I If PHILOSOPHICAL TRANSACTIONS. Giving Some ACCOUNT O F T H E Trefent %)ndertahings^ Studies and Labours OF THE INGENIOUS. In Many Confiderable Parts of the WORLD VOL; XXX. For the Years 1717. 1718. 1719. L 6 T> 0 N: Printed for W. and J. I n n y s, at the Trinces-Arms^ at the Weft Corner of St. P^z//’s Church -Yard. MDGC XX. To the Right Honourable THOMAS Lord PARKIER, Baron of (jMacclesJield ; Lord High Chancellor Of Great-Britain : By Inclination as well as O f f i c e, Firft PATRON of Ufeful Arts and Difcov cries. This THIRTIETH Volume OF THE Philofophical Tranfadtions (As a fmall Acknowledgment for very Great Favours) Is Humbly inferib’d by His Lordp7tp"s mojl obliged SerVanty ( 545 ) Number 95?. PHILOSOPHICAL TRAN S A C T ION S. For the Months o^Januar, Febr, s.nd March^ \7\J> The C O N T E N T S, . I. Chfervationes Stella in Geminis a corf ore Jovis- cccultat£, Januarii iimo. St. vet. 1717. Tranfitus arilijfimi Martis infra Borealem in fronte Scorpii Febr. ^into mane. II. An accurate Account of a teflellated Pavement, Bath, and other Roman Antiquities, latelj difcover d near Eaft" Bourne in Suflex. Being fart of a Letter of January 26. 1717 from the learned Dr. John Tabor «/ Lewis, - to Dr. John Thorpe, R. S. S. and hj him communicated to the Royal Society. ^ III. A jhort Account of the Nature and Vertues of the Pyr- ■ mont Waters ; mth feme Obfervations ufon their Chal)-- heat fiualit). Communicated by Dr. Frederick Slare, R, S. See. IV. Remarks on the fecond Pafer in the Hifery of the Royal Academy of ScienceSj for the Tear lyii. concerning the Caufe of the Fariation of the Barometer : to Pew that the Wa"j «f accounting for it in that P afer is irffufficient, and that the E^feriment made ufe of to frove what is there averted, dors no way frove it. By J. T; Delaguliers, M. A. F. R S. V. An Account of an extraordinary EffeB of Cholick : communicated to Royal Society, by that curious Ana-- tomift Mr. St. Andre* and read March zi. 1717. VI. An Account of two late Northern Aurora’j as they were obfeived at the Vicarage of Sutton at Hone in Kent® By the Reverend Edmund hdcciCWyP rebend of Rochefterv; ( ) L Ohfer^atlones StelU fixk in Geminis a corpore Jovis Januarii xuno. St. Vet. 1717. Tranjitus arStiJfml Martis infra, ^orealem in fronte Scorpii Febr, j. mane, Ante biennium in TranjaB, Fhilof. No. 344. pag. 294, rerum coeleftium {tudiofis indicavimus, Jo^ vem corpore fuo ftellam quandam fixam obcegerc debe- re, eofque ad obfervationem Phsenomeni rari/Iimi, & magno in Aftronomicis ufui futuri, invitavimus, fignan- tes diem Januarii hujus anni decimum. Jove autem pene Stationario, & paulo amplius in orientem quam per Tabulas noftras provedo, non ante undecimum in- cidit pr^edida Occultatio ; quam quidem Londini ob Nu- bes non contigit ex voto obfervare Nec tamen fruftra invigilarunt Aftronomi noftri. D. Martinus Folkes Londiniy pnefentibus aliis nonnullis e Societate Regia, Jan. undecirao %h. P, M. vidit Jovii centrum una diametro corporis ejus Fixam fequi, quas dido centro Borealior erat quafi dodrante femidiame* tri Jovis. Poftea Nubes Jovem occuparunt, fed, habira ratione motus Jovis paulo poft medium Nodisflellam Jovt conjundam fuifle, & a Borea dilci ejus parte oc- culcatam, conclufit. Reverendus Dominus J. Theoph. Defagulkrs, R, S. S. & Stephams Grey, Wefiwonaflertt, viderunc Fixam, Hor^i Sexta vefpertina, integra Jovis diametro diftare a limbo ejus. Corum verfus. Unde & ex fequentium di- ctum Obfervationibus, circa medium nodis incidilTc conjundionern evincitur Reverendus quoque D J. Found, ipud iVanfied, in- frafcriptas nadus ei^ ob(erva(iones, quas ucique accura- tiiiimas ( 547 ) tiffimas, Tube fcil. pridongo <5c Micrometro captas, hue tranferibere non pigebit. Itaque Januarii Quinto 6'. T* jeq, Jovis centrum diftabac a Fixa 31'. 49'''. quam 5^ 38'. fequeba* tur 34^ ii" Afeenfionis redes: fimulque limbus Jovis Auftrinus eandem habuic Declinationem cum ftella. Die autem Nono fequeme 6\ 6'. Jovis centrum dift^ bat a ftella 10'. \ & poft odo minuta erac differen* tia Afcenfionum redarum n'. 31"; & turn centrum Planetx, tantiiJo, ita uc vix perciperetur, erac Stelll Aa- ftralius. Die Undecimo s’’. 30'. T. ssq, crat diftantia centro- rum i'. 2.4'. fimulq; vifa eft ftella quaft quadrante diametri Jovis Borcalior centro ejus. Diameter autem ■ minima Jovis inventa eft o' 43". Deinde Nubes. Die vero Duodecimo 5^ 17'. erac diftantia centre-* rum 3'. 7"; ac 5^ 50'. Jupiter ftellam prxeedebac 3V ' 30''. Afcen. Red. Eodemq; tempore limbus Jpvis Bo- reus eandem habuic Declinationem quam Fixa accu? rate. Collatis autem his Obfervationibus manifeftum eft 4 Fixam banc Jovi conjundam, Januarii undecim-o i circitcr, non nifi 17" veri8" centro ejiis Borealiorem i fuifie, ac proinde occulratam. Fixa hese, etiamfi nulli Catalogo hadenus aferipta, Locum tunc habuic jr az®. 13'. cum Lac. Auft, 0°. 13'^; Comicemque habet 17 min. earn prxeedentem = & 7 min.- Borealiorem, five in n 1 1°. 56' cum Lac. Auft 0°. ewi Jupiter conjungi vifus eft Jan, i6. d**! ' 30'. veCperi. Sic fpatio minus bimeftri Jupiter corpocaliter eclipfa- vir duas Fixas, cujus rei ne fingulare quidem exem** plum ab invento Telefcopio extar: proinde base obfer- - vara inter pretiofiftima Uraniae in ufum Po» Rerotum, merito reponenda funt. 1 . f 548 ) Noftra autem ftellula anno 1634. Feh. 6. Jovi Stati- onario conjunfta, tribus ejus diametris Audralior erac, obfervante Gaffendo : unde conftabit, calculo rite infticu- to, Jovis Nodos quoad fenfum immobiles hsEfiile, per S3 annos ultimo elapfos, idque ad x® 8®. 35'. a Ad alteram autem Obfervationem Tranlltus Marti s prope Boream Fronth ScorpH non minus infignem, iidem Aftronomi eadem cum cura invigilarunc omnes. Mars autem, Februarii Quinto Mane, vel Quarto 16’’* vifus eft adeovicinus ftellae didas, ut ea nudis oculisnon con- fpiceretur ; fed per Telefcopium inventa eft (upra & ad ortum, adeoque Mars nondum ei conjundus. Hora 10'. T. app. Mars erat in recfta cum Borea frontis & Telefcopica qujs earn fequitur ad Boream, ad diftan- tiam ocfto circiter minurorum. i6^ 35'. Mars interme- dins erat in reda cum Borea & Medii Frontis; & poft horse quadrantem, cum Auftrina Frontis, ita ut i6'‘. 54'. T. app. seftimabatur Conjundio ipfa quoad Longi- tudinem, quo tempore Mars fat accurate duobus tan- turn minutis auftralior erat ftella. Obfervavit etiam D. Pound Conjundionem refpedu Afeenfionis Redae I7^ a 5'. T. app. cum diftantia centrorum a'. 07"" Jucun- dum autem erat fpedaculum, Martem viderc ftellam pedetentim aggredientem, motumque fuum, lentiftimum licet, manifefte prodentem. Conferatur cum hac Obfervatio Horroxii noftri anno 1638. Februarii Septimo mane, quam vide in Epiftolis ejus pag. 3oq. Tunc enim Mars ad eandem ftellam appulfus, etiam multo propius ad earn acceflir, fed ante ortum ejus prseterierat Conjundio. His adde Saturni obfervationem Januarii a 5” to. la^. 25'. T. aq. a D. Pound habitam. Cum Planeta difta- bat a ftella 58va. Virginis Catal. Brit^ 13'. i6\ verfus Auftrum, eamque fequebacur 2'. 30". Afc. Red, Stella in e? I 9 21'. 5a". cum lat. Bor. a% 47". 25". II. An ( 549 ) II. accurate Account of a teflellated Pavement, Bath, and other Roman Antiquities^ lately dif~ coyer d near Eaft Bourne m Suffex. ^ein^ part of a Letter of J^Lnu^ry i6, xyxy. from the learned 2)r. John Tabor of Lewis, to 2)r. John Thorpe, R. S. S. and by him communicated to the Royal Society, ADefcriptipn of the tefTerated Pavement at Eafi Bourne, near Pevenfey, mufl: have been more im- perfed than what is now *^iven, had it come to youc hands much fooner. I thought an exadi Account could not be taken, unlefs the Ground about it was open’d.- and it being part in a Meadow, and part in plough’d Ground, and under a Fence which parts two Perfons Lands; by realbn alfo the one was fow’d; I could not procure the Digging in both Places at the fame time. It was in Marcli laft when the Meadow was dug; and the laft Weekfave one in November, befoae we had leave to open the Ground in the Corn Field. The Mea- dow in which the greateft part of the Pavement lyes, is near a Mile and half South Eaft of Bourne ; it contains about four Acres, and is of a triangular Form ; the Southern Side is againft the Sea 5 only a few Filhers Cot- tages, and a fmallpublick. Houle or two being between that and the Sea. On the Northern Side of the Meadow is a High-Way, which leads from Bourne to Pevenfey : the Weft Side is by a Fence of Polls and Rails leparated from a large Corn Field, in Common belonging to the Parilh. Q^q q q About ( 530 ) -About the middle ef this Fence is the Pavement, diflant from High-Water-Mark a Furlong ; In former times it might have been fomewhat more, becaufe from this Point to the Weftward, the Sea is always gaining from the Land, More than four Years (incc, viz,, in the Summer 1712,, when the Fence was repair’d ; the Workman fink- ing a Hole ro fix a Poll in, was hinder’d by fomeching Solid like a Rock ; but calling out the Earth clean, found the Obftacle to be Artificial. Mr. Thomas Willard of Bourne, Owner of the Meadow, being inform'd of the Novelty, gave Order that it Ihouid be uncover’d ; and lent alfo to Herflmonceux, for one Purceglove an in- genious Ingineer (who formerly had been imploy’d in the Mines in the Northern Counties^, who with his In- llruments bored through th^Pavemenc; and in many pla- ces of the Ground about it, which he found to be full of Foundations.