The calculated Times of the Eclipfes I have infert- ed, where I had them from others, or could calculate them my felf, as being of good Ufe to amend the Ta- bles of Mr. Flamfteed , Caffini , or others, taken Notice of in the Column on Purpofe. And for the fame Rea- fon 1 thought good to add the Place of Jupiter alfo. And laftiy, 1 thought it good to mention the Length and Power of the Telefcope I ufed ; as being, in fome Meafure, neceffary in the comparing Obfervations of different Places ^ becaufe Obfervations may differ feve- ral Seconds, by the different Length and Goodnefs of the Telefcope ufed j a long and good Telefcope {hew- ing the Satellite, when the Shadow of Jupiter doth but juft touch it : Whereas a fhort, or bad one, doth not (hew it, until one half, or more, of the Satellite is enlightened. Which Difference is moft remarkable in the ( 428 ) the Eclipfes of the two outermoft Satellite?, in their greateft Latitude? ^ at which Times they go into, and come out of Jupiter's Shadow, in an oblique and lon- ger, not a direft and Ihorter Path : An inflance of which maybe feen in the Obfervations of rhe Eclipfes of the Third Satellite in the Months of Auguft and Sep- tember , 1703. II. A Defcription of a Roman Pavement found near Grantham in Lincolnfihire, with the Oecenomy of the Roman Times in this Tart of England, communicated in a Letter to Dr. Rutty, S. Seer, hy IV. Stukeley, M. D. Col. Med. Lond . S. Soc. S T R, LAST Week I had an Occafion of examining a cu- rious Piece of Roman Antiquity difeovered near us, and refolv’d to fend you the following Account of it, together with a Drawing I made of it. In Feb. 1717-8. Plowing in the open Fields of ‘Den- ton, about i \ Miles from Grantham, they happen’d upon a Roman ‘Pavement in Mofaic Work, as com- monly call’d. I had Notice of it from my Neighbour, the Rev. Mr. Saul, Minifter of Harlaxton, the next Parilh, and went to fee it. It lies partly in the glebe Land, partly in Madam W elby's, who affifted us with Workmen to clear it. It has been a very large Room about 30 Foot both ways, as we found by digging in divers Places j but being fo near the Surface, not above a Foot, or a Foot and half deep, and having been plow’d ( 4*9 ) plow’d over Time out of Mind, the major Part of it is ruin’d and imperfed. Belides many Fragments of it, we had only the Pleafure of viewing one Piece entire, which was 30 Foot long and 6 broad ; and this was ex- treamly pretty, the Colours lively, the Pattern or Figure finely defign’d, as you will fee by the Drawing, which is exadly taken. {See the Fig .) There are only 3 Colours, white, red. and blue ; but of the middlemoft or moft beautiful Part of it, which is but 9 Foot long and 3 broad, the white and red is Double in Quantity to the blue. In the outermoft Part or Verge of the Work, there is no Variety of Colour, but ’tis entirely blue ; and that made of much larger Squares than the reft. On the Eaft and Weft Sides this was 6 Foot broad, on the North but 3. The red is formed out of Roman Bricks , feveral Fragments of which we found about the Work; the white Colour is made of the common Lime-ftone of our Country; the blue, of the Stone that comes from Benyngton towards Newark , 5 Miles from this Place : And thefe Colours wear welt toge- ther, and produce a good Effed. We found in digging, feveral Parts of the Foundations of the Walls that terminated this Room, and feemingly Foundations of other Rooms adjacent, which Foundations were made of the common white Stone of the Country fet on Edge Side by Side, with here and there a Bit of Roman Brick. The Building was plac’d parallel with the Quarters of the Heavens. They found in digging, fome human Bones, and I took many Bones of a Hand, which pro- bably belong’d to fome unfortunate Perfon kill’d in the Ruins, or when the Houfe was demoftfhed. After this Ihort Defcription of the Work, take this Account of the O economy of the Roman Times, in 3 this ( 43? ) this Part of the Country, and I need detain you no longer. Three Miles South of Grantham is Great 'Taunton, a Village fer in a Tweet Valley, where the Be- ginnings of the Witham River are collected from ma- ny Springs a little higher up. Hard by upon the Edge of the Hill runs the great Roman Road call’d Hermen- Jireet : This Village I alferted in my Itinerary to be the Caujennis in Antoninus's Itinerary, which Commenta- tors have found Difficulty in fettling. The Terms or z Towns between which it is placed in IterV. with the Diftance of the Miles, Efficiently eftabliffi the Situati- on, and they are well known and acknowledged ; thus cDurohrivas , Gaufennim m. p. xxx. Lindum m. p. xx vi. for Taunton is 30 Roman Miles from cDurobri - va, or thePaffage of the Hermen-Jireet over the Nen- river above Teterborough , and z6 from Lincoln. At Taunton , fiace I came to live at Grantham , I have heard of much Antiquity being found, efpecially Mo - faic Tavements ; and undoubtedly it was the Station upon the Hermen-Jireet , between Brigcajierton iz Roman Miles off, and Ancajier 7, which were like- wife Roman Stations and wall’d about, but now their Names are loft. All about Taunton the Romans in- habited very frequent, as at Kirkjioke particularly, where great Quantities of Antiquities have been found ; likewife at Strawjion 1 have feen many Roman Coins dug up, in Poifeffion of my Neighbour Captain Hacket , who owns the Town. He fays likewife fub- terraneous Vaults have been found there, and near it is the Place where our Pavement was difcovered. Be- tween Taunton and Grantham a Road paffes the River at Salter’s Ford , this Road is called Salter's Gate , and much frequented. I believe it has continued ever ftnce the ( 40 > the Roman Times, being the Paftage from Holland in Lincolnjhire by Brigend Cattfey , (a Rowan Work) to all the Towns upon the Fojjway in Nottinghamshire and Leicestershire : For along this Way they carried Salt, made by the Sea Side, to thofe mediterranean Parts, both in Roman and SaxonTimcs. Our Pave- ment Hands within a Bow-fhot of this Road, upon very high Ground, and feems to have been a Summer -villa , or Pleafure-houfe, where on one Side they were enter- tained with the Sight of Travellers going on the Road ; on the other they commanded a moft noble Profped Northwards, of a prodigious Extent. When we are up- on the Spot, you may without Difficulty fee the Rea- fon why they fxed it in that very Point, and ’tis the moft delightful Place that can be imagined for a Sum- mer-retreat. ’Pis placed juft at the Head of a Convah lis , or leffier Valley falling down into the great Valley of Denton underneath, from which Denton has its Name, fignifying the Town in the Valley . This Con- vallis is extreamly beautiful, and running Northward, muft needs be very pleafant and cool in the Summer- time. Our Villa had this further Advantage in its Si- tuation, that it commanded a View between the Open- ing or Gap that in this Place appears, between Bar- rowby and IVolpthorp Hills ; which leads the Eye into the boundlefs Profped of the Vale of Belvoir. You fee from hence Newark , the Trent , Kelham Bark and Houfe , Southwell Minjter , the Foreji of Sherwood, 6c c. belides the neighbouring Cajile oS Belvoir , where in thefe Times was a Roman exploratory Camp , like- wife the Roman Camp of Hunington j infomuch that we may well commend the Wifdom and good Tafte of of the Builder, who contrived fo well for Security and M m m Tie a fare. ( 43* ) i Tleajure . For Air , the Country hereabouts has always, and defervedly, been reckoned the Montpelier of Eng - ; for Water , /TW, Heath , and Trofpett, it may be thought the Frejcati . / W0/? obedient Servant and Brother , William Stukeley. III. Sowze (Reflections on Mr. de Lillet Comparifon of the Magnitude of Paris iwffe London W fede- ral other Cities, printed in theMemoirs of the Royal Academy of Sciences at Paris/or 1 72 J. Communicated in a Letter to Dr. Rutty, Secreta- ry to the Royal Society, by Peter Davall, of the Middle Temple, Efq. MR. de Lijle in the Account he gives of his Me- thod of making an exad Plan of Baris, and comparing it with London , and other Cities , firft fhews, by what Means he proceeded in determining, and laying down the true Situation of the feveral Places in Baris : After which he explains his Manner of draw- ing a true Meridian Line through that City ; whereby he ( 43? > he was enabled to divide it by Meridians and Paral- lels^ as is practis’d in a general Map : And then he goes on in the following Words ; <£ I traced the Parallels from 15 to 15* Seconds , and “ the Meridians from zo to zo. And , as under the cc Parallel of Paris, 15 'Degrees ^/Latitude are equi- “ valent to zo of Longitude, and the like is true of “ Minutes and Seconds ; by allowing ? Seconds more cc to the Intervals of the Meridian?, than to thofe of “ the Parallels, I form'd perfect Squares.” He fays, the chief Ufe he intended to make of thefe Squares, was to compare the Magnitude of Paris with that of London , and gives an Account of what Me- thod he took to procure a juft Plan of this City, which he reduced to the fame Scale as that of Paris , and proceeds thus : “ 1 traced upon it in like Manner , Squares from “ 15 to 15* Seconds of a great Circle, and then 1 <£ was prepared to compare the Greatnefs of the two “ Cities. ” t£ The Refult of this Comparifon is, that Paris con- ct tains 63 of thefe Squares, which makes for its Su - ££ perficies s^^6^y/quare Toifes : And that £C don contains only 60 of thofe Squares 5 or 3370140 £l fquare Toftes.” And from hence he concludes, that Paris is one twentieth Part greater than London , tho’ he fays he has excluded feveral Gardens, contained within Paris , out of this Menfuration, which would have made it bear ftill a greater Proportion to London. Upon reading this Account of Mr. de Life's, it imme- diately occurred to me, that the Method which he has here taken of comparing the Magnitudes of Paris and M m m 2. Lon - ( 434 ) London , from whence he infers that the firft of thefe Cities is one twentieth greater than the latter, is found- ed on a falfe Suppofition, vit. That under the Parallel of ‘Paris 20 Degrees of Longitude are equal to 15 of Latitude , and confequently that by drawing Meridians from 20 to 20 Seconds, and Parallels from if to if, the Figures formed by their lnterfe&ion will be per- fect Squares : For the Equator and its Parallels are to each other as the Sines of their refpeCtive Di- fiances from the Pole. Whence, as the Radius , or Sine of 90 Degrees, is to the Sine of the Difiance of any Parallel from the Pole , or Cofine of its Latitude :: fo is a Degree or any other Part of the Equator , or of any great Circle , to the like Part of the given Paral- lel. Therefore taking the mean Latitude of Paris at 48°. fi', the Proportion of the Degrees of a great Circle to thofe of the Parallel of Paris will by a Table of Sines be found to be as 1 to .6580326. Whereas ac- cording to Mr. de Life , that Proportion is only as 20 to if, or as 1 to .75. The Figures therefore which Mr.’ de Life calls Squares, are not fuch, but Rectangles , whofe longeft Side containing 15 Seconds of a great Circle , bears the fame Proportion to the fhortelf, con- taining 20 Seconds of the Parallel of Paris , as .7? does to .6f 8, &c. or nearly as 8 to 7. And the Inter- vals, which he ought to have allowed to the Meridians, to make perfect Squares of thefe Figures, ought to have ben A? &c. Seconds, or nearly 22"f or 22". 48'" of the Parallel of Paris. Now Mr. de Life fays, thefe Figures are perfect Squares , and has computed them as Squares, whofe Side was if" of a great Circle ^ for he fays Paris con- tains 63 of thefe Squares, which makes 3 f 38647 fquare Toifes , ( 43 5 ) Toifes , which laft Number being divided by 63, the (Quote 56169 will be the Number of fquare Toifes con- tained in each Square, whofe fquare Root gives 237 Toifes for the Side of each Square, which is juft if or 4* of a Degree of a great Circle. Mr. de Life hath therefore by this Account made the faperficial Content of each Re ff angle, and confe- quentiy of the whole City of Taris too great by near one feventh. To confirm which beyond Contradidion we have Mr. de Life's own Teftimony, who in the Plan he himfelf has drawn and publifhed of Taris, and which he refers to in this very Account, has not made Squares of the above-mentioned Figures, but has given to their refpedive Sides the Proportion of 8 to 7, which is as near the true one as can well be exprefs’d by Lines, in a Plan of no larger a Scale than this. Now in the Account we have been confidering, Mr. de Life fays himfelf, that in his meafuring of London he drew Squares , whofe Sides contained 15 Seconds of a great Circle , and of thefe he fays, London contains. fxty. Therefore to compare Taris with London , we ought for the foregoing Reafons to make an Abatement out of the 63 Redangles which Tar is contain0, near- ly in the Proportion of 8 to y5 but becaufe that is a lit- tle greater than the true one, let us make fuch Abate- ment only in the Proportion of 9 to 8, which is pretty confiderably lefs than the juft one. By which Abate- ment the Number of Squares, whofe Side is 15 Seconds of a great Circle contained in Taris , will be reduced from 63 to 56. And copfequently, acccording to Mr. de Life's own Way of meafuring, the Magnitude of London ( 45^ ) London will be to that of Tarts as 60 to £ 6 , or as is to 14 ; or London will be one fourteenth greater than Taris. But to determine what Proportion thefe two Cities really bear to each other, requires a more ex- ad: Menfuration of London than any w.e yet have, which whoever would undertake, 1 think he cannot follow a better Method than that Mr. de Ltjle has taken, and would advife him to confult the Ac- count upon which the foregoing Reftedions are made, which he may find in the Memoires of the Royal Academy of Sciences , for the Year 1715* M- 48. IV. An Account of an Aneuryfm of the Aorta, (dif- fered in St. Bartholomew's Hofpital) hy Pierce Dod, M. V. Fellow of the College of Tbyjicians, and Phyjician to that Hofpital. AN Aneuryfm, without Doubt, is a Tumour arifing from fome Diforder in an Artery ^ but what that Diforder is, or whence it arifes, is not fo well agreed, the Accounts which are given of it, being widely dif- ferent and uncertain. The Name feems to imply, that it is a Dilatation of the Veffel j but Galen defcribes it to be a Tumour, which arifes not from any Dilatation or' Relaxation of an arterial Veffel, and the Blood therein contain’d j but from an Extravafation of the Blood from fome Rupture of the Artery. Agree- ( 437 ) Agreeable to this are the Opinions of all the reft of the Antients, as likewife of the Arabians , who bor- rowed moft that they have from them. Fornelius , as ’tis faid, is the firft who maintained, that the Artery was only dilated, and not burft in an Aneuryfm, and that the Blood was contain’d within the Coats of it, as it is within thofe of the Vein in a Va - rix 3 which is therefore called by fome, £ dvevpva* [Awn. Sennertus makes it to be a Dilatation, not of both the Coats, but of the outward one only, the inner or mufcular one being firft burden, or broken, and he is followed herein by moft of thofe who have fucceeded him, excepting Wifeman and fome others, who tell us, that it is nothing but an Extra vafation of the Blood, burfting through the Coats of the Arteries into the Interftices of the Mufcles, and there forming a Tu- mour fuitable to the Cavity that it findeth, the Artery remaining undiftended or undilated all the While , and that in all thofe Aneuryfms, which have come to be examined, both the Coats of the Artery have conftant- ly been found open. This being the State of Opinions with relation to an Aneuryfm, we had lately an Opportunity of examining further into it, by Means of a Patient, who was taken into our Hofpital. She was about four and thirty Years of Age, and of a good Conftitution, but there was a Tumour, bigger than one’s Fift, which began from the upper Part of the Sternum, between the Origins of the Mufculi Maftou d#t> and extended it felf to the Tomum Adamt , almoft up to her Chin, and polTefs’d all the Breadth between the two Carotid Arteries , z The ( 438 ) The Account that {he gave of the Occafion of it was, that her Husband, being a paflionate Man, took her by the Throat one Day as file was crying out upon fome Occafion or other, and grip’d her To hard as almoft to throttle her. She was then with Child, and immediately perceiv’d fomething of a Pain a little above her Heart, and a few Days afterwards there appeared a Tumour about the Bignefs of the Top of her Finger, juft above the Ster- num, and fo continued without Encreafe or Pulfation, till (lie was brought to Bed, when it began to be enlarg- ed, upon her having a hard Labour , agreeable to what Practitioners have obferv’d, that Accidents of this Na- ture often, happen to Women in Labour. This was about four Years fince, and from that Time it had continued gradually encreafing, until it was ar- rived to almoft the higheft Pitch of Extenfion ; and fhe had all along been troubl’d with a Palpitation, Pain and Straitnefs within the Thorax , great Interruptions in her Reft, and frequent Sinkings, together with a conftant beating along the Cheft up to the Tumour * in which like wife there was a Pulfation correfpondent to the regu- lar Pulfe, (baking the Tumour at every Stroke, and manifeft to the Eye as well as the Touch. Notwith- , (landing this file was otherwife hearty, had her Menfes regularly, had a good Appetite, and was moftly chear- ful and lively, and never more fo than juft before the fatal Period of the Tumour. The Apex of the Tumour, which was towards the Middle, in the prominent Part of it was beginning to mortifie, through an over Diftenfion, and the common outward Integuments were the firft that feemed to buf- fer : But the Diftenfion continuing, the Mortification encreas’d, C 4?9 increas’d, and was quickly communicated to the outer Coat of the Artery likewife, which therefore Hough'd off as well as the other Integuments, and being at Length wore away, juft at the Extremity made a hid- den Aperture, about twice the Bignefs of a Goofe’s Quill. The Blood inftantly guflTd forth, as from a Stream or Torrent, and the poor Patient died in lefs than a Minute. Upon opening the Body, we began from the Heart, in which there was little remarkable, except that the left Ventricle was fomewhat larger, as were likewife the Column a earner , than they naturally flaould be. There was little obfervable likewife in the Aorta itfelf, till we came to the Curvature ; upon the upper Side of which was the Bajis of the TumouT, forming a cy* lindrical Stem of four Inches long while in the Cavity of the I borax-, but extending it felf into a circular Form'bf a larger Dimenfion, when it became external. Upon opening the under Part of the Aorta oppofite to this Bajis, and carrying the Incilion throughout its •whole Extent in the Thorax , the Trunk retain’d its ufual Form and Dimenfions, and was not at all dilated ; but in the upper Part above deferib’d, juft on this Side the Orifice of the right fubclavian Artery (which was nearer than ufual to the Orifice of the left Carotid ) there was a preternatural circular Aperture of half an Inch Diameter. Upon dividing this Aperture, and car- rying on the Incifion to the Apex of the Tumour, its whole infernal Subftance appear’d. The Edges of the Aperture at the Bafis of the Tumor were hard, and almoft cartilaginous, andfeemingly the Remains of thick and flefhy Fibres*, which upon a nicer Infpe&ion they appear’d to be in Faft, viz. the broken Fibres of the in- N n n ner. ( 44° ) ner, or what is commonly call’d, the mufcular Coat of the Artery : which terminating here, the Tumour im- mediately encreas’d to 2 Inches in Diameter, and con- tinued of that Dimenfion, till it came out at the Neck, between the Clavicles ^ but then extended it felf circu- larly to a Diameter of above 3 Inches, the Covering of which was nothing elfe but the outer Coat of the fame Artery all along dilated from the Bafe, even to the Extremity of the Tumour. The Cavity was for the moil Part fill’d with a Sort of ‘Polypus , or Sarcoma ; in which neverthelefs there were three Sinufes, or Paflages, that were kept open by the confiant Influx of the Blood, and communicated near the Jlpex with one another } (that in the Middle being the larged,) and terminating in one towards the Extremity of the Tumour, not far from where it broke. Such was the State of the Aneuryfm in this Subjed, what it may be in others, future Enquiries mud de- termine. Y. Some Obf creations on Aneuryfms in general , and in particular , on the fore-going . (By F. Ni- cholls, M. Tr•. !.il 0': "'f j. '• Obfervatto ' ( 4 77 ) Ob fern) at io Solaris deli quit die 14 Septembris 1717. N. S. habita in Obfervatorio Bononienli a Cl, Euftachio Manfredi. . . • ■ -i j : ' ' » . * • -* • t - * * . iu T jr \ \ f L « * f ’ 1 3 1 L 1 ' " * v * ~ ■*'.**») f T PLurima in Sole macula hujufce Eclipfis tempore videbantur: Cum tamen pra nubibus necelTaria circa illas inftitui obfervationes non potuerint, ut earum litus in Solari difco deprehenderetur, pracipuarutn tantum afpedus in appofita figura exhibetur, qualis inferri potuit ex obfervationibus vefpere diei 14. circa hor. 5*. 1 6r. habitis j idque fatis efie arbitror ad eas in- dicandas qua funt a Luna occultata Eclipfis tempore, Notandum tamen, pradidas maculas, ex quo obfervata funt vefpere diei 14. ufque ad Eclipfis tern pus, non mo- do lingulas in fuo parallelo Solari procefiifie, quantum regularis motus Solis fert, verum etiam plerafque earum line lege immutatas apparuilfe turn figura, turn raagni- tudine 5 nonnullas etiam in plures divifas, aliafque in unum compadas j alias demum in Limbo Solis orienta- ls vifas, qua vefpere pracedenti non apparebant. Initium Eclipfis obfervari non potuit^ fed hor. 18. S$K Allronomic. fenfibilis apparebat defedus, ut inter nubes. H. / f 18. 59. 37 • Unus digitus, & ampfius fortalfe latebat. 19. 3. 12. Digitus cum dimidio. 19. 6. so. Duo digiti. 19. 10. 11. Duo cum dimidio. dub, Paulo poft nubes Solem obtegunt. 19. 30. 35. Sol inter nubes videtur deficere plus digitis 4 cum dimidio. Eclipfis ( 4 n > H ' " * ■* « , * • m f • . . . . 19. 3 f. 46. Eclipfis nondam pertingere videtur &d c digit. 19. 40. 47. Quinque digiti circiter. 19. 44. 31. Macula, by dy ey jam latebant. Nunc occaltatur centrum, /. 19. 47. 27. Limbus 1 inter maculas, s. 19. 47. 46. Secunda ex duabus maculis, j, ornnino te- gitur. 1-9. $ 1 . 37. Eclipfis eft pauIo. minor f digit, inter nubes. 19. f 4. 12. Centrum macula;,/, occultatur. *9- 5'5'- 37- Centrum, <7, item occultatur. 19. 5*9. 2. Quatuor dig. cum dimidio eclipfantur. dub. . 20. 1. 22. Una ex maculis prope limbum (fortaile //) occultatur. ±0, 10. io. Eclipfts paulo min. dig. 3 J. 20. 11. 47. Tota macula i, emerfit. 20. if. o. Eclipfis 3 digitorum. 20. 18; 48. Duorum cum dimidio. 20. 18. 49. Incipit emergere macula, s. 20. 22/26. Duo digiti circiter eclipfantur. 26.2*6. 14. Digitus it. /. ’ 20. 36. 6. Finis Eclipfeos a tribus obfervatoribus no-' tatus, in eodem fecundo temporis con- cordibus. : 14. Sep* { 4 79 ') 14- Septembris, 1717, bora 5. min. 1 6. Figura macularum Solarium inverfo fitu. Obfervatio defe&us Solis habit a Tatavii XVIII. Kal. Ottobris 17x7. N. S. a Comite Joanne Poleno. DEnfioribus tamen nubibus faepius intercurrentibus, non plures obfervari potuerunt Phafes, quam eas, quas fubjeci. Temp. Ver. " . 19- 3- 4 S- — 0 10 a4. ia. -30 41. a 7. n *■ ' 4 30 ao. 30. 45-. — ~ 1 30 38. 4a. — — — r Finis. m.A I ( 48° ) III. A Second Letter to Dr . Rutty, R. S. Seer. containing farther ObferVaftons towards compojing a natural Hiflory of Mines and Metals. ©^ Vr. Nichols, Prjtl Anat . Oxon, and S. 5. cj Dear SIR , * \i • IN my laft I acquainted you with fome Particulars relating to Mines in general, and that the Loads in Cornwal yielded Iron, Tin, Lead, and Copper. \ ' * v *' \ Of I R O N. Of all the Subftances concurring to form the ter- reflrial Globe, Iron probably bears the greateft Share j as it not only abounds in raoft Kinds of Stone, (hewing it felf in Varieties of Crocus, all which gain a more intenfe Colour by Fire^ but enters likewife greatly into the Compofition of common Clay j as may be judged from the Similitude of Colour between Clay and dry Iron Oar ^ from the eafy Vitrification of Clay \ from the Refemblance between Clay fo vitrify’d and the Clinkers of Iron^ from its deep red Colour after Calcination j and laftly, from its yielding pure Iron, by being burned with Oil. But while Iron is thus entangled with other Bodies, it rarely employs the Care of the Miner } who finds the Expence of reducing it to Metal too feldom bal- lanced by the Price it yields: For which Reafon, tho’ we frequently meet with large and rich Loads of Iron, yet ( 48* ) yet (the Woods having been apply 'd to more advanta- ges Ufes) they are there entirely negleded. When it is moft pure, 1 find the Oar under three different Appearances. Paper the firfl contains a Piece of rich dry Iron Oar, whofe Scrapings exadly refemble an ALkohol Martis : This Kind of Iron Oar has very nearly the Colour of common Clay. Paper the fecond contains a Piece of rich Iron Oar, with Part of the Wall of the Load formed by a Concretion of yellow Cryftals. In this Stone the Iron radiates from Points forming Segments of Spheres, and where thefe Spheres leave any Interfaces, you will find a Crocus, or Oker. Paper the third contains a Stone of Iron of the Kind ufed for burnifhing Plate j it is of the Species of the Hematites. Both thefe laft Stones fcrape into a deep Crocus. From the fecond Inftance we may conjedure, that the yellow Colour in Cryftals arifes from a Crocus en- tangled with the ftoney Salts. Though the Want of Wood in Cornwal deprives it of the Advantages it might otherways reap from Iron as a Metal, we (hall neverthelefs find it far from being a ufelefs Oar, when we conlider it as fometimes im- pregnating the Waters with vitriolick Salts, thereby making them a proper Menftruum for dilTolving the diffeminated Particles of Metals- fometimes deftroying the fulphureous Menflrua, which (tho* they diifolve the diileminated Metals) do neverthelefs obflrud their new Concretions and fometimes as being it felf the Magnet by which the metallick Particles are attraded into new Concretions. Of Ttt ( 48i ) Of T I N. The next metallick Subftance found in Cornwall and from which thefe Iflands are fuppofed to take their Name, is Tin. It is never found but as an Oar^ whereas Gold is never found but as a Metal, at leaft its Oar is unknown, and all other Metals are found fometimes as a Metal, and fometimes as an Oar. Tin always ftioots into Cryftals which are of diffe- rent Magnitudes from two Ounces in a fingle Cryftal to fuch as efcape our Sight. Thefe Cryftals are for the moft Part interfperfed in Loads of other Subftances. Paper the fourth contains Tin Cryftals interfperfed in a Load of a Kind of Clay, in which is obfervable a conftderable Quantity of Red-oker. Paper the fifth contains a Stone of hard Iron-Stone, in which are exceeding fmall Cryftals of Tin. Paper the fixth contains fomewhat larger Cryftals, interfperfed in a dry Red-oker. Paper the feventh contains Tin Cryftals, interfperfed with Sparr-ftone and a Sort of Marl. Paper the eighth contains larger Cryftals, interfperfed in a Kind of Clay and Red-oker, as in Paper the fourth. When a hundred Sacks of the Load (each contain- ing more than a fVincheJier Bufhel) yield one Gallon of clean Oar, the Load is efteemed very well worth working. Sometimes thefe Cryftals are fo colleded into one Mafs, as to form Loads of pure Tin Oar, and fo large as to yield to the Value of ioo/. every twenty-four Hours. i Paper ( 483 ) Paper the ninth contains two Stones of fuch pure Loads, in which obferve the one is black, and the other nearly white. Thefe Cryftals concrete fometimes into the Form of a Parallelipepidon, whofe Summit is covered by a Pyramid ^ fometimes the Angles formed by the Sides of the Pyramid, and fometimes the Summit of the Pyra* mid are as it were plained away. Paper the tenth contains feveral of thefe Cryftals, of which Number the firft contains a whole Cryftal, which has none of its Angles off. ( See Flate the zd. Fig . the 8 th.). The fecond contains a Cryftal which has only two of its Angles plained away. (Fig* the yth(). The third contains a Cryftal which has all its Angles plained away. (Fig. the 10 th.). The fourth contains a