* but this his Difeovery of thofe Founda- tions, was only a Confirmation of what the Inhabitants there have always obferv’d, as well in Ploughing, as in the Growth of their Corn and Grafs* for in the common Corn Field, Weft to the Meadow, to the diftance of near half a Mile, they often raife bits of Foundations with their Ploughs ; and in dry Summers, by the different Growth of the Corn, they can plainly perceive all that Tracft of Ground to be full of Foundations. The Pavement was little more than a Foot below the com- mon Surface of the Ground ; what lay next it was a fmall Sea Gravel 5 the Pofition of it is very near due Eaft and Weft fabout two Foot of the Weft end of it reaching into the Corn Field^ ; its length is feventeen Foot and four Inches; its breadth eleven Foot. At firft it Teem’d to have been bounded with a thin Brick Tet on Edge, about an Inch above the Tejfer£, To exadly ftrait and even, as if Shot with a Plane ; and To well Cemented, as ( ) as if one entire Brick. But when the outfide of the Pavement was broke up, we found, that inftead of Bricks fet on Edge, as was imagin’d, it was bounded with a Border of Bricks laid flat, and their ends next the Tf(fer£ turn’d up. The Thickncfs of thefe Bricks was an Inch and a Quarter ; the Breadth not under Eleven, and not more than twelve Inches; the length full fif- teen Inches ; which, before they were turn’d up at their Ends, could not have been lefs than Seventeen. They were very firm, and not in the leaft Warp’d or Cad in Burn- ing ; when broke, their Subftance was fine and well mixt, of as uniform and clean a Red Colour, as a piece of fine Bole: Except at the ends wliere turn’d up, they were all over cover’d with a Plafter (the fame which Vitruvius calls the Nucleus, of which more afterwards), half an Inch thick ; fb hard, entire, and even, that it feem’d as one Stone, quite round the Pavement. Next within the Bricks, there was a Lift or Bordet of white TefjerA, thirteen Inches broad; within that, a Lift of brown Teffera (fomewhat darker than a Whet- Stone, and fomewhat lighter colour’d than the Touch- Stone ) four Inches broad ; then a Lift of the White, five Inches broad ; next within that, another Lift of the Brown, four Inches broad : all the reft of the Pavement was fet with white Teffera, without any Ornament or Figure ; which though not Gay, lookt very Neat and Clean. When' this was firft view’d, none of the Curious doubted, but that the Work was Roman, many were of opinion, that it might have been the Floor of a Temple, or place of Worftiip- Pli^y indeed (a) informs us, that thefe fort of Pavements or Lithofirota^ began to be in ufe in Italy, in the time of SylU ; who caus’d one of them («) Plin. Sec. Hilt. Nat. Lib. XXXVI. Cap, XXV. q q I to { > fo be made in the Temple of Fortune ac Tr<.tnefte ; perhaps the fame which not long fince was taken notice of by the Honourable Mr. Addifon {b ). \ was rather inclin’d to fuppofe, it had been that A- partment belonging to the chief Officer where Jufticc was adminifter’d ; and the more, becaufe Pilats final Sentence on our Saviour was pronounced from a Throne on the Lithofiroton (e); which Appellation was given to thefe kinds of Pavements by Farro (d) not lefs than fixty Years before; and by Plin) {e) not lefs than forty Years after our Saviours Suffering. That the Ro- man Generals caus’d fucb Pavements to be made ac their Stations; we may have juft reafon to conclude, from that paflage {f) in Suetonius cited for this pur- pofe by Dr. ( f ) Plot, When the Ground about the Pavement was dug, all thefe Suppofitions were quafh’d ; for on the North Side of the Pavement, we difeover’d an entire Bath, fixteen Foot long, five Foot nine Inches broad, and two Foot nine Inches deep (which the Draught fent with this reprefents) : Fig- 1. It was fill’d with Rubbifh of Buildings, which feem’d to have been burnt ; fc. hard Mortar adhering to pieces of Roman Brick, fquar’d Stones, and headed Flint, mingled with Afhes and Coals of Wood. From the Northweft Corner of the Pavement, was the Paflage into the Bath, three Foot three Inches wide; ac which place, the Bricks that bounded the Pavement, were not turn’d up ac their, ends, but lay even with the Tejfera. At the diftance of fifteen Inches from the Tefferdt, there was a Fall of two Inches, to the Land.ing- ( 6 ) Remarks on feveral places in ItalVy Fag. 377^ . ( c ) K. XIX. 19. ( dy Ter. Var. de Re LiB. 3.' ^ C «-> PUn. Hift. Nat. Lib. XXXVI. C.-XXV, (/) Jnl.C«f,Sca.4(J. i g y Oxferdjhire Plots.-Nat...Hiftoj:y, Chap. X.-, , . . . place s ( 553 ) place out of the Bath ; the Landing place v^as allb three ' Foot three Inches long, and two FOot two Inches broad .* * Thence by two Stairs, was the Defcent into the Bath ; the length of the Stairs, the fame as of the Landing- place; the breadth of each Stair was eleven Inches; the height of each Step a little more than ten Inches; the lowed Stair was twenty Inches from the farther Side of the Bath. The whole Work was very cempadi, and exatdly well made; not in the lead injur’d by Time, nor the Violence it underwent when fill’d up ; truly an- fwering the Precepts of Viiruvim\ which (^) ad vile, that for all Buildings, refpedt Ihould be had to the Strength, Gonveniency, and Beauty of the Work de- fign’d ; and that in order thereto, a careful and judicious ' Frovifion fliouid be made of Materials, without Parfi- ■ mony. Although the Author and Time of thefe Works , can- not as yet be difeover’d ; yet ’tis evident the Artificer near enough follow’d the diredlions Vitruvius (F^gave- for framing iuch like Strudures. ( ) yi. tollio Vitruv. de Architeftur. Lib. II. Cap. III. Hasc autem ita fieri debent, ut habeatur ratio firmitatis, iitilitatis, venuftatis. Fir- mitatis erit habita ratio, cum fuerit fundamentorum ad folidnm depref- fio, & ex quaque materia copiarum fine avaritia diligens. eleftio. ( r ) M. Vitruv. Fol. Lib. VII. Cap, I. Primumque incipiam de Rude- ratione, quae principia tenet Expolitiomim, uti suriofius fummaque pro- videntia folidationis ratio habeatur. Et fi. piano pede erit ruderandum, quaeratur folum fi fit perpetuo folidum. — Si aut omnis aut ex parte con- - geftitius locus fuerit, fiftucationibus cum magna cura folidetur. — Tunc infuper ftatuminetur ne minore faxo quam quod poffit manum implere; ftatuminibus induftis ruderetur. Rudus fi novum erit, ad tres partes una cal cis milceatiTt, fi redivivum fuerit, quinque -ad duum mixtiones ha- beant refponfum, Deinde Rudus inducatur, & veftibus ligneis Decuriis indudis crebriter pinfatione folidetur ; & id non minus pojl pinfum abfolu- > turn cra>ffitvjdinc fit dndrantis. Infuper exTeftaNucleus inducatur, rerixtio- • ncm habens ad tres partes unam Calais ; uti ne minore fit craffitudine pa- vimentnm digitorum fenum. Supra Nucleum, ad Regulam 8c Libellam exa£ia Pavimenta fttuantur, five. Seftilibus, feu Tefleris.. Cura ca ex-* tnulat^ fuerint, & faftigia extru£Hones habuerint, ita fricentur, uti, fi ScSilu fiut, nulU gradus in feutulis, aut trigonis, aut quadratis, feu favis Fkftj . ( 554 ) ' Fiffl:. as to the Pavement, it was fecur*d on every Side, and the Edges of it refted on a very firm and neat built Wall, made of Roman Brick, fquar’d Stone and headed Flint ; between five and fix Foot deep be- low the Surface of the Pavement, and full twenty three Inches thick; which we may fuppofe to have been two foot by the Roman Meafure. The Bricks were not in regular courfes, as they are to be feen in thole Roman Buildings, which are in view above Ground ; but with- out order difpers’d about in the Wall. The Top of the Wail indeed was but fifteen Inches thick; and that was cover’d with the Bricks firft mention’d, which bounded the Pavement : but about fourteen Inches be- low the Top, there was a Set-ofF (as our Mafons term it) in the infide of the Wall, eight Inches broad. We did not dig up the Foundation of the Pavement to the Bottom, but opened it at one Corner only, that we might difeover how it was Fram’d : for wdien it was bor’d through, they obferv’d, next under the Tejfer£, a Bed of very ftrong Mortar, more tlian a Foot thick ; under the Mortar a Bed of Clay two Foot thick ; and under the Clay a firm Foundation of Brick. We ob- ferv’d the Clay (which the Ground thereabouts do not afford) to be very fine and red, and alfb clofe; no .doubt but carefully Ramm’d. The Surface of the Clay was neatly pitch’d with finall Flint and Stones, Pointed at their lower ends, and Headed at their up* per ends. This Pitching or Paving is by Vitruvius . call’d Stutumimtio \ and the Stones ’tis done with, he extent. Sed coagmentorum compofitio planam habeat inter fe dircQio- nem. Si Tefleris ftruftum erit, ut eae omnes angulos habeant seqxiales, nullibiquc a fricatura extantes. Cum enim anguli non fucrint omnes squalLter plani, non critexada ut oportet'fricatura. calls ( 555 ) calls Statitmina. He diredJs them to be fee, when the Underwork is made Sound and Firm, by well Ramming. Becaufe the firfl: Chapter in his Seventh Book, treats only of the Method of making thefe kinds of Pavements, which in his rime, and as may be obferv’d from his words, were had in no fmall efteem by the Grandees of Reme ; I have tranferibed what may fliew the accurate Me- thods which that great People had in Framing them. But to return, this pitch’d Work was exadUy even with the Sct*ofF in the infide of the Wall; on it was laid a Bed of coarfe Mortar of about nine Inches thick ; the Skirts of this Mortar (which by Vitruvius is call’d the Rudus) refled on the Set-ofF above-mention’d ; it was compos’d of Lime, a (harp courfe Sand, fmall Peb- bles, and bits of Brick. Upon this Rudus was a finer Compofition, made, as near as I could guefs, with Lime, a fine lharp Sand, fome kind of Afties, and (which was the greater part) flampt Brick and Poc-fiicrds, in grains not larger than Cabbage»Seed, and the Flower or fine Powder feparated from it. This Bed w’as about half a Foot thick ; and is what Vitruvius calls the Nucleus, Whether we may call it Terrace, I mufl leave it to thofe who are better skill’d than my felf, in giving proper Ap- pellations to the feveral parts of Mafonry. Both this Nucleus and the Rudus under it, very near equall’d the TortUrtd>SionQ in hardnels and compadnefs. Upon this Nucleus or Terrace were the Teffera fet : they were fet an end ; but fb exadi was the Workman in Petting them, that he us’d two forts of Cement to fix them withal ; their lower ends flood in a Cement of Lyme only, well work’d ; their upper halves were cemented with a fine gray Mortar, confiding of fine Sand (and as it feem’d) Afties and Lyme. This gray Cement every where fill’d the Intervals at their Heads ; and was much harder than the Teffeya themfelves. ^ ’Twas, ( 55<5 ) ' *Twas before intimated, that the Tejfera were but of i two Colours, White, and of a dark Brown; they were harder than a glaz'd and well burnt Tobacco*Pipe, and of a Grit fomewhat finer ; the Brown feem’d to be of ^ the fame Subftance wich the White, but colour’d by Art, {as Pliny informs us the workers in Clay of old bad a Method to do) : they Teem’d to have been form’d in a Mould, and afterwards Burnt. Hence I am inclin’d to take the meaning of Vitruvius), where he makes fo plain V a diftin fUn) ruppofed that thefe Lithoftrota (i ) or tefFerated Pavements had their original in Greece ; but perhaps the Grecians borrow’d their Patterns from Afia : for from the Book of Efther ( w / we learn, there was a mod Royal Banquet at Suza^ on a Lithoflroton (io tire Septuagint has ic^ of cohly Stones, four Hundred Years before the time of S-jlU, who brought them firft into Italy. Jofe~ phiu afSrms (»), that the Grecian Laws, Learning and Arts were fetch’d from Afia ; and indeed when we reflecd on the Antiquity of the Law , the Pyramids of Egypt ‘-f the Temple of Sdmbn; the Walls and Palaces oY Babylon; and the fumptuous remains of i'almyra and Ferfepol/s; We have no reaibn to eflccm the Grecians Au- thors, but as good imitators of thofe early Examples of Learning and Arts th:y had to follow. When ^in^us Cicero was here with C^fir, the fecond lime he invaded Britain ; his Brother the incompaiable Tfli/y, had the overfight of fome Buildings he had ap- pointed to be made in the f^illa dar/l/ana atArcano . and in a Letter fent into 77/i/y informs ^inU u, that he was well pleas’d with the Seat, and the more, be- caufe the Pavimented Piazza was Magnificent : that the Pavement feem’d {o) to be exadtly well made ^ that he had direded fome Chambers to be alter d bccaufe he did not approve of them.* that in the Bathing Apart- ment, he had remov’d the Sweating Room into another corner of the Apodyterium. And afterwards in the fame. Letter makes mention of fuch another Work which was in band for him in the City alfo. Again, about the time ^inclus return’d out of Britain, and was fixt with the Legion he prefided over, in Winter Quarters 1_ ( / y Plin. Sea. Hift. Lib. XXXVI. Cap. XXV. ( ZB ) Efth. Chap. I V. ^ ( » ) jofeph againji Appion. Book II. {a ) Tull. Cic. ad Qviinft. Frat. ^ib. III. Ep. I. among ( 5^1 ) among; the l^ervH ('of which Cafar in his Commentaries makes mention^ ; TuUy (p) takes notice of a Pavement that was making for himidf alfo .• Expolitiones utriufqus nojirum, f'int in manihus \ fed uta pcene ad ttcluni jr-n per- duda res e(l rufiica. Arcani Laterii. ’Tis hinted by Far- ro that a Litho[troton was one of the Members of a coni- pleat ViUj. (qj: Farro vvas eighty Years old when his Books de Re ruft ca were compoled : Tully was fomerhing more than fifty when the above cited Epifiles were W’rote; Lafar when a General, made the Te(ferr { r ) and Sedilia for Pavements, to be part of his Baggage ; and Fifruviiis, Coremporary with thefe three, calls the Litho- firotay : rincipia Expolitionum (/) ; which make it evi- dent theie Floors were held in efteem, by as great Men as the World has afforded, even in their riper ^ Years. From ail this, we may obferve, that fometime before, and in the firfl Age of riie Empire, the humour of thefe kinds of Floorings much prevail’d among the Romans % wherefore ’tis no wonder they are found in fb many places of this Ifland. Bur, as unprofitable Inventions and Culloms in time grow Stale, and are laid afide, fo fared it with that of Pavements : For in the time of Eliny they began to be out of ufe on the Ground; but then he relis us, they were made above Stairs ( r ), or in his own Words in Chambers. Whether the Li- thofirota in Chambers were ufual in Fitruvius'^ days, we have no Warrant to fuppofe, from any hint in his Writings ; notwiihftanding he gives Rules for making them, piano pede^on the Ground ; and fab (h) dio, (which ( ^ ) Ibid. Ep. ri. ( ^ ) Ter. Varro de Re ruft’e. Lib.-III. (r) Suet. Tranq. Jul Caf. Cap. 4^. (r) M.Viiruv. Pol. Lib VII Cap, I. (t) Plin. Hift. Lib. XXXVI. Cap. XXV, Pulfa deinde ex hiimo Pavimenta in cameras tranfiere e vitro: novitium & hoe inventum. ( « ) M. Vitruv. Lib. Vll. Cap. I, Sob dio vero maxime idonea faciunda funt pavimenta, from ( ) from the Method by him prefcrib’d muft be) aloft : be- caufe for fuftaining thofe f«h dio, he oidcrs the work un- derneath to be well fecur'd, with two lays of Plank that (hould crofs (rr) each other, and be nail’d down ; then the Statumtmtio or Pirching, the Mortar^ Terrace and Tepr^, as before on the Ground, but bccaulc by fuh dio Vitruvius could not defign Chambers ; and although Flitiy informs us the Grxeiam us‘d ( x ) lo cover or flat- roof their Houfes with thefe Pavements; yet fmee nei- ther Vitruvius nor Plir.) mention any luch Mode prevail- ing in their times at Rcme\ it remains, that we may imagine Suh dio, or the Subdi^Iia of P'itruviiu, to mean Pavements mounted on Pillars or Arches, which might afford delightful Terraces out of the upper Rooms, and lhady Piazzas underneath: and in this Senlc perhaps may be underllood the Porticos Pavim>:ntata of 7«//y above-mention’d. By the many Apartments, the Found- ations about thefe Works point out, there feems to have been nothing wherein the Buildings that once flood there, might come fhorc of the magnificent Strudlures, wherewith the Romans delighted to gratify their Luxury. The ufes each were dcfign’d for, is not to be deter- min’d: whether there was a Piazza cover’d with a Li- thofrotott, cannot be affirm’d. But be that as it will; *tis next to Demonflration, there was fomc upper Floor fuflain’d by Wood, and pav'd with the Tejfer£, after the fame manner as Pltravius directs ; and, on the Brick Pavement (lafl difeover’d), the Coat of Afhes and Wood Coals with Nails, cover’d with large pieces of the Rudus, and great lumps of the Tcffer^ well cemented ( w) Ibid, itaqne fi neceffitas coegerit, ut minime vitiofa fiant fic erit faciundum: cum coaxatum fuerit, fuper altera coaxatio tranfverfa fter- rvatnr, clavifque fixa, SPr.-- »-Statuminatione fafta rudus inducatur, &c, C ;r ) Plin, Hift. Lib. XXXV. Cap. XXV. Subdialia Grsci invencre tali- fcoj domuscontegentes. together ( 5^; ) together, and the Nuchuf adhering to them • {hew there was an upper Pavement broke by its fail, when Fire had confum d its lupport. I have been thus prolix, in giving you the mofl: exaon their Chalyheat Quality. Communicated by Vr, Frederick Slare, R. S. Soc. HAving procur’d about a dozen Quarts of P are fubjedt to be. The Chalybedt Mineral is here throughly diflblved and well united, and mix’d in this Water, fo that it does not eafily precipit^er. for which Reafon it may alfo the better pafs the vafa U5iea^ and even enter into the Mafs of Blood it felf, and work the more confiderable Effeds. That this is not a bare Hypothefis may be prov’d by this Experinaent. Having fufferd the Spdw Water co be expofed in a Bottle which was half full, and unftopc iz Hours,.! examin’d it, and found it taft juft like common Wa- ter; but the Pyrmom Waters that were open’d to the Air after the fame Manner, tafted ftrong of the Mine- ral, and gave their Tindure as at firft; nay, they coii' tinued thus for full two Days, and perhaps might have done longer, buE.,1 thought chat TimefUffied. There ( > There remain (cver^l. other Ej^pcriments to he made, jn order to a further Search! ^to, the. Excellencies, of this noble Water, bvjt’ this I cannot do at prelent for want of a Quantity, which I hope to obtain the next Sunsmers for they can with more Eafe be brought into EngUnd than the S^arv, 1 may allb fairly conclude, that lince the has been very beneficial to our Patients in Chronical Dileafes, thefe Waters of a much fuperior Virtue will lurpafs them in conquering many of our obllinate Dillempers. Sorm Additions to the aforefatd Account of the Pyrmont Waters . Having had lately fome Dilcourfe about a Purging Quality contained in thefe Waters, I am now inquiring into the Truth of this Quellion, whether they in Reality do contain any Purging In» gredients or Properties. I evaporated about a Quart of this Water ad ficcita- im\ I then poured on the reliquU fome Rain-Water, •enough to dilTolve and take up the Salts, and exhal’d that Water, and had a Grane or two of the Salts, that tailed murhtic, fuch as moll River and Pump Waters give. It is well known that the Purging Waters have a very bitter Talle, and by the moll learned Dodor Qrm fU MemorU, and an illullrious Fellow of this Society, that Salt was called Sal Catharticum amarum, which dillinguilh’d it from all other Species of natu- ral Salts: that of the Pyrmont Water abovementioned has no Relation to this, but to the Sea- Salt, not being in the kaR bitter. Sfff a R L ( 5-58 ) It is alfo Well known,, that u;ilefs,0Dt; Waters be im- pregnated witb a confidfei^ble^'Qba^Vnfy^ 'bfrter Sale, it will fiQt purge at, all; jTwo pV three’ Gianes fignifie nothing,, nor have the Cathartic Power, For Example, Put two Drains of the purging S^lts.rOa' Quart of common Water; and this t^^Atltj^Vull '^iv'e^ but a Stool or two to orre :Wh6 is hAtar,aliy ’^'tj eafle’ to work upon, f have exarhM’d feweral/blheY' Chd)^'^at Waters, and found much the like ingredients, and ne- ver any that I could (ufpedf to carry any purging Pro- perties. I think, we -cAo Vnuch better, dtiflorcflcjtte riiar ihe Chaljheat Waters do contain Stipric and ReQringent Vir* tues, becaufe they owe their Birth to the Iron Mineral, and mpre particuj.9rly to die wjiicli .Dodor X//fany Hours without Danger of lofing them by Dejedion, But if any, one will be careful, and cake ^h^s■Cautibn'‘^^hth him, he will fcarce fail of Succefs ; that is, let him be very quiet and {fill, both in Body and Mind; the lefs he ftirs or walks, the better he will pa(s off his Waters by Urine, And tho’ this will appear a Paradox, efpcciaUy to thofe Phyficians who pradife abroad, .and commend to their Patients' much Adion in walking, yet I know I have both Reafon and Experience on my Side. To avoid Prolixity I {lull not declare them at this Time, and {liall only ask leave to mention one Obfervation 1 have made, that none of, our Ertglifh Steel Waters do ftrike fuch a Purple as the Foreign celebrated Chaljheat Waters do: for ours do give a more turbid and dark Colour, and the worfe the Waters are, the blacker Sediment- they make.