Cryftal which has all its Angles and its Summit plain* ed away. (Fig. the n th,) Sometimes the Cryftals reprefent two equal pentela* teral Pyramids joined at their Bafe, As in Paper the eleventh, which contains two Clufters of Cryftals, which considered feparately are of that Form* Under whatfoever Form thefe Cryftals (hoot, they always carry an exceeding fine Surface } which, when rubbed off, can be renewed by no Art. In Paper the fourth one Side of the Parallelipepidon is rubbed away, to fhew its Appearance after lofing its natural Surface. Thefe Cryftals are of different Colours from the White (like white Sugar candy’d) to the deep Black. Thus Paper the twelfth contains a groupe of fmall white Tin Cryftals, which are very uncommon. Thefe white Cryftals feem to me to carry a finer Luftre than any other I ever faw, and are perfe&ly tranfparent • fo T 1 1 2 that ( 4«4 > that were they found of equal Size with the black Cryftals, and of a white Water (which 1 imagine may be) their Hardnefs and Weight (in both which they exceed any other Foflil) would probably make them preferable to the Diamond. However, as the deeper Colours of thefe Cryftals feems to arife from a greater Proportion of Iron in their Compofition, which they throw off in an Iron Slag upon Fufion, and which changes by proper Degrees of Heat into a Crocus, thereby changing the Colour of the Cryftal to a brighter Red j fo the white Tin Oar is certainly to be efteemed both richeft and beft, as moft free from Iron. Paper the thirteenth contains a Piece of the Load contained in Paper the feventh, in which the Cryftals are of a brighter red, from its being heated red-hot. {Thefe Specimens were all produced before the Soci- ety, and are fince prefented to Sir Hans Sloane, *P ref dent.) Thefe Cryftals feem to be the heavieft Bodies the Earth produces, except Quick (liver and aftual Metals. Their fpecifick Gravity is to Water as 90 ~ to 10 • to Rock Cryftal in Water as 90 i to 2 6 ; to Diamond as 90 i to 34; and to pure malleable Tin, as found by repeated Trials, as 90 i to 78 ; from whence appears the Poffibility of what fome Miners affirm, viz,. That a cubical Inch of fome Tin Oars, will yield more than a cubical Inch of Metal. Having already taken Notice that the Cryftals of Tin are fometimes fo fmall as to efcape the Eye, and fo difteminated in the Load as not to make above |octh, or *000 Part of the Load, one would naturally imagine it an endlefs Labour to cleanfe the Oar from fuch a vaft Difproportion of Rubbiffi. But the great 3 fpecifick ( 48y ) fpecifick Gravity of thefe Cry fills renders the cleaning it lefs troublefome, and lefs expenfive, than in any other Oar whatever. It requires no more, than that the whole Stuff be (lamped to a fine Powder, after which it is wafhed by a Water, whofe Force is fo moderated as to wa(h away only the lightefl Parts. This Stamping and Wafhing is repeated till the Oar is left exceedingly clean, and yields in Metal from 20 to f§th, according as it is cleanfed from the Load, and as it is in its own Nature more or lefs free from Iron. Begging Leave to defer the Account of Lead and I am juiy the lfV Tour very humble Servant , 1728. ♦ F. Nicholls. IV. A Method of raijing fome exotic 4 Seeds , which have been judged almoft impoffible to be raifed in England, communicated in a Letter to Dr. Douglas, Coll Med. Soc. honor ar. and S'. S. Dy Mr. Philip Miller, Gardiner to the Dhyfick - Garden at Chelfea. SIR, According to my Promife, I here fend you an Ac- count of the Methods 1 have taken to raife the Coco-Nut , with the Succefs of each ^ which hath led me w ( 4*ut Mortuum remaining in the Retort. is ( 494 ) Spirit 1 found to be a perfect volatile A leal i, altogether of the fame Nature with that which is extracted from Blood, from Urine, and from Bones. Hence again it is evident, that this tophaceous gouty Subftance is compofed of the fame Principles with the other fluid and folid Parts of the human Body, or, that the Caufe of the Gout is nothing elfe but a volatile, a lea- line, corrofive Salt, which by corroding the fenfibie Membranes about the Joints, occaflons thofe acute Pains, which we call the Gout. FINIS. LONTON i Printed for William Innys, at the Weft End of St. Tanl’s. M.DCC.XXV1II. * 1 rfla/c 2 . Numb. 404.1 PHILOSOPHICAL transactions r ¥ . . fk' * 1 \ * ‘ * FOR THE Month of OCTOBER, 17x8. The CONTENTS. I. Of Fofiile Teeth and Bones of Elephants, Tart the Second . Ty SVr Hans Sloane, Tart, II. A Method for determining the Number of im- po/Jible L(oots in adfeEled Equations, Ty Mr . George Campbell. III. A Letter from Charles Price, Efq 5 of Trinity- Coll. Oxon, relating to the Villi of the Stomach of Oxen , and the Expanfion of the Cuticle through the TuEius Aliment alis . Communicated by Dr. F. Nicholls, F. 3^. 5. W Tral Anat. Oxon. IV. Obfer- V The CONTENTS. IV. Obfertationes Aftronomic# habit# in ObferVato- rio Rononienfi Anno 1727, a CL Euftachio Manfredi, % S . S. Ex Epiftola J. Baptiftct Carbone ad Ifaacum Secyueyra Samuda, M T>. Coll. Med. Lie. & (j^. S. S. ( 497 ) — — ■■ — - I. Of Foffile Teeth and Bones of Elephants. Tart the Second. By Sir Hans Sloane, Bart . I Proceed now to the Second Part of this Difcourfe, wherein I propofe to offer forae Remarks on divers Accounts of Bones and Teeth found under Ground, which I met with in feverai antient and modern Au- thors, and which will give me an Opportunity of ex- amining into the Skeletons, and Parts of Skeletons, which are (hewn up and down as undeniable Monu- ments of the Exiftence of Giants. And hrft, as many of thofe Bones and Teeth, which are kept and (hewn about for Bones and Teeth of Gi- ants, have been found, upon a more accurate Infpefti- on, to be only the Bones and Teeth of Elephants or Whales, it may from thence very probably be in- ferred, that others alfo, which for want of a fuftici- ent Defcription cannot be accurately enough accounted for, muft have belonged either to thefe, or elfe fome other large Animal. Thus the Fore-tin of a Whale, ftripp’d of its Webb and Skin, was not long ago pub- iickly (hewn for the Bones of -a Giant’s Hand ^ and I have in my own PolTeflion (N° 10x7) the Vertebra of the Loin of a large Whale, which was brought me from Oxfordjbire , where 1 was ahured it was found un- der Ground, and afterwards made Ufe of for a Stool to fit on (Fig. 1.). Now if a Computation had been made from the Proportion of this Vertebra to that of the other Parts of the Skeleton, and all had been fuppofed to X x x have ( 498 ) have belonged to a Man, fuch a Skeleton would have exceeded in Meafure, all thofe fabulous Skeletons of Giants mentioned by Authors. I cannot forbear on this Occafion to obferve, that it would be an Objed well worthy the Inquiries of inge- nious Anatomifls, to make a Sort of comparative Ana- tomy of Bones j I mean to examine, with more Accu- racy than hath been hitherto done, what Proportions the Skeletons and Parts of Skeletons of Men and Ani- mals bear to each other, with Regard either to the Size, or Figure, or Strudure, or any other Quality. This would doubtlefs lead us into many Difcoveries, and is otherwife one of thofe Things, which feein to be wanting to make Anatomy a Science dill more per- fed and com pleat. The very Vertebra I fpeak of may ferve to fhew the Ufefulnefs of fuch Obfervations. It differs in many Things from the Vertebras of Men and Land-animals, as do the Vertebras of Whales and the Fifties of the cetaceous Kind in general \ and it is a very eafy Matter to diftinguifti them from each other. The Body of the Vertebra is confiderably larger in Proportion, and alfo lighter and more porous. The tranfverfe Proceffes arife from the Middle of it on each Side. The oblique defcending Proceftes are altogether wanting j and the Arch, or Foramen, which the fpinal Marrow paftes through, is made up by the fpinal Procefs and the oblique afcending ones only: The Body of the Vertebra is very rough and uneven on each End, full of fmall Holes and Eminences, which re- ceive the Holes and Eminences of a round Bone* or Plate, which anfwers to the Epiphyfis in a human Vertebra, whereof there are two between each Vertebra, joined together ( 499 ) together by an intermediate ftrong and pretty thick Cartilage, probably to facilitate the Motion, and par- ticularly the Flexion of thefe Animals in the Sea. (Fig. 2, 3.) But to return from this fhort Digrefiion. There are many Skeletons, that were from Time to Time found under Ground, and are mentioned by the Authors, who fpeak of them, as Skeletons of Giants, and undeniable Monuments of their Exiftence, which, as I have already obferved, I fhould rather take to be the Skeletons of Elephants, Whales, or fome other huge Land or Sea-animal. Of this Kind feem to be the pretended Skeletons of Giants of 12, 20, and 30 Cubits in Height mentioned by Thiloftratus * : The Skeleton of fix and forty Cubits in Height, which according to Tliny f was found in the Cavity of a Mountain in Cretan upon the overthrowing of that Mountain by an Earthquake : The Skeleton fixty Cu- bits high, which Strabo ^ fays, was found near Tin* gis (now Tangier') in Mauritania , and was fuppofed to have been the Skeleton of Anteus : The Skeleton of T alias , as pretended, found at Rome in the Year if 00, which was higher than the Walls of that City : And likewife that, which Simon Majolus fays was found in England in the Year 1171 : Longd ante Fulgoji faculum (are his Words ||) annis plus trecentis , anno fcilicet 1171. in Anglia , illuvione flumints , retetta funt humati olim Hominis ojfa adhuc or dine compojita : Longitudo totius Corf oris invent a eft longa ad pedes quinquaginta. There are others, the Description whereof con- cludes more clearly for their having once belonged to * In fuis Hcroicis. *{• Hift. Naf. Lib. vii. C. xvf. £ Lib. xvi«L il Dierum Canicularium Colloq. u, fag. 36. X x x 2 Elephants, % C 500 ) Elephants, though it could not be pofitively afferted, that they did. S. Auftin *, difcourfing of the Ex- iftence and great Feats of the Giants before the De- luge, mentions in Proof of what he advances. That he himfelf, with feveral others, faw at Utica, upon the Sea-fhore, the Grinder of a Man fo large, that if it had been cut into Teeth of an ordinary Size, at leaft an Hundred might have been made of it. Hiero- nymus Magius f, although himfelf very much pre- judiced in Favour of the Exiftence of Giants, yet fufpe&s this Tooth, mentioned by S. Auftin, to have been rather the Tooth of an Elephant, or elfe fome huge Creature of the Sea, than that of a Man. But Ludovicus Vives , in his Commentaries upon that Paf- fage of S. Auftin , takes Notice, that in the Church of S. Chriftofther at Hifftella, he was ftiewn a Tooth bigger than his Fift, which they pretended was one of the Teeth of that huge Saint, no Doubt, upon as good Ground, as that very large Shoulder-bone, which Hieronymus Magius fays f, was fhewn in a Church at Venice , was the Shoulder-bone of S. Qhriftofther . The pretended Skeleton of a Giant, which was found near fDraftani, a Caftle in Sicily , upon dig* ging the Foundation of a Houfe, and is defcribed by Job. Boccatius || , is again not unlikely to have been the Skeleton of a large Elephant. For although the. greateft Part of the Bones, through the Length of Time, and the Force of the fubterraneal Steams, were fo rotten, that after their being expofed to the Air,. . they fell to Pieces alraoft upon touching, yet three * De Civit. Dei. Lib. xv. C. ix. citatus per Caflanionem 6c Lam- becium. | Mifcellaneorum Lib. i. C. ii. pag. iy, $ L. C. pag, io, 6* jj Genealogia degli Dei. L. iv, ad fin. pf ( 5°i ) of the Teeth were found entire, which weighed an hundred Ounces, and were by the Inhabitants of P) ra - pani hung up in one of their Churches, to perpetuate the Memory of this Fad. They like wife found Part of the Skull capacious enough to hold fome Bufiiels of Corn, and one of the Shank-bones, which was fo large, that upon comparing it with the Shank-bone of an ordinary Man, it was judged, that this Giant, whom fome took to be Erick , others Ethellus , others one of the Cyclops , and again others the renowned ‘Polyphemus himfelf, mull have been zoo Cubits high, according to which Calculation, he is figured and re- prefented by F. Kircher * as by far the largeft of a whole Gradation of Giants, whom, after this, lie places in the following Order : Cubits. The Giant of Strabo , whofe Skeleton was dug up near Tingis in Mauritania , and was found to be — — — 60 high. Pliny's Giant, found in a Mountain in Creta. — — — ■■ — The Skeleton of Afterius , Son of AnaBles The Skeleton of Orejies , dug up by fpecial Command of the Oracle The Giant, whofe Bones were found under a large Oak, not far from the Convent! of Reyden in the Canton of Lucern inj Swijferland. fioUath) as defcribed in Sacred Writs — — The Cafe is flili lefs doubtful with Regard to thofe Bones, which were found in France in 1456, in the * Mtfnd. Subterran. L. viii, Seft. 2, Reign ( 502 ) Reign of Charles VII, by the Side of a River in the Barony of Crujftole (afterwards ere&ed into a County) not far from Valence. Johannes Alarms in Libris de Galliarum llluftrationibus , C a lam a its in fuis de Bitnrigibus Comment arijs, Fitlgofus in his Annals , & Job. CaJJanio of Monftroeuil , in his Treatife of Giants *, feverally take Notice of thefe Bones, which were fo large, that the whole Height of the Giant, to whom it was thought they belonged, and who was fuppofed to have been the Giant Briatus , was con- jedured to have been of iy Cubits. The Skull alone was two Cubits thick, and the Shoulder-bone fix Cu- bits broad. Sometime after, other Bones of this Kind were found in the fame Barony near the fame Place, Part of which Cajfanio faw himfelf, and gives fuch a particular Defcription of one of the Teeth, as leaves little Room to doubt, but that it was the Grinder, and confequently the other Bones, the Bones of an Ele- phant. His Words are f, Mira magnitudinis dentem multi ibidem con/peximus , longitudine unius fedis^ fonder e librarum olio ; multo autem oblongior quam craffus vijus eft , radicefque aliquot habere quibus gingiva inhare bat. Vifa eft infufer ea fars , qua cibus terebatur , aliquantulum concava , latitudine digitorum quatuor. He adds farther. That fuch ano- ther Tooth was kept at Charmes , a neighbouring Caftle, that he meafured the Length of the Place, whence thefe Bones were dug, and found it to be nine Paces \ that fome Time after more Bones were difcovered at the fame Place, and that the Coun- try all thereabouts was very mountainous, and fuch, "* Pag. *>7> & feq. f Pag. 62. as ( 5°3 ) as the Giants in all Probability delighted to dwell and command in. I have feen fome of thefe Bones brought by a very curious French Merchant from this lafl mentioned Place, which I took to have belonged to an Elephant, by fome large Cells between the Tables of the Skull, which are in the Skull of that Animal. Hieronymus Magius * gives an Account of a very large Skull, eleven Spans in Circumference, and fome other Bones, probably belonging to that Skull, which were dqg up near Tunis in Africa by two Spanijh Slaves, as they were ploughing in a Field. He was informed of this Matter by Melchior Guilandinus , who faw the Skull himfelf, when he had the Misfor- tune to be taken by the Rovers , and carried into Slavery to that Place in the Year 1579. I am the more inclined to believe, that this Skull and Bones was Part of the Skeleton of an Elephant, becaufe, as I lhall (hew hereafter, a like large Skeleton was dug up near the fame Place fome Time after, which by one of the Teeth fent to Teiresk was made out to have been the Skeleton of an Elephant. I now come to thofe Bones, Teeth and Tusks, (or Horns, as fome call them) which are mentioned by Authors to have been dug up in divers Parts of the World, and have been made out by them, or do otherwife appear by their Defcription and Figures, indifputably to belong to the Elephant. Johannes Goropius Bee anus j-, notwithftanding he lived in an Age, when the Stories of Giants were very much credited, and had found their Advocates, even * Mifcellan. Lib. i. Cap. ii. pag. 19. 6. f Originum Antwerpiana- rum Libro. ii. quern Gigantomachiam appellayit, pag. j7s. among - ( j'04 ) among Perfons eminent for their Learning and Judg- ment, yet ventured to aider t, that the Tooth, which was kept and (hewn at Antwerp , as the Tooth of that un- merciful Giant, whole Defeat, brought about as they pretended, by Brabo a Son of Julius C iefar, and King of the Arcadians , was fabuloufly reputed to have given Occalion to the building of that Caftle and City, was nothing but the Grinder of an Elephant. How- ever difplealing this Aifertion might be, as Goropius farther adds, to thofe who are delighted with fuch idle and ridiculous Stories, yet to the Judicious it will appear the lefs furprizing, on Account of what padded not long before he wrote this Book, when the almoft entire Skeletons of two Elephants, with the Grinders, and likewife the dentes exert i, or Tusks, were found near Wielworda , Vilvwdeni as they were digging a Canal from Brnjfels to the River Rupel , to defend that Town and Country from the Incurlions of thofe of Me - chlen. Goropius conjectures, that thefe Elephants had been brought thither by (he Romans, at the. Time either of the Emperor Galien , or Tof humus . A very large Skeleton, likewife of a Giant, as pre- tended, was dug up near Tunis in Africa about the Year 1630, whereof one Thomas d' Ar cos, who was then at that Place, fent an Account, together with one of the Teeth, to the learned Teiresk. The Skull was lb large, that it contained eight Meilleroles (a Mea- fure of Wine in Trovence ) or one Modius, as Gajfen - dus calls it *, or a Pint and a Half Tar is Meafure. Sometime after a live Elephant having been Ihewn at T onion , Teiresk ordered, that he fhould be brought to his Country Seat, on Purpofe to take that Opportunity * Gaffendus in vita Peitesk. Lib. iv. Anno 1632. Z to ( 505 ) to examine the Teeth of the Creature, the Iqnpreflions whereof he caufed to be taken in Wax, and thereby found, that the pretended Giant’s Tooth fent him from Tunis , was only the Grinder of an Elephant. This is the fccond large Skeleton dug up near Tunis in Africa , and it appearing plainly by the Tooth fent to Teiresk , that it was the Skeleton of an Elephant, it may from thence very probably be conjedured, fome other Circumftances concurring, that the other alfo, ' which Guilandinus faw there, mufl have been rather of an Elephant, than of a Giant. Thomas Bartholin * mentions the Grinder, or Maxillar-tooth of an Elephant, which was dug up in Ijland , and fent to him by Tetrus Refenius. It was turned to a perfeCt ftony Subftance, like Flint, as was alfo the Tusk of a Rofmarus , dug up in the fame Ifiand. A large Tooth, which by its Shape appears plainly to be the Grinder of an Elephant, is defcribed and figured by Lambecius f, who had it out of the Em- peror's Library, though he could not be informed where it was found, or how it got thither. It weigh- ed 'i 8 Ounces, and was commonly taken to be the Tooth of a Giant. Antonins de Tozzis, chief Phy- fician to the Emperor, in a Letter to Lambecius affirms it to be an Elephant’s Tooth, and conjectures, that it was dug up at Baden , about four Miles from Vienna , where, but a few Years before he wrote this Letter, they had found alfo the Os Tibia & femoris of an Elephant. * A&. Medic. Sc Philofoph. Hafn. To. I. Obf. xlvi. pag. 83. “ } Biblioth, Caefar. Vindob. L. VI. pag. 311. j lb. Lib. vi. pag. 315. ^ y y Another ( 5°6 ) Another Tooth, probably of an Elephant too, is defcribed and figured by Lambecius *, who had it out of the Emperor’s Library. It weighed 23 Ounces, and was found in the Year 1644 at Krembs , in the lower Aujiria , as they were increafing the Fortifica- tions of that Place. The Year following, when the Swedes came to be- fiege the Town of Krembs , a whole Skeleton of a Giant, as was pretended, was found at the Top of a neighbouring Mountain, near an old Tower. The Befiegers, in their Intrenchments there, being very much incommoded by the Water that came down from the Mountains, dug a Ditch three or four Fathoms deep, to lead it another Way. It was in digging this Ditch „ they found the Skeleton aforefaid, which was very much admired for its unufual Size. Many of the Bones, chiefly thofe of the Head, fell to Pieces upon being expofed to the Air, others were broke by the Careleflnefs of the Workmen \ fome efcaped entire, and were fent to learned Men in Poland and Sweden. Among thefe was a Shoulder-bone, with an Acetabu- lum in it large enough to hold a Cannon-ball. The Head, with Regard to its Bulk, was compared to a round Table, and the Bones of the Arms (or Fore- legs) as thick as a Man of an ordinary Size. One of the Grinders, weighing five Pounds, was given to the ' Jefeiits at Krembs : Another is figured by Happe - Lius (in his Relationes CuriofiSy Tom. iv. pag . 47, 48.) to whom I am indebted for this Account, and it appears plainly by the Figure of it, that it is an Ele- phant’s Tooth. It weighed four Pounds three Ounces Nuremberg Weight. * lb. Lib. vi. M* 313. * Again, ( 5®7 > Again, in Lambecius his Bibliotheca Cat fared Vin- dobonenfs *, are two Figures, and the Defcription of a very large Elephant’s Tooth, which weighed 4 £ Pounds. It was fent from Conft ant inop le to Vienna in 1678, and offered to be fold to the Emperor for 2.000 Rixdollarsy having been before, for its unufuai Size, and pretended great Antiquity, valued at 10,000 Rixdollars. They pretended that it was found near Jerufalem , in a fpatious fubterranean Cavern, in the Grave of a Giant, which had the following Infcription upon it in the Chaldaic Language and Characters j Here lies the Giant O G *, whence it was conje&ured to have been the Tooth of Og , King of Bafan , who was defeated by Mofes , and who only remained of the Remnants of Giants ; whofe Bed-Jiead was of Iron , nine Cu- bits was the Length thereof and four Cubits the Breadth of it , after the Cubit of a Man f. As the whole Story look’d very like an Impofition, the Emperor ordered, that the Tooth (hould be fent back again to Confl ant inop le. Hieronymus Ambrofius Langenmantel , a Member of the Imperial Academy of Sciences, inferted into the Ephemerides of that Academy £ an Abftrad of a Letter to hiinfelf, from Johannes Ciampini in Rome , concerning fome very large Bones, to wit the Shank- bone, the Shoulder-bone, and five Vertebra*, of the Number whereof was one of the Vertebrae of the Neck, which were dug up near Vitorchiani , in the Bifhoprick of Viterbo , in the Year 1687. They weighed altogether upwards of 180 Roman Pounds, and having been compared with other the like Bones T Lib. viii. fag. 652. f Deuteronom. Cb. iii. v. 2. £ Decur. if. Annus vii. 5. 1688. Obf. ccxxxiy. pag. 426. Yy y i m ( 5°8 ) in feveral Collections at Rome , particularly the Chi- flan one, they appeared to be by far the largeft. Mod People took them to be the Bones of a Giant, but Ciampini , and fome others, taking them, with more Probability, for the Bones of an Elephant, or fome other large Animal, and knowing that there was in the Medicean Collection at Florence a com- pieat Skeleton of an Elephant, they procured a Copy of it, and found upon Comparifon, the above-men- tioned Bones fo exactly to correlpond with it, as to leave no Room to doubt, but that rhey had been Part of an Elephant’s Skeleton. The Skeleton of an Elephant which was dug up in a Sand-pit near Tonna in Thur ingen , in 1695*, is one of the molt curious, and alfo the molt compleat in its Kind, forafmuch as they found the whole Head, with four Grinders, and the two dentes exerti , or Tusks, the Bones of the fore and Hind-legs, one of the Shoulder-bones, the Back-bones, with the Ribs, and feveral of the Vertebras of the Neck. But the whole hath been fo accurately defcribed by JVilhel- mns Ernejlus Tentzelius , Hiftoriographer to the Dukes of Saxony , in a Letter to the learned Magli- abechi , printed in the Thilofophical Tran factions that it is needlefs to add any thing, the rather, as that Gentleman was pleafed to oblige the Royal Society with fome Pieces of the Bones of this Ele- phant, with Part of the Skull, wherein appeared its Cells, fome of the Grinders, and Part of the dentes exerti ; all which being produced at a Meeting of the. Royal Society , were found exaCtly agreeable to his Defcription, and ordered to be carefully preferved in '* Nc 134. p*g. 737- their 2L ( 5 °9 ) their Repofitory. From the Surface of the Ground down to the Place where thefe Bones were found, the Difpofition of the Strata , or Layers, was as follows : A black Soil four Foot deep, Gravel two Foot and a Half, the Middle whereof was made up of Ofteocolla and Stones to the Depth of two Foot, Ofteocolla and Stones half a Foot, a fandy Clay fix Foot, with about two Inches of Ofteocolla in the Middle, Ofteocolla and Pebbles one Foot, Gravel fix Foot, a white and fine Sand, the Depth whereof was unknown, and in this the Bones were found. In the Second Volume of Count Mar fill's cDanu - biusy where he treats of the Antiquities he obferved along this River, there is Mention made of feveral Bones and Teeth of Elephants, which that inquifitive Nobleman met with in Hungary and Tranjylvanlay and which are now in his valuable Colledion of natural and artificial Curiofities at Bologna. Accord- ing to the beft Information, the People of whom he had them could give him, they were found in Rivers, Lakes and Pools. One of the Vertebra?, a Grinder, and a confiderable Part of the dens exert us, or Tusk, were found in the Lake, or Pool of Hiulca. Two Fragments of the Os Tibia, a little corroded on the Infide, were taken out of a Pool near Fogheras in Tranfylvanla, once the Seat of the Princes of that Country ; and the whole lower Jaw, with two Grinders as yet flicking in it, he had from fome Fifhermen, who found it in the Handing Waters by the River Tlblfcus, a little above die Romerskantz, or the Roman Fort. All thefe the Author caufed to be figured as big as the Life. I have above related the Opinion of Goroplus about the Antiquity of thofe two ( JIO ) two Elephants, the Skeletons whereof were found near Vilvorden , which he traces no higher than the Time of the Romans , and their Expeditions into thofe Countries, particularly under Galien and Roft- humus. Count Marfili is of the lame Opinion with Regard to thofe Bones and Teeth found by him in Tranjylvanta. He takes Notice, that whofoever is acquainted with the vaB Ufe the Romans made of Elephants in their military Expeditions, ought not to be furprifed that there are Bones and Teeth found of them in thofe Northern Countries, where otherwife there cannot have been any ; and he urges, as a farther Proof of this ABertion, That they are found in Pools and Lakes, it having been the CuBom of the Romans , to throw the CarcaBes of dead Ele- phants into the Water, as it is Bill pra&ifed to this Day with the CarcaBes of Horfes and other BeaBs, to prevent the DiBempers and other Inconveniencies, which their Putrefaction might otherwife occafion. On the other Hand, there are many Arguments, ta- ken from the Largenefs of the BeaBs, the Skeletons whereof are thus found under Ground, which lome- times far exceeds any that was, or could have been brought alive into Europe , from the Condition they are found in, and from the particular Difpofition of the Strata above the Places where they are found, whereby it appears, almoB to a DemonBration, that they muB be of much greater Antiquity, and that they cannot have been buried at the Places where they are found, or brought thither any otherwife, but by the Force of the Waters of an univerfal Deluge. To infiB only upon one of thefe Arguments : If the Skeletons of Elephants, which are thus found under Ground, ( 5 1 1 ) Ground, and at confiderable Depths too, had been buried there either by the Romans , or any other Na- tion, the Strata above them mult neceflarily have been broke through and altered; whereas on the contrary leveral Obfervations inform us, that they were found entire, whence it evidently appears, that what is found underneath, mull have been lodged there, if not before, at lead at the very Time when thefe Strata were formed; confequently long before the Romans. But there is another Argument, which feems to me to bear very hard againft the Conjec- tures of Goropius and Count Marfili. Tentzelius hath already mentioned it, and it is urged from the great Value of Ivory at all Times, and particularly among the Romans , which appears by many Paffages in antient Authors ; as for Inftance, by a very re- markable one in Rliny *, who takes Notice, That among the valuable Prefents, which the Ethiopians were obliged to make to the Kings of Rerjia , by Way of a Tribute, there were twenty large Teeth (unqueftionably the dentes exerti ) of Elephants, and then adds, Tanta ebori auEior 'ttas erat . Now it is to be prefumed, that the Romans would not have neglected to take away the Teeth, and particularly the dentes exerti of dead Elephants, before they flung their CarcafTes into the YVater, whereas there hath fcarce been any Skeleton, or any Part of the Skeleton of an Elephant dug up any where, but the Teeth were found along with them, and even among thofe figured by Count Marfili , there are three Grinders, and a confiderable Part of one of the dentes exerti . Du Lib. xii, C. 4. ( 51 4 ) Dr. Robert Tlot in his Natural Hiftory of StafFord- fhire *, fays. That he was prefented by {Villi am Levefon Gower of 'Trent ham, Efq; with the lower Jaw of fome Animal, with large Teeth flicking in it, dug up in a Marle-pit in his Ground, and which upon Comparifon he found exa&ly agreeable to the lower Jaw of the Elephant’s Skull in Mr. AJhmole1 s Mufettm at Oxford. In the Mufeum of the Royal Society there are two Foflil-bones of Elephants : One was given by Sir Thomas Brown of Norwich , the other was brought from Syria for the Os Tibia of a Giant, but Dr. Grew j proves by an exaCt Computation, that it can never have been the Os Tibia of a human Skeleton, by being full 20 times as thick, and but three times as long. It is an Englijh Yard and half a Foot long, and hath a Foot in Circumference, where it is thinned. Dr. Grew obferves, that by the Fi- gure it appears to have belonged to the Leg, and not to the Thigh, and he conjectures the whole Elephant to have been about five Yards high. Before I difmifs this SubjeCt, I mud beg Leave to mention a few more. Gejfner j: takes Notice, that he was prefented by a Toli/h Nobleman with a Tooth four times as large as that, which he figured under the Title of Hippopotamus in his Book de Aquatili- bus. It was found under Ground, as they were dig- ging for the Foundation of a Houfe, together with a very large Horn, as they called it, which many took to be an Unicorn’s Horn, but wrongly, as he, Gejfner , thought, becaufe of its being too thick and * Cb. vii. <). 