- Thofe of Jflington abound with a coarfe Oksr, the Mi- neral is not well dillolved, but gives an atramentarions Colour ; but the Pyrmont Waters excell all i have hap- pened to examine, in its bright Luftre. N. B. Moft of the Experiments alledg'd- hy Dr. Slare, in the foregoing Difcottrfe, vrere likerrife by him [bervn before the C 570 ) ^oyal Society, Feb. 28. lafi: and. it was found that thr Pyrmont Waters gave a much brighter TitdSure with Gatls and Tea, and had a much more exalted Cbalybeac Tafle than the Spaw; and a [mail ^antity of each being kept for fome time in Bottles, to compare them, the Pyrmont was • found to have retained its Virtues much better than the Spaw. The Vrefident^ and feveral of the Members prejent, 'having drunk a Glafs of it, found it of a very agreeable Re- difh, and to fit eafie on the Stomachs rV. ^emarkg on the fecond Taper in the fdiflory of the ^oyal Academy of Sciences ^ for the Tear 171 u concerning the Caufe of the Variation of the Taro» meter ; to fhew that the Way of accounting for it in that Taper is injufficient^ and that the Experiment made u/e of to prove mhat is there ajferted, does no way prove it, TyJ, T. Defaguliers, M A, F, % S, The Paper is as fo Hows, * T T appears by the Barometer, that when it rains, * or a little before Rain, the Air commonly be- ‘ comes lighter. ‘ That it mull rain when the Air becomes lighter it * is eafie to imagine ; for the imperceivable Particles of ‘ Water, that fwim about in the Air in prodigious Quantity, not being fiiificiently fuftain’d when tlie * Air has loft a pertain Degree of its Weight, begin to ‘ fall, and feveral of them joining together in the Fall, * make Props of Rain.« when about half of tlie ^ Air is drawn out of the Recipient of the Air-Pump, : (and C 57' ) * Cand confeqiiently the remaitiiag Air is as weak again * as at fomeching like a fmall Rain falls. But ‘ why Ihou’d the Air become lighter? One might ima- * gine that in the Place where it rains, it may have loft ‘ feme of its Weight and Bulk, by means of the Winds * carrying away fome Part of it; but Monfieur Leibnitz, ‘ in a Letter to the Abbot Bignon, gives a more inge' * nious and more new Reafon for it. ‘ He pretends that a Body, which is in a Liquid, * weighs with that Liquid, and makes up part of its ‘ whole Weight, fo long as it is fuftained in it; but if ‘ it ceafes to be fullain’d, and confequencly falls, its ‘ Weight no longer makes a Part of the Weight of the Liquid, which thereby comes to weigh lefs. This * may naturally be applied to the abovementioned Par- * tides of Water; they encreafe the Weight of the Air ‘ when it fuftains them, which is diminiftied when it lets * them fall : and as it may often happen that the Parti* cles of Water that are higheft, fall a confiderable time * before they join with thofe that are low, the Gravity ‘ of the Air diminilhes before it rains, and the Barome* ‘ ter Ihews it. ‘ This new Principle of Monfieur Leibnitz^ is furpri* ‘ zing. For muft not a Grange Body, whether ruftain*^ ‘ ed in a Liquid or not, always weigh? Can it gravi- * rate upon any other bottom than that which fuftains ‘ the whole Liquor.^ Does that Bottom ceafe to car- ‘ ry a ftrange Body, becaufe it falls? And is not that.. * body all the while it is falling, part of the laid Li- ‘ quid as to the Weight .> ALthat race, whilft a Chy# ‘ mical Precipitation is made, the whole Matter ought * to weigh left, which has never been obferved, andt ‘ fcarce appears credible, * Notwithftanding thefe Objections the Principle' ^ holds goodi when more clofely examin’d. What fu- ‘ ftaitis. C ) (lains a heavy Body is prefs’d by ic. A Table, for Example, which fuftains a Pound Weight of Iron, is prefled by ic, and is To only becaufe it fuftains the whole Adion and Effed of the Caufe of Gravity, (whatever it be) to pufli that Lump of Iron lower. If the Table (hou’d yield to the Adion of that Caufe of the Weight (or Gravity) it would not be prefs’d, and therefore would carry nothing. After the fame manner the Bottom of a Veflcl, which contains a Liquid, oppofes it fclf to all the Adion of the Caufe of Gravity againfl the faid Liquid : IfaflrangeBody fwims in it, the bottom oppofes it felf alfo to the faid Adion againfl that Body, which, being in yEquilihrio with the Liquid, ii' in that refped really a Part of it. Thus the Bottom is prels’d both by the Liquid and the Orange Body, and luflains them both. But if the Body falls, it yields to the Adion of Gravity, and confequently the Bottom does no longer fuflam it ; neither will ic fuflain it, till the faid Body is come down to the Bottom There.fore during the whole Time of the fall, the Bottom is eafed of the Weight of that Bo- dy, which is no longer fuflain’d by any thing, but puili d down by the Caufe of Gravity, to which no* thing binders'it from yielding. ‘ Monfieur Leihitz, to confirm his Notion, propofed an Experiment, tie fays, that two Bodies mufl be tied to the tw*o Ends of a Thread, the one heavier, and the other lighter than. Water, yet fuch as both together may fwim in Water : Put them into a Tube full of Water, the Tube being tied to one End of the Beam of a Bailance whofe other End has a con- frepoiiing Weight: Then if we cut the Thread which ties the Bodies together (that are of unequal Weight) fo that the heavieft may prefently defeend. He fays, that in filch a Cafe the Tube would be no longer in hrio, but its counterpoifing Weight wou’d preponde- ‘ race C 573 ) ' rate, becaufe the Bottom of the Tube wou’d be lefs * prefs’d. It is plain, that the Tube mufi; be fufhciently ‘ long, that the falling Body may not reach the bot- * tom before the Tube has time to rife. !n Chymical * Precipitations, the Veflels are either too fliort, or * what is precipitated falls fometimes too faft and ‘ fometimes too flow^ for then the little Bodies are ‘ always (as to Senfe) ift /Equilibrio with the Liquor * that contains them. ‘ Monfieur Rantazzini, the famous ProfelTor at Padua, * to whom Monfieur Leibnitz had propoled his Expe- ‘ riment, has made it with Succefs, after fome fruitlefs ‘ Trials. Monfieur Reaumur (to whom the Academy ‘ had recommended itj has alfo made it with Succefs.* ‘ This is a new View in Natural Philofophy, which, ‘ tho’ it depends upon a well known Principle, is very ‘ fubtie and far-fetch’d 5 and gives us juft Reafbn to fear ‘ that in Subjeds that Teem to be exhaufted, feveral things may yet efcape us. ^mnr/{S upon Monfieur Leibnitz’^ principle. Figure 4. Let a B be the Bottom of a Veftet full ©f any Fluid, whole Top is either wider than the Bot- tom as GH, narrower as EF, or equal to \t as CD. The Preflure of the Fluid upon the Bafe AB will be equal to the Weight of CB, or of a Cylinder or Prifm of the fame Fluid, made up of the Area of the Bafe multi* plied into the perpendicular Height above it. Jf the Fluid be equally dcnfe every way as Water, or of a Denftty uniformly diminifh’d as you go upwards* this Propofition (call’d by Mr. Boyle the Hydroftatical T t t c Pa- ( 574 ) Paradox^ will hold good. This is demonftrated by aU: Bydroftaticai Writers. s Figure 5“. Let EF reprefent part of the Surface of the Earth; and GEFH a Pillar of the At:7iofphere, whole Height is GE the whole Height of the Air. Let us imagine the Vapours rifing out of the Earth to form themfelves into two Clouds A and B, and to fettle in that Place where the Air is of the fame fpecifick Gravity with themfelves. It is evident that they will caufe the Air to rife fo much higher as their Bulk amounts to, and will therefore make the Surface which was at GHto rife up to IK, fo that the bottom EF which was pfefs’d by a Pillar of Air as GEFH, is now prefs’d by an higher Pillar as lEFK. Now if the Clouds A, By by any Caufe Ibever, change their Place, fo as to come downwards, ffor Exemple to E, D) the Height of the Pillar I EF K will remain the fame as it was, and therefore the Bottom E P will be prefs’d as before .- by th& foregoing Propofition, Corollary L If the Clouds A, B defeend, and in their Delcent keep the fame Bulk as they had before, the Surface IK will remain the fame, and therefore EF will be prefs’d. as before. CoroUar'j II. Whether a Body be fpecifically lighter or fpecifically heavier than a Fluid ; fo long as it is detain’d in it, it will add to the Fluid as much Weight as the Weight of an equal Bulk of that Fluid: wherefore a Body does not. iofe all that Weight which it added to the whole Weiglit f 575 ) Weight 6f the Fluid, when it ceafes to be fudain’d in the faid Fluid : contrary to Monfieur Ldhnitz's Princi- ple. Scholium. If a Cloud (by any Caufe whatfoever) becomes fpe- cifically heavier chan that Parc of the Air in which ic fwims, the Excels of its Gravity above an equal Bulk ■of Air will make it delcend, and accelerate its Motion downwards; and then indeed ic will lofe of its Weight by the Refiftance of the Medium, till it comes to an uniform (or lenfibly uniform) Motion : but all the Weight that ic will lole will only be the Excefs of its Gravity above that of the Air ; for with the reft of its Weight it will ftill make up part of the Weight of the Air. E>efeYiment I. Figure 6. Having with a Weight in the Scale C of the Balance B counterpois’d the long Glafs of Water E /, with a Horfe-Hair I let down the leaden Weight fV into the Water, which from F6 arofe up to EH; and therefore the V'/ater became heavier by the Weight of a Bulk of Water equal to ^he Lead. Having with ano- ther Weight in C made up the Counterpoife to the whole, with fine Sciftars I cut the T hread of the Plum- met ; and all the while the Plummet was falling, the Water defcended rather than rofe ; and when the Lead was at the bottom the Water overpois’d, becaufe it had then added to it all the Excefs of Weight of the Lead above an equal Bulk of Water, which by Experiment is about n of its Weight. Had Meftieurs Reaumur and Ramazzini trfd the bxperiment thus, the Succefs had been the fame ; but Mr. Ramazzini (as I under flood from a Gentleman who was prefent) tried it in the fol- lowing Manner, as I have fince done. T 1 1 t L C 57<^ > Experiment II. Figure 7,. Making ufe of the abovemention’d Machine, after I had balanc’d the Water and Lead in it, I fix’d to the End of the Beam B the Thread of the Plummet, which in tbe former Experiment I held in my Hj»nd. This added to the Weight hanging at B, and oblig’d me to put into the other Scale a Weight equal to n of the Lead, to recover the Mquilihrium. Then cutting the Thread or Hair, the Scale with the Weights overpois’d whilfl: the Lead was falling ; but the Equilibrium was reftor’d when it came to the Bottom. So that the Lead even then mull have loft only its Excefs of Weight above Water, Experiment III. Figure 8. I tried the Way propofed by Monfieur Leibnitz in the following Manner. I took a Cork C weighing an Ounce, and fomething more than four times lighter than an equal Bulk of Water, and a Ball of Antimony fV about four times fpe- cifically heavier than Water, and of four Ounces Weiglit. The Cork laid upon the Water in the Veftel EAB D rais’d the Water from SS'^to 6G, and added an Ounce to the Weight of the whole Water: then fufpen- ding the Bali of Antimony by a String, and letting it hang in the Water at N, it rais’d the Water from 6 6 to HHy and fo added another Ounce to the Weight of the Water. Then tying the Antimony to the Cork fSee the Figure of the Veftel mark’d with little' Letters) the Cork had added to it three Quarters of the Weight of the Antimony which the Hand before had fuftain’d, and made it fink fo as to be almoft cover’d, and raf- fed the Water to ik, adding three Ounces to its Weight. Hanging this Veftel of Water upon the Balance, and a Coun- ( 577 ) Counterpoife at the other End, upon cutting the Strings the Veflei of Water was rais’d up, and the ^quilihrium. was not reftor’d tiil the Antimony came to the Bottom. By obferving that as the Cork (being freed from the Weight of the Antimony^ arofe, and that during the Fall of the Body, the Water funk to hh^ it appears that tills is, in efTed:, the fame Experiment as the former, and concludes no more. As to the real Caufe of the Va- riation of the Barometer, namely, the Accumulation of the Air by Winds over the Place where the Barometer rifes ; and part of the Air being blown away where the Mercury in the Barometer finks, fee Dodor Hallefe> Account of it in the Thil. Tranla6ihns. Numb. l8i, - TO s I N making the firfl Experiment before the R. Society, of a Piece of Lead liifpended by a Thread, whilft^ it was wholly cover’d with Water in the large Tube in which it hung (whofe Length was 4 Feet) it was obfervable, not only that the End oTthe Balance (to * which the Tube of Water with the Lead in it w^as fixed) did not rife when the Thread was cut, (to • Jet the Lead fall from the Top to the Bottom of the Tube) as it muft have done according to Mt. Leibnitzs Principle; but that the Paid End of the Balance began ' to defcend from the Time that the Lea'd began to fall. Therefore to be fure that it was not the Plummets rubbing againft the Sides of the Tube in its Fall, which caufed that fhtznomenony I hung to the Balance a long Giafs of three Inches diameter inftead of the Tube; and making the Experiment as before, it fucceeded in ( 578 ) fame mannec ; the End of the Balance which carried the Veflel of Water funk as Toon as the Thread of the Plummet was cut ; tho’ this Glafs was not above half To long as the Tube When by holding the String I drew the Lead upwards and downwards in the Water, there was no fenfible Alteration of the y^quilihrmnt. Neither was it alter’d by cutting the String cf a Stone- Plummet, becaufe of the Shortnefs of the Glafs, and the little Excefs of fpecifick Gravity in the Stone ; for the greater the Difference is betwixt the Body made ufe of in this Experiment and Water, as well as the bigger the Body it felf is, the better the Experiment will fucceed. Hence it appears, that when a Body, fpecifically hea- vier than a Fluid, is (by what caufe foever) detain’d iti any Place of the faid Fluid, it adds as much to the Weight of the whole Fluid as an equal Bulk of the faid Eluid amounts to: And when the laid Body, by the Adion of its Excefs of fpecifick Gravity above the Fluid, defcends with an accelerated Motion; fo long as that Motion is accelerated, the Refiflance of the Fluid C which is as- the Square of the Velocity^ takes off Tomething of the whole Weight of the Body ; but as much as the Body lofes, fo much the Water gains, over and above what was given it by its rifing on Account of the immers’d Body. A Body therefore that falls in a Fluid is fo far from making the Fluid lighter as it falls, that it makes it prefs more upon the Bottom that fuflains it, when it is falling, than when it was at reft in the Fluid. If the Veflel of Water be long enough for the falling Body to come to an uniform Motion before it reaches the bottom, the Force impref ’d on, the Water under the Body will make it prefs the Bottom, as much as if the Body were adually at bottom ; the Body in that Cafe lo- fing I { 579 ) fing all its Excefs of Gravity above that of the VVater^ and the Water gaining it. Hence it follows, that a falling Oloud, when it comes to an uniform Morion, will not only add to the Weight of the Air as much as the Weight of an equal Bulk of Air; but even as much as its whole Weight amounts to, tho’ it be fpecifically heavier than the Air about it. All the Diminution of Weight that can be allow’d in this Cafe is this. If we imagine the Air to have a fmooth, regular Surface, as we have at firft flippos’d, for if that be not allow’d, we may take any imaginary Sur- face of it above the Clouds) when a falling Cloud is diminilh’d in Bulk, (as when ic is chang’d into Rain j the Surface of the Air will fubfide in proportion to that diminution, and therefore will weigh lefs, by lb much as is the Weight of a Quantity of Air equal to the Bulk- that Cloud has loft: But when the Drops of Rain after* their Acceleration (occafion’d by their Excefs of Gra- vity above that of the Air^ are come to an uniform^ Motion by the Refiftance of the Air, they reftore ro the Air the Weight that it had loft. Now this uniforns' Motion being acquir’d in about two Seconds of Time, and the Diminution of Gravity in the Air being infen- fible, when compared to near three Inches of Mercury ffor fuch is the Variation of the Barometer with us) can ^ no way be the Occafion of thofefofenfible Alterations iiii it, which happeaforae time before Rain or Fair Weather. Add to this that the vphole ^antitj of Rain that falls in England and Vtuncc, in the Space of one Tear, [cares ever equals tm Inches yf Mercury s And in moji t laces^- between the Tropicks, the Rains fall, at certain Seafons,. in very great ^anilties, and yet the jhervs - there very little or no Alteration^ ( 5^0 ) • V. Account of an extraordinary EjfeB of the Cholick : communicated to the Royal Society, . hy that curious Anatomifl Mr, St. Andre, and ^read March 21. 1717. TH E Peri/fall ick Motion of the Tnteftins is by all Anatomifts fuppos’d the proper Motion of thofe Cylindrical Tubes. The ufe of this Motion is to propel the Chyle into the vafa la^ea, and to accelerate the grofler Parts of the Aliment downwards, in order to expel them, when all their nutritive Contents arc extraded. This Motion thus eflablilli’d, it naturally (eems to ' follow that an Inverfion of it (call’d for that Realbn an JfitiperiAaltick Motion) fliou’d force the Aliments, Bile, pnncreatick jmee, and laftly the F-£ces to alcend cowards the Mouth. The Caufe of this imaginary Antivermkular Motion, •is affigned to a Stoppage of the Inteftin, or to a great length of it being ingaged in the fame manner as the Fingers of a Glove are choak’d by inverting the Glove in drawing it off : Or like as a Silk-Stocking, which when ’tis not gartered, falls upon the Foot, and is in a manner ffrangled, fo that Tome Force is required to bring it up again. This fuppos’d, the Antiperifialtick H'jpcthejis ieems at firft Sight very natural, and anfwers moft Difficulties. For if the P'ermicuUr Motion accelerates the Contents of the Inteffins downwards ; the Antwermiedhr, by the Law of Contraries, Ihould force them upwards cowards .the Mouth. Was f ) Was this Suppofuion as certain as 'tis generally re* ceiv’d, I Ihou’d not prefume to advance chat there is no fuch thing as an Antipertftaltick Motion of the In- teftins; nor that the Miferere mti is ofrner a violent Contradlion of the Abdominal Mufcles, than a Stoppage or Inverfion of the Inteftins, as 'tis fuppos’d. So laying afide all Prevention, let it be granted that this Difeafe is a violent Contradion of the Abdominal Mufcles, as I have already fuppos’d it, caus’d by the Redundancy of the Inceftins or tlieir Contents. Then comparing the Symptoms of this Difeafe, with thofe of the different Kinds of Hernias, vve (hall find by the Analogy of the Parts, Reafon and repeated Experience, that the Chordapfas, fo call’d by Cdfns, is a Difeafe in which the Inteftins and Omentum \ at other Times the Pancreas or Spleen ; nay, even the Mcfentery it felf arc forc’d through the Diaphragma into the Thorax. All thefe tender Parcs being flrongly comprefs’d, by the continual Motion of this Mufcle, muff by confe- quence caufe the fame Accidents as in the Buhonocele or com pleat Hernia, there being no difference in thefe two Cafes ; but that the firft is a ffrangling of the In* teflin by the Diaphragm, and the latter a choaking of the Intefiins by the Abdominal Mufcles. One Example of the many of the like Nature, that I can produce, will much confirm this Affertion, and may ferve to convince any Perfbn that is impartial. The Cafe is this: A Gentleman that came to Town yefterday was Sevennight in good Health, meeting with fome Friends, drank a great deal of new bottled Oat- Ale, after fome Pints of Wine. Thefe Liquors fer- mented fo violently in his Stomach and Inteftins ; that he was taken with a violent Cholick the fame Night. In the morning an Apothecary was fent for, who adminiftred a Clyfter, and took fome Ounces of Blood U u u u' to (5^1 ) rte reKevc the Patient, who complain’d I S S B ^ T At 10. III. Extracls from Mr. Gafeoigne’^ and Mr. Crabtrie’i Letters, proving Mr. Gafeoigne to haye been the ln\entor of the Telefcopick Sights of Mathematical InflrumentSy and not the French. !Bjy W. Derham, Prebend of Windfor, and R. Soc. Soc. IV. An Attempt towards the improyement of the Me~ thod of approximating., in the ExtraBion of the ^oots of Equations in Numbers. (By Brook Tay- lor, Secretary to the Royal Society. V. Broprietates qu^dam fimplices Sed:ionum Conica- rum ex natura Focorum deduB^e 5 cum Theoremate generali de Virtbus Centripetis 5 quorum ope Lex Virium Centripetarum ad Focos SeFtionum tendentium, Velocita- tes CoYporum in illisreyByentium^ gs* Deferiptio Orbtum faciliime deter minantur. Ter Abr, de Moivre. R.S.Soc. X X X X L An ( 5^6 ) L M Account of tk Aurora Borealis, at Lon- don, on the 3 oth of March lafl, as it was cu^, rioufly OhferVd by Mart^in Folkes, Efc['^ R. S. Soc. BEing in the Street, between 8 and 9 a Clock on Sa- turday lad,- (30 Martii) I perceiv’d a Lighp over the Houles to the Northwards, Htrle inferiour to that the Full Moon gives when (he firfl: rifes, Upon. this, fufpeding lome fuch Meteor as we fawthe lafl; Year, 1 made all the halt I could into the Fields, where I immediately found my Conjedure. verified,; and was for fome time