78. fag. 78. t Mufxum. Reg. Soc, fag. 32. Figuris Lapidum. fag. 157. t De too I ( 5»? ) ' too crooked. It is very probable, that this pre- tended Horn was the dens exertus of an Elephant. The fame Author mentions a fubterraneous Cavern near Elbingeroda , wherein were found the Bones and Teeth of Men and Animals fo large, that it was fcarce credible, that ever any of that bulky Size fhould have exifted. The Grinder of an Elephant, petrified, is kept in the King of 'Denmark his Cabinet at Copenhagen , as appears by the Catalogue *, but there is no Mention made how it came thither, or where it was found. They {new in the fame Collection a large Thigh- bone, which weighs about twenty Danijh Pounds, and is above three Foot in Length f. It is fo old, according to the Author of the Catalogue, that it is almoft become ftony. The fame Author takes No- tice of another large Bone, then in the Collection of Otho Sperling, , which weighed 25 Pounds, and was four Foot long. It was, as Sperling told him, found in the Year 1643 at Bruges in F lander s, near the publick Prifon, in Prefence of Bernard de Aranda , and his, Sperling s, Father, who law the whole Skeleton there, which was of 20 Yards of Brabant in Length. A Piece of Ivory was dug up in a Field on the River Vijiula , about fix Miles from JVarfaw , which having been fhewn at Dantzick to Gabriel Rzac~ zynski , Author of the Natural Hiftory of Poland, it feemed to him to be the dens exertus of an Elephant p * Muf. Regium. Part I. Sect. vii. N° 109. f Ibid. Part I. Sect, i, N° 73. ^ Rzaczynski Hilt. Nat. Reg. Polon. pag. z, Z z z 111 ( 5>4 ) In the Notes upon the laft Edition of Dr. Her- man's Cy no fur a Medica , publifhed by Dr. Boeder of Strasburg *, under the Title of ‘Vnicornu Fof- file, there is Mention made of a remarkable Piece of Foflil Ivory, or rather of an Elephant’s Tooth, in the Hands of Jaques Samfon de Rathfamhaufen de Ehenweyer , an Alfatian Nobleman. It was found in the Rhine upon one of his Eftates near Nome - ville, and was three Baris Foot, three Inches and a Half long: It had near a Foot at the Bafis in Circumference, where thickeft, and about 8 Inches and a Half at the other Extremity. It was filled within with a Sort of Marl, but the outward Sur- face was (tony in fome Places, and bony in others. The bony Part fcrap’d, or burnt, fmell’d like Ivory. The Scrapings boil’d made a Sort of Geliy. The Author of the Notes adds, That they find Foflii Ivory in feveral Parts of Europe, particularly in the Schwartzwald ( Sylva Hercynia) in Moravia , in Saxony , and near Canflad in the Dutchy of Wirtemberg. * 1716. 4 to, P. iii. fag. 133. II. A Me - N ♦ ( ? xl — B x ~b i = 0 will be > , 5 5 |9 abed impoflible. ~ , and therefore two of them to wit - , - Lemma III. In every ./Equation xn — B xn~l -f- C a”*”2 — 5D a1”- 3 + £ #”*-4 — . &c. + e at4 + } + c x 2 Ip b x -b_A—0> all whofe Roots are real, if each Term be multiply ’d by the Index of x in that Term, and each Produd be divided by x , the refulting /Equation 71 xn~~l — // — i B xn~2 -f- n — z C x n~~i — 7i — 3 © — 4 E xn~~* — + 4 e # * 4I3 d x~ c x~^ b = 0 lhall have all its Roots real. Thus if all the Roots of the Equation x 4 — B x' -b- C x* — © x + A = 0 be real, then all the Roots of the .Equation 4 x } — 3 Z? # * + 2 C" * — — 0 will alfo be real. This Lemma doth not hold converlly, for there are an Infinity of Cafes where all the Roots of the .Equation n xn~l — n— 1 B xn~ 2 + n iCx*-* — 0 — 3 cDxn~*-b &c. + 3 d x2-±. 2, c 'x -bb = 0 are real, at the fame Time fome or perhaps all the Roots of the Equation xn — B xn~ * + Cxn~~2 — T> a’”~3 + &c. -j-dx3 -t-cx3 + bx-t-A= 0 are impoflible: But whatever be the Number of impof- fible Roots in the Equation nxn~l . — n — 1 B xn~ 2 ~b n — zCxn~* — &c. + z c x +b = 0, there are at lead as many in the Equation xn — B xn~I + Cxn'~7 &c. Hb c x2 4- b x -bA — 0. Thus all the Roots of the Equation 4 x 3 — 3 B x 2 + z C X *D = 0 may be real, and yet two or perhaps ail the four t C 5 >7 ) four Roots of the /Equation x * — B x* C x2 — xn~ * + Exn~* — F -f- &c. e x* ±d x* + c x2 ± b x + A=.o be real, and by this Lemma all the Roots of the /Equation nxM~l — n~—iBxn'~2 -{-n — zCxn~l — n — xn~ * -\-n — 4 E xn‘~'s — n — 5 Fxn~6 -f- &c. ±5fx*+ ^ex* ± 3 dx2 + zcx ± b = 0 will be real, and therefore (by the fame Lemma) all the Roots of the /Equation nxn' — 1 xn~ 2 — n — ix n — z B xn~ 1 n — 2 x « — 3 C xn~'* — IT— 3 x n — 4 7) xn~s + « — 4 xn—fE xn~~6 — n — 5 xn — 6 F x*"1 + <&c. +20 f xz+ izexz±6 dx + zc = 0 . or (dividing all by 2) of nx xn~2 — n — ix n — 2 _ n — 3 Bxn~*-\-n — 2 x Cxn~ 4 — ©r. + 2 2 ~ 10 fxl + 6 e x2 ± 3 d x + c == 0 will be real. After the fame Manner all the Roots of the /Equation 71 nx 1 n -x - X n — 3 — 8 IX 71 2 77 — x - 2 3 B x 11 ~ * 4- 3 ( ) 0 3 0 — 4 Cxn‘-s~. &c. + io fx*+4ex±d=o will be real} and thus we may defcend until we arrive at the quadratick iEqua- n — i tionwx- xx — n — i Bx + C=o. The fame Equations do afcend thuswx n xz — 0— . i Bx^[~ n — i n — z C=zO , 0X X xl — n — i X n< B x^-\- fi « — i n — z n — 3 n — z C x — - ±) — 0} 0 x x X x+ n — z 0 — 3 n — 3 0 — ix X 5 x3 + 0 — z X X 2* 3 2, trrs n n 1 11 X C x2 — n — 3 x E = o, n x X X x 3 0 — 3 0 — ^ n — x — 3 7* — ^ x tf5 — » — IX x X 4 S z 3 4 n — 3 » — 4 _ 0 — 4 £ x * -4- 0 — xx X Cxl — 0 — 3 X z 3 x ©#*-[-0 — 4 E x — F = o, and fo on. LetAfre- prefent any of the Coefficients of the ^Equation xn — B xn~ 1 -\-Cxn~ 2 — *D xn~i + E xn~ 4 — &c. ± A = o, and let L N be the adjacent Coefficients, let M be the Exponent of the Coefficient M: By the Exponent of a Coefficient I mean the Number which z expreffeth ( .5*9 ) exprefleth the Place which it hath among the Coeffi. cients, thus if M reprefent the Coefficient E fand therefore L = T> and N= F) then m = 4. it Will be eafy to fee, that, amongft the foregoing amending Equations, that which hath its abfolute Number N will be n x 2 i n — x - x x &c. n — m i — n 7 ® — X n — m n — 1 X x &c. B xn -|- m n 71 — m — IX 0 VC. -* F£r 4- „ . — PI — i — W. — « iX » — W Lx' + n — mM x±N=o, all whofe Roots f X fi- /qUadT Let i\T= F and therefore 2^ 2 * = * then that of the afcending ^Equations whofe abfolute Number is F, will be n x # — 3 » — 4 X * x n—iX Bx* + n-iXnJZ±xn_Z^. : * i x + A — o, where n = 4, making M ~C and therefore L = B, N = Z), and m =z z, then 1X4 — 1 ==_ x C2 or — Ca will exceed BxD i+IX4 — x+i 9 providing all the Roots of the /Equation be real. Becaufe (by Lem. 3.) the Roots of the quadratick /Equation n x n x 2 — n — 1 B x -j- C = o, are real, therefore (by Lem. 1.) \n— i|2xi?2 mult be n — 1 greater than n x X C and (dividing both by n x - — - ^ x B 2 greater than 1 x C. Therefore in z J zn the /Equation xn — B xn~~ 1 C xn~2 — E) xn ■~3 -f» &c. ± A— 0 of the n Degree, all whofe Roots are real, the Square of B the Coefficient of the fecond Term, ( Jit } Tern, multiply’d by the Fradion ~ is greater than Bw ^bv £I ^an?Ie i^nter the adiacent Coefficient?. Ax’ y/vI-l,S) 3 the Roots of the Equation Ax-bx* < + cX~;>_&c. +Cx> + B.v± 1 = 0 or (dividing by A) of x»~~ x 4. A ^ a- C - B 1 ®C- + ~X‘ +-x±- = 0 are reaJ) c — x * ■— 1 3 A therefore (from what hath been juft now faid) — X^muft be greater than 1 X~ and confe- quently ~~~ x t‘ greater than cXA. Therefore in an Equation x’~ B #•-« 4. C ^ ±cx’^bx±A=o, of the n Decree ,11 1 r Roots are real, the Square of the Coefficient tnultiply’d by the Fradion is greater than ^ Ef Ztrh!^C0erfficiem of and Ae abfolute JN umber. But by Cor. Lem. 3. aU the Roots of the /Equation n x n n — 1 n X * 3 M+ I n~i x 2r . ?i m - X &c. x m B x 79 -f. n — % x gfc. I A a a a \ ( 5“ ) n pt M x ±N = o are real, therefore (feeing this iEquation is of the m + i Degree) the Square of . . 7Ti — }— I » — m x M mulriply’d by the Fraction = z x m i will be greater than the Rectangle under » — w+i x 77/ 0 m x L and iV, that is Z X 77/ -j- I x n — «/l * x n — m M 2 will be greater than n — m + i x — — N .. n — m \ and therefore (dividing both by n — m+ i x — — ) m x n x Af2 greater than LxN. tt/ -f- 1 y. n — 7// + I Corolary. Make a Series of Fractions n n — i » "7 fg*-. unto — whofe De* 7’ x ’ 3 4 » nominators are Numbers going on in the Progreflion T - 2 A &c unto the Number n which is the Di- mentions of the iEquation x* — Bx +C x — and whofe Numerators are the tame Progreflion inverted. Divide the fecond of thefe Frac- lions by the firft, the third by the fecond the fourth by the third, and fo on, and place the Frafhons which refult from this Divifion above the middle Terms of the iEquation, thus x" — B x"~l ■+■ C #* a — © **“ ’ + ESx"~ 4 _ &c.±A = 0. Then if all the Roots of the ./Equation are real, the Square of any Coefficient multiply’d by the Fraction whicli ftands above, will be greater than the Reftangle un- der the adjacent Coefficients. This Corolary doth not hold converfly, for there are an Infinity of /Equa- tions in which the Square of each Coefficient multi- ply d by the Fraction above it, may be greater than the Reftangle under the adjacent Coefficients, and notwithftanding fome or perhaps all of the Roots may be impoffible. Therefore when the Square of a Coeffi- cient multiply’d by the Fraflion above, is greater than the Reftangle under the adjacent Coefficients, from this Circumftance nothing can be determined as to the Poffibility or Impoffibility of the Roots of the /Equa- tion : But when the Square of a Coefficient multiply’d by the Fraftion above it, is lefs than the Rectangle un- der the adjacent Coefficients, it is a certain Indication of two impoflible Roots. From what hath been faid, is immediately deduced the Demonllration of that Rule which the mod illuftrious Newton gives for de- termining the Number of impoffible Roots in any gi- ven iEquation. J & Scholium. Let the Roots of the iEquation x* B xn^1 JL Cx"-‘—‘Dx*-> + E x"~* — Fx—< -f &c. ± A = o (with their Signs) be reprefented by the Let- ters a, b, c, d, e,f,g, &c. then (as is commonly known) B will be the Sum of all the Roots or = a + b + c + d -f-e-f-/-f (Sc. C the Sum of theProdu&s A a a a z 0£ ( 524 ) of all the Pairs of Roots or = a b + ^ c -f* a d + af *4- & g -f* &c. F> the Sum of the Prod lifts of all the Ternaryes of Roots or — abc-^abd-^abe-^ abf+abg — I- & o • F — ci b c d' — J— a b c 6 —J” ci b cf “|“ abeg-\- &c. F = a b c d e -j- a b c d f -(- ab c dg + bcdef -j- &c. and fo on. Let (as in this Propoli- tion) M reprefent any of thefe Coefficients, L, N the adjacent Coefficients, and m the Exponent of M ; let Z reprefent the Sum of the Squares of all the poffible Differences between the Terms of the Coefficient let a, be the Sum of all thofe of the forefaid Squares whofe Terms differ by one Letter, /g the Sum of all thofe Squares whofe Terms differ by two Letters, y the Sum of thofe Squares whofe Terms differ by- three Letters, £ the Sum of thofe Squares whofe Terms differ by four Letters and fo on. Thus if J\j[ — F = a b c d € — J— ci b c d — j-* ci b c d g — then Z— ab c de — abc df\2 -\-abc de — ab cdg\ 2 -{- a b c d e a b c fg\2 + b c d e f — a b f gh\2 + &c. a — ci b~cd e~ cTb c df\ 2 -j- a b c d e — a b c d g\*-\- abode — ab c dh\ 2 + b c d ef — b c d e g\* -\- &c. 0 — abc de — ab c f g\‘ ab c d e — abcfh\‘ + bcde f—acdfh\‘+ f$c. y = abcde — abfgh\‘- f- abcdf—abTgh\* + = abc de — afghk\ + acdfg — abe h k\- + &e. This being laid down I fay that the Square of any Coefficient ft 1 multiply d by the Fraction m x n m __ ~ exceeds the Rect- m-\- i%n — m + i angle under the adjacent Coefficients L x N by n + i X Z n + i X Z I ( 525 ) ixn — m + i cc 3 — y — ~— 4 5 ^ — &c. The Series — * — a — /3 — y — x 3 4 muft confift of m Number of Terms. Let the ^Equation be xs — B x* -f- C xi — 2) x 2 4* E x — A — o , whofe Roots let be dy b , c, d , e, in which Cafe n = 5. Let A/= i?= ^ 4* b -|- c + d + ei then L — 1, N = G, m = 1, ^ — <£j2 + # ej 2 4- d d\f 4" u — e|2 4" b — c\2 4- &c- = a ; therefore IX) 14- 1 x 5 — ‘i 4- I X B2 or — B2 exceeds 1 x C by = — ~X ^ 5 14-1x5- 1 31 — — a. ~ — Z a = ( becaufe Z ~ ) 2k 2/ 1 4* 1 * ~ 1 - — Z=. — a 10 10 4 + — X a — f|> -j , m — z, Z = d b — a c\2 d b — d d\ 2 4- d b — c d\2 4- d b — d e\2 4- a — db — d c\2 4- a b — a d\2 4- a b — d e |2 4- &?- fi = a b •— c d\2 4~ * . — e e\2 4- - , 2 X ( mr « ^ — de\2 + ©**. therefore ===== — - x C 2- + 1 x 5 — 2 4* 1 ( ) or — C2 furpaffeth B x 2D by — ' • 1 x + i X y — x + i I 1 j — ~ a ~ (becaufe Z = a + /3) = — . T i » & ~ — Xab—* c d\ 2 + — - a b ~ c e\2 x f ^ — e are real Numbers, pofitive or negative. Let M = 2) =z a b c + a b d + & b c — |— ' a c d — |— a c e -f- &c. then L = C, N — E, m = 3? Z = a b c — a b d\x + a b c — ~cTb 7|2 + abc — ade |2 &r, c^=abc — abd\ 2 -\-~abc — afe\2 -|_ abc — ac d\ 2 + &c. @=abc — ade |a -\-abc — ede |2 + abc< — bde |2 + &c. y = o. therefore zz~-* - r — x 3 + iXJ — 3 + 1 2)’ or — T> 2 exceeds Cx £ by ==±4=- x 3 4- ixy — 3 4- I rji I I j ^ ~^cl — - /3 = (becaufe i? = a, + /S)= — x $ =='~X x A by L'^~ 1 5 - 44-1x5-— 44-i i-a=±z_. 1 5 xZ — _ ^ I ^ — — -X — abceV 4- io io 11 io y^abed — bcde\* 4- &c. which is a politive Number when the Roots are real Numbers. Proposition II. Let x^—B xn~l -{-Cxn-~2 — 2) xtl~i-\-Exi~4 &c. -^A~o be an ./Equation of any Degree, whole Roots with their Signs let be expreffed by the Let- ters by c, dy e , f9 &c. let M reprefent any Coeffi- cient of this ^Equation, L , N the Coefficients adja- cent to M ; K, O the Coefficients adjacent to L , N; I, T thofe adjacent to K, O 5 H, ^ thofe adjacent to IyT, and fo on. Let m reprefent the Exponent of M and let Z (as in the preceeding Proportion) reprefent the Sum of the Squares of all the poffi- ble Differences between the Terms of the Coeffici- ent M. Then the Produft of the Square of any Coefficient M multiply’d by the Fraffion x 'L I doth n x n - x7i X &c. x - — 'L1 m always ( 5*8 ) always exceed LxN— KxO+IxT— HxQ+ (Sc. hY — .. — which n x -- l yJllZLl x &c. x U m ^ 1 2 3 m is always a pofitive Number, when the Roots a , ^ are real Numbers pofitive or negative. L>ct the Equation be of the feventh Degree or x? — Bx6 q- Cx'-cDx + + Exi—Fx2-£Gx— A == o, whofe Roots let be a , b, , r, d, e , ^ g, in which Cafe » = 7. Let A/ — E = ab c d -j- a b c e ^ ^ c f a b c g -f- b c d e + &c. then m z=z 4. £ = — N = — E, K =z C, O = G, I=—B, 5P = — ^7, ^ = ab c d—abc e |2 -J- abc d — ^ £ c /|2 -}- abed — a b c g\2 -f" Therefore — ~ x 1 X E2 or *7 E 2 exceeds T> x 35* /r_CxG + ^x^ by Kabcd—abceV -1 x ^ bed — a b cfU 4, 70 '70 &e. From this Proposition, is deduced the following Rule for determining the Number of impoffible Roots in any given ./Equation. From each of the Unche of the middle Terms of that Power of a Binomial, 1 whofe ( 5*9 ) whofe Index is the Dimenlions of the propofed Equa- tion, fubtrad Unity, then divide each Remainder by twice the Correfpondent ‘Vncia, and fet the Fradi- ons which refult from this Divifion, above the mid- dle Terms of the given Equation. And under any of the middle Terms if its Square multiplyed by the Fradion {landing above it, be greater than the Red- angle under the immediately adjacent Terms, Minus the Redangle under the next adjacent Terms, Tins the Redangle under the Terms then next adjacent — &c. place the Sign ~f-, but if it be lefs, place the Sign — . And under the firft and lafl Term place -f*. And there will be at lead as many im- pofiible Roots, as there are Changes in the Series of the under-written Signs from -f- to — , or from — to +. Let it be required to determine the Num- ber of impoffible Roots in the Equation x^ — £ x6 -|- 1 $ xs — 23 x 4 -f- i8a?s-J- i ox2 — 1 8 x + 1 4 = o. The Vncia of the middle Terms of the 7th Power of a Binomial are 7, 21, 35, 35^ 21, 7, from which fubtrading Unity, and dividing each of the Remainders by twice the correfpondent 20 * Vncia , the Quotients will be — , r4 34 20 6 3 10 1 7 or 70 10 42 14 21 3 S 34 70 17 3? , — • which Fradions place above the middle 21 7 Terms of the Equation, has xi + B b b b * 1.0 2 1 5 x6 + 15 + 2 3 x 4 -£■ ( 53° ) JLX 3 i 11 3 5 i.o a i -L 7 23tf4-J-i8 ) - - 5 the Term io^3. Becaufe zSxl2 x — or 33 6x* 7 is greater than 1 ox2 x 2, 4 = 140^* under 2 8 a? I place +> ^len under the firft and laid Terms I place + ; and the fix Changes of under-written Signs fhews that there are fix impofiible Roots. If the impofiible Roots were to be found by the Newtonian Rule, the Operation would Hand thus: i i i 1 i 7 9 4 _ 3 9 + 1 5 Xs 2, 3 + -f. I 8#* -j- 1 o x2 — » + “ + + + + 3 7 z 8 x + z 4 = 0, by which Rule there are found + + only two impofiible Roots, whereas there are fix to wit i + fZT 3, I — -/HI , I 4. v'' — i, * — V — 2,, 1 + V — i> 1 + V — - Ij the fe- venth Root being — 1. B b b b 2 III. A ( 55* > III. A Letter from Charles Price, Efq-, of Trinity-Coil. Oxon, relating to the Villi of the Stomach of Oxen, and the Expanjion of the Cuticle through the Lucius Jlimentalis. Communicated by Dr. F. Nicholls, R ft. S. and Pr&l, Anat. Oxon. * Trinity-Coil. Oxon, July the 28th, 17*5. : Dear S I /?, IN Purfuance of your Advice, I have fpent fome Part of this Summer in enquiring into the more intimate Conftitution of the alimentary Paflage of large Animals j in Hopes that the Analogy between them and human Subjects may lead us into a more per- fect Knowledge of our own Structure. In the Stomach of the Cow I find two Things well worth obferving : The hrft is, that the Villi compofing the Villous Coat, (which are in Man fo very fmall as to be fcarce vifible when examined feparately) are in this Animal fo very large, as to allow an exad Scrutiny into their Strudure. Each Villus is formed by a Duplicature of the internal Lamina of the vafcular Coat j from which it receives three Blood Veffels, as in the annex’d Figure, which reprefents one of the Villi of the Stomach of an Ox magnify’d. Whether or no the two Side- veffels are Arteries, and the Mid- dle-veffel a Vein ; and whether thofe fmall Branches arifing from the Side- veffels ( m ) veffels are fecretory Dads carrying a Fluid from thofe Arteries into the Cavity of the Stomach, making a Kind of Rivus perpetually running through theDu&us Alimentalis, I muft leave others to judge. The other Thing remarkable in the Stomachs of thefe large Animals is, that their internal Surface is covered by a Produ&ion of the Cuticle, which de- fends from the Lips quite through the alimentary Paflage. I am induced to believe, that the Cuticle is continued through the Inteflines as well in Man, as in large Animals } though its exceeding Finenefs may make it lefs obfervable. I have fent you a Piece of the firft Stomach of an Ox, in which the Veftels running in the Villi are filled with Wax, and the Cuticle raifed in Part} by which the above Particulars are fufficiently proved. If you think thefe Things new, and worth com- municating to the Royal Society , I defire you will communicate this to them in fuch Manner as you think moft proper : And that the Piece of Stomach (if worth the Acceptance of Sir Hans Sloane) may be prelented to him, with my belt Refpe&s, as an Acknowledgment of the Efteem of, SIR, Tour Humble Servant , Ch. Price. ( 534 ) IV. ObferVationes Jftronomica baliu in ObferVato - no Bononien.fi Anno 1727, a CL Euftachio Manfredi, 5^. S. S. Ex Epijtola J. Baptiftae Carbone ad lfaacnm de Sequeyra Samuda M. D. Coll . Med. Lie. & 5^. S. S. 2. TAnuarii St. N. h. 9. 45'. 47^. Immerf. 3* Sa- J tellitis in umbram V. Telefcop. ped. 14. h. ii. • 53'. 38". ejufdem Emerfio. Dub. 5. Jan. h. 6. 51'. 54". Emerf. i; Satell. Telefc. pe- dum 11. Bononienf. Clar. 7. Jan. h. 8. 54'. 12". Emerf. 1 eodem Telefc. Cla- riff. 7. Febr. h. 5-. 5*0'. $,f. Imm. 3** eodem Telefc. h. 7. $z'. 54 ft. Emerf. ejufdem Telefc. ped. 14. 8. Febr. h. 8. 3 yf. 59". Emerf. 2 1 Tel. ped. n. aere nonnihil nebulofo. 21.Aug.l1.13. 34'. 39". Imm. i* eodem Telefc. 6. Sept. h. 11. 55'. 15*". Imm. i1 eodem Telefc. 1 7. Sept. h. 10.48'. 5*9". Imm. 3* dub. eodem Telefc. h. 12. 40'. 30". Emerf. ejufdem. fubdub. eodem Tel. 9. Mart. h. 8. 50*. 6". Emerfit fpica v&. a limbo Luns obfeuro. Incipit ( m ) 18. Sept. h. o. 27'. 21 ff. Incipit Venus occultari poft limbum Lunse obfcurum. h. o. 28'. 13". Immerfio totalis ?. h. 1. 1 6'. 45 Incipit $ emergere e limbo in circulo horario 21 " tem- porise 6c limbus Borealis C item illuminatus eft au- ftralior $ 29'' temporis. 'T'HE Second Tlate at the Front of this Tranf- x a&ion reprefents thirty-fix Stones cut out of the Bladder by the Lateral Operation , as it is now improved by Mr. Cheflelden, Surgeon to 7/erMajefty and St. ThomasV Hofpital , and F. R. S. who pro- duced them before the Society, and at the fame Time informed them , that the Terfon was fixty . three Tears of Age when he performed the Ope- ration, and is not wit hfl an ding perfectly recovered l FINIS. ADVERTISEMENT. LL Perfons concern’d in the Pradice of Inocu- lating the Small-Pox, are defired to keep a Re- gifter of the Name, Age and Habitation of every Perfon inoculated, the Manner of the Operation, the Days of (ickening and of the Eruption, the Sort of Small-Pox that is produced, and the Event. Where the true Small-Pox is not produced by In- oculation, it will be of Ufe to take particular Notice, whether the Patient had any other Kind of Eruption, what Symptoms preceded or attended it, whether the Incifions inflam’d and run, and for what Time their Running continued. In Cafe any Perfon (hall happen to die after Inocu- lation, either in the Courfe of the Small-Pox, or after they are gone off, it is defired that a particular Rela- tion of the Cafe may be made, and attefted, if it be judg’d necelfary, by the neareft Relations of the Party deceas’d, or by other credible Perfons, that were Wit- nefles to the Fad. They are intreated to fend thefe Accounts, or an Extrad from them, comprehending all Perfons inocu- lated from the Beginning to the End of the Years 1727 and 1728 to Dr. Scheuchzer , M. D. and F. R. S. at Sir Hans Sloane\ Bart, in Great RuJfel-Jireet by Bloomsbury-Square , fome Time in January , or at farthefl' in February next, that fo the Refult of them may be publilh’d early in the Spring. L 0 NT) O N : Printed for William 1 n n y $, at the Weft End of St. F aid's. M.DCC.XX.V11I. ♦ Numb, 405*. PHILOSOPHICAL TRANSACTIONS E O R THE Month of NOVEMBER, 1718. The CONTEN TS. I. The Barometrical Method of ?neaf tiring the Height of Mountains , with two new Tables Jhewing the Height of the Atmosphere at given Altitudes of Mercury. Extra tied chiefly from the ObferVa- t ions of John James Scheuchzer, M. V . Bro. feffor of Mathematicks at Zuric, and a Member of the Imperial , and R oyal Societies of London and Pruffia. By J. G. Scheuchzer, M. V. R S* Coll . Med. Lond L/c. II. ObferVations of a Difference of Sex in Mifleto, in a Letter from the (Reverend Mr. Edmund Barrel to Sir Hans Sloane, Bart. See. IN. An uncommon Sinking of the Ground in Kent. Communicated in a Letter to Mr. Peter Col- li nfon. 1 IY. OR The CONTENTS. IV. ObferVationes AftronomicA Pekin i 'habit & Ignatio Ko'gler Soc. Jefu Tribun, Math, in Sin is ( Vrafide . Ex Epiftola 2^. (p. Joh. Bapt. Carbone ad Ifaacum de Sequeyra Samuda, M. 2). S. 5. with great Expedition and Cer- tainty 3 J1?ewn to the (Royal Society , by J. T. Defa- guliers, L L. D . and 2^. S . S', contriv'd by the (Rev, Mr. Stephen Hales, F. 2^. S. and Himfelf. VII. ExtraEl of Two uncommon Cafes of Tumours of the Abdomen , from a Latin Trail publifb’d at Strasburgh, Anno 1728, and entituled , Joannis Boecleri, M. D. See. ad Exteros Me- dicos Epiftola 3 by W. Rutty, A/. 2). R. S. Seer. VIII. Account of the Culture and Management of Saffron in England, by James Douglafs, M. D, Med. Regin. Extr. & F. R: S. ERRATUM.