agreeably en- tertain’d with the fight of an Aurora Borealis^ attended with, moft of the Phenomena that have been delcribd ia that very remarkable one of the 6th of March, 1 7 1 5-6. The whole Northern Part of the Horizon was in the fame manner cover’d with fomewhat refembling a very confiderable Light, whole lower part was pretty well de- fin’d by the common Edge of the Cloud, but the upper dy’d away more gradually. This upper Limb of rhe Light refembling the Arch of a Circle, whofe highefl Point be* tween 9 and 10 of the Clock (when the Meteor was moft confiderable) was elevated about Degrees, and bore, as I imagin’d, about zo deg; Weft ward of the due North. It touch’d the Horizon in the Weft at the difiance of about 65 or 70 Degrees from the North, whence the whole inter- cepted Arc of the Horizon would have been of near 100 Deg. had not fome few Degrees in the Eaft been hid by Clouds which lay between us and the Meteor. The feeming black Cloud, when I firft (aw it, ran near- ly parallel to the Horizon, and at the diftance of 6 or 7 Degreear but in about half an Hour it changed its Figure very ( 5Sr ) very much, finking down in the North to about half its height, and rifing in the Wed near as much. What J principally took notice of this for, was that the Light iduing from behind it did not change with it, but re- main’d of the fame Figure, hovvever the Cloud ap- proached or receded from differing Parts of its Limb. There arofe at firft fome Streams in the N.N.fV, but of no confiderable Length, few of them paffing j De-, grees above the Arch ; but beginning from behind the Teeming Cloud, To as to be about ix Degrees high in alL They were Pointed at the Ends, and nearly vertical to the Horizon. Between times there Was nothing but the Arch to be feen, and that only refembling a com- mon Aurora ; and again in an inftant, by a fort of tremu • ious Motion, feveral Parts of it would appear convertcd into a vad number of parallel Streams, for the mod part very little higher than the Arclv it felf About xo Mi' nuces before Ten, afmall part of the Arch, almod due North, grew remarkably lighter than the red, and con-, tinned to encreafe for about half a Minute ; when there fuddenly broke out fome very tall Streams of at lead 6o Degrees high, as I found by one in particular which arofe, full North, and pading over the Pole .Star itfelf, reach’d fome Degrees beyond it. This was the mod remarka-, ble time of the Appearance, fome fuch Lances, though not fo high, immediately fhooting out of the Place that firdof all radiated, as did fome more a good way to, the Ead. They were all nearly Perpendicular to the Horizon, and mod of them did arife quire from the black Subdanc*^ at bottom, tho* i faw fome few that did, not reach fo low, appearing as if their lower Parts had been broken off. Some of them were full as bright as any 1 Taw the lad Year, the Axes fif 1 may fo call them) of fome of, the called Streams coming up very ( 588 ) near to the Colour of that pale Fite we fee in feme forts of Lightning. About this time the Ground Weftward was all co- ver’d with an odd fort of Mill:, the fame from which I remember lad Year a great many People faid there came an ill fmell, which I did not at all perceive ; how- ever as I remember it to be the very fame Appearance, I thought it might not be improper juft to take notice of it. About 10 the Phenomenon very much decreas’d, and fo continued till after 1 1 , only fending up now and then 2. or 3 Streams. At half an Hour after ii it was again pretty much encreas’d, and I faw it^^again fend out fome Streams almoft as confiderable .as any I had before feen this Evening ; the Arch yet continued, but not fo entire ; and from wdiat I could judge, its mid- dle was fome Degrees nearer the North than when I firft took notice of it. Till a quarterof an Hour before iz the light continually abated, .and then I left it; but ' a Watchman, 1 order’d. to bring* me an Account of it next Morning, tells me it continued till towards Day- break, but never ftream’d . remarkably after I w’enc a- way. Tho’ I could. not this time fee any Stars through vthe black Matter at Bottom, l am fenfible it was not a Cloud, tho’ tit bore the refemblance of one; for when a real Cloud (as fevcral fmall ones didj came over any part of it, their difference was very confpicuous. I have ftnee receiv’d two Letters, one from Wislkh in the Mle of El'^^ the other from within iq Miles of the ' both which take notice of it, tho’ with no further Particulars, than that on Saturday Night, they had feen the fame Light, tho’ not fo confiderable, as in fethe beginning of March the iaft Year, II. Guil- ( 5 8? ) II. Guilhelmi Mufgrave Soaetatis Sodi^ de Britannia quondam pome Infula^ D IS S U M Belgmm noftrum a Britunnico adluitur 0» ceano, illo latere Infulse hajus triquetrse, quod eft ex adverfo GallU ; vifum mihi fuit, pnufquam id de- fcribere conarer, antiquam & diuagitatam movere quse- flionem, .de Britannia cum GaUu conjundioue, &, an revera unquam eflet, exquirere. ' PR/IMUM igitur, pofita Cherfonefo Britanmca^ urrum exedi potueric i Deinde, utrum exefa fueric, ediG- feram. * D E priori propterea dicendum, quod a dodd & magni nominis Viro, Vojftorum altero, ftrenue negatum fit, unquam, ubi hodie Fretum eft, fuifle Cheribnefum: & quidem ideo negatum, quoniam, illo fentiente, nihil oi deterendae dividendaeque par inveniatur. Uc Tapro* banam (Infulam Ct)lon'^ a vicina continente non avelli probet Vir ClarifE [Otio (a), inquit, abundant, qui ifttuf- wedi fahelUs:, jam mi flies froduBis, totiefq; reco~ Bis, aurem commodant. ^am conflans © tenoris fui eh- fervans Jit rerum natura, patet e Bojporis^ omnihufque omni- um terrarum Fretis. lis cum pracipue Mariam & ipjius Oceani vis femper incuhutrit, eadem tamen uhique a tot an- fjoram millibus & ah ipfo, ut verifmile efi, rerum exordio, ■fervaret intervalla. Currant licet, ac recurrant JJnd/R, al- latrent undequaque FluBus, fortius ejl Elementum quod re- -fa) In Notis ad Mclam., i 7 AT 10. Y y y y JiJIit JifUtf qaam quod oppuguat. Exeji Scopuli, ac vafla marit 'atitrd, fafil ubique ojhndunt, quantum Oceani impetus lapfu feculorum pojfit efficerex vzrum h£c ipfa qucque, quid non fojjtt efficere Ocemus, multercUrius ofiendunt.] Haec Ifaacus. UT' difputationem ea de^re ingrediar, Vir hie Cla- riff Naturse, ncc qua agit ilia nec qua paticur, flatum ac conditionem, ex omni parte, fic, ut eft revera, ani- mo fatis advertifle videtur. Cum nen de Taprohan£ fo- lum FretQ commentatur, fed de Fretis in univerfum, & quidem Argumento a conjlante tenoris fui ohjervante reram natura accepto, videamus quam hsec cum Ocea- nis & Freto noftris convenianc, & in iis quam conftan- ter agat Natura. OCEANI Britannici^ prout nunc dierum eft, cum latitudo turn profunditas inveftiganda, ut ex iis de prifeo feu Freto, five Sinu, poflimus fententiam ferre. Ut autem eas comperiamus, adeunda eft Tabula Hal- leiana, fui generis omnium accuratilTima, ex juftii Regis Guilhelmi ejus nominis Tertii conftrudJa. Ea docemur, in Oeeano Britannko, ubi Terrarum hiatus, hac iliac ampliflimus eft, a veterum OcrinoiLizard-Point) ad Infu- 1am ei oppofitam ZJfhant, unum efie gradumeum femifle, id eft Leucas quafi triginta, five milliaria fo. Hinc Oceanus fe in oriente parum adducit, at multo magis ubi Promontori um in eum procurrit Normannkum : ibi enim eft dimidio addudiorj cum inter Feverel-Point, & Cap. de Hague e regione ftta, Leucarum Anglkarum quafi i6 diftantia fit. Tunc fe iterum effundit, ubi Sequa- nam recipit; at brevi in ardlum agitur, inter Beachf- Head & Qape St. P'allery. Dein paulatim anguftior, fa- ftigiat fe molliter, ufque dum in Fretum contrahitur^ inter Nefs Angiorumt & Gallorum Blacknefs, non ampli** us o(fto Leucis, id eft: 24 milliaribus patens. Terrs tunc / - ( 5P* ) tunc aperiuntur longe lateque vaftilTimc, & fpatium Mari faciunc GtrmAntco. func Oceani Fretique^Sr/w^^/V/ Jiverfe lacitu- dines; quibus apparef, eas, fi non coritinuo, tamen adeo rara tamque exigua cum ampliatione minui, ut argii- mento noftro nihil inde queac derogari. Tta cnim O' ceanus contrahitufj ut qui initio, feu Facicibus ejus -5;'/- tanniciSi Leucas triginta, five Milljaria prsterpropter nonaginta latus fit, poft Leucas 153. circiter, five Milliaria 460, (quae hujus Oceani longitudo eft) ad ^4 milliaria contrahatur; id eft ad prim^e latitudinis par- tem quafu quartam. PROFUNDA hujus Oceani altero jam loco funt Cxpifcanda, & quidem optime beneficio ejufdem Tabu- la. In ea dividitur Oceanus Bntannicus una cum Fre- to, in Columellas numero decern, oblongas. Harum fingulae latera funt ex circulis Meridianis accepta ; qu£C cum in piano duda finr, yidentur efte ^reita. Colu- ipelhe terminantur adverfis GMU ; hoc eft, Lineis hue illuc curvatis in litorum morem. " INCIPIAMUS a prima in occidente, quae & iongiflima Columella eft : & (prsemiftb, quod Hibernia Am & Galliam inter, Oceanus orgyias alt us fit in locis compluribus o(ftoginta; iiti paulo ulteiius in a perto Mari, 100, 12,0, 140) notandae funt in prima CdlumeTIa frofunditates omnium akiftimae ; quse decies exploratJe fe habent, ut 58, 66, 63, 6 58, 65, 68, 60,. 60, 60., quae profupditatum Summae faciunt 6zy orgyias, Lae per de- cern, i* e. pofunditatum numerurh, divifae, mediam ea- rum profunditAtem oftendunt efte 62. IN Columella altera, decem altiflimarum media fro' funditaSi fimili modo inveftigata, eft orgyise 51. In tertia 51. In quarta 40. In quinta 43. Infexta 40. In feptima 36. In oeftava 37. In nona ^ ^. Poft no- nam Columellam, cum Oceanus in laevam fleeftitur, & Y y y y 1 * obli- ( 59* ) obliquas iii Ftetum defmit, accipiam illud ut Terris in- terjacet, in Britannia lo^is appellatis $outh-ForeUnd &t Haftings, in Gallia, St, Valery & Bftaples inclufum. Hie frofurjditatum dQczm media eft 30, In Freto anguftiffi- mo 16 : quae ad profunditacem mediam in prima Colu- mella, eft, uc 16 ad 62; id eft, ut i ad 4 fere; & ad altiftimam profundicatem Galliam inter Hjherniamque, uc 16 ad 80, i. e._ i^t i ad 5 .* ad alciftimam in aperto Mari, uc 16 ad' 140 ; i. e. ut i ad 9 fere. QU A proportione minuitur altitude Maris, ea crefeic Terrae Mari fubjedtae acclivitas; & eft illi inratione in» verfa; quae udque propofitio, .ft non exomni parte ve- ra, ('propter orbis figuram rninim^ rotundam) tamen adeo vera: proxima eft, ut argumentatiohi noftrae fuffi- ciat. Eft ergo Terra, in Freto noftro anguftilfimo un- dis fubjeda, quam in Oceani Britannici faucibus, or- gyias 46, id eft pedes z 76 aftior ; & quam Terra, Gal^ Ham Hihernidmque inter, Oceano fubjeda, orgyias <^4, five pedes 384 altior s & quam Terra, aperto Mari fub- jeda, iz4 orgyias, five pedes 744 altior. Vide quanta fit Terrce ab alto Mari ad Fretum accliviras; eaque uc ex cakulo prkdido patet, fere continua, Hxc eft O- ceani Britannici,, tarn in illius Laticiidine, quam Pro* funditate contradio, AGE, nunc tendamiES ultra, velis expanfts, in Oce- anum Germanicum: Hie Mare fubito patentius. ftc, uc etiam ■'profund ius/ qUpd ititer Promontoria l^orth-fore* iandy Orfordnefst Oppida Cai/^/»w & interfluic de^ cem maxirrias habet menfuras. quarum media z4 Qrgyi- as cum f continec : quod inter /rfirdrjefsf & Tarraouthi Texdlam & Oflenddm eft, maximas decern men I’uras ha- ber, quarum media 2 y Orgyias cum, 7. Quicquid ul- tra eft, Terris,' --hinc ad oeddentem illmc ad orientem, fe retrahentibuS', vaftilTimus eft Oceanus, .in quo mem furae func ab orgyi'is 4*5 ad 5'6''numef6 quaniplutite. H^C ( 593 ) H /E C a Freto Britarmko tarn in orience, quam oc* cidente Terrs declivicas (qus a Maris alticudine utro- biquc auda patefit) omnino probatT in iffo Freto jugum e(fe Terra exeelfumy. acutum ; quod cum hodie non mul- tum infra Maris fuperficiem die reperiatur, olim fc emei' gere, hoc eft Cherronefum olim fiic fui^e, monflrat. ALIA funt duo, qus cum in hac re momenti fine immenfi, tenore rum minus cerco, & nacura minus funt conftanci; quandoquidem a Maris motu & ventis ac- cepca. In refluxu Maris Aqus nunc quiefeentes incu- bant areas ; nunc earn mollicer prsterlabuntur. In situ miciori, Litus & ima Rupium blandidime lam- bunt, tenerrime ofculantur. Fervente vero situ, res omnino alia eft: Aquarum Fremitus auditur, Fludtus cernunrur, & fe non parum attollunt. Nihilominus fine multa ftrage, terrifve aliquot annorum millibus exefis, hsc omnia pofle fieri, cum yojjio, cogitandum eft. S I N sftuanti Mari, quod alcero loco dicendum eft, Ventus fuperveniat (F/4? autera Ventus fie, ut vdt, Sz quis ei tempos fiatueric, aut modum impofueric?) pa- ps ! quoti, quantique Fludus advolvuntur ! Alpes exifti- mare licet Cryftallinos, nifi quod, cito diifluant. Mon- tem enim Mons invadit, detrudit, difeutit ; tantifper ejus fpoliis adau6tus, dum in coelum altiffimus exurgic_ Aqus Mons. Tanta vis Aquarum ex Oceano Occident tali in Britannicum immittetur, & tanto impetu, quan- tus in univerfo Terrarum orbe rams inveniatur; imo quantus ab ipfo rerum initio rarifiime. Oceani Britan- niei turn brevia, turn anguftis, continue poene (quod ofienfum eft) creicentes, faciunt, ut Aqus fic impulfs iuirum in modum elevencur,. & in Ifthmum fquem argument! gratia fuifle damus) arietenr, ita ut ab iis Ifthmum exundari, deteri, ablui ; ficque Infulam . fieri. Brhanniam non videatur dS'uvd'rm verum e contra- rio fadu probabile, Quants Ventorum, at prscipue Zs' ( 594 ) Zeplryri Cauriq; virtutes fine, in cogendo impellendoq; hoc Oceano Brttamko, paucis expendam, a DodiiiTimo viro Rad. Bohun, (Novi olim Colkgii Socio, qui de Men- tis omnium erudiciflime fcripfiO hac in re adjutus. E T I A M S I Zephyrus a Poetis vitam rehus ferre di- cacur. <*r, ejufyue tefentihus auris Laxent Arva Sims\ — — interdum ita fit, ut — — Euriq'-i 2,efhyriq\ tenet domus ; & ut — — !Zefhyo multa turhentur arenae. Adeo fevus, horribilis, iracundus faepe Zephyrus, Vires in Oceano, qui Europdm & Americam vaftus interjacet, acquirens, & in ampliffimo hocce campo recenfens, vix concipi poceft, quanto BritannU Galliaique oras impetu invadac. Exploratidimum enim eft, in hafee oras eum communirer anni plus dimidio flare, (quod jam olim a Julio Cafare notatum) & flacu eas fteviftime verberaie.* maxime autumno, a quo fumunt originem Tempeftates Idiomate noftro dicftiE [Michaelmafs-S terms'] eumq; adeo interdum fevire, ut ft cum reftu fervente jungi Ventus hie acciderit, tarn Oceanus Britannieus, quam Frerum Sahrtnianum immane quantum augeantur. Sahrina va- ftiflime turget. UzelU longe lateque Somerfettenfem Agrum exundat; Mirum ab hifce Cataclyfmis quantum mea patria perpefta eft. Continuatur reftus ad ufque Tevpkeshry, id eft milliaria magis ducenta. Apud Chef- fiovp Aqua pedes interdum odoginta aflhrgit. Idem fere dicendum de Oceano Britannico, Venti ejufdem viribus elato: nifi quod hie, Cherfonefo ^am effrada, liberius Aquse moveantur, non adeo ftftantur, non tantum eleventur; qqse utique Aquarum libertas ante Cherfonefum abrupcam, nequaquam adeo magna efle potuit. HAC ( 595 ) H A C igitur de caufa [Zefhyro nempe, Cauro, five alio Ventorum aliquo, Maris seftui fuperveniente] Oce- ani Britannki Undam in Ifthmum validiffime impingi, & ab illis primum ejus fuperficiemf quae ex Silice & Cake Cprout hodie Terrae e regione oppoficte^ confta- banr, ablui ; deinde Iflhmi quod rcliquum erac, fpatio bis mille annorum & eo ampiius. Aquae fluxu refluxuq; ad 1 6 orgyias, quce hodierna Freti hujus Fquod dixi- mus^ alticudo eft, atteri credibile, verifimile eft, T A N T U M abeft, ut Vejfio^ Fretorum perpetuita- tem a naturae in operjbus fuis conflantia tenoreque eodem arguenti, fidem habeamus, ut e contrario Fretum hocce noftrum illius i/JC6»fia»tU deberi, lubens agnofcerem^ Vir ille c!a.riftimus, naturae ufitatum agendi modum unice rerptciens, extraoydharium fratermifit ; qui tamen, in raris huju(modi effedis, potifTime videtur rerpicien- dus. In Freto Siculo confiderando, ejufque diducendi modo inveftigando, quis Ignis fubterranei fupra mo- dum erumpent^’s, tamquam Caufe hac in re probabilis, non meminerit? nifi iftam Catanenfium d'ro'mctv con- fecutus, qui (tradente Alphonfo f Boreh) poft Eruptio- nem diu intermifTam, Ignem ejus immodicum ne^ femel quid&m unquam fuifle, latis infulfe putavcre. Ut Vento nihil inconftantius, fic ad Fretum hoc apcrien- dum (pofito caufarum apparatu c^tero) nihil conducibi- lius: & cum CO res deduda eft, fortiui dementum ejfe quod oppugmt, quam quod refiflitf Calicer quam Fojfws ftatuit) omnino probabile mihi videtur Salmajjum ille, Virum & candidum & dodum convellic, quod de Navibus ablque Coftis & Interamentis, ita fcripfic, ac fi in HurgundU manfiftet, nec quid rei Navis aur Mare forct, intellexiflet. Nequeo Tatis Ifaacum mirari, quod de Mari & Ventis fcriptor luculentus, horum vires in Marit -j- In Libro de Irtcendiis Mtn<» p. 1I7> tUft ( 596 ) tiirbando agitandoque, in terris obrucndis abrnmpendi(q; prorfus omicteret; atque adeoquod BatAvus : ea fcil. Regione oriundus, qux Mari & Venro tarn obnoxia, NON alienum eric hie Inundarionum aliquot ex- cmpla, uti revera fuere, in medium proferrei quibus abunde patet, Terrse faciem frequenter obrui, & ab iis non parum mutari, Hie autem nihil necefle eft, uc fielken ^ Burin ^ Jc hai ^ Urhes adeamus: de quibus tamquam magnarum Inundationujn argumencis, (i^ OvidiuSj & diu ante ilium Arifioteles. Graviftimas fuifle Oceani noftri, tarn Germnnici quam Britannici, (atis oftendunc Hiftorici Geographique. IN Zeelandid (3) Infulx undecem, & in iis Oppida Pagi fquorum hodie fummitaces aliquae, refluxu Maris in conlpedum veniunr) numero ter centum (^) obrue- bantur. ANNO 1014. [fl^are Lit us egreditur III. Cal, Odoh. ^ in Anglia VtlUs quamplurimas innunterabilemffue fofuH multitudimm fummer/it.] (q) Simeonis Dunelmenjis Hiftoria <^de Geftis Regum Anglorum De hac, ut opinor, Inunda- tione videatur etiam Chronicon Job. Brompton (6), ANNO 1099. [Tertio Non. Novemh. mare Litus egre- ditur ^ villas & homines cpuamplures, Boves Oves in- numeras demerfit\.Sim. Dundmenfis (7) Hiftoria. A D. 1176 [Mare extra fines in Anglia erumpens muU tos in Hollandia homines d? pccora abforhuit, df quap /i) Invenies fub Aquis, 8c adhuc oftendcre nauta ^Inclinata folent cum mcenibus oppida verfis. 1 Metam. Lib. 15. (i-) Ta Apdreyev ffviiA'Ati 7«T0it tv ydg, yip^Ai apA^a^n/xATA v»r.\AKii, KvyLATaip verS tAiV eLv'l^rpAKO'TrlA ’JTOjl am-Ne'WS appcllatum ; Aftorr.m Rhilofoph. No. 272. Et Clarifr'^^////?i de hac Cherfonefo Dif= fertationera. Ad, Phil, No. 275. nunc ( <5oz ) ' nunc exftat (i. e- Herodoti) Hiftoriam, .3500 circiter anni funt; & a Ifoa Diluvio, 1800. At cam immenfo temporis fpatio Cquod fupra innuimus) qua? Caufarutn accidere poflint cv^vylcu ; qu^eque ex iis in orbe noftro fieri mutationes, nemo cam cito ftatuere debebic. D I X I hoc mqtiaquAm ex mni parte veram : quid enim planius illo VirgHii^ — Tenitus toto divifos orhe Britannos. futatis, (inquic eruditifljmus & Anciquiratum Pifit Annie AY um fcierttifilmus (19) Joh, Twinui) vocahulum [divilos] hAhere earn vim ut fignificAt AhfciJJionem alicujus ah Aliquot Et Angler em mire gnarum Jigni^cationis fuijfe, & rerum antiquArum maxime peritum, ^ bene memorem fait Ad h£C verba Servius [^ia olim junlla fuit Orbi 'Britannia.] Nihil clarius efie poteft ad demonftrandum ifihmi hujus divifionem veteribus fuifie notam. Uc omnino fruftra efie P'ojJiuSy & nimio plus VTo^ea-st cTou- . ?vei>eiv exiftimetur, cum in Fabellis jeEgyptiacis (quo nempe fuse opinioni habcatur honos^ earn poni voiu- erit CONCLUpIMUS ergo e praedidis fimul acce pcis, Britanniam non jam inde ab initio fuifje Infulam , fed ex Pane-fnfula fa6tam: idque ut videtur^ a Vento e fdviorihus aliquo, cum Maris afiu concurrente ^ Jfthmum perrumpente. ^ij>) De rebus AWionicUy pag. 22. ExtraSfs ( <5o3 ) III. ExtraSis from Mr. GafcoigneV and Mr. Crab- trie x Letters, proVing Mr. Gafcoignc to haye . been the Inventor of the Telefcopick Sights of Mathematical hiftruments^ and not the French. !By W. Deiham, Trehend of Windfor, and R* Soc. Soc. IN Monfieur de U Hire's firfl Part of his T alula A> (Iron, publifhed in 1687. I find an Invention, which was undoubtedly our Countryman Mr. Ga[~ coignes, afcribed to Monfieur Picard, and that is, the .application of Telefcopick Sights to Aflronomir.al Infiru» ments. Mr. de la Hires Words are, Paucis ahhinc an- nis D. Picard infignis Aflronomus, afcjue in eadem Acade- mia ^ Regia Scientiarurn\ Socius, Dioptrarum crenas ah in- firumentis fujlulit, eorumque loco fuhfiituit Telefcopia ; res Predytis Myopikus,8iC. In which Words it is not indeed exprefly (aid that Mr. Picard was the Inventor of this way, but only that he applied Telefcopes. But by reafon it implies that it was that curious and in- genious Gentleman Mr. Picards Invention, and it is in effecfl: claimed as luch, in Monfieur Auzout's Account of the Telefcopick Micrometer^ in the Philof Tranf. No. xi. therefore I think my felf in Duty bound, to do that young but ingenious Gentleman, Mr. Gafcoigne. the Juftice, to aflert his Invention to him ; by reafon all his Papers, that by the late ingenious Mr. Torvnelefs Diligence could be picked up, are now ^together with Mu Towneleys own Papers^ in my Hands. As for the Invention of the Micrometer, which Mr. , A uz>out claims as his and Monfieur Picards, I fliall fay little to it, Mr. TortneUj having fufficiently prov’d it to be Mr. Gafeoignes, in the Philof. Jranfa^' No. And the OeCcriptions and Draughts of that, and Come other Jndruments of that kind, are now by me, in Mr. Gaf- ceigne's own Hand, to confirm Mr. Torvnekjs Account, if occafion were. (And, as Mr. Gafcoigne.'