^ Png. 554. lin. z6. dele e. c 537 > I. The Barometrical Method of meaf uring the Height of Mountains , with two new Tables Jhewing the, Height of the Atmofphere at given Altitudes of Mercury. Extracled chiefly from the ObferVa* tions of John James Scheuchzer, M. V . Fro- fejfor of Mathematicks at Zuric, and a Member of the Imperial , and (Royal Societies of London and Pruffia. By J. G. Scheuchzer, M. D. F. (R. S. & Coll. Med. Lond. Lie. TH E Height of Mountains, and their Elevation above the Level of the Sea, hath been at all Times thought worthy the Attention of inquilitive Philofophers. We find in Tliny *, that TAcaarchus, one of the old Geographers, a Difciple of Ariftotle , and, as Rliny himfelf (files him, a Man of great Learn- ing, had by particular Order of fome Princes meafured the Heights of feveral Mountains, and that the higheff of them, Mount Telius in Thejfalia , was found by his Obfervations 125*0 Paces high perpendicularly. C leomedes alfo, a Grecian Aflronomer and Geographer, who lived fometime before our Saviour's Nativity, af- ferts f, that the higheff Mountain cannot be above 15- Stadia, or 9375 Roman Feet high. But Tlutarch ^ fixes the perpendicular Height of the higheff Mountains, as alfo the greatefl Depth of the Sea, only to 10 Stadia, or 6250 Roman Feet. It will appear by the Sequel of this Paper, that the * Hift- Nat. L. xi. c. 6*. f Cyclic* Theor. Cap. x. $ In vita Aemilij. C c c c Height Height of Mountains, as determined by thefe early Writers, doth not fo very much deviate from Truth, as one would be apt to fufped from the infmt State o t Arts and Sciences in thofe Times. Particularly the iy Stadia of Cleomedesy which make out 9375" Roman , or \oy'i\\cParis Feet, will be found by the following Obfervations to come very near the Height of the Moun- tains of Swifter land which, although the higheft of Europe^ do not rife above 10,000 *Paris Feet above the Level of the Sea ; and it may feem furprizing, that fubfequent Writers, even fuch as were otherwise deeply skill’d in mathematical Learning, have run them up to an extravagant, and altogether unnatural Height. At firfl, it is not improbable, they went only upon bare Conjectures ; but afterwards, when Geometry came to be more and more improved, Quadrants, Semi- circles, and other Geometrical Inflruments were call'd in Ufe, by the Means of which, and by a Trigonome- trical Calculation, the Heights of Places could be de- termined in a more fatisfadory Manner. And yet, however true the Principles be, upon which this Me- thod is founded, however nice the Inflruments, and however curious the Obferver, the Method itfelf muft be owned, and hath been found by undoubted Experi- ments, to fall far fhort of that Accuracy, which it feems to promife and the more confiderable the Heights are, the more uncertain it will beA For in the firlf Place, as the State of the Air is very different in dif- ferent Seafons and different Weather, its RefraCtion alfo becomes thereby greatly altered, which occafions the Tops of Mountains to appear higher at fome Times than they do at others, and at all Times higher than they adually are. But befides, there is another In- x conveniency. ( 539 ) conveniency, which whoever is acquainted with the true State of mountainous Countries, muft needs be fenlible of, and that is the extream Difficulty of meet- ing at the Bottom of high Mountains with Plains large enough for a proper horizontal Stand, or Balls, to fuch a Triangle, as an accurate and knowing Obferver would think fatisfaflory to determine a conliderable Height, making even proper Allowances for the Air’s Refra&ion. Among the many Improvements in Natural Philo- fophy, which are owing to the Toriceliian Tube, one of the molt conliderable Inventions of the laft Century, it hath been thereby enriched with a new Method of meafuring the refpe&ive Heights of Places, and their Elevation above the Level of the Sea} a Method, which, although it mult be owned, that it hath not as yet, and perhaps, conlidering the Inconlfancy of the Air, hardly ever will be brought to an abfolute De- gree of Certainty, is yet in many Refpe&s preferable to the Trigonometrical one, as it hath alfo been found by Experience to come nearer the Truth, and leads us, by a new and lingular Scale, from the very Horizon of the Sea to the Tops of the higheft Mountains, a Di* fiance far beyond the Reach of Geometrical Inftruments. This new Method is grounded upon that effiential Qua* lity of the Air, its Gravity or Prelfure. As the Column of Mercury in the Barometer is counterpoifed by a Column of Air of equal Weight, fo whatever Caufes will make the Air heavier or lighter, its Prelfure will be thereby increafed, or lelfened, and confequently the Mercury rife or fall. Again the Air is more or lefs condenfed, or expanded, in Proportion to the Weight, or Force, which prelfes it: Hence it is, that C c c c z in ( 74° ) in England ', Holland, the maritime Provinces of France, ana in general all thofe Countries which border upon the Sea, the Mercury Hands higheft, that the higher you remove from the Sea into the midland Countries the lower the Mercury will defcend, becaufe the Air alfo becomes more rarefied and lighter, and that upon the Tops of the higheft Mountains it falls loweft, and thefe Heights of the Mercury in different Places are reciprocally, as the Expanfions of the Air. From thefe Principles, fupported by a competent Number of Ob- lervations, it hath been attempted by feveral learned Men, to derive proper T ables, whereby the Height of any Place may be determined, if the Height of the Barometer be given, or the Height of the Barometer determined from the given Altitude of the Place, and like wife the Expanfions of the Air fettled, as they an- fwer to every Inch, or Part of an Inch, in the Baro- meter. I pafs over the firft Experiment of this Kind, which was made in the Year 1648 (but a few Years after the Invention of the Torricellian Tube was made publick in France by Father Merfenne) by Monfieur Eerier according to the Directions of the celebrated Monfieur Eafcal, his Brother-in-Law, upon the high Mountain Tuy de Homme, near Clermont in Auvergne, the Height whereof was thereby determined to yoo French rotfes, or 3000 Ear is Feet. (See the Appendix to M. Eafcali Trait e de /’ Equi libre des Liqueurs * ) Nor will my prefeut Purpofe admit a particular Enu- meration of thofe made fometime after, in 1661 166 c and 1 666, by George Sinclair, ProfefTor of Philofo- phy in the Univerlity of Glafgow,. upon the Cathe- * PMSi 1665, 8 vo. pag. 177, dral ( 54* ) dral of that University, upon feveral high Mountains in Scotland, , and likewife in fome Wells and Coal-pits, a particular Account whereof he inferted in his Ars magna gravitatis & lev it at is *. I will only obferve, that theie Experiments of Sinclair , as well as that of Monfieur Eerier , were intended not fo much to lay the Foundation of a Calculation, whereby to determine the differing Heights of Places, as to prove the Gra- vity and Prellure of the Air, a Problem very much controverted at that Time, and to fhew, that the fame is much more confiderable in Valleys than at the Top of Mountains, and hill greater in Proportion at the Bot- tom of Wells, Mines, &c. But this Matter was purfued hill farther by the Members of the Royal Academy of Sciences at Tar is, particularly, when by Order of Lewis XIV, they drew that expenfive Meridian Line acrofs the ’whole Kingdom of France. M. Mariotte , a celebrated Mem- ber of that Academy, was one of the firft that laid down certain Rules for the Conftru&ion of fuch Tables, as might ferve to determine both the Elevation of Places above the Level of the Sea from given Altitudes of Mercury, and the Heights of the Air, anfwering to every Line of Mercury in the Barometer, from 28", where the Mercury was fuppofed to Hand at a Medium near the Sea. The Principles he went upon, and the Me- thod he followed, he difcourfed of at large, in his Second Ejfay de la Nature de /’ Air. Sometime after, in 1686, the ingenious Dr. Edmund Halley went about another Calculation, which he de- rived partly from Principles agreeing with thofe of * Rotcrodam;, 1669,4/0. pag. 129, J32, i44^ & fe(j M . Ma- ( 54* ) M. Mariotte , partly from the fpecifick Weight of Air and Mercury, which were found by Experiments to be as i to 10,800 •, Air being to Water as 1 to 800, and Water to Mercury as 1 to 13 or very near it. If fo, as the Column of Mercury in the Barometer is counterpoifed by a Column of Air of equal Weight, a Cylinder of Air of 10,800 Inches, or 900 Feet will be equal to one Inch of Mercury, and 90 Feet to *0 of an Inch, or 75* to Part of it. The Height of the Air, as it anfwers to one Inch of Mercury, being thus de- termined, and the Expanlions of the Air being recipro- cally as the Heights of Mercury, Dr. Halley , by the Help of the Hyperbola and its Afymptotes, calculated two Tables, one (hewing the Altitude to given Heights . of Mercury, the other the Heights of Mercury at given Altitudes. Thefe Tables, the firft that ever were cal- culated, together with the Do&or’s whole Method of proceeding, and an ingenious Attempt of his to difcover the true Reafon of the Rife and Fall of Mercury upon Change of Weather, were printed in the Thilofofhical Tranfattions *, and the Tables themfelves were very lately re-printed, with fome Obfervations upon them, by Dr. cDefaguliers f . In the Year 1703, when the Meridian Line, firft begun by M. Ticard in 1669, afterwards continued in 1683, was farther purfued, feveral Obfervations of this Kind were made, and the Heights of feveral confidera- ble Mountains, particularly in the Southern Parts of France , determined as well by Trigonometrical as Ba- rometrical Obfervations. Monlieur CaJJini the Younger took that Opportunity to compare thefe Obfervations J N° 181 . pag. 106; f phi1, Tranfaft. li® 386. with f 545 ) with the Rules laid down by M. Mariotte * in or- der to which, and conform to the faid Rules, he cal- culated two Tables, one Ihewing the Height of the At- mofphere ,as it anfwers to every Line of Mercury in the Barometer, the other determining the Height of the Atmofphere above the Level of the Sea at given Alti- tudes of Mercury. But having afterwards, upon Com- panion, found that the Obfervations made in 1703, did not in the Main agree with the Rules of M. Mariotte , and that the Heights of Places, as they appeared by thofe Obfervations, exceeded, generally fpeaking, the Numbers refulting from the Tables made by him ac- cording to the faid Rules, he thought it neceffary to calculate two new ones, wherein indeed the Refults are conliderably greater than in the Tables framed ac- cording to the Rules of M. Mariotte ; infomuch, that for Inftance, a Place, where the Mercury falls to zz Inches, rifes above the Level of the Sea, according to Mariotte , 852, Toifes, or ^nzFaris Feet} and, ac- cording to Gajfini) n^B loifes, or 6948 Feet, which, makes a Difference of 1836 Faris Feet, or 306 Toifes. Dr. T>efaguliers, 'm his Diilertation concerning the Fi- gure of the Earth f, hath already (hewn how far the Obfervations made by the Gentlemen, that drew the Meridian acrofs the Kingdom of France , differ from each other j infomuch, that there are not two in nine, where the Number of Toifes, faid to correfpond to the Heights of the Barometer, agree together- and that con- fequently the Heights of Mountains, as determined by thefe Obfervations, are little to be depended on. * Mcmoires de 1’ Acad. Royale, 1705. pag. 6 1. & feq, + Phil. TrariC 386. pag. 211. *• . * 4 ( 544 ) . My Father, Dr. J. J. Scheuchzer, in his Journeys over the Mountains of Swifferland , as they were more particularly calculated for the Improvement of Natural Philofophy in its feveral Branches, negleded no Opportunity, along with his other Obfervations, to make fuch Experiments with the Barometer, as might ferve to illuftrate the Qualities of the Air, to fettle the refpective Heights of Places, and particularly to fhew, how much our Mountains rife, as well above the Level of the Sea, as above other neighbouring Mountains in France , Italy, Spain, 9XI "Paris Feet, 8'/, which exceeds the true Height by 207 Paris Feet, 8 Inches 1 whereby it appears, that the Table made according to the Rules of Mariotte is much preferable to that of CaJJini the Younger. The fame was likewife confirmed by ano- ther Experiment made in June 1715-, upon the Steeple of our Cathedral at Zurich. At the Foot of the Steeple the Barometer ftood at 2.6", io'" and at the Top at z6l', 7 s'", and the Height of the Steeple was found by the Line of 141 Paris Feet, 4 Inches, which gives very near 69 Paris Feet for one Line. Accord- ing to the Table of Mariotte , the Height of the SteeHe fhould have been of 237 Paris Feet, according to LaJJim, z 65, and according to the new Calculation (of which by and by) made purfuant to the Experiments above it comes to 2430, t6", 2//', or about two Foot more than the true Height. D d d d It ( 54<5 ) It appearing by the Experiments made at Tfeffers, that from 9t" the Barometer defcends to 24", 11 > that is, juft 10 Lines, for the Height of 714 Fee^ *and the Expanfions of the Air being reciprocally as the Heights of Mercury, my Uncle, Dr. John Scheuchzer, undertook, purfuant to thefe Principle?} and the Properties of the Hyperbola, to calculate a new Table, after the following Method. • * 1 As the Difference of the Logarithms of the two given Heights of the Ba- rometei 2,7 p7 and 14" 1 1 7 that is 309! and 2pp or So the Difference of the Logarithms of the Height of Mercury near the Sea, 28" 1"' to any leffer Height, as for Inltance 28" o'", that is 33 7 — 336, oi- ls to Foot To the Height of the Atmofphere above the Level of the Sea, as it anfwers to one Line of Mercury, is 518 — 898 IOII— 1008 141717 7*4 , 11906 6j, 6", 9"' Thus the Height of the Atmofphere at 28" appears to be of io°, 4, 6", 9"', but, according to Mariotle , it is only of io°, 3 or 63 Feet, and CaJJini fuppofes it only at io°, or 60 Foot. In like Manner the Height of the Atmofphere, from 28", o'", to 27", ix is found to be 64', 9", 2"'. According to the fame Rule half the Height of the At- mofphere, that is, the Height of the Place, where the Mercury in the Barometer would defend to 14 Inches, appears to be, 15060', 3". o'",or25io°, o', 3", o'". Still upon the fame Principle the Mercury will defend to one Line at the Height of 133)397 1 civis Feet above the Level of the Sea, which make 22,232 Toifes, 5 Feet, ( T47 ) 5 Feet, or XI Darts Miles (at 2000 Toifes the Mile) 23 2 Toifes, 5 Foot. But as in order to determine the whole Height of the Atmofphere, the Logarithm of i"' ought to be deduced from the Logarithm of 3 3 or 28" o % and as that Logarithm is ooooo, it follows from thence, that beyond the Place, where the Mer- cury would defcend to i,/;, the Air is expanded into an Indefinite Space. For the Satisfaction of the Curious, I have added the Tables themfelves, to wit, thofe which CaJJini the Younger calculated according to the Rules of Marl - otte , thofe which he deduced from the Obfervations made by the Gentlemen of the Royal Academy of Sciences, who drew the Meridian Line, and thofe which my Uncle calculated from the Obfervation made at P Jeffers in 1709. In another Paper on this SubjeCt I intend to com- pare the Height of Mountains, as determined by divers antient and modern Writers, with the true Pleight of them, as it appears to be by the Barometrical Obfervati- ons, particularly thofe made by my Father on the high Mountains of Swijferland. II. ObferVations of a Difference of Sex in Mifleto, in a Letter from the Reverend Mr. Edmund Barrel to Sir Hans Sloane, Dart. See. SIR, AFTER I had mentioned my being pretty well allured, that the Plants of Mifleto were fome of them Male, and fome Female 3 and had promifed to Dddd 2 com- ( 54« ) communicate to you, fuch farther Obfervations as I mould make of that Matter , I was difcouraged from giving you any Trouble about it, by an Information I received, that the eminently learned ‘Dr. Herman Boerhave had already told the World of a Difference 1:L^l(iet0- But having, fmce that, fee a the Hijtoria T lantarum, winch is publifhed as of his dic- tating; I find, that he mentions it in fuch a Manner “ makej! me fufPeft> that he only took his Notion from Tournefort and was not fully apprized of the true Nature of thefe Plants. Ovarium alio d Flore loco natum teems to fuppofe both Flower and Ovary’ to be on the fame Plant, though in difiincl

» The Female Plant flowereth alfo now, with a Blof- S'pnMW|hlCri Boerhave calls fbe Ovarium) exadly like the Male Flower ; fave only, that the whole Female Hower is^ not bigger than one Leaf of the Male Flower. ( 55° ) Flower. They both continue in full Bloom till the Middle of March , when the Male BloiToms begin to wither and drop off. And by the loth of March the young Berries begin to fhew themfelves, fweiling forth, one under each Female Bloffom ^ which often adheres to the Top of the Berry ; and being carried up with it, prefently withers, and foon falls off again ^ tho* lome continued on till the 12th of May^ when the Berries were of the Size of a great Pin’s Head. This cotnpleated the Year’s Obfervation. And I think it is much to be wondered at, that this Plant, which hath been the Admiration of all Ages, ftiould (fcarce ever) find one Obferver fo curious as to fol- low the Changes of it, through one whole Year’s Re- volution. For if this had been done with any Accu- racy, it muff have been very evident, that one Sort of Mifleto was very different from the other: One Sort bearing very fmall Flowers, with Berries fuccceding them : the other bearing much larger Flowers, not fuc- ceeded by any Berries *5 the very Footftalk of the Male falling off with the Flower:, whereas the Footftalk of the Female, becomes a Footftalk to the Berry. It is poffible, that this Difference of the Sex, in the Plants of Mifleto, may be of Confequence in Medicine : To thofe therefore, who would make any Experiments of the different Virtues of thefe Plants, I offer this gene- ral Obfervation : That there is no Time of the Year wherein the Difference of thefe two Sorts, or Sexes of Mifleto, is not very eafy to be feen and known, by the Marks I have mentioned: And the meaneft Herb-woman will foon have Skill enough to bring the Sort they are ordered to procure ; there being as great ( 55' ) great a Plenty of the Male Plants as there is of the Female. I follow your Commands, rather than my own Inclinations, in giving you this I rouble, and am, with the greateft Refpeft, SIR , Tour mojt obliged , and Sutton , near Dartford, Au^uji zo, 172S. ofodient humble Servant , Edmund Barrell. III. An uncommon Sinking of the Ground in Kent. Communicated m a 'Letter to Mr. Peter Col- lin fon. SIX, IT is within this three or four Days, that I have fir ft been able to get a more particular Account of the linking of the Lands at Lymne in Kent, and even now, perhaps, it will be but an imperfect one. It is now about two Years lince it happened, and was the Confequence of a very .wet Seafon, when the Waters, that had fallen on the Up-lands, and were not carried off by Drains, foaked into the Ground in fuch Quantities as to form a quick Sand at fome conliderable Depth in the Earth (at leal! this is what we look on to have caufed the Phenomenon) which not being able to bear the Weight upon it, broke out at the Side of the w. ( 55* ) Hill, and railed the lower Parts of it ; letting the Brow fink 40 or so Foot, as I guefs. I am but a rude De- ligner, but can truft you fo far as to give fuch a Sketch as I can draw ; for, perhaps, you may underftand me the better for it. abed the Profile of the Land. a the flat Land at Bottom 3 or 4 Mile from the Sea. d the flat Land at Lop, ftiff Ground and rocky. * Place of the Farm at prefent, which not only funk down from d 40 or 50 Foot, but was alfo moved fomewhat towards a. b the lower Part raifed to NOV. 5*. Satelles 3US* immerfus? . eft in V umbram. -$ 9 °P-m* Nov. *0. Satelles ius* prodiit ex um-? . Tr r bra v * - - S 6 44°Vefp. Nov. 30. Sat. ius- ex U umbra emerfit. 6 14 o Vefp. Dec. 13. Emerfio Satell.j. ex umbra #. 6 19 o Vefp. 171S- Martij die 11. circa hor. 9. matut. © inter tenues nubes allucens, 6c colorato halone cin&us, in eo ad dex- teram laevam duos parhelios efFormabat multum refplendentes, Duravit fpe&aculum perfemihoram. Maij 10. hor. 4. mane,dift. Jovis a

47,; Aug. 2. Immerf. Intimi. Telefc. 12 ped. Aug. 14. Immerf. 2l* eodem Telefc. Aug. 25*. Immerf. Intimi. Tel. 23 ped. Aug. 16. Incipit emergere ex Ombr. Satelles 3US- - -j Sept. 1. Imra. Intimi. Telefc. 23. Sept. 2. Totalis Immerf. Satell. 3^ in Uinbratn V. Eodem die ia* Emerf. 3U* e U Umbr. Tel. 10. Sept. 9. Immerf, Telefc. 14. 2 20 *3 24 45* .01 . " 15 16 40 5 6 z 5 1 7 1 53 6 1 59 11 41 20 ii 6 II 5 6 19 II 43 17 13 yi s* 13 17 15 4 f 9 40 9 circ. Eodein ( 558 ) H Eodem die Iinm. Intimi. Telefc. 23. Eodem die Immerf. plena SatelDO 3“. in V Uinbr. - -J Sept. 10. Immerf. Intimi. Has duasEclipfes obfervatas Bitur-' 1 gi refidentke Collegii Ingolfta- [ dienjis * quam alias definivi in > ortum vergere V 40" ab In- golft. Meridiano. -/ Sept. 10. Immerlio Intimi. Telefc . 14* Sept. 26. Immerf. ejufdem, eod. Telefc. H. ' lS So 30 17 20 30 circ. i* w ^ ■ . i. r ^ . 10 19 o 10 1 7 10 39 Eclipjis Solis ibidem obferVata die 1 5 Septembris. IN loco obfcuro excepta per helio- fcopium Solis imago casptas Eclipfis| initium prasbet circa 46°^ a Nadir adj Boream. - - In fpecula aftroptica 100 circiter patfibus' a loco priori diftante, Telefcop. I2,&< 1 6 ped. detegitur Sol jam obfcuratusj unius digiti Immergitur centrum macula Solis limboj propinquioris - Centrum maculae infignis Centrum maculae 3** 2 Digiti obfcurati, a Nadir, in Bor. 390 3 Digiti - - - -35* 4 Digiti - - 27 Solem 4 Digit, cum dimidio circ, de-j ficientcm nubes furripuere H. ' " S 1 7 2,2 S 19 24 5 2-3 30 5 5 5* 5* 5 24 40 26 36 30 46 37 12 43 10 5 49 Thafes ( 55 9 ) , r ■ ■ _ or;: ■; r Chafes Micrometro dimen fa . Dig. i x 3 4 4 33' H. / // * 5* xx 30 • 30 50 37 54 44 30 47 30 Solis Semidiameter faspius micrometro dimenfa exa&e implebat 16 1 o". In difco Solari macula a quatuor notatis in immerfione diverfae plures apparuere ; Sed e* exiliores, quam ut immerfio lllarumquoqueper vapores Phcebiim ob- fcurantes difcerni poffet. VI. Jn Account of a Machine for meafuring any Depth in the Sea, with great Expedition and cer- tainty ; Jhcum to the (Royal Society, hy J. T. Def- aguliers, L. L. D. and R. S. S. contriv'd hy the Rev. Mr. Stephen Hales, F. R. S. and Himfelf. THere have been feveral Machines contriv’d for meafuring the different Depths of the Sea, efpe- cially fuch as could not be determined by the Lead and Line ; but as thofe Machines confifted of two Bodies (the one ftecifically lighter, and the other fpecifically heavier than Water) fo joined together, that as foon as the heavy one came to the Bottom, the lighter Ihould get loofe from it, and emerge ; and the Depth was to be eftimated by the Time of the Fall of the compound Body ( J<5o ) Body from the Top to the Bottom of the Water, to- gether with the Time of the Emerfion of the lighter Body, reckoned from the difappearing of the Machine, till the emergent Body was.feen again, no certain Confequence could be drawn from fo precarious and complex an Experiment. ^ - For even in ftill Water, and in the fame Place, the Time will hardly be the fame in two Experiments : Much lefs will this Machine anfwer in ‘the Sea, on Account of Waves and Currents, and many other Hindrances. But as the PrelTure of Fluids in all Directions is al- ways the fame at the fame Depth, a Gage which ex- actly difcovers what the PrelTure is at the Bottom of the Sea, will fhew what is. the true Depth of the Sea in that Place, whether the Time of theDefcent of the Machine be but a Minute or two, or twenty Times' as long. The Reverend Mr , Hales, in his Vegetable Statieks, defcribes his Gage for eftimating the Preflures made* in opake VelTels ; where Honey being poured over the Surface of Mercury in an open Veffel, rifes upon the Surface of the Mercury as it is prelTed up into a Tube whofe lower Orifice is immerfed into the Honey and Mercury, and whofe Top is hermetically fealed. Now as, by the PrelTure, the Air in the Tube is con- denfed, and the Mercury rifes, fo the Mercury comes down again when the PrelTure is taken off, and would leave no IVfcrk of the Height to which it had rifen ; but the Honey (or Treacle, which does better) which is upon the Mercury, Ricking to the Infide of the Tube, leaves a Mark, which Ihews the Height to which the Mercury had rifen, and confequently makes appear what was the* greateft PrelTure. My ( 5<*» ) My Contrivance therefore is a Machine which will carry down .Mr. Hales's Gage to the Bottom of the Sea, and immediately bring it up again. See the Figure. A R, is the Gage Bottle. F f, the Gage Tube cemented to the Brafs Cap of the Bottle at G, with its open End f immers’d in the Mer- cury C, which by the Preffure of 31 Foot of Water is carried up to d with a little Treacle or Honey d up- on ir, rais’d up from D, a fmall Thicknefs of Treacle pour’d on upon the Mercury. When the Preffure of Water is from a Depth of 64 Foot, the Mercury and Treacle rife up to E, | of the Height of the Tube j and fo higher proportionably to the Depth. J N. R. A Scale may be^mark'd on the Tube with a 'Diamond. K, is a Weight hanging by its Shank L in a Socket m, fix’d to the Ring M B cemented at the Bottom of the Bottle. When the Hole L of the Shank is fhov’d up to m, , the Catch l of the Spring S holds it from falling out of the Socket, whiift the Machine is de- fcending. But as foon as K touches the Ground at the Bottom of the Sea, the Hole L rifmg, the Catch flies back and lets go the Weight, as it is feen in the Figure. ^ hen the empty Glafs Ball I (which at Sea may be a Plog’s Bladder) rifesup to the Surface of the Water with the Machine, in which obferving how high the Infide of the Tube is daub’d, the PrelTure, and confequently the Depth of the Sea is known. J FI G, is a Brafs lube to guard the Top of the Gage Tube. & There are Holes at F, G and E, to admit the Water to pafs freelv every wThere. Ffff - To / ( 5*0 To confirm the Ufe of this Sea-Gage, fhewn before to the Society, I made another Experiment in the fol- lowing Manner. Having pour’d feme Quick-fiver in- to the Bottle of the Gage, I pour’d on upon it Treacle to the Depth of half an Inch, then ferew’d on the Brafs Cap of the Bottle to which theGlafs Gage-Tube was cemented ; by which Means the open End of the Tube was brought under the Surface of the Mercury, the fealed End being upwards. The Machine, thus fit- ted,was immers’d in a cylindrick VelTel of Water, which with a Plate at Top wasprefs’d between two Pillars, in fuch Manner that Air might be condens’d over the Wa- ter without efcaping. Then having forc’d in fo much Air with a Syringe, as to lay on a PrefTure equal to what would be in a Depth of 40 Foot of Water, I open’d the Cock of the upper Plate, let out the Air, and, upon taking out the Machine, it appear’d how high the Qpick-fllver had rifen in the Gage-Tube, by the greafy Mark which the Treacle left within. VII. ExtraFl of Two uncommon Cafes of Tumours of the Abdomen , from a Latin Trabl pubhjtid at Strasburgh, Anno 1728, and entituledy Joannis Boecleri,M. D. &c. ad Exteros Me- dicos Epiftola 5 by W. Rutty, M. D. 5^. S. Seer . TH E firft is concerning a Woman, an Inhabitant of Strasburgh^ of Thirty-two Years of Age, whole Belly, after an immature and hafty Labour, grew gradually for Ten Years together. During the whole ( 5<*3 ) whole Time of Geftation, fhe complain’d of fcarcely any other Symptom than the Weight and Heavinefs of her Belly ; only now and then of a tenfe Pain and a Difficulty in Refpiration: She fa id neverthelefs, that Flatufes would fometimes be difcharged from the 'Pu- denda, and the more they were fo, the lefs Uneafinefs ffie perceived. The Menftrua were regular as to Time} but as to Quantity ffie did not explain her felf : But in the latter Months, towards her Death, ffie grew plainly cachedick. Her Countenance was cadaverous ; her Bread: and upper Limbs perfectly emaciated ; her Feet oedematous, and the Belly much more turgid and pro- minent than before ; fo that at length ffie breathed with the utmoft Difficulty, and upon taking any Nouriffi- ment, complained of a great Straitnefs in her Cheft. Upon opening the Abdomen y two Days after her Death, fome Water flow’d out, of a wheyiffi Colour, tho’ in what Quantity was not taken Notice of} but upon di- viding the 'Uterus, a plentiful Quantity of a bloody Liquor iifued from it, together with feventy-t wo Moke of different Figures and Solidity, and chiefly of a black Colour. One only, the 76th, was fix’d to the lower Part of the right Side of the 'Uterus , contiguous to its internal Orifice. Thefe folid Subftances weighed 64 Ounces ; as the Liquor alfo filled 15* antient Alface Meafures, fo- that taken together, the Whole weighed 80 Pounds Apothecaries Weight. The Skin of the Abdomen was very thin, and almoft tranfparent } the Navel perfedly obliterated} the Fat almoft entirely confumed} the Muffles pale, flaccid, and very thin al- fo } and the Peritonaeum in fome Places fo ftrongly at- tach’d to the 'Uterus , that it could not, without the utmoft Difficulty, be torn from it. The Body of the . F f f f x 'Uterus , ( 5^4 ) Vterus, which is naturally thick, was extenuated to the fame Degree of Rarity and Tranfparency with that of the Cutis of the Abdomen , and of a furprifing Ca- pacity. The Liver appear’d pale, and fo flaccid ° that it might be eafily rubb d to Pieces. X he Height of the Belly from the Vertebra of the Loins to the Navel meafured i* Foot ; its Length from the Cartilago enfi- formis to the Tudenda , 22 Feet; and its Circumfe- rence at the Waid, 4 Feeet 24 Inches, tho’ the Woman was naturally of a fmall Size and Stature. The Second is of a MaidTervant in the fame City, of twenty-three Fears of Age, whofe Belly, from a Suppreffion of the Mendrua, grew flowly for three A cars, without any other notable Diforder ; till upon an accidental Fall, it encreafed fo much in fix Days* as to obliterate the Navel y and not being capable of a farther Didenfion,Part of the Matter which caufed the Tumefaction, flowed down to the Legs and fwelled them likewife ; which brought on a Difficulty of Breathing, a fmall, frequent, and uneafyPulfe, with a total Lofs of xAppetite. But what was more remark- able, the Syftole &vi&cDiaJtole of the Heart were plain- ly felt under the left Clavicle, the Heart being, upon Dilfedion, found thruft up to that Part of the Thorax . The 14th Day from the Fall, a * Diarrhoea came on, which kill’d her in a few Days. Upon making a fmall Incifion in the right Hyfochondrium , there guflied out from the Cavity a Liquor, in Colour, Confidence, and Froth refembling well boiled Beer } which upon en- larging the Incifion, was followed by a foetid purulent Matter, with entire Portions of the putrified Caul ; which Matter filled 56 Strasburgh Pints. Upon this the Belly fubfided , but a large folidSubftance dill re- mained ( 5^5 ) mained under the containing Parts of the Abdomen . Opening therefore the whole Cavity, there was found under the left Groin a confiderable Tumour, nourifhed by its proper Veftels, and every where fixed to the cir- cumjacent Membranes- which being freed from, it weighed 6 Pounds common Weight. This Tumour proved a Congeries of incy hated Abceffes (wrapt up in one common Covering) of different Sizes ; the lameft as big as a Man’s two Lifts, the final left the Size of’an Egg • and each of a different Sort of Subftance : Be- fides which was a great Number of Hydatides . The Peritonaeum was as thick as the Cutis • the Caul al- moft entirely deftroyed ; the Stomach natural, but per- fectly empty ; the Guts livid, very much thickened and vaftly inflated, and moreover connected preternaturally to each other by peculiar Membranes. The Liver ftrongly adhered to the right Hypochondrium , and its Coat parted from its Parenchyma almoft fpontaneoufly. The left Kidney very near equat’d the Spleen in Bulk, and the Pancreas was as hard as a Cartilage ; but the P ter us and Biadder were found in ftatu fano. 1 he Cavity of the Thorax was much fmalier than ufual, from the Contents of the Abdomen preffina up the Diaphragm into it ; in which Cavity alfAvas found the fame Sort of bloody putrid Liquor, as like- wife in the Pericardium . The right Ventricle of the Heart was preternaturally foft and1 flaccid, and bein ' opened, was lined with Hydatides. The upper Parts of the Body were emaciated ; the lower much tume- fied by the Water contained within them. The Author, after this, cites three other Cafes of extraordinary preternatural Tumours of the Abdomen communicated to him by Dr. Valentine Scheide, the prefent ( I*6 ) prefent chief Phyfician of Strasburgh , all which oc- curr’d in his own Practice \ as the foregoing are re- corded in the Regifter of that Univerfity. Thefe like- wife are very remarkable : But as they are not altoge- ther fo uncommon, a particular Account need not be given of them. VIII. An Account of the Culture and Management of Saffron in England, by James Douglafs> M. D. Med. Regin. Extr. Cr S. R. S. AS Saffron grows at prefent moft plentifully in Cam- bridge Jbire, and has grown formerly in feveral other Counties of England , the Method of Culture does not, I believe, vary much in any of them, and therefore I have judged it fufficient to fet down here the Obfervations which I employed proper Perfons, in different Seafons, to make in the Years 1723, 24, 25-, and 28, up and down all that large Trad of Ground that lies between Saffron- Walden and Cambridge , in a Circle of about ten Miles Diameter. In that Coun- try Saffron has been longed cultivated, and therefore it may reafonably be expeded that the Inhabitants there- of are more throughly acquainted with it than they are any where elfe. I fhall begin with the Choice and Preparation of the Ground. The greateft Part of the Trad already men- tion’d is an open level Country with few Inclofures j and the Cuftom there is, as in moft other Places, to crop two Years, and let the Land lie fallow the third. Saf- fron ( 5 67 ) fron is always planted upon fallow Ground, and all other Things being alike, they prefer that which has born Barley the Year before. The Saffron-grounds are feldom above three Acres, or lefs than one? and in chooling them, the principal Thing they have Regard to is, that they be well ex- pofed, the Soil not poor, nor a very Riff Clay, but a temperate dry Mold, fucli as commonly lies upon Chalk, and is of a hazel Colour ^ though if every Thing elfe anfwers, the Colour of the Mold is pretty much negle&ed. The Ground being made choice of, about Lady-day, or the Beginning of Aprils it muff be carefully plough- ed, the Furrows being drawn muchclofer together and deeper, if the Soil will allow it, than is done for any Kind of Corn, and accordingly the Charge is greater. About five Weeks after, or during any Time in the Month of May, they lay between twenty and thirty Loads of Dung upon each Acre, and having fpread it with great Care, they plough it in as before. The fhorteft rotten Dung is the beft ; and the Farmers who have the Conveniencies of making it, fpare no Pains to make it good, being fure of a proportionable Price for it. About Midfummer, they plough a third Time, and between every (ixteen Foot and an half, or Pole in Breadth, they leave a broad Furrow or Trench, which ferves both for a Boundary to the feveral Parcels, (when there are feveral Proprietors to one Enclofure) and to throw the Weeds in at the proper Seafon. To this Head likewife belongs the Fencing of the Grounds, becaufe mofl commonly, though not always, that is done before they plant. The Fences confift of what they call dead Hedges, or Hurdles to keep out not only 1 i ( 568 ) only. Cattle of all Sorts, but efpecially Hares, which would otherwife feed on the Saffron Leaves during the Winter. About the Weather we need only obferve, that the hotteft Summers are certainly the beft, and if there- with there be gentle Showers from time to time, they can hardly mifs of a plentiful rich Crop, if the extream Cold, Snow, or Rain of the foregoing Winter have not prejudiced the Heads. The next general Part of the Culture of Saffron, is planting or fetting the Roots • the only Inftrument ufed for which, is a narrow Spade, commonly termed a Spit -/hovel. The Time of Planting is commonly in the Month of July , a little fooner or later, according as the Weather anfwers. The Method is this. One Man with his Spit-fhovel raifes between three and four Inches of Earth, and throws it before him about fix, or more Inches j twoPerfons, generally Women, following him with Heads, place them in the fartheft Edge of the Trench he makes at three Inches diftance from one ano- ther, or thereabouts. As foon as the Digger or Spit- ter has gone once the Breadth of the Ridge, he begins again at the other Side, and digging as before, covers the Roots laft fet, and makes the fame Room for the Setters to place a new Row, -at the fame Diftance from the fir ft, that they are from one another. Thus they go on till a whole Ridge, containing commonly one Rod, is planted, and the only Nicety in digging is to leave feme Part of the fir ft Stratum of Earth untouched to lie under the Roots ;■ and in fetting, to place the Roots direcftly upon their Bottoms. What Sort of Roots are to be preferred, (hall be Ihown under the fourth Head ^ but ( 5b ) but it mult be obferved in this Place, that formerly when R°°ts were very dear, they did not plant them o thick as they do now; and that they have alwavs fame Regard to the Size of the Roots, placing the larg- eftat a SreateF Diftance than the fmall ones 1 he Quantity of Roots planted in an Acre is gene- rally about fixteen Quarters, or iz8 Bulhels, which according to the Distances left between them, as before ntiignec, and fuppofing them all to be an Inch in Dia- NumbT/ Wlth an°ther’ °Ught t0 am°Unt t0 391°4° ln from the Time that the Roots are planted, till about the Beginning of September, or fometimes later there is no more Labour about them ; but as they then begin to fpire, and are ready to Ihew themfelves above Ground, which is known by digging a few out of the Earth, the Ground mull: be carefully pared with a (harp Hough, and the Weeds, *c. raked into the Furrows, becaufe otherwife they would hinder the Growth of the 1 lants. In feme Time after appear the Saffron Flowers and T|Ib Fids US t0 t le tl]Ird Branch of °ur prefent Method, ihe FiQwers are gathered as well before, as after thev are full blown, and the molt proper Time for this is early in the Morning. The Owners of the Saffron get together a fufccient Number of Hands, who place themfelves in different Parts of the Field, ’pull off the whole Flowers, and throw them Handful by Handful into a Basket ; and fo continue till all the Flowers are o’ Clock ’ W11Ch happenS commonly at,out ten or eleven Having then carried home all they have got, they immediately fpread them upon a large Table, and plac- ing themfelves round if, they fall to picking out the Fiiamenta Styli, or Chives, and together with them, a G 8 S S pretty ( J7o ) pretty long Portion of the Stylus itfelf, or String to which they are joined. The reft of the Flowers they throw away as ufelefs. The next Morning they return into the Field again,, whether it be wet or dry Weather, and fo on daily, even on Sundays, till the whole Crop be gathered. The Chives being all picked out of the Flowers, the nextLabour about them is to dry them on the Kiln. The Kiln is built upon a thick Plank (that it may be move- able from Place to Place) fupported by four ftiort Legs. The Outfide confifts of eight Pieces of Wood, about three Inches thick, joined in Form of a quadrangular Frame, about twelve Inches fquare at Bottom on the Infide, and twenty-two Inches at Top,, which is like- wife equal to the perpendicular Height of it. On the Forelide is left a Hole about eight Inches fquare, and four Inches above the Plank, through which the Fire is put in. Over all the reft, Laths are laid pretty clofe to one another, and nailed to the Frame already mentioned, and then are plaiftered over on both Sides, as is alfo the Plank at Bottom very thick, to ferve for a Hearth. Over 'the Mouth, or wideft Part, goes a Hair-Cloth fixed to two Sides of the Kiln, and likewife to two Rollers, or moveable Pieces of Wood, which are turned by Wedges or Screws, in order to ftretch the Cloth. Inftead of the Hair-Cloth many People now ufe a Net-work of Iron-wire, with which it is ob- ferved, that the Saffron dries fooner, and with a lefs Quantity of Fewel ^ but the Difficulty of prefer ving the Saffron from burning, makes the Hair-Cloth be preferred by the niceft Judges in drying. The Kiln is placed in a light part of the Houfe, and they begin by laying five or fix Sheets of white Paper on the Hair-cloth, upon which they fpread the wet Saffron, between two and three Inches thick. This ( 571 ) This they cover with other Sheets of Paper, and over thefe lay a coarfe Blanket five or fix times doubled, or inflead thereof, a Canvas Pillow fill’d with Straw, and after the Fire has been lighted for fome time, the whole is cover d with a Board, having a large Weight upon it. At firfl: they give it a pretty ftrong Heat, to make the Chives fweat,as their Expreffion is ; and in this, if they co not ule a great deal of Care, they are in danger of fcorching, and 16 of fpoiling all that is on the Kiln. When it has been thus dry’d for about an Hour, they take off the Board, Blanket, and upper Papers, and take the Saffron off from that that lies next it] railing at the fame time the Edges of the Cake with a Knife. Then laying on the Papers again, they Hide in another Board between the Hair- Cloth and under- Papers, and turn both Papers and Saffron upfide down, afterwards covering them as above. This fame Heat is continued for an Hour longer ; then they look to the Cake again, free it from the Pa- pers and turn it ; then they cover it, and lay on the Weight as before. If nothing happens amifs, during thefe firfl two Hours, they reckon the Danger to be over ; for they have nothing more to do, but to keep a gentle Fire, and turn their Cake every half Hour, ’till it be thoroughly dry ; for doing which as it ought, there are required full twenty- four Hours. In drying the large plump Chives they ufe nothing; but towards the latter End of the Crop, when thefe come to be fmaller, they fprinkle the Cake with a lit- tle fmali Beer, to make it fweat as it ought j and they begin now to think, that ufing two linnen Cloths next the Cake, inflead of the two innermoft Papers, may be of fome Advantage in drying ; but this Practice is followed as yet but by few. Their Fire may be made of any kind of Fewel ; Gggg* but 4 ( 571 ) but that which fmoaksthe leafl is be(l,and Charcoal for that Reafon is preferred to any other. What Quantity of Saffron a firfi: Crop will pro- duce is very uncertain. Sometimes five or fix Pounds of wet Chives are got from one Rood ; fometimes not above one or two, and fometimes not enough to make it worth while to gather and dry it. But this is always to be obferved, that about five Pounds of wet Saffron goto make one Pound of dry, for the firfi: three Weeks of the Crop, and fix Pounds during the laffc Week ; and now the Heads are planted very thick, two Pounds of dry’d Saffron may, at a Medi- um, be allow’d to an Acre for a firfi Crop, and four and twenty Pounds fo t he two remaining, the third being considerably larger than the fecond. In order to obtain thefe, there is only a Repeti- tion to be made every Year of the Labour of hough- ing, gathering, picking and drying in the fame man- ner as before fet down, without the Addition of any thing new:, except that they let Cattle into the Fields, after the Leaves are decay’d, to feed upon the Weeds; or perhaps mow them for the fame Ufe. About the Mtdfummer after the third Crop is gather- ed, the Roots mufl all be taken up and tranfplanted : TheManageraent requifite for which is the fourth Thing to be treated of. To take up the Saffron Heads, or break up the Ground, as their Term is, they fometimes plough it, fometimes ufe a forked Kind of Hough called a Pattock, and then the Ground is harrowed once or twice over , du- ring all which Time of ploughing, or digging and har- rowing, fifteen or more People will find Work enough to follow and gather the Heads as they are turned up. They are next to be carried to the Houfe in Sacks, and there to be clean’d or rafed. This Labour con- fiffs in clearing the Roots thoroughly from Earth, and * from ( 57? ) from the Remains of old Roots, old Involucra, and Ex- crefcencies and thus they become fit to be planted in new Ground immediately, or to be kept for fome Time without Danger of fpoiling. The Quantity of Roots taken up, inProportion to thofe that were planted, is uncertain j but at a Medium it maybe faid, that allowing for all the Accidents that hap- pen to them in the Ground, and in breaking up, from each Acre may be had twenty-four Quarters of clean Roots, all fit to be re-planted. The Owners are fure to choofe for their own Ufe the largeft, plumpeft,and fatteft Roots,but above all, they rejed the longifh pointed ones, which they call Spickets or Spickards ^ for very fmall round or flat Roots are fometimes obferved to flower. This is the whole Culture of Saffron in the Country above-mentioned ; and we have only now to confider the Charges and Profits which may be fuppofed, one Year with another, to attend this Branch of Agriculture; and of thefe I have drawn up the following Computa- tion for one Acre of Ground, according to the Price of Labour in this County. Rent for three Years Ploughing three Times Dunging Hedging - Spitting and fetting the Heads Weeding, or paring the Ground Gathering and picking the Flowers Drying the Flowers Inflruments of Labour for three Years with the Kiln, about Ploughing the Ground once and - ] harrowing twice - < Gathering the Saffron Heads Rafing the Heads Total Charge zj "71 o l. s. d. 300 0 18 o 3 11 o 1 16 o I 12 o 140 6 10 o 160 O 10 o 0 12 o 10 o 1 12 O ( 574 ) This Calculation is made upon the Suppofition, that an Acre of Ground yields twenty fix Pounds of neat Saffron in three Years, which I dated only as a mean Quantity between the greatedand the lead j and there- fore the Price of Saffron muft be adjuded accordingly, which I think cannot be done better than by fixing it at thirty Shillings per Pound ^ fince in very plentiful Years it is fold for twenty, and is fometimes worth be- tween three and four Pounds. At this Rate, twenty-fix Pounds of Saffron are worth thirty-nine Pounds, and the neat Profits of an Acre of Ground producing Saffron, will in three Years amount to fifteen Pounds thirteen Sliillings,or to about five Pounds four Shillings yearly. This, I fay, may be reckoned the neat Profit of an Acre of Saffron, fuppofing that all the Labour were to be hired for ready Money - but as the Planter and his Fa- mily do a confiderable Part of the Work themfelves, fome of this Expence is faved : That is, by planting Saf- fron, he not only may reafonably exped to clear about five Pounds yearly per Acre, but alfo to maintain him- felf and Family for fome Part of each Year • and it is upon this Suppofition only, that the Refult of other Computations which have .been made of the Profits of Saffron, can be fa id to have any tolerable Degree of Exadfiefsj but the Calculations themfelves are un- doubtedly very unaccurate. I have faid nothing here concerning the Charge in buying, or Profits in felling the Saffron Heads, becaufe in any large Trad of Ground thefe muff at length al- ways ballance one another, while the Quantity of Ground planted yearly continues the fame, which has been pretty much the Cafe for feveral Years pad. finis. — - •f TO HIS royal highness FREDERICK Prince of W A L E S, sir . r SINCE your Royal Highness has gracioufly condefcended to in- fcribe Your Name in the Book of Charters and Laws of the Royal Society, as a Token of your Favour and Encourage- ment of it, I prefume to offer this Thirty- fifth Volume of Thilofophical Tran facti- ons, fomeof its lateft Productions, to your Royal Highness’s more immedi- ate Protection. This alone would be fufficient Honour to the feveral Authors of the TraCts con- tained in it : But they mull ftill have a pri- vate Satisfaction in knowing, that they are a fub- DEDICATION. 4r fubmitted to the Obfervation of a Prince, whofe Difcernment renders him a compleat Judge of the Merits of their Labours; and whole Benevolence, at the fame Time, will readily incline Him to think favourably of them. If, belides this, they Ihould chance to furnilh any Matter for your learned, or in- genious Entertainment, I beg your Royal Highness to receive it, as one In- ftance of the grateful Senfe conceived of the late Honour done us, and particular- ly, of the profound Refpedt, with which I am. Tour Royal Highness’s 1 Moft Devoted, Obedient, * % ; 4 [ ' • ' '44 f , i * * and Humble Servant, William Rutty, R. S. Seer. ti=*dT RB Imi'lV.i'.ii ^3 r 6 1 J° r -GE03J JB A ;P * jr r*> JT\ L:\J kJ h'v' y ^ r Numb, vp Numb. 40 <£, PHILOSOPHICAL TRANSACTIONS FOR THE Month of ‘DECEMBER, 1718. The CONTENTS. I. Remarks on the Height of Mountains in general, and ofthofe of Swifferland in particular, with an Jccount of the Rife of fome of the mofl conjide- rable fevers of Europe. By J. G. Scheuchzer, M. 1). See. II. Optical Experiments made in the Beginning of Auguft 172.8, before the Brefident and federal Members of the (Royal Society, and other Gentle- men of feVeral Nations, upon Occafion of Signior Rizzetti’r Op ticks, with an Account of the J aid Book, By J. T. Defaguliers, L L. t>. and F. % S. a % III. The The CONTENTS. III. T7;e Method of making Tin-Plates, extracted from the Memoirs of the Academy k of Sciences , for the Year 1715, by William Rutty, M. T>. R. S . Seer . IV. ^ Letter from the (Reverend Mr . James Brad- ley SaVilian Trofeffor of Aftronomy at Oxford, andF.RS. to ZV.Edmund Halley Aftronom. Reg. See, giving an Account of a new dif- coVered Motion of the Fixt Stars. E Re- ( 577 ) L (Remarks on the Height of Mountains in general , and of thofe of Swifferland in particular , with an Account of the Rife of fome of the moft confide - rable Rivers of Europe. G. Scheuchzer, M. X). See. IN a former Paper, I took Notice that TAcaarchus found Mount Telius in Thejfalta , to be iijo Pa* ces high, which make 625*0 Roman , or 6822 Tarts feet, a Height which we may well pronounce too great even for the abfolute Height of Mount Tel/us, I mean its Rife above the Level of the Sea. Conform to the Determination of 'Dicaarchus , I mentioned, that Tint arch fixes the Height of the higheft Mountains, and the greateft Depth of the Sea to IO Stadia, and Ueomedes affirms, that they cannot exceed 16 Stadia. The celebrated Galileus de Galileis is one of the moft modeft among the modern Writers on this Head; For he ays, * that the higheft Mountains do not rife above a Mile, or 8 Stadia, or $000 old Roman Vejpajian Feet, which make s^Taris Feet above the Level of the Sea’ which we ffiall find by and by to agree pretty well with fome of the higheft Mountains in France , and may conje&ure to do fo with thofe in Italy. Kepler went rather too far f when he affigned the Mountains of Rhcetia (thought the higheft in Swijferland) a Height of 26 Stadia, or 10000 old Roman Fejpajian Feet, which make 10916 Tar is Feet. The Opinions of fome other antient and modern Geographers and Ma- thematicians, will appear better by the Table annexed. * Nuntius Sidercus, p. 14. t Aftronom. Optic, p. 129, 135. 5c Epitom. Aftronora. lib I. pag. 2 0. H h h h - ‘ A Table C 578 ) A Table fhewing the Height of Mountains according to feveral antient and modern Writers. Strabo ( Lib. II. Geog .) fays, that the higheft Mountain, call- ed by him ‘Petra Sogdiana , is of . - Pzrerius (Lib. XII. in Ge- nejiri) determines the higheft Mountains to - Leo Bapt. Albertus (Architect. Lib . x. Cap. i.) to - Ath. Kir c her. ( Ars magn. luc. & umbr . P. II. Probl. 5.) brings them to - Fromond. {Lib. I. Meteor. Cap. < 2. Art. i. - •! Gilbertus de magnet e. L. IV. C. i.. Pliny {Lib. III. Cap. lxiv.) ac- cording to the Explanation of Fortunius Licetus {de Luna }> Luce fubobfcura , Lib. II. p. 306.) to w ; r Ficciolus^Geophr .{Lib. VI.) is of' Opinion, in Purfuance of what he imagines to have demon- ftrated of the Mountains A- thos and Caucafus , that pofli- bly there may be Mountains of * • v Stadia. Old Roman Vefpajtan Feet. Parts Feet. » 30 1875'© 20468 • 3* 20000 21831 xzsoo 23661 43 26875' *9 337 • . - 64 J ( 40000 43664 118 80000 87318 - 400 < 2 5*0000 271900 Six 310000 34931* Now, ( 179 ) Now, in Oppofition to this Table, wherein the Heights mull needs, upon firft View, appear romantick and unnatural, let us confider the Height of fuch Moun- tains, as have been meafured,either by Trigonometrical or Barometrical Obfervations. In England, the Height of Snow don-hill, one of the higheft Mountains in IV ales, was meafured Trigo- nometrically, by Mr. J. Cafwell of Oxford , and found to be of 1240 Yards, or 3710 Englijh Feet, which make 3 48 8 Tar is Feet. At the Top of this Mountain, the Mercury fubfided to f 6,lt, which being redu- ced to Tar is Meafure, make juft 2 4". Now in the Tables above, the Height of the Place where the Mer- cury fubfides to 24 is, according to Mariotte , of 5*44 Toifes, two Foot, or 3266 Foot above the Level of the Sea, according to ‘Caffini, 676 Toifes, or 40 <7 6 Feet, and according to my YJncle’s Calculation 5*59° 2*, or 335^, fo that Mariotte comes 222 Feet fhort of its Height, as it was determined Trigonometrically, . Dr. Scheuchzer but 132', but Caffini exceeds this Height by 568 Feet, which confirms again, as I have ftiewn in a former Paper, that the Mariottian Table is preferable to that of Caffini, though pretended to have been corrected upon the former, and that that of Dr. Scheuchzer is an Improvement upon both. According to the Obfervation made by Dr, Halley, May 26, 1 697* the Mercury flood at- the Top of. Snow den-hill, at 2 6" \f,f Englijh , which, if reduced as above, would give the Height of the Mountain fomsthing lefs. In France , when the Meridian Line5 firft begun in 1669, was continued in 1703, the Heights of feveral Mountains, particularly in the South of France, were determined Trigonometrically by the Members of the H h h h z Royal ( j8o,) Royal Academy of Sciences : And I find up and down in their Memoir?, the Heights of the following. Height in Toifes. Feet. 2-77 or 1662 397 — 2,382 408 — 2448 6 48 — 3888 Mont Clairet in Provence La Majfane in RouJJilion - - The fame according to another d Obfervation j Bugarach , a Mountain in Lan- guedoc Mountains in Auvergne. Le Buy de Demme , near Clermont 810 4860 La Courlande - , 8 3 8 — 5-028 Ba Cofte - - - 851 — 5106 Le Buy de Violent - - 8c? <-118 LeCantal - - - 984 — 5904 Le Mont dy or - - 1030 — 6180 In the County of Avignon . Le Mont ventoux Pyrenean Mountains. S. Barthelemy dans le ]>aix\ de foix La Montague du Moujfet Le Canigou 1036 — 6116 ii8y — 7110 125-8 — 7548 1440 — . 8640 Before I proceed farther, I rauft beg Leave to obferve that the Heights of thefe Mountains, in the main, feem rather too great. This indeed is eafily accounted for, as they were meafured byTrigonometrical Obfervations which will, as I have took Notice above, becaufe of the Re- ( 58‘ ) Refra&ion of the Air, give the Heights greater than they a&ually are. But what confirms it flill more, is, that according to the Tables above, the Numbers which anfwer to the Heights of the Mercury, as they were obferved at the Top of fome of thpfe Mountains, are confiderably lefs, and that even Monf. CajJinis own Numbers, which yet we have by fome undoubted Ex- periments (hewn to be too great, fall often fhort. It will be enough to mention two or three Inflances. At the Tower of Maffane in RouJJillonjhe Mercury flood at and the Height of that Place was deter- mined trigonometrically, of - 397 Toifes. Now 25'' 5/// anfwer according?' Mariotte , to - - ^ 341 0 According to CaJJini , - - 392 4 According to Dr. Scheuchzer - - 350 o ^ 4 J - ft £ Si j ' ' J ‘ * ( - % ’ • , . [ | ^ j i l j T At the Top of the Mountain called la Cofie in Au- vergne, the Mercury flood, 061. 9, 1700, at 23"' ^fry and the Height of this Mountain was determined Tri- gonometrically of Now 23 " 4r// anfwer ac- - 851° Toifes. cording to Mariotte £0 Cafjini Dr. Sbeuchzer The Difference is flill more' confiderable withRegardto the high Mountain Mont A' or enAuvergnejtheYleig whereof was determi: ed Trigonometrically to 1040 Toifes. . At ( 5gl ) At the Top of this Mountain the Mercury fell, ac- cording to an Obfervation made by F. SebaJUen Truchet,June 8, 1705*, to which anfwer according to Mariotte, to 7070 c$ 31$ v CaJJint to • - 915 1 >differ.omme , where Monf. fPerier obferved the Mercury, Sept. 19, 1648, at 2, 3" x,n. Upon Jochy a high Mountain in the Territory of Ett- gelberg, where it confines upon the Canton of Bern, full South of Zuric , the Mercury Rood, June 23, 1706, at xi" 4'", which gives the Height of that Mountain according to Mariotte * * 961® o* or 5766 Dr. Sheuchzer, - 987 4 or 9926 This Mountain, though very high, is far from being the higheft in that Neighbourhood, for next to it . there ( 585 ) there rife another called the Tit Usher?, covered with everlafting Snow, which we may, upon a moderate Computation, pronounce at leafl 1000 Foot higher nan the Top of the Jocb, and confequently one of the higheffc in the Country. j *e AviculB by the Italians called Monte del Uccello, and by feme S. Bernhard's Mountain, from a Chappel built in Honour of that Saint, a high Mountain in Rhcetia, towards Italy, the Mercury was cording 3°’ I7°7’ ^ ^ " 1 1'"’ which S‘ve ac- Mariotte - - 707° 5' or 4i47< Dr. Scheuchzer - . 7*73 Is 6 c This Height mull be underftood only of that Part of the Mountain which is palled over by Travellers, the Mountain it felf riling conliderably above it, andthe^f- dula, or Aiatl'siAAas of Strabo, Geog. L. III. of which the Avtcula is only a Part, being ftill higher. The Rhenus Jojlerior, or Hinder Rhein, and the Mori Is which at laft lofes itfelf' into the Tejin, near Bellin’- zone, not much above the Entry of the Tejin into the Lake of Locarno, arife upon this Mountain. At Santa Maria, upon the Luckmannier Bert bv fome S. Barnaby s Mountain, which is likewife a branch of the Adula, the Mercury flood, Au? o 171c as upon the Avtcula, at zz" n» which ihews the Height of there two Places to be equal. In the Alp San Torta,ntw the Source of th eHinter Rhetn, Rhenus fojterior, five Hours and a half from Sfeluga, Sjlugen in Rhcetia, the Mercury was ob- ferved, July z9, i7o 7, at zi" J", where it I food like- wile upon the above-mentioned Mountain Joch whi- ther the Reader is referred for the Height of this Alp ! i i i At* ( 58* ) At Splugen itfelf, the Mercury flood the fame Morn- ing early, at if which give the Elevation of Splugen according to Mariotte 644° F or 3865, and according to Dr. Scbeucbzer , 66 1° 5' or 3971'. So that the Fall of the Rhine from the Alp aforefaid to Splugen , in five Hours and a half, comes, according to Mariotte , to 1901, and according to Dr. Scbeucbzer , to 1955 Tar is Feet perpendicular. At the Capuchins, upon the high Mountain S. Gothard , a celebrated PaiTage out of Swijferland into Jta/y, the Mercury flood, June 30, 1705, at zz" c, which gives the Height of that PaiTage, which with Regard" to the highefl Tops of S. Gothard , lies but as it were at the Foot of a high Mountain, according to Mariotte 85^°, or $111', and according to Dr. Scbeucbzer , 875° 5', or 5155, above the Level of the Sea. e . r Upon the Furca , a high Mountain between the ‘Vrferen Thai , T)rfaria Vallis , and the upper P*/- /*/&, and one of the Branches of the S. Gothard , the Height of the Mercury in the Barometer was obferved, ; July , 31. 