^2LS x\\Q, .firft that meafured the Diameters of the Planets, ^c, by a Micrometer r fb I fhall prove that he was the firft that applied Telefcopick Sights fo Aftronomical Inftruments. In a long Letter to his fagacious Friend Mr Crahtrie, of Jan. 164V C wherein he deferibes his Micrometer, and ihews his way of finding the Refradtions, the Moon’s Parallax, and how he meafured the Diameters of the Planets) Mn Gafeoigne tells him how the meafuring Glajfes, which he had been (peaking of, might be applied to a Quadrant. If, faith he, here (that is in the Diftindi- Bafe) place the Scale that meafures — , cr if here an Hair he fet, that it appear per f elf If through the 6lafs—r., you may ufe it in a ^adrant\ for the finding of the Alti* fude of the leaf Star vifihle hf the Perfpeliive wherein it is. If the Night be (0 dark, that the Hair or the Point- ers . of the Scale he not to he feen, I place a Candle in n Lam horn, fo as it cafi Light fuficient into the Glafs^^ which I find very helpful when the Moon appear eth not, or it is not othenvije light enough. In another Letter, dated on Chriftmas Eve 1641. fwlierein he deferibes the Wheel Work of his Micro- meter, and Ihews how he could apply it to the taking of three Points ; and fpecifies his ()bfervations of the Diameters of the Sun and Moon; and mentions a Theory he had contriv'd of the Sun ; &c. and faith what pains he had taken in the Anatomy of the Eye) he tells Mr. Crab- ( <5o5 ) Crahtrie how he had applied his Telefcopick Sights to a Sextant. Saith he, Mr. Horrox hh Theory of the Moon J (hall be fhortly furntihed to try. for I am fitting my Sex^ tant for all manner of Obfervations, by trro Perfpicills mth Threads. And alfo I am confulting my Workman about the making of Wheels like (i. of f Diagr. 3, to uje trro Glajfes like a Seilor. If I once have my Tools in rea- dinefs to my Defire,! fhallufe them every Night. I have fitted my Sextant by the Help of the Cane, two Glaffes in it, and a Thread, fo as to be a pleafant Infirument, could Wood and a Country-Joiner or Workman pleafe me. In another Letter (the Dare of which is worn our, but is, in Mr. Crabtrus Hand, called his icth Letter to him) he faith, I have given order for an Iron filua- drant of Five Foot, which will give me the 1000th Part of One Degree, which (hall be furnifhed like my fir ft Scale ; only my Workman is fo * throng for my Father, that / fear it will not he finifhed before the Eclipfe. I have caufed a very firong Huler to be exalily made, and intend to fit it with Curfors of Iron, with Glajfes in them and a Thread, for my Sextant. To thefe I could have added many other PafTages •of the like Nature: but thefe may be fufficienr,to fliew that Mr. Gafeoigne, as early as 1640, made ufe of Te- lefcopes cn Quadrants and Sextants, as well as in his Invention of the Micrometer. What Commendations thefe Contrivances got him, and what Expedations they railed in fome of the A- flronomers of that Time, particularly in two of the mofi: acute of that Age, Mr. Horrox, and Mr. Crabtrie, may be feen in the fame Mr. Crahtrie s Letters to Mr. Gaf coigne, which are alfo in my Hands. Some PafTages of which I (hall recite, and at the fame time give the Society a Tafte of what thofe curious Letters do contain. This Diagram is wanting in the Letter. * A Tor.kjhire Fhrafe for fully employed. A a a a a !n C 606 ) Tti Mr. Crahtrits fecond Letter, which is of Oiibher 30. 1640; after a very clear Demonftration that the- Solar Spots are not Planets at a Diftance from the Sun^ but fomething adhering to, or very near the Sun’s Bo- dy ; and alfo after a no lefs clear Demonftration of the Errors of Lansherges Hipparchian Diagram, his Lunar Farallax, his Dod:rine of Edipfes, and indeed bis whole Lunar Afironomy, together with divers other curious Matters, too many to be fpecified : after this, I fay. Mr. Crabtrie faith thus, Something I am fare you rrere telling me concernin'T a way of obferving the F laces of the Planets ly your Glajfes. But 1 have not a little lamented that my Time cut me fo fhort, when 1 was with you, that I could not more fully ruminate and digeft thofe flrange Inventions which you Jhewed me, and told me of. My Laffitude after an unexpeded and unacquainted Journey ; my unpreparedncfs for thofe Cogitations {not intending that Journey the Day le- fore) and the Multiplicity and Variety of the Novelties you jhewed me, fo wholly difiraded my Thoughts into Admiration, that I cannot now give my Meditations any reafonabie Ac- count of what I favp r but mufl intreat you, in a few LineSy . to rub up my Memory, and tell me again what you fhewed me, and the Extent of thofe your Inventions^ Which I dcftre^ that I might confidcr, and rejoice to conftder^ how much and wherein Urania’/ Strudure will grow to Perfedion by your Ajiflancei and that {what in me lies) I may help you to remember when and wherein your Inventions and Obferva- . tions vcilL be of mofl ufe. I Jhould alfo defire you to inform me what Bignefs of a Quadrant you . conceive, to he large enough for Obfervation with your Devices. For I ant e’re long going to Wigan, iz Miles from hence^ where much Brafs is cafl 5 and then / could fee whether I could procure fuch an one cafl. Toutold me as I remember) you doubted not in time to be. able to make Obfervations to Seconds. J can- not but admire it and yet, by what 1 faw^ believe it i hut long ( ^07 ) to have [ome farther Hints of four Conceit for that Tur^ fofe. One Means, I think, you told me voas, hy a ftngle Glafs in a Cane, ufon the Index of your Sextant, hy vphich f^as / remember) you find, the exati Point of the Sun's Rays* But the may how, I have quite forgotttn, and much defire: Tour Device for the exaSi Divifion of a ^adrant, hy divi- ding i I Degrees into i o Parts, I did then under f and, hut do not now fully remember. If it might not be too much Trouble to you, I Jhould intreat you to give me fuch a Paper- Demonfration thereof as you fhevred me, and two or three Lines plainly of the Z)fe thereof, how to find thofe [mall Parts. I loft the little Paper, wherein I noted the Moons r Diameter, which we ohferved when I was with you i I pray you fend it me, if.^ 8ic. I cannot conceal how much I am tranfported beyond my felf with the Remembrance fof that little I do remember) of thofe admirable Inventions which you [hewed me when I was with you. I fhould not have believed the World could have afforded fuch exquifite Rarities, and I know not how to flint my longing Deftres, without fome further Tafte of thefe fe- lelled Dainties. Happier had I been, had I never known there had been fuch Secrets, than to know no more, hut only that there Are fuch. Of all Defires the Defire of Knowledge is mo ft vehement, moft impatient : and of all kinds of Know- ledge, this of the Mathematicks affelis the Mind with mofl imenfe Agitations. I doubt not hut you can experimentally witnefs the Truth hereof, and one time or other have been no Stranger to fuch Thoughts as mine. And therefore although Modefty would forbid me to requeft any thing [until you give me leave) hut what you pleafe voluntarily to impart, yet the V chemence of my Deftre forceth me to let you know how much I defire, and how highly I fhould prize any thing that you fhould be p leafed to communicate to me in thofe Optick PraHices. Could 1 purchafe it with Travel, or procure it for Gold, / would not long be without ^ Telefcope for eh- A a a a a z fervinr c (5oS ) fervhg (mail /Angles in the Heavens ; nor want the Ufe of your other Device of a.Glafs in a Cane upon the movealle Kuler of pur Sextant (as I rememher) for helping to the ex&6t Point of the Suns Rays. But feeing Urania //, ike. Thus was the mofl: ingenious Mr. Crabtrie tranfpoit- ed with Mr. Gafeoigne’s Devices, although at that rime far iefs perfed than they were in a ftrort Time after. And no lefs affeded was the incomparable Horrox, as Mr. Crabtrie fets forth, in his third long Letter of Dec. a8, 1640. which hath thefe iVords, My Friend Mr.Yioc- rox prfejjeth, that little Touch which I gave him of your Inventions, hath ravijhed his Mind ejuite from it felf, and left him in an Extafie between Admiration and Amazement, 1 befeech you, Sir, flack not your Intentions for the perfelf ing of your begun Wonders* We travel with Defire till rre hear of your full Delivery. Tou have our Votes, our Hearts, and our Hands fhonld not be wanting, if we could further you. And then after many curious Matters f which would take up too much of the Societies time to relate^ he thus proceeds, Diagrams for Perfpe6Hves 1 have view- ed again and again, and cannot fufjciently admire your inde- fatigable induflry, and profoursd Ingenuity therein. I arr» much afelied with the Symbolical Exprefftons of your De- monflrations* I never ufed them before (but I will do) yet I underfiand them all at the firfi Sight, and fee well the Truth of your Demonf rations. To thefe I fliall only add one Paflage more, and this becaufe it fhews feme ocher of Mr. Oafeoigne’^s exqui- iite Contrivances, or at lead the Accuracy of what are mentioned ; and chat is in Mr. Crabtrie’s Letter of Dec: 6. 1641. arthe Beginning of which he faith. That which you give me a full FrojeBion of was above my Hope : and if the Screws keep an exalt Equality of Motion forward in each Revolve, it is a mofl admirable Invention’, and with the ether Accommodations, I had almoft [aid without Com- (, 6ogi ) Compare. But that the Divifiom of a Circle fhould he mea~ - fired to Seconds, without the Limh of an Infirument, or* that Diflances, Altitudes, Inclinations, and Azimuths Jhould he taken all at one Moment, without the Limb of an flrument likewife, and each to any required