1707, at 2i,; 5'", which give the Height of this Mountain above the Level of the Sea, according to Mariotte , 9470 F or 5683', and according to Dr. Scbeucbzer , 973 0 3' or 5841. Near this Mountain there are others, which cannot be lefs than 800 or 900 Foot higher. Thefe Mountains, I mean the Avicula , the Luck - ' mannier Berg , the S. Gothard , and the Furca , toge- ther with the Grimfula, the Crifpalt , the Semproniery or Sempronius Mons , the Adula , and a Chain of others, are the Lepontia Alpes of * and the Summa • * Lib, iii. c, xx. Alpes ( 587 )' Alpes of Cafar *. They begin in the upper Vallefia , traverfe the Canton of ‘Vri , and fo run on Ea ft wards, a-crofs the Country of the Grifoons , towards Tirol . Their greatefl Height above the Level of the Sea, may be fixed in round Numbers to 750 o, or 8000 Tar is Feet. *Tis upon thefe very Mountains, that fome of the mod confiderable Rivers of Europe take their fir ft Rife, within very fmall Diftances of each other. The Rhofne, for Inftance, Rbodanus , by Marcellinus call- ed, maximi nominis flumen , and by Varro , Fluvius inter tres Europe maximus , arifes from two G letch - *r.r, as we call them, or Montes glaciates, huge Moun- tains of Ice, near the Furca , whofe Height hath been above determined, and thence runs with great Impetu- ofity down Vallefia , the tValliJferland , forming a long Valley, furrounded on both Sides with huge Mountains, till it loofes its Waters and Name in the La - Lemannus , or Lake of Geneva , but refumes it again near the Town of Geneva, whence it flows with a more gentle Defcent through fome Provinces of France into the Mediterranean Sea. The Thefin, Ticinus , by Claudian , in his Pane- gyric upon the Confulate of the Emperor Honor ius, called Fulcher , handfom, takes its firft Rife from two fmall Lakes upon the S. Gothard ', and fome late- ral Sources from the Lago fopra la Cima di Fettine , upon a Mountain called Fettine, the Lago della Sella, the Lake of Rot tom upon the Luckmannier Berg , the Lake of Tom , and the Lake of Bedret to, upon a Moun- tain of this Name. It defcends the Lavinia Vallis , or Liviner Valley , and in its Way to the Lake of * De Bello Gallico 1. in. . I i i i 2 -Lo* ( 588 ) Lommo , receives many Brooks and Rivulets from the adjoining Mountains : It unites its Waters with the Bo, near Bavia, and loofes itfelf jointly with that River into the Adriatick Gulf. The Rhine, Rhenus , by Qafar de Bello Gallico termed, lattjjimus atque altijjimus , arifes in three fe- veral Branches, which are called Rhenus anterior , foferior , ® me dins, the further , the hinder , and middle Rhine . The hinder Rhine takes its Rife upon the high Mountain Avicula , Colmen del Occello , Part of the Adula , in the Alp *5^ Borta , from a Gletcher , or Ice-mountain, which extends in Length full two Hours. The middle Rhine , Rhenus medius, arifes upon the Ltickmannier Berg , which islikewife Part of the Adula, in the upper Part of a Valley called Maria , oppofite to one of the Sources of the Thefin. The further mofl Rhine , Rhenus anterior , arifes upon that Branch of the Crifpalt , which is call- ed Badut , Badtiz , and foon receives feve- ral lateral Branches from the Mugels and Come- ra. My prefent Purpofe will not fuffer me to purfue the Courfe of this River in its feveral Branches. Near the Monaftery of T)ifentis , the further and middle Rhine join together, and the united Stream falls into the hinder Rhine, near Reichenau . Below Rheineck , the Rhine falls into the Lacus Bodamicus , or Boden Sea , and comes out of it near Stein • whence wafhing for fometime the Borders of Swijferland , it then tra- verfes great Part of Germany in a very irregular Courfe, till at laft, in Holland , it loofes itfelf into the great Ocean. The Reufs , Rufa, arifes from a fmall Lake called Lago di Luzendro , upon the S. Gothard , but foon receives a conliderable Inforcement from the Furca, and . , ( 589 ) and near ‘Vrfelen, another from a mountainous Lake in Oberalp. Near Fluelcn , not far from Ury, it en- ters the IV. IValdjletten Sea , Lactts quatuor Givi* tatum Sylvejlrium , but refumes its Courfe and Name at Lucern, and at lad falls into the Aar below JVin- dijb , Vindonijfa, 1 he Aar , Arola , Arula , arifes upon the high Moun- tain Grimfula , in the upper Vallefia. About three Hours below that, it falls into the Lake of Brientz , and out of that, not far from the Monadery Inter la- then , into the Lake of Thun , which it leaves near the Town of Thun , and thence running by Bern , Solo - thurn , and fo down, falls at lad, after many Windings and Turnings into the Rhine near Coblent z, Conjluen- tia , probably fo called from the uniting of thele two condderable Rivers. But to proceed. Gemmius Mons , the Gemmi , is a very high and deep Mountain in ^ allefia^ over which there is a Paf- fage, but only in Summer-time, from the Frutttnger V illey^ in the Canton of Bern , to the Mineral Waters at Leiik in V dlefia. The Defcent, on the South-fide of this Mountain, is deep and frightful, even to the Afped, beyond what can be imagined, being a narrow Path, cut on the Side ofalmod perpendicular Precipices, fometimes with trembling woodenBridges,or Planks over the Clefts in the Mountain, and here and there fupported with low Walls. Having been geometrically raeafu- red, it was found of 101 10 Feet in Length, or rather Height, its many Windings and Turnings included. At a fmall Cottage, called Zur T)auben , a poor reding Place for weary Travellers, being the highed Part of the Mountain which is paflable, the Mercury fub- fided July 1, 1709, to 21" 3"' which gives the Height of ( 5?o ) of that Place, according to Mariotte And Dr. Scheuchzer iooi o or 6012 974° s' or 5-849' Not far from this Cottage, is a fmall mountainous Lake, called the 'Dauben Sea , or the Tidgeons Lake , encompaffed on all Sides with high Mountain?, the Tops whereof, for their Steepnefs, it would be impof- fible to reach. At Kandelftag. , the fir ft Village in the Frutinger Valley , in the Territory of Bern , going up to the Gemmi , the Mercury rofe on the fame Day to 24" i'", which give according to Mariotte - - ^io° 1' or 3111' Dr. Scheuchzer - - 534 1 or 3105 And at Mullenen , at the Foot of the Gemmi^ it flood at 15" 7"', which anfwer according to • Mariotte to - - 318° 5' or 1913'. Dr. Sheuchzer - - 317 o or 1962 On the other Side of the Gemmi , at LeiicL a celebra- ted Place for its Mineral Waters, the Mercury was obferv- ed July i, and July 5, 1709, at 23" 9'", which anfwers according to Mariotte , to 581° 4', or 3490', and ac- cording to Dr. Sheuchzer to 597° 3', or 3587'. So that the Cottage 'Dauben , rifes above Le 'uck , ac- cording to Mariotte , - - - 2359' Dr. Scheuchzer - 241 7 Above Mullenen , in the Frutinger Valley , accord- ing to Mariotte - - - 3936 ' Dr. Scheuchzer r 4050 And ( 59 1 ) And the perpendicular Height of the Gemmi , above the Level of the Sea, conftderabiy exceeds 6000 Paris Feet. But high above all the Mountains of Swifter land rifes the Stella , Piz Static a deep Mountain in the S chamfer Valley, in Rhcetia, or the Grifoons 5 the Height whereof was by my Uncle Dr. John Scheuchzer , by fome Obfervations made in the Year '1709, determin- ed to 9585 ‘Paris Foot, above the Level of the Sea, according to his own Calculation, or 9441 according to Mariotte , and 12196 according to Caftmi : A Height, which the Rufttcayra^ or Shamoys themfelves fcarce venture toafcend. And his to thefe only, and the like Heights the following Verfes of Si litis It aliens ought to be applied. Cunlfa geluy candque aternum grandine tefla^ Atque avi glaciem cohibent : riget ardua mentis /Etherei facies > fur gentique obvia Phcebo Pduratas nefeit flammis mollire Pruinas. Nullum ver ufquam^ nullique aft at is honor es^ Sola jugis habitat diris^fedefque tuetur Perft etnas deformis hyems Having thus determined the Heights of the Moun- tains of Swifterland from Barometrical Obfervations, I will now clofe thefe Remarks, which are infenfibly grown to a much greater Length, than I at firft intended they fhould, with a few general Obfervations on the na- tural Hiftory of that Country, arifing from the Height of its Mountains. The firft Obfervation (hall regard the Lakes, of which there are feveral, and very remarkable ones, in and ( 59 i ) and upon the Borders of Swijferland^ which will af- ford me a lingular Inftance of Divine Providence. The A fee nt of the Mountains of Swijferlandbzin.gfo -very fudden and quick, that as I have above Ihewn, the Ele- vation of the Mountains in the Canton of Glarus a* bove the Horizon of Zuric, though not quite three Days diflant, is more than three Times as great, as the Elevation of Zunc ltfelf above the Level of the Ocean, of which it is upwards of 375 ‘ Englijb Miles diftant in a (freight Line and fo in Proportion of others ; and the Rivers, which arife in thefe Mountains, rufhing down, in Confequence of fo quick a Defcent, with great Force and Impetuofity, it was to be feared, they would often overflow their Banks, and caufe frequent Inunda- tions in the flat Countries, (of which there are too many Inftances in our own Vallies and Plains,) if this Force and Impetuofity was not in great Meafure broke, and their Waters difpofed to a more gentle Defcent. And this is cffe&ually done by thofe great Receptacles of Water, the Lakes, which are befides of infinite Ufe to the Inhabitants around them, fupplying them with Plenty of Fifii for their Sufienance, and enriching them by the Facility with which Commerce may be carried on over them. Thus the Rhine falls into the Lacu$ Bodamicus, Boden-Sea , the Rhofne into the Lacus Lemannus , or Lake of Geneva , the Muefa and The - fin into the Lake of Locarno , the Reus into the Lake of Lucern , the Adda and Maira into the Lake of Co - moy the Lint , or Limat , into the Lake of Zuric , the Aar, into the Lakes of Brientz and Thun. And it feems, that the more confiderable the Rivers are, and the more impetuous their Courfe, fo much the greater mull the Receptacles be, wherein they are to loofe their Force 1 ( 591 ) Force and Rapidity. The Lake of Geneva, and the Boden-Sea, the two largeft in Swiferland, evidently eV1 jCC ii a.t I here aflert, and the others above-named gradually decreafe in Largenefs, in proportion as the Rivers, which fall into them, are lefs and lefs rapid. The extreara Smallnefs of the Alpine Plants is ano- ther Obfervation, I intend to make. They become lefs and lets, in proportion as the Mountains, upon which ■ they grow, rife higher. Whether this be owing to the bharpnefs and Purity of the Alpine Air, or the decreaf- ing 1 reifure of the Atmofphere, which is far lefs upon ^ than in Valleys and lower Countries, or to a Want of a fufficient Quantity of fubterraneous Heat, to pulh the Nourilhment into the Roots and Veflels of the Plants, or rather to a joint Concurrence of thefe and other Caufes, would require a more leifurely Con- ”f erra5Jon' The ^ is an indifputable Matter of fad, and it extends alfo to Trees and Shrubs, which become fmaller, as they grow higher. Nay, what is itill more remarkable, no Trees will grow beyond a certain Height, which is the Reafon why the Tops of Mountains appear fo bare and naked, if viewed at a Dilhnce, though a curious Traveller fhall not fail meeting upon their rich Paftures with an agreeable Vari- ety of Deautiful Plants. The Height, where the Trees ceafe to grow, hath been found, by Barometrical Obfer- vations, nearly to be the fame in divers Parts of Swiffer- land. Otherwife, the Smallnefs of the Alpine Plants is a- bundantly compenfated by the Richnefs of their Virtues' which are, as it were, purpofely centred there into fo narrow a Compafs. But to another Obfervation. The Mountains are much more abrupt, and fteep, and the Precipices greater Kkkk ( 594 ) to the South, than to the North, and Weftwards than Eaftwards. Many Inftances of this might be given in particular Mountains in Swifferland , as the Gemmi , the Mons fraElus and fo forth j but it is alfo evident- ly true with Regard to the whole. Thofe are the highefl Mountains, which feparate Vallefia, the Can- ton of *Vri, and the feveral Leagues of the Grifons , from Savoy , Tiemont , and the Tirol, which lie to the South, or South-Eaft. Thofe very Countries are, as it were, one continued Set of high Mountains, quite to the Mediterranean Sea, and the like Strufture feems to be continued farther on into that Sea itfelf. The ! Tyrenean Mountains alfo are but a Continuation of that vaft Chain, which begins in the Lepont'ue Alpes , or the Mountains in the upper Valle Jia^ the Canton of Dry and Rhcetia , and from thence fpreads itfelf chiefly Well and South. On the contrary to the Eaft and North they break off by Degrees into gentle Plains, which appears evidently by the vaft 1 rafts of Ground, which the Rhine for Inftance, and the ‘Danube com- pafs, before they lofe themfelves, the one into the Ger- man Ocean, the other into the black Sea, whereas the Rhofne on the other Side, quickly and with a pro- portionable Velocity reaches the Mediterranean. The fame Obfervation, with Regard to the abrupt Steepnefs of Mountains to the South and Weft, holds true in other Parts of Europe , remarkably in England and Norway , more or lefs in other Countries. And fo far as our Maps, and the Accounts of Travellers go, the fame Thing is obfervable in other Parts of the World, but mod evidently in the high Mountains of T eru and Chi - It in South America , which terminate very abruptly Weftwards into the Eacifick Sea, but gradually decline • to ( $95 ) ta the Eaft into immenfe Plains, watered by fome of the mold conliderable Rivers in the known World, par- ricularly the River of Amazons and the Rio della Plata> which arife in the faid Mountains. To conclude, from what hath been hitherto faid, it appears evidently, that the Mountains of Swijfer - land are the higheft of Europe , and the great Store- lioufe, whence all the Countries around them are fup- plied with Water } conform to what the learned Lo - 7 itus Glare anus hath long fince elegantly expreifed in the following Verfes. Prat ere a caput Europes hanc ejfe probabunt : /Eternis Alpes nivibus, juga Olympic a, quorum Porgitur in coelum caput, , & fub Tartar a venter : Et quod ad Auroram, Boream^Solemque cadent em Flumina perpetuo non deficientia curfu *1 arturit , ilia volant & in omnia membra re dun* . . ( dant , Ad Lephyrum & Libyen Rbodanus, Rhenana fa. ftt a y/fr Vnda citat Bor earn, gelidus rot at Ifter ad Ear am • Virus aquas , Getico novas Hofpes © advena An i' n “w * ( POfltO . / ytahos fileo, Jileo quos Italia accipit amneis Alpibus d nofir is , quaque alto d vertice montes Agmina difparibus fundunt latijfima Sulcis. Whether the Depths of the Sea correfpond with the Heights of Mountains, mull be left to future Obfer- vations. K k k k 2 II. Opn- ( 59* ) II. Optical Experiments made in the Beginning of Auguft 17*8) before the Treftdent and federal Members of the Bpyal Society , and other Gentle- men of federal Nations , upon Occafion of Signior Rizzetti’x Opticks , with an Account of the faid Book, By J. T. Defaguliers, L L. D. and F. % S . SOme Time in the Year 1712, Signior Gizlanzoni , an Italian Gentleman, fhew’d me a Paper of Signi- or John Rixzetti, wherein he denied the different Refrangibility of the Rays of Light, becaufe an Ex- periment mentioned in Sir Ifaac Newton's Opticks (B.i. Brop. 1. Exp. 2.) concerning an oblong Paper paint- ed half blue and half red (whole Image projeded by a Lens upon a white Paper at a confiderable Di- ftance became diftind in its blue half, nearer the Lens than in its red half) had not fucceeded with him, tho* after many Trials. Sir Ifaac Newton being acquaint- ed with this, delired me to repeat his Experiment above- mentioned, which 1 did at my own Houfe, before him and Signior Gizlanzoni and fome other Perfons, who were fatisfied with the Succefs of it, according to Sir Ifaac Newton's Aifertion. Afterwards on the 13 th of ^December 1722, I again repeated the Experiment before the Royal Society , with the fame Succefs, the full Account of which is printed in the Thilofophical Tranfatlions , Number 374. After this, Signior Gizlanzoni read me a Letter from Signior Rizzetti , wherein he faid j “ He wanted to know whether the “ Expe- ( 597 ) “ Experiment would fucceed, if the Paper was turned ‘ fo as to bring the red Half in the Place of the blue ‘ one; and that if it fucceeded then, yet he would ‘ n°ta«iuiefce, but he Ihould have fomething (till to ’ objeft againft it And further, that he wanted to know what could be faid to feveral other Objeftions (I think there were twelve in the Paper Ihewed met againft many more of Sir Ifaac Newton's Optical Experiments, the greateft Part of which he faid, U c-e fucceed differently from what Sir Ifaac had related j and would not allow the ‘ Confequences to be juft, which were drawn from <• the other Experiments which he had found to agree « with his Trials’’. Upon this I acquainted Signior G izlanzom in a Letter, which I deftred him to com- “ mumcate to Signior Rizzetti ; “that as" Signior ‘ toxzetti had put the Iffue of the Difpute upon the Succefsofan Experiment, which after repeated Trials had fucceeded contrary to his Opinion, he ought to acknowledge his Miftake j and then I ihould willing v repeat all the other Experiments which he had called in Queltion, and endeavour to remove his other Diffi- ‘ culties. That if it was Truth and not Victory which hecontended for, I did not doubt but he would com. “ ply with me, in what I infifted upon ; and then 1 Ihould “ be ready to make any Experiment, or clear up anvDif- “ ficulty relating to the Doftrineof Colours, inthebeft mannet I could”. ButI never heard any more from Signior Rizzetti ; but was told by others that he was very angry at Signior Gizlanzoni, and faid he was got into Sir Ifaac Newton's Party. N°W at Eft Signior Rizzetti haspubliflied a Book, entituled De Luminis Affeftmibus Specimen Rhyfico- mathematicum , << « (i ( 59^ ) ?nathematicum , dedicated to Cardinal Tolignac , and printed at Trevife and Venice , 1717, which being prefented to the Royal Society , and by the Society re- commended to me to give an Account of it, I hope no^ Body will blame me for making a faithful Report. The Author in his Preface, and throughout the whole Book, in a moft arrogant manner, has infulted the greatefl Philofopher that this or any other Age ever bred, triumphing in what he thinks the Miftakes of Sir Ifaac Newton and his own Difcoveries. Had he modeftly related the Fa&sas they appeared to him, and his Reafons for drawing Confequences different from thofe of Sir Ifaac Newton , the World might have thought him urged on by the Love of Truth in his ten Tears Labours , * and his Errors might have been excufed according to what he fays in his Preface Si forte decifior , baud turf is eft in re Fhyfico-mathe - matica error , & magnis fe quifque tuetur exemflis . Neither would his Fame have been the lefs (if he had been right in his Experiments and Reafonings) for treating his Adverfaries in a civil Manner, and really doing what he fays at the End of his Preface “ Flacita “ quidem authorum laceffo ; at iffos tamen authores ct obfequio & veneratione frofequor For ill Man- ners can never be excufed by what he calls Thilofo • fhica Libert as. Now nothing lefs than owning, that a greedy Defire of Fame , and an Obftinacy to main - tain what he once laid down as his Of inion , mifled him fo far , can excufe him to the learned IVor Id. Wehear indeed in a Letter from Sir ThomasDereham to Sir Hans Sloane , Prefident of the Royal Society , that now Signior Rizzetti alledges, “ That he was * See Preface, p. 3?. deceived C 599 ) “ deceived in his Experiments, by Reafon of the Bad- this being the Place of Contad where the Refledion downwards (of the Surface D F) ceafes. This happens becaufe thofe Rays, which (coming, from the Candle K) were bent in Curves under the Sur- face A B of the upper Prifm about feveral Points near I, are by the Nearneft of the Surface D F of the lower Prifm brought down to R, inftead of being turned up again to the Eye at E; whilft thofe Rays, which (com- ing from the Paper at k thro’ the Surface GF of the lower Prifm, and palling thro’ the upper Surface of it FD) were bent in Curves about feveral Points near I, are prevented from turning down again to R, and are ( *»4.) brought up to the Eye at E, which confequently muft fee a round Part of the Paper at ky juft as big as the Place of Contact, which appears like an Hole $ or as if the two Priftns being changed to a Parallelopiped, were covered with a dark Paper that had only afmallHole in it. But to make this more evident, efpecially to fuch as are not well acquainted with Sir Ifaac Newton's Op* ticks, 1 beg Leave to explain the Manner of the bend* ing of the Rays where they are refraded or refleded. Of the Bending of the Rays in their Refratfion. Let DD (Fig iz) reprefent a denfe Medium (as Glafs) whole Surface is GG, and A A a rare Medium (as Air). Now let us fuppofe a Power to extend all over the Surface G G, ading from A A towards D D in Lines perpendicular to the Surface G G, very ftrong in Contad, but infenhble at a very fmall Diftance from the faid Surface, which we will call th z Attraction of the Surface G G, without confi- dering whether it be any real Virtue in the faid Surface, or the Adion of a Medium impelling towards it. Let Lines n, u, 3 3, fuch as exprefsthe Lines in which the Attradion exerts it felf, and the LineM M (extremely near to G G) the Limits of the Attradion, beyond which it cannot affed a Ray of Light. Let the Ray of Light R a moving from a rare Medium into a Denfe in the Diredion R r, come towards the Surface G G in fuch an Angle that it may be refraded. When the Ray comes to a , by the Attradion at a it will be aded upon * in 0 ( <*<5 ) in ^le |yme a b> an^ (by the known Laws of Mecha- mcks) be turned out of the Way into the Diredion * a inftead of at: When it is got to b, being aded upon’ tn the Oiredion ^ 4, its new Direction will become b b : At e, by the Power aCting in the Line e c, it will irnoXpi ?lrea‘°nrt0fc’ and la%> » d « will go into the Glafb in the Line dd, continuing in that ftreigiy Line whil ft it moves in that Medium. 8 ' Now if the Lines i 1, ii, 3 3, », c, b, a, be infinitely near (as they mult be fuppofed to be) the Ray, in- ftead of being broken into the feveral ftreight Lines ab,bc, and in the Diredion a r ; its changed Direction at a will become a a, and at b> b b, or "ra- ther the Ray will be indexed in the Curve ab\ and at b getting out of the Power of the Attraction of the Surface A B, it will ( for the Reafons before given ) move in a ftraightLine from b to c , where it will be bent again the contrary Way in the Curve c d of the lame kind as a b, and laflly emerge in the Direction dd parallel to the firft Diredion R r. From hence it fol- lows, that when thePrifmsare brought fo near as to touch, their mutual Attractions deftroying each other, the Rays of Light will not be bent, but pafs through the two Prifms ( which in this Cafe perform the Of- fice of a Parallelopiped ) in the fame Direction with which they came into the firft Prifm, and confe- quently produce no Colours ; contrary to what is affirmed by Rizzetti ( Rage 78, 79, &c.) and when the Rays R a fall obliquely upon the Surface CB, the EfFed of their Refradion at their Immer- fion at S to produce Colours, is taken off by the Refradion which they fuffer at their Emerfion at z. Experiment VIL I took the Cube of Fig. 8, and looking oblique- ly through it at the Hole of the Window of my dark Chamber ( the Suu lhining or not Aiming) the Hole appeared entirely colourlefs, as did alib a Candle, Nnnn x both ( 6i o ) both appearing fringed with Colours when feet* through the Prifm. Then holding two Prifms to- gether, as in Fig. io, if the Hole of the dark Cham- ber be at k, it appears white to the Eye at E ; bat if the Angles of the Prifms at B F be a little fepa- rated, whiift the Points A D touch, the Hole will appear coloured : When the Surfaces are feparated at A D5 and touch at B F, the Colours appear in an inverted Order ; but if the Surfaces A D and B F are parallel, whether they touch or not, the Hole will appear white. N. B. In this Cafe the 'Prifms muft be fimilar^ that the Surface F G may be parallel to AC ; other - wife A B and D F muft be fo inclined to one another as to render A C and F G parallel. Indeed if one of the Priftns be very far removed from the other , the heterogeneous Light which entered in at F G, may be fo far fpread by the Separation of the dif- ferently refrangible Rays , that the Prifm ABC will not take it all in , then the Eye behind the fe - cond Prifm may fee Colours , as I fuppofe Riz- zeti did. See Page 79 of his Book. If the Ray of Light R a b c d d ( Fig. 15. ) changing its Diredion in the Manner above-men- tioned, makes an Angle of about 45 Degres with the Perpendicular P a , upon the removal of the lower Prifm, the Ray will be turned up again, as in Fig. 14. But if the Angle P^R be greater, the Ray will Bill be turned up again in a Curve, as a b c d e ft ( Fig. 16 ) notwithftanding the lower Prifm is at D F G ; but if that Prifm be brought up clofer to the Surface A B, the Curves will be destroyed where the Prifms touch, and all the Rays in the Place of Contad brought down through the lower Prifm. THE ( 6n ) THE ffloft refrangible Rays confift of fmaller Par- ticles than the leaft refrangible Rays, and therefore muft have leaft Momentum , the Velocity of all th^ Rays being the fame ; and confequently are more eafilyturned out of the Way by Attraction or Re- pulfion, which makes the Curves made by the pur- ple and violet Rays under the Surface A B, to be lefs and nearer the faid Surface than the Curves made by red and orange Rays. Suppole a Violet R a moving in the Direction R r { Fig. 1 6.) to be fo bent under the Surface A B, that at the Vertex of the Curve, or where its Tangent cc is parallel to A B, there (till remains a fmall Space be- tween the Curve and the Line n n , where the Limits of Attraction ( contracted by the Proximity of the undermoft Prifm D F G end) that Ray will be turn- ed up again in the Curve d e fi and fo reflected in the Line /f, the Directions having been fucceftively changed, as in Fig. 14. But a red Ray with the fame Inclination, would pafs on into the lower Prifm, as was explained in Fig. 15*. Becaufc the Momentum of the red Ray being greater than that of the Violet, the fame Degree of Attraction could not give it the fame Flexure. This is confirmed by Experiment, for when the lower Prifm is not preffed hard againft the upper (as in Fig. 11.) the Rays brought down to R make a Spot of a Colour made up chiefly of red and orange Rays ; but when the Prifms are preffed clofer, the Spot grows bigger and perfectly white in its Middle, becaufe all Sorts of Rays are brought down to the Spot ; but it is inclofed round with a reddiih Border, occafioned by the. Parts of the Prifm which are very near. i ( 6iz ) •near, but not in ContaCt, or at lead not near enough to bring down the green, blue, purple and violet Rays. This ihews that the Reflection is not made from the interior folid Parts of the Glafs, nor from the Parts in the Surface, as Rizzetti affirms. But this is made more evident by Experiment VIII. Fig. 17. A Candle being in the Pofition K, the Eye at E, and the Prifm at ABC; a ftrong Image of the Can- dle was feen at k as in Fig. 7. But lifting up a Veflei of Water VSS V till the Surface of the Water V V touched A B the lower Surface of the Prifm, the I- mage of the Candle became almoft infenflble, as the Eye loll all thofe Rays which now were attracted in- to the Water. And for a farther Proof, that the Re- flection is made under the Surface and not in it, when the Prifm was taken out of the Water, being wet at its lower Surface, or having a Stratum of Water ( whofe Surface was VV Fig. 18) under A B, the Image of the Candle did again become vivid, the Rays being turned up again under V V. Indeed the Image, in this Cafe, though ftrong, did not ap- pear well defined, by Reafon of the Unevennefs of the watry Surface VV Fig. 18. I am very well aware that Rizzetti may anfwer here, that what I have faid above, does in fome Mea- fure favour his Notions; and that the Rays which (in Fig. 7, having pafled through AB, the lower Surface of the Priim) are turned up again to the Eye at E, do not luffcr a Reflection but a new Immerflon ; for .he .fays, in Tage 115. ‘e Anglus (meaning Sir “ Ifaac ( 6i] ) K Ifaac Newton ) fecundo fubjangit, quod ft lumen “ in tranfitu e vitro in aerem obliquius incidat , If at be anfwered, that fome Part E I of the Line EF { Fig. 19 ) is turned up to the Eye at E f Fit. 17 ) what becomes of the lateral Cohefion of Light on which Rtzzetti founds his chief Propofition, and iroin which he draws his Confequences ? It would be tedious as well as ufelefs to be particu- lar in mewing all Rizzettis Miftakes- therefore I ihall only mention one more Experiment from Sir Ifaae * Newton 9 which I repeated on Account of what is laid in Rizzett? s Preface, Rage 1 <5, viz. that if {according to Sir Ifaae) Rays were differently reflex - Me, Colours muft be produced by Reflexion from a plane Surface ; but this , fays our Author, is contrary to Experience . Now this his Aflertion is difproved by . Experiment IX. As this Experiment was made exadly in Sir Ifaae Newton's Manner, and with the fame Succefs, I re- peat the Account of it in his own Words. “ Let H F G [ in Figure 20] reprefent a Prifm in the open Air, and S the Eye of the Spectator, view- “ lfig the Clouds by their Light coming into the Prifm c at the plane Side F1GK, and receded in it by its “ Bafe H El G, and thence going out through its plane - Side HEFK to the Eye : And when the Prifm and « Eye are convenient ly placed, fo that the Angles of « Incidence and Refledion at the Bafe may be of about * 40 Degrees, the Spedator will fee a Bow M N, of a that is, between t and C, many tc of thefe Rays will be tranfmitted through the Bafe: * And all the mod refrangible Rays which fall upon tc the Bafe beyond /, that is, between p and B and can w by Reflection come from thence to the Eye, will be “ reflected thither, but every where between p and r, u many of thefe Rays will get thro9 the Bale and be u refraCted ^ and the fame is to be underflood of the *■ meanly refrangible Rays on either Side of the Point u r. Whence it follows, that the Bafe of the Prifm mud every where between t and B by a total Re* £ fleCtion ( 6*7 ) fiC fle&ion of all Sort9 of Rays ro the Eye, look “ white and bright. And every where between p c< and C, by reafon of the Tranlmiflion of many Ra^s of either Sort, look more pale, oblcure and “ dark. But at r, and in other Places between p “ and t, where all the more refrangible Rays are re- “ fl^ed to the Eye, and many of the lefs refrangi- “ gible are tranfmitted, the Excefs of the molt re- “ frangible in the reflected Light will tinge that Light “ with their Colour, which is violet and blue, this “ happens by taking the Line CprtB any where « between the Ends of the Priftn H G and E I. If this needs any farther Explanation, let us fup- pofe CAB the Se&ion of the Prifm in Fig. zo transferred to Fig. 21. at AC B. If R 0 be a red Ray inclined to a Perpendicular to A B in an Angle of more than 41 or 42 Degrees, it will at its Emer- son under the Surface ABbe turned into the Curve onmi , and fo go up again to the Eye at E ; but a- nothcr red Ray coming in the Diredion r^makino- an Angle with the Perpendicular fufficiently lefs, vviU after its Emerfion at be only bent fo much as to be turned out of the Way, and refra&ed to y, in an Angle of Rcfra&ion agreeable to the Refrangibi- lity of red Light. But V m a violet Ray with the fame Inclination as the lad red one r n fhall not be refraded, but turned up in the Curve m i P, and fo go to the Eye at E. Another violet Ray \m making an Angle fomething lefs with the Perpendicular, will pals through the Glafs, and be refra&ed in the Line m S. Upon this Account all that Part of the Bafe of the Prifm ( of which A B is the Se&ion ) between A and p will be dark or faint, all that Part between P rs ^ ^ t ( 6i 8 ) and n be tinged with a bluilh Colour, and all be- tween o and B of a bright White. TOSTSCRITT. THE Bending of Rays of Light juft as they come to be reflected or refra&ed, may be eafily underftood by fuch as are well acquainted with thole Properties of Light, which Sir Ifaac Newton calls their Fits of eafy Reflection , and Fits of eajy Tranfmijflon ; without any Hypothefis, but by Con- sequences fairly drawn from Experiments and Ob- fervations. But as Signior Rizzetti does not feem C in his Book ) to have the leaft Notion of thofe Properties of Light, and the nice Obfervations on which they are founded ; and feveral other Perfons have not Time to read thofe Parts of the Opticks with fufficient Application ; to Ihew how the fame Power of the Surface of a denfe Medium may both attra Cou- fin to Cardinal Lercari. The Abbot Cuzzoni. The Abbot Roll's^ and his Brother. Ilf. The ( 6$ o ) Ilf. Tlx Method of making Tin-Plates, extratted from the Memoirs of the Academy of Sciences , for the Tear \ 725, by William Rutty, M. D. (2^. 5. Seer. TH E making of Tin-plates, or Lattin, as it is called, being not commonly praCtifed in Eng- land, though there is fo great a Confumption of it, either becaufe the Method is not fufficiently- known, or becaufe that in Ufe to make fmall Quantities for particular Purpofes is much too dear to anfvver the Artificer's Expectation in making larger, whereby we are obliged to export our own Tin to Germany , to receive it back again manufacture A 1 thought it not improper to lay before the Society the Method the Germans themlelves make ufe of, as I have ex- tracted it from a Differtation of Mr. T>e Reaumur prin- ted in the laft Volume of the Memoirs of the Aca- demy of Sciences of Taris, in which alfo he lays down fome Improvements, as he thinks, of his own. He takes notice then that the making of Tin-plates, (which is called in France , white Iron) does not pro- perly begin, till they go about to prepare the Leaves or Plates of Iron that are to be tinned, which are fup- pofed to be fufficiently thin and flat, and cut into Squares : But there are only certain Sorts of Iron which can be reduced into thefe Leaves, of which thofe are the moft proper, that when heated are eafi- eft extendible, and yet can be forged with a Hammer when cold ; the more fofc and extremely flexible, as wrell ( ) well as the more brittle being to be rejected. Thefe Leaves are drawn from Bars of Iron, about an Inch fquare; which being made a little flat, they cut into thin Pieces or Soles ( femelles ) which they fold toge- ther, and having made them into Parcels containing forty Leaves each, beat them all at once with a Ham- mer that weighs from 600 to 700 it> Weight. After this, the principal Part of the whole Art is to prepare thefe Leaves \ for the lighted: Duff, or the leafl Ruff upon their Surface will prevent the Tin from uniting with them. This may indeed be taken off by filing, but that being much too expend ve, the fame may be brought about by deeping the Plates in acid Waters, for a certain Time, to what Number they pleafe, and when they are taken out, fcouring them with Sand, in order to fetch off any Thing that may remain upon the Surface : And by this Method a Woman may clean more Plates in an Hour, than the mofl expeditious Workman can file in many Days. Of thefe Waters the Author mentions feveral ; but what the Germans themfelves ufed, and which they make a mighty Se- cret of, he found to be only common Water made ea- ger with Rye, which requires very little Pains. For after they have ground the Grain groOy, and pounded 1 it, they leave it to ferment in common Water for a certain Time, and with a little Patience they are fure to have an eager Menftruum. With this Menftruum they fill Troughs or Tuns, into which they put Piles of Iron - Plates ; and to make it grow eager the better, and to > have more A&ivity, they keep thefe VefTels in Vaults or Stoves which have little Air, and in which they keep lighted Charcoal. The Workmen go into thefe Vaults once or twice in a Day, either to turn the Plates* ( 6 3* ) Plates that they may be equally expofed to the A&ion of the acid Liquor, or to take out thofe that are fuffi- ciently cleanfed, or to put others in their room : And as the Liquor is more acid, or the Heat of the Vault or Stove is more intenfe, the Plates are fooner cleanfed * but it requires at lead: two Days, and fometimes a great deal more. This is the Method which the Germans employed in the Tin-works in France, conftantly made ufe of to prepare the Iron-plates to receive the Coat of Tin : But as the Author obferved, that the conftant Attendance upon them in the Stoves was very labori- ous, the Heat therein being almoft infupportable to thofe who are not ufed to it, he propofes fome other Methods which are attended with very little Trouble, and as fmall, if not a lefs Expence } and which upon Trial fucceeded full as well. Having therefore ob- ferved that the Iron-leaves or Plates are covered with a Scale or Layer, half vitrified by the Fire, on which Acids have none or very little Effed, he imagined that mftead of dijfolving the Iron in thefe acid Waters, it would be better to make it ruji , and thereby put it in a Condition to be eafier cleanfed from thefe Scales j as Ruft is accompanied with a fort of Fermentation and Rarefaction, and the Matter which rufts takes up a great- er Space, and raifes up whatever oppofes it. To this Purpofe he fteeped Iron Plates in different eager Men- ftruums, as in Water in which Alum, common Salt and Sal-armoniack were feparately diffolved $ and others of the fame Iron he only dipped into the fame Waters, and inftantly taking them out expofed theuT to the Air. Thefe latter were rufted by all of them, but fooner by that in which the Sal-armoniack was diffolved. Af- ter two Days, during which every Plate had been dip- ped ( <*3? ) ped into the Menftruum but twice or thrice, he fcour- ed them, and likewife thofe he had left to fteep for that 1 ime ; and comparing them together, found that thofe which had been only wetted at different Times, cleanfed better than thofe which were fteeped i the • 3 tlC Surface of the latter without raif- mg the Scale ; whereas in the former, as foon as one Part of the Metal is detached, it is attracted by the I^nftruum, and the Surface is raifed into Blifters of Buff. Thefe Diilblvents.the Author takes notice, tho* weak in themfelves, yet produce the Effed as well as the ftronger, which are much dearer : But amount the latter he prefers Vinegar, which being very plen- tiful in France, may be ufed with little Colt For you need only dip each Leaf into it, and take it out again immediately leaving it afterwards in fome moift Place, and it will be fcaled in eight and forty Hours if you take care to repeat this 3 or 4 Times in a Day.’ Th„ fcaling will ftill be more expeditious, if you diT- folve a little Sal-armoniack in the Vinegar, a Pound ™Cl,t0fa eTche0n ’• ff asthe Vinegar dilfolves I- ron well, fo Sal-armoniack, as juft obferved, rufts it fooner than any other Salt : But this muft be ufed verv moderately, and the Leaf muft be left to fteen in clean Water to diffolve any Particles of it that may ftick to its Surface, which may otherwife make itruftafterit is tinned. If you fcale with Vinegar, and want to do it at a lefs Expence, you need only plunge the Leaves once or twice at fartheft, and when the Vinegar is dr ! ed upon the Surface, fprinkle it with Water": or din them into it, and take them out immediately. There are feveral other Ways of making Iron ruft, as keeping « in a moift Cellar, expofing it to the Dew, fprinklinf p P P P it ( ^34 > it with (Tmple Water, feveral Times in a Day, which will dill aft quicker by diffolving Sal-armoniack in it. In thofe Countries where the Pyrites is common, the Vitriol ick Waters will fcale them foon enough, which are almod as cheap as common Water : You need only heap the Pyrites together, and leaving them to moulder in the Air, make afterwards a Lixivium with them and common Water, which Lie will have the defired Effect : But as the Leaves of Iron are fendbly much ealier cleanf- ed on one Side than the other, the bad Side rarely taking the brilliant Polifh in the tinning, but having always fome Spots, which proceeds in that in the beat- ing one Side is more expofed to the Adion of the Ham- mer, and is therefore better plained, the Author again advifes not to deep them, but only to moiden them, in order to make them rud, whereby you need moi- den that Side only that wants it mod: Whereas if you deep them, as the bad Side will take double or triple the Time of the other, the acid Mendruum will diffolve the Surface, and occalion a Lofs of Iron. He next gives two Cautions neceffary to be followed : the fird is in the Management of the Plates before they come to be prepared ; which is in the beating of them, to change the Place of each in its Turn, that every one may receive the immediate Adion of the Hammer, otherwife they will not extend equally : the fecond is to deep them in Clay or Fuller’s earth tempered with Water before you heat them, to prevent their foldering with one another. He then clofes this Part of the Ope- ration with remarking that whatfoever of thefe Me- thods are pitched upon, whether the old one, of which he has learnt the Secret, op any of the new,, which he has here (hewn, it i9 abfolutely neceffary after the Plates - rV ‘ are' { 6] 5 ) are fufficiently fcaled, to fcour them with Sand, and when there remains no more black Spots upon their Surface, to throw them into Water to prevent their rufting again, and leave them in it till the Inflant you would tin them, or in the Term of Art, blanch them. This he obferves is the very Objed of the whole Art, and is kept as much a Secret by the j Blancher^ as the a- cid eroding Menftruum is by the Scaler : But the Man- ner of doing it is thus. They flux the Tin in a large iron Crucible, which has the Figure of a broken Pyra- mid with four Faces, of which the two oppofite ones arelefs than the two others. This Crucible they heat only from below, its upper Border being luted in the Furnace quite round. The Crucible is always deeper than the Plates which are to be tinned are long, which they always put in downright, and the Tin ought to Iwim over them. For this Purpofe Artificers of differ- ent. Trades prepare the Plates in different Manners, which are all exceptionable : But the Germans he per- ceived made ufe of no Preparation whatfoever, exceot putting the fcoured Plates into clean Water, as juft remarked j but when the Tin is melted in the Crucible, they cover it with a Layer of a Sort of Suet, an Inch or two thick, through which the Plate mult pafs before it comes to the Tin : The fir ft Ufe of which is to keep the Tin from burning, and if any Part fhould take r ire, as the Suet will foon moifteoit, to reduce it to its natural State again, d his Suet is compounded, as the Blanchers fay, and is of a black Colour, which the Au- thor thought might be given it with Soot or the Smoak of a Chimney, only to fpread a Myftery over their Work ; but he found it true fo far, that common unprepared Suer was not fufficient : For after feveral Attempts" there ^ ^ P P P 2. -was ( 6y6 ) was always fomething wanting to render the Succefs of the Operation certain. The whole Secret then of Blanching lies entirely in the Preparation of this Suet : And this he at laft difcovered to confift only in firft frying and burning it- which not only gives it the Co- lour, but puts it into a Condition to give the Iron a Difpofition to be tinned, which it does furprifingly* TheTin itfelf ought to have a certain Degree of Heat- for if it is not hot enough it will not ftick to the Iron- if it is too hot, it will cover it with too thin a Coat, and the Plates will have feveral Colours, as a Mixture of red, blue, and yellow, and the whole appear of a villain- ous yellow Caft. To prevent this, by knowing when the Tin has a proper Degree of Heat, they might firft make an Effay with fmall Pieces of the fcaled Plates, and they would learn from them when the Tin is in proper Order: But generally fpeaking, thev dip the Plates in- to Tin that is more or lefs hot, according to the Thick- nefs they would have the Coat to be of. Some Plates they only give one Layer to, and thefe they plunge in. to Tin, that has a lelfer Degree of Heat than that in- to which they plunge thofe Plates which they would have take two Layers ; as alfo when they give thefe the fecond Layer, they put them into Tin that has not fo great a Degree of Hear, as that into which they were put the firft Time : Befides which, it is to be obferved that the Tin, which is to give the fecond Coat, ought ro be frefh covered with Suet, but only with the common Sort without Preparation ^ for melted Tin is fufftci- ently difpofed to attach it felf to folid Tin ; and in this Cafe it is to tin itfelf, to which the new Tin is to be joined. As to the Choice of the Tin, the Man- ner of making it is as bright as poflible, with a Num- ber ( <*3 7 ) ber of little Articles neceflary to thePratfice,the Author refers them to another Time, as more properly belong- ing to the Defcription of the whole Art, than to a Memoir in which he only gives the Principles of it. IV. A Letter from the <%eVere?id Mr. James Brad- ley S civilian (profeffor of Aftronomy at Oxford, and F to ZV.Edmond Halley Aftronom. Reg. See, giving an Account of a new dif- fered Motion of the Fix'd Stars, SIR, YOU .having been pleafed to exprefs your Satis- faction with what I had an Opportunity fome- time ago, of telling you in Converfation, concerning fome Obfervations, that were making by our late wor- thy and ingenious Friend, the honourable Samuel Molyneux Efquire, and which have fince been conti- nued and repeated by my felf, in order to determine the ‘Parallax of the fixt Stars ; I fhall now beg leave to lay before you a more particular x\ccount of them. Before I proceed to give you the Hiflory of the Ob- fervations themfelves, it may be proper to let you know, that they were at firft begun in hopes of verifying and confirming thofe, that Dr. Hook formerly communicat- ed to the publick, which feemed to be attended with Circumftances that promifed greater Exa&nefs in them, than could be expected in any other, that had been made andpublifhed on the fame Account. And as his Attempt was what principally gave Rife to this, fo his Method in making the Obfervations was in fome Mea- ( ) Meafure that which Mr. Molyneux followed : For he made Choice of the fame Star, and his Inftrument was conftruded upon almoft the fame Principles. But if it had not greatly exceeded the Doctor’s in Ex- a&nefs, we might yet have remained in great Uncer- tainty as to the Tarallaxot the fixt Stars-, as you will perceive upon the Comparifon of the two Experiments. This indeed was chiefly owing to our curious Mem- ber, Mr. George Graham , to whom the Lovers of Aftronomy are alfo not a little indebted for feveral o- ther exad and well-contrived Inftruments. The Ne- ceflity of fuch will fcarce be difputed by thofe that have had any Experience in making Aftronomical Ob- fervations:, and the Inconfiftency, which is to be met with among different Authors in their Attempts to de- termine finall Angles, particularly the annual Paral- lax of the fixt Stars , may be a fufficient Proof of it to others. Their Difagreement indeed in this Article is not now fo much to be wondered at, fince I doubt not, but it will appear very probable, that the In- ftruments commonly made ufe of by them, were liable to greater Errors than many times that Pa- rallax will amount to. • The Succefs then of this Experiment evidently depending very much on the Accuratenefs of the In- ftrument that was principally to be taken Care of: In what Manner this was done, is not my prefent Purpofe to tell you ; but if from the Refult of the Obiervations which I now fend you, it hiall be judged neceftary to communicate to the Curious the Manner of making them, I may hereafter perhaps give them a particular Defcription, not only of Mr. Molyneux' $ Inftrument, but alfo of my own, which ( 619 > which hath face been crc&ed for the fame Purpofe and upon the like Principles, though it is fomewhat different im its Conftru£Hon, for a Reafon you will meet with prefently. Mr. Molyneitx's Apparatus was compleated and htted for obferving about the End of November 1725, and on the third Day of “December following, the bright Star in the Head of Draco ( marked y by Aayer) was for the firft Time obferved, as it parted near the Zenith, and its Situation carefully taken With the Inftrument. The like Obfervations were made on the fth, nth, and nth Days of the fame Month, and there appearing no material Difference in the Place of the Star, a farther Repetition of them at this Seafon feemed needlefs, it being a Part of the Year, wherein no fenfible Alteration of Parallax in this Star could foon be expected. It was chiefly therefore Curiofity that • tempted me (being then at Kew, where the Inftrument was fixed) to prepare for obferving the Star on December 17th, when having adjufted the Inftrument as ufual, I perceived that it parted a little more Southerly this Day than when it was oblerved before. Not fulpetfting any other Caufe of this Appearance, we Jfirft concluded that it was owing to the Uncertainty of the Obfer- vations, and that either this or the foregoing were not fo exacft: as we had before fuppofed ; for which Reafon we purpofed to repeat the Obfervation again3. in order to determine from whence this Difference proceeded ; and upon doing it on December 20th I found that the Star parted ftill more Southerly than in the former Obfervations. This fenfible Alteration the more furprized us, in that it was the contrary waJ ( <4o ) way from what it would have been, had it pro- ceeded from an annual Parallax of the Star : But being now pretty well fatisfied, that it could not be entirely owing to the want of Exa&nefs in the Ob- fervations ; and having no Notion of any thing elfe, JutL could caufe fuch an apparent Motion as this in the Star j we began to think that fome Change in the Materials, &c. of the Inftrument itfelf, might have occafioned it. Under thefe Apprehenfions we remained fome time, but being at length fully con- vinced, by feveral Trials, of the great ExaCtnefs of the Inftrument, and finding by the gradual Increafe of the Stars Diftance from the Pole, that there muft be fome regular Caufe that produced it ; we took care to examine nicely, at the Time cf each Obfer- vation, how much it was : and about the Beginning cf 2^1 arch 1726, the Star was found to be 20^ more Southerly than at the Time of the firft Obfervation. It now indeed feemed to have arrived at its utmoft Limit Southward, becaufe in feveral Trials made a- bout this Time, no fenfible Difference was obferved in its Situation. By the Middle of April it appear- ed to be returning back again towards the North ; and about the Beginning of June , it pafted at the fame Diftance from the Zenith as it had done in ‘Decem- ber, when it was firft obferved. From the quick Alteration of this Star’s Declina- nation about this Time ( it increafing a Second in three Days ) it was concluded, that it would now proceed Northward, as it before had gone Southward or its prelent Situation , and it happened as was con- jectured : for the Star continued to move Northward Uil September following, when it again became fta- tionary, ( <4i ) tionary, being then near 20" more Northerly than in June, and no lefs than 39" more Northerly than it was in March. From September the Star returned towards the South, till it arrived in 'December to the lame Situation it was in at that time twelve Months, allowing for the Difference of Declination on account of the Preceffion of the Equinox. This was a fufficient Proof, that the Inftrument had not been the Caufe of this apparent Motion of the Star, and to find one adequate to fuch an Effect ieemed a Difficulty. A Nutation of the Earth’s Axis was one of the firff things that offered itfeif upon this Occafion, but it was loon found to be inlufficient ; for though it might have accounted for the change of Declination in y Draconis yet it would not at the lame time agree with the Phenomena in other Stars ; particularly in a finall onealmoff oppofite in right Afcenfion to y Draconis , at about the fame Diffance from the North Pole of the Equator : For, though this Star feemed to move the fame way, as a Nutation of the Earth’s Axis would have made it • yet it changing its Declination but about half as much as y Draconis in the lame time (as appeared upon comparing the Obfervations of both made upon the lame Days, at different Seafons of the Year) this plainly proved, that the apparent Motion of the Stars was not occafioned by a real Nutation, fince if that had been the Caufe, the Alteration in both Stars would have been near equal. The great Regularity of the Obfervations left no room to doubt, but that there was fomc regular Caufe that produced this unexpected Motion, which did not depend on the Uncertainty or Variety of the Seafons ( ^ ) Seafons of the Year. Upon comparing the Obfer- vations with each other, it was difeovered, that in both the fore-mentioned Stars, the apparent Dif- ference of Declination from the Maxima , was al- ways nearly proportional to the verfed Sine of the Sun’s Diftance from the Equino&ial Points. This was an Inducement to think, that the Caufe, what- ever it was, had fome Relation to the Sun’s Situa- tion with refpeCt to thofe Points. But not being able to frame any Hypothecs at that Time, fuffi- cient to folve all the Phenomena, and being very defirous to fearch a little farther into this Matter ; I began to think of ereCting an Inftrument for my Self at JV an fled , that having it always at Hand, I might with the more Eafe and Certainty, enquire into the Laws of this new Motion. The Conside- ration likewife of being able by another Inftrument, to confirm the Truth of the Obfervations hitherto made with Mr. Molyneux9 s, was no fmall Induce- ment to me; but the Chief of all was, the Oppor- tunity I Should thereby have of trying, in what Manner other Stars were affeCted by the fame Cauie, whatever it was. For Mr. Molyneux's Inftrument being originally defigned for obfervingy cDraconis fin order, as I faid before, to try whether it had any fenfible Parallax ) was lo contrived, as to be capable of but little Alteration in its Direction, not above feven or eight Minutes of a Degree : and there being few Stars within half that Diftance from the Zenith of Kew , bright enough to be well observed, he could not, with his Inftrument, throughly examine how this Caufe affeCted Stars differently fituated with refpeCt ( $43 ) refpecF to the equinoctial and folflitial Points of die Ecliptick. Thele Confiderations determined me ; and by the Contrivance and Direction of the fame ingenious Perlon, Mr. Graham , my Inflrument was fixed up- Augufl 19, 1717. As I had no convenient Place where I could make ufe of fo long a Telelcope as Mr. Molyneux’s, I contented my felf with one of but little more than half the Length of his {viz. of about 12- Feet, his being 241.) judging from the Experience which I had already had, that this Ra- dius would be long enough to adjufl the Inflrument to a fufficient Degree of Exa&nefs, and I have had no Reafon fince to change my Opinion : for from all the Trials I have yet made, I am very well fatisfied,. that when it is carefully re&ified, its Situation may be fecurely depended upon to half a Second. As the Place where my Inflrument was to be hung, in fome. Meafure determined its Radius, fo did it alfo the Length of the Arch, or Limb, on which, the Divifions were made to adjufl it : For the Arch could not con- veniently be extended farther, than to reach to about, 61° on each Side my Zenith. This indeed was fuffi- cient, fince it gave me an Opportunity of making. Choice of feveral Stars, very different both in Mag- nitude and Situation; there being more than two. hundred inferred in the Britijh Catalogue, that may be obferved with it. I needed not to have extended the: Limb fo far, but that I was willing to take in Gapella ,. the only Star of the firfl Magnitude, that comes fa near my Zenith* My Inflrument being fixed, I immediately began, to obferve fuch Stars as I judged mofl proper to Q, q q q 2 give ( *44 ) give me light into the Caufe of the Motion already mentioned. There was Variety enough of fmall ones ; and not lels than twelve, that I could oblerve through all the Seafons of the Year } they being bright enough to be feen in the Day-time, when neareft the Sun. I had not been long observing, be- fore I perceived, that the Notion we had before en- tertained of the Stars being farthefl; North and South, when the Sun was about the Equinoxes, was only true of thole that were near the folftitiai Colure : And alter I had continued my Oblervations a few Months, I difeovered, what I then apprehended to be a gene- ral Law, obferved by all the Stars, viz. That each of them became ftationary, or was farthefl; North or South, when they palled over my Zenith at fix of the Clock, either in the Morning or Evening. I per- ceived likewife, that whatever Situation the Stars were in with relpedi to the cardinal Points of the Ecliptick, the apparent Motion of every one tend- ed the fame Way, when they palled my Inftrument about the lame Hour of the Day or Night ; for they all moved Southward, while they palled in the Day, and Northward in the Night ; fo that each was far- theft North, when it came about Six of the Clock in the Evening, and farthefl; South, when it came a- bout Six in the Morning. Though I have fince difeovered, that the Maxima in moll: of thefe Stars do not happen exactly when they come to my Inftrument at thefe Hours, yet not being able at that time to prove the contrary, and iuppofing that they did, I endeavoured to find out what Proportion the greateft Alterations of Decli- nation in different Stars bore to each other ; it being very ( <45 ) very evident, that they did not all change their De- cimation equally. I have before taken notice, that it appeared from Mr. Molyneaux's Obiervations, that y ‘Draconis altered its Declination about twice as much as the fore-mentioned fmall Star almoft op- pontc to it 5 but examining the matter more particu- larly, I found that the greateft Alteration of Declina- tion in thefe Stars, was as the Sine of the Latitude o each relpediivcly . This made me lufpedt that there might be the like Proportion between the Maxima of other Stars ; but finding, that the Ob- iervations of fome of them would not perfectly cor- refpond with fuch an Hypothefis, and not knowing whether the fmall Difference I met with, might not be owing to the Uncertainty and Error of the Ob- iervations, I deferred the farther Examination into the Truth of this Hypothefis, till I fhould be fur- ' nifhed with a Series of Obfervations made in all Parts of the Year ; which might enable me not only to determine what Errors the Obferva- tions are liable to, or how far they may fafely be depended upon; but alfo to judge, whether there had been any fenfible Change in the Parts of the Jnftru- ment irielf. Upon thefe Confiderations, I laid afide all Thoughts at that Time about the Caufe of the fore-mentioned Phenomena, hoping that I Ihould the eafier difeover it, when I was better provided with proper Means to determine more precifely what they were. When the Year was compleated, I began to exa- mine and compare my Obfervations, and having pret- ty well fatisfied my felf as to the general Laws of the 'Phenomena, I then endeavoured to find out the Caufe I ( 6^6 ) Caufe of them. I was already convinced, that the apparent Motion of the Stars was not owing to a Nutation of the Earth’s Axis. The next Thing that offered itfelf, was an Alteration in the Direction of the Plumb-line, with which the Inftrument was con- stantly rectified ; but this upon Trial proved infuffi- cient. Then I confidered what Refraction might do, but here alfo nothing latisfaCtory occurred. At laft I conjectured, that all the Thanomena hitherto men- tioned, proceeded from the progreflive Motion of Light and the Earth’s annual Motion in its Orbit. For I perceived, that, if Light was propagated in Time, the apparent Place of afixt ObjeCt would not be the lame when the Eye is at Reft, as when it is moving in any other Direction, than that of the Line paffing through the Eye and ObjeCt; and that, when the Eye is moving in different Directions, the appa- rent Place of the ObjeCt would be different. I confidered this Matter in the fol- lowing Manner. I imagined C A to be a Ray of Light, falling perpendi- cularly upon the Line B D ; then if the Eye is at reft at A, the ObjeCt muft appear in the Direction A C, whether Light be propagated in Time or in an Inftant. But if the Eye is moving from B towards A, and Light is propagated in Time, with a Velo-* city that is to the Velocity of the Eye, as C A to B A ; then Light mov- n ing from C ro A, whilft the Eye moves from B to A, that Particle of C ( 647 ) itj by which the Obje& will be dilcerned, when the Eye in its Motion comes to A, is at C when the Eye is at B. Joining the Points B,C, I fuppofed the Line CB, to be a Tube (inclined to the Line BD in the Angle D B C ) of fuch a Diameter, as to admit of but one Particle of Light ; then it was cafy to conceive, that the Particle of Light at C (by which the Objed muft be feen when the Eye, as it moves along, arrives at A) would pafs through the Tube B C, if it is inclined to B D in the Angle D B C, and accompanies the Eye in its Motion from B to A 3 and that it could not come to the Eye, placed behind fuch a Tube, if it had any other Inclination to the Line BD. If inftead of fuppofing CB fo Email a - Tube> vve imagine it to be the Axis of a larger ; then for the fame Reafon, the Particle of Light at C, could not pafs through that Axis, unlels it is inclined toBD, in the Angle CBD. In like manner, if the Eye moved the contrary way, from D towards A, with the fame Velocity ; then the Tube muft be inclined in the Angle BDC. Although therefore the true or real Place of an Objed is perpendicular to the Line in which the Eye is moving, yet the vifible Place will not be fo, fince that, no doubt, muft be in the Diredion of the Tube ; but the Difference between the true and apparent Place will be (ceteris paribus) greater or lefs, according to the different Proportion between the Velocity of Light and that of the Eye. So that if we could fuppofe that Light was propagat- ed in an Inftant, then there would be no Difference be- tween the real and vifible Place of an Objed, altho* the Eye were in Motion, for in that cafe, AC be- ing infinite with Refped to AB, the Angle A C B (the 2 Dif- ( <48 ) fcrence between the true and vifible Place) vanifhes. But if Light be propagated in Time (which I prefume will readily be allowed by mod of the Philofophers of this Age) then itr is evident from the foregoing Confiderations, that there will be always a Difference between the real and vifible Place of an Object, un- lefs the Eye is moving either direddy towards or from • the Objed:. And in all Cafes, the Sine of the Dif- ference between the real and vifible Place of the Ob- jed:, will be to the Sine of the vifible Inclination of the Objed: to the Line in which the Eye is moving, as the Velocity of the Eye to the Velocity of Light. If Light moved but 1000 times fader than the Eye, and an Objed (fuppofed to be at an infinite Didance) was really placed perpendicularly over the Plain in which the Eye is moving, it follows from what hath been already laid, that the apparent Place of fuch an Objed will be always inclined to that Plain, in an Angle of 89° 56^; fo that it will condantly appear 3; f from its true Place, and leem fo much lefs inclin- ed ro the Plain, that way towards which the Eye tends. That is, if AC is to A B (or AD) as 1000 to one, the Angle AB C will be 89° 5 ;6' »,and ACB = 3' 4, and BCD = i ACB=7'. So that according to this Sup- pofition, the vifible or apparent Place of the Objed will be altered 7', if the Diredion of the Eye’s Mo- tion is at one time contrary to what it is at ano- ther. If the Earth revolve round the Sun annually, and the Velocity of Light were to the Velocity of the Earth’s Motion in its Orbit (which I will at prefent fuppofe to be a Circle) as 1000 to one ; then tis eafy to ( <4$> ) ^?nCp'Ye’ thfc a St« really placed in the very Pole . rhe Eel'Pticfe, would, to an Eye carried along with ftt mr° ^nge its P,ace continually, and the^Earrh’s f 11 Difference on the Accost of ftem rn if d,To R,evolution “s Axis) would ieem to defcribe a Circle round that Pole, every Wav diftant therefrom 3>(. So that its LongitudeCuld be varied through all the Points of the Ecliptick Iver v S risht A f S Lrat'tUde w;°l,l^a,ways remain the fam£ «s right Afceniion would alfo change, and its Decli nation, according to the different Situation of tie Sun in refpea to the equinoctial Points ; and its an parent Diftance from the North Pole of the Equator Wdbe / Ms „ ,he thm „'5/£S rhJp e, gTf uA',Ceration of the Place of a Star m Po c of th.c bidiptick (or which in EffeCt amounts to the fame, the Proportion between the Velocity of Light and the Earth’s Motion in itsOrbit) being known - it will not be difficult to find what would be the Dif’ ference upon this Account, between the true and ap- parent Place of any other Star at any time ; and on the contrary, the Difference between the true and appa- rent Place being given ; the Proportion betweenthe V elocity of Light and the Earth’s Motion in its Or- bit may be found. As I only obierved the apparent Difference of De- ' cl.nat.on of the Stars, I ihail not now rake any far- ther Notice in what manner ftch a Caufe as I have here fuppofed would occafion an Alteration i„ their apparent Places in other Refpetfs ; but, iuppofing the Earth to move equally in a Circle, it may be Jher- ed from what hath been already faid, that a Star which Rrrr is ( <$jo ) is neither in the Pole nor Plain of the Ecliptick, will feemto deferibe about its true Place a Figure, infenff bly different from an Ellipfe, vvhofe Tranfverfe Axis is at Right-angle to the Circle of Longitude palling through the Stars true Place,, and equal to the Diame- ter of the little Circle deferibed by a Star fas was before fuppofed) in the Pole of the Ecliptick ; and whofe Conjugate Axis is to its Tranfverfe Axis, as the Sine of the Stars Latitude to the Radius. And al- lowing that a Star by its apparent Motion does ex- adrly deferibe fuch an Ellipfe, it will be found, that if A be the Angle of Pofition (or the Angle at the Star made by two great Circles drawn from it, thro* the Poles of the Ecliptick and Equator) and B be another Angle, whofe Tangent is to the Tangent of A as Radius to the Sine of the Latitude of the Star ; then B will be equal to the Difference of Longitude between the Sun and the Star, when the true and ap- parent Declination of the Star are the fame. And if the Sun’s Longitude in the Ecliptick be reckoned from that Point, wherein it is when this happens ; then the Difference between the true and apparent Declination of the Star (on Account of the Caufe I am now confidering) will be always, as the Sine of the Sun’s Longitude from thence. It will likewife be found, that the greatefl Difference of Declination that can be between the true and apparent Place of the Star, will be to the Semi-Tranfverfe Axis of the Ellipfe (or to the Semi-diameter of the little Circle de- fended by a Star in the Pole of the Ecliptick) as the Sine of A to the Sine of Bi If the Star hath North Latitude, the Time, when its true, and apparent Declination are the fame, is be- fore ( <$Ji ) fore the Sun comes in Conjunction with or Oppofition to it, if its Longitude be in the firft or laft Quadrant (viz,, in the afcending Semi-circle) of theEcliptick ; and after them, if in the defcending Semi-circle ; and it will appear neareft to the North Pole of the Equator, at the Time of that Maximum (or when the greateft Differ- ence between the true and apparent Declination happens) which precedes the Sun’s Conjunction with the Star. Thefe Particulars being fufficient for my prefent Purpofe, I (hall not detain you with the Recital of any more,, or with any farther Explication of thefe. It may be time enough to enlarge more upon this Head, when I give a Defcription of the Inftruments &c. if that be judged necelfary to be done; and when I fliall find, what I now advance, to be allowed of (as I flat- ter my felf it will) as fomething more than a bare Hy- pothecs. I have purpofely omitted fome matters of no great Moment, and confidered the Earth as moving in a Circle, and not an Ellipfe, to avoid too perplexed a Calculus , which after all the Trouble of it would not fenfibly differ from that which I make ufe of, efpecial- ly in thofe Confequences which I fhall at prefent draw from the foregoing Hypothefis. This being premifed, I fhall now proceed to deter- mine from the Obfervations,what the real Proportion is between the Velocity of Light and the Velocity of the Earth’s annual Motion in its Orbit ; upon Suppofition that the ‘Phenomena before mentioned do depend upon the Caufes I have here affigned. But I mull firft let you know, that in all the Obfervations hereafter men- tioned, I have made an Allowance for the Change of the Star’s Declination on Account of the Precefiion of R r r r 2 the ( 651 ) the Equinox, upon Suppofition that the Alteration from this Caufe is proportional to the Time, and regu- lar through all the Parts of the Year. I have deduced the real annual Alteration of Declination of each Star from the Obfervations themfelves ; and I the rather choofe to depend upon them in this Article, becaufe all which I have yet made, concur to prove, that the Stars near the Equino&ial Colure, change their Declination at tins time i" ; or 2" in a Year more than they would do “ r f * rece^10n was only 50", as is now generally fup. poled. I have likewife met with fome fmall Varieties m the Declination of other Stars in different Years which do not feem to proceed from the fame Caufe, par- ticularly in thofe that are near the folftitial Colure which on the contrary have altered their Declination ieb than they ought, if the Preceffion was 50". But whether there fmall Alterations proceed from a regular Caufe, or are occafioned by any Change in the Mate- rials fee. of my Inftrument, I am not yet able fullv to determine. However, I thought it might not be a- mifs juft to mention to you how I have endeavoured to allow for them, though the Refult would have been nearly the fame,, if I had not confidered them at all Whatthat is, I will fhew, firft from the Obfervations Of- y ‘Dracoms , which was found to be 39" more South erly in the Beginning of March, than in September From what hath been premifed, it will appear that the greateft Alteration of the apparent Declination of ypr acorns, on Account of the fucceffive Propagation 0 , L[Sht would be to the Diameter of the little Circle which a Star (as was before remarked) would feem to defcnbe about the Pole of the Ecliptick, as 39'' to 40 , 4- The half of this k the Angle A C B_'(as repre- fented ( 6{3 > fented in the Fig,) This therefore being i©", z,AC will be to AB, that is, the Velocity of Light to the Veio- city of the Eye (which in this Cafe may be fuppofed the fame as the Velocity of the Earth’s annual Motion' in its Orbit) as iono to One, from whence it would follow, that Light moves, or is propagated as far as from the Sun to the Earth in 8' ii". It is well known, that Mr. Romer , who firft attempted to account for an apparent Inequality in the Times of the Eclipfes of Jupiter* s Satellites, by the Hypothefis of the progrdliye Motion of Light, fuppofed that it fpent about iT Minutes of Time in its Paffage from the Sun to us : but it hath fince been concluded by others from the like Eclipfes, that it is propagated as far in about 7 Minutes. The Velocity of Light therefore deduced from the foregoing Hypothefis, is as it were a Mean betwixt what had at different times been determined from the Eclipfes of Jupiter's Satellites. . Thefe different Methods of finding the Velocity of Light thus agreeing in the Refulr* we may reafonably conclude, not only that thefe Fhawomena are owing, to the Caufes to which they have been afcribed • but alfo, that Light is propagated (in the fame Medium ) with the fame Velocity after it hath been reflected as before : for this will be the Confequence, if we allow that the Light of the Sun is propagated with the fame Velocity, before it is refle&ed, as the Light of the fixt Stars . And I imagine this will fcarce be. queftioned, if it can be made appear that the Velocity of the Light of all t!i ejfxt Stars is equal, and that their Light moves or is propagated through equal Spaces in equal Times at all Difiances from them: both which points (as I ap- prehend) are fufficiently proved, from the apparent Alte- ration ( ec ember than in June . Hence the Maximum would be 40", 8. $ lDraconis was 39" more Northerly in the beginning of Septem- ber than in March 3 hence the Maximum would be 40", 2. Capella was about 16" more Southerly in Augujl than in February, hence the Maximum would be about 40". But this Star being farther from my Zenith than thofei have before made ufe of, J can- not fo well depend upon my Obfervations of it, as of the others ; becaufe I meet with fome fmall iterations of its Declination that do not feem to proceed from the Caufe lam now confidering. I have compared the Obfervations of feveral other Stars, and they all confpire to prove that the Maximum is about 40" or 41". I ' will therefore fuppofe that it is 40"!' or (which amounts to the fame) that Light moves, oris propagated as far as from the Sun to us in 8' 13 ". The near Agreement which I met with among my Obfervations induces me to think, that the Maxi- mum (as I have here fixed it) cannot differ fo much as a Second from the Truth, and therefore it is probable that the Time which Light fpends in paffing from the Sun to us, may be determined by thefe Obfervations within 5" or io'' 5 which is fuch a degree of exadtnefs as we can never hope to attain from the Eclipfes of Ju~ piter's Satellites, Ravine- ( M ) : Having thus found the Maximum , or what the great- eft Alteration of Declination would be in a Star pla- ced in the Pole of the Ecliptick, I will now deduce from it (according to the foregoing Hypothefis) the Alteration of Declination in one or two Star?, at fuch times as they were actually obferved, in order to fee how the Hypothefis will correfpond with the Pheno- mena through all the Parts of the Year. It would be too tedious to fet down the whole Se- ries of my Obfervations ^ I will therefore make Choice only of fuch as are moft proper for my prefent Pur- pofe, and will begin with thofe of y 'Draconis. This Star appeared fartheft North about September 7th, 1717, as it ought to have done according to my Hypothecs. The following Table fhews how much more Southerly the Star was found to be by Obfervati- on in feveral Parts of the Year, and likewifehow much more Southerly it ought to be according to the Hy- pothefis. 1727. D. The Difference of Declination by Obfervation. ^ The Difference of Declination by the Hypothefis. s 1728. D. The Difference of Declination by Obfervation. i The Difference of Declination by the Hypothefis. ^ October 20th — 4! 44 March • 24 37 38 November - 17 12 Jpril - - 6 35. 3<>4 December - 6 184 May - - 6 284 2-Pr - - - 28 zr . 2(5 1 t <*> 5$ xs 18; 20 1728 - - - If *7f l7 January - 24 34 34 July - - 3 nf n| February -10 38 37 Auguji - 2 4 4 March - - 7 32 3P September - 6 0 1 0 Hence ( 6} 7 ) Hence it appears, that the Hypothefis correfponds with the Obfervations of this Star through all Parts of the Year} for the fmall Differences between them feem to arife from the Uncertainty of the Obfervations, which is occafioned (as I imagine) chiefly by the tre- mulous or undulating Motion of the Air, and of the Vapours in it $ which caufes the Stars fometimes to dance to and fro, fo much that it is difficult to judge when they are exadly on the Middle of the Wire that is fixed in the common Focus of the Glaffes of the Telefcope. I ffluft confefs to you, that the Agreement of the Obfervations with each other, as well as with the Hy- pothefis, is much greater than I expeded to find, be- fore I had compared them ; and it may poflibly be thought to be too great, by thofe who have been ufed to Agronomical Obfervations, and know how difficult it is to makefuch as are in all refpeds exad. But if it would be any Satisfadion to fuch Perfons (till I have an Opportunity of defcribing my Inftrument and the manner of ufmg it) I could allure them, that in above 70 Obfervations which I made of this Star in a Year, there is but one (and that is noted as very dubious on account of Clouds) which differs from the foregoing Hypothefis more than z", and this does not differ 3". & This therefore being the Fad. I cannot but think* it very probable, that the Thanomena proceed from the Caufe l have affigned, fince the foregoing Obfervations make it fufficiently evident, that the Effed of the real Caufe, whatever it is, varies in this Star, in the fame Proportion that it ought according to the Hypothefis. But lead y Tiracoms may be thought not fo proper to fhew the Proportion, in which the apparent Altera- S f f f tion ( ) tion of Declination is inereafed or diminifhed, as thofe Stars which lie near the Equinodial Colure: I will give you alfo the Comparifon between the Hypo- thecs and the Obfervations of n ^Orfa Major is, that which was fartheft South about the 17th Day ot Janu- ary 1718, agreeable to the Hypothecs. The following Table fhews how much more Northerly it was found by Obfervation in feveral Parts of the Year, and alfo what the Difference Ihould have been according to the Hypothefis. 1727. d. The Difference of Declination byOb- fervation.v, ^ The Difference of Declination by the Hypothefis. s 1728. d. The Difference of Declination byOb- fervation.. ^ The Difference of Declination by the Hypothefis. ^ September - 14 29 f 28 f Jpnl - -1 6 l8 r 18 - - - M 24f Mi May - - y 24 f 23# October - - 16 191 1 9# June - - y 3* 31 f November - 1 1 l°f — — - 2. y 3f 34* December - 14 1728 4 3 July - - 17 3« 3^ February - 17 2 3 dugujl - 2 3f 3f 1 March - - 2J ii| i°l September - 20 z6 1 26 i I find upon Examination, that the HypotheCs a- grees altogether as exadfly with the Obfervations of this Star, as the former \ for in about 50 that were made of it in a Year, I do not meet with a Dif- ference of fo much as z/f9 except in one, which is ’ mark’d ( *59 ) mark'd as doubtful on Account of the Undulation of the Air, &c. And this does not differ 3" from the Hypothefis. The Agreement between the Hypothefis and the Observations of this Star is the more to be reguard- ed, fmce it proves that the Alteration of Declination, on account of the Proceffion of the Equinox, is (as I before luppofed) regular thro’ all Parts of the Year; 10 far at lead, as not to occafion a Difference great enough to be difcovered with this Indrument. It iike- wiie proves the other part of my former Suppofition, vtz. that the annual Alteration of Declination in Stars near the Equinoctial Colure, is at this Time greater than a Precelllon of ;o" would occafion : for this Star was 20" more Southerly in September 1718 than in September 1727, that is, about 2“ more than it would have been, if the Precetfion was but 70" But I may hereafter, perhaps, be better able to deter- mine this Point, from my Obfervations of thole Stars that lie near the Equinoctial Colure, at about the lame Didance from the North Pole of the E- quator, and nearly oppofite in right Afcenfion. I think it needlefs to give you the Comparifon between the Hypothefis and the Obfervations of any more Stars ; fince the Agreement in the foregoing is a kind of Demondration (whether it be allowed that I have difcovered the real Caufe of the Th < . £ R KATA. t N9' 399. Tab. content, pag. 2. lin. 14. leg. Curienfis. N5- id. pa g. 294. lin. 19. leg. latifolta. ibid. 1. 1 1 . leg. pyri-incijis, pag. 315. }, 23. leg. Curienfis. pag. 317- 1- U- leg. cuticula. ibid. 1. 17. leg. Heifieri. p. 32a. I. 2 leg. differentes. N*. 400. p. 351. 1. 7. leg. Cafes. N»* 403. p.47j. 1. 2o. leg] rite. ibid. pag. 489. 1. 15. leg. hexaedra. p.490. 1. 27. leg. per. N°* 404. p] 535-1. 14. leg. thirty- three. 0- A An INDEX to the Thirty Fifth Volume of the Philosophical .Transactions. EDp°5^EN’ extrawdi™y Tumours of it, n.+0J. Equations, their impojjible Roots thurmhU, n. 404. p. Anatomy, Cerebra Epilep/ia mortaorum obCervata n ihTiumJti" 400 ’ pblP- fifrnmutalfierforli.lll Rattle-Snake, n 4qi V , Apparatus of a V ■ 413. Ancuryfm dJesll 'n 'xPX iK mach of Oxen, a. 404. p. 53I 4 P 43 4' 1,1,11 °t ,he Sto- Aztm 0¥~ - * £ p.:fr3’ ib- p- 45 5- At •' * p. «* Aop,og„t f7t^ n. /-//, ib.p.3,4. Thirty rhreJ Stops’ J\^ffT;:t Blnif£Z™t!'msofa Verfm bron&ht U SV* b* ««**, Book, a farther Account of one entitled. Vegetable Staticks n 599 p. 323. ji Refutation of one entitled n, r • c fedionibus, &tu n. 40 6. p. 5 69. ^ De Luminis af- G. Camphire, /A Efficacy in maniacal 2)i borders n 4.0 « , CataraCl, its Sub fiance, n. 399. p. 317/ 5 ’ 4C0‘ P* 547* Cerebra, Epilepjia mertuomm cbfervata , n. ;oo D ~Te Chi'rurgicai Queftions, n. 399. p. ,l8. ’ >PP* P* >IJ* Chronology, <5Vr If. Newton’; Syfiem of it defended, n. 399. p. 2^. Damps drawn from Mines, n. 400. p. Ductus alimentalis of Oxen defer ibed, n. 404. p. 532. Earth, uncommon Sinking of it, n. 405. p. 551. Earthquake felt in Kent, n. 399. p. 3o? T t t t Eclipfes INDEX. Eclipfes of Jupiter’s Satellites , n. 401. p. 408. n. 402. p. 415. n. 404. p. 5 34- n. 405- P* 55 3- iK p. 557'. Ecliple of the Moon objerved at Lisbon, n. 400. p. 338. At Pekin in China, n. 405. p. 554. Eclipfe of the Sun objerved Lisbon, n. 400. p. 335. At Vera Cruz, n. 401. p. 388. Near Lisbon, n. 403. p. 471. At Rome, ib. p. 473* dt Bologna, ib. p. 477. At Padua, ib. p.470. At Ingolftadr, n. 405. p. 558. Elephants, their Teeth and Bones found under Ground, n. 403. p. 45 7. n. 404. p. 497. ’ • » • r* > /• Experiments on the Effetfs of the Eoifon of a Rattle-SnaJce, n. "90. p. 309. n. 401. p. 380. For drawing Damps out of Mine] n* 400. p. 35 3- For meafuring the Depths of the Sea, , n. 405! p. 559. Several in Opticks, n. 406'. p. 607. Eyes, a new Operation on them , n. 402. p. 451. F. Falling Stars, the Geographical Longitude of places determinable by them, n. 400. p.. 351. J Finlanders, an Account of them, n. 400. p. 357. Fire Subterraneous, a Species of it objerved in Kent, n. 399, p. 307 . Fixt Stars, a new Motion dijcovered in them , n. 406'. p. 6yj. Forces of moving Bodies confidered , n. 400. p. 343. n. 401. p. 381. Foffil Teeth and Bones of Elephants, n. 403. p. 457. n. 494. p.4.97. G. Gage to meajure the Depth of the Sea , n. 405. p. 559. Gout, its Nature and Caujes, n. 403. p. 491. Ground, an uncommon Jinking of it, n. 405. p. 551, H. Hernia aquofa, a remarkable one, n. 401. p. 414. Holt-Waters, their Impregation whence, n. 403. p. 489. Hydraulicks, Remarks upon jome Experiments in them, relating to the Forces of moving Bodies, n. 400. p. 343. 0 L Iris contrasted, its Cure, n. 402. p. 451. Iron Oar, different Species oj it, n. 403. p. 480. Jupiter, his Satellites eclipjed, n. 401. p. 408. n. 402* p. 415. 11.404, p. 534. n. 405. p. 553. ibid p. 557. K. Kent, an Earthquake felt then, n. i99. p. ?0j. A Species of fub- **p™**> »• 3 99. P- 307. An uncommon Sinking cj the Ground in the fame, n. 405. p. 551. Kidneys, remarkable Stones found in them, n. 402. p. 4y2. Lateral INDEX. ... L. Lateral Operation, Thirty three Stones cm cut of the Bladder by it , n. 404. p. 535. Latitude oj Lisbon, n. 401. p. 409. London And Paris, their Magnitude compared , n. 402. p. 432. Longitude Geographical oj F laces determinable from Falling Stars, n. 400. p. 3$ 1. Of Vera Cruz, n. 401. p. 389. Long Life, Examples of it , n. 400. p. 354. M. Maniacal Tiforders cured by Camphire, n. 400. p. $47. Marriages, an Account of them , n. 400. p. 355. Mars, an Occult ation of it by the Moon, n. 405. p. 5 5 (S'. Materia purulenta per triennhim ex ore defluens , n. 400. p. 374. Meteors,^ new Method for a natural Hi /lory of them, n. 401. p. 390. Metals, Obfervations towards a natural Hifiory of , hem, n. 401. p. 402. n. 403. p. 480. 5 Mines, Experiments for drawing Tamps out of them , n. 400. p. 353. Obfervations towards a natural Hifiory of them , n. 401. p. 402. n. 403. p. 480. r Mifleto, its germinating principle, n. 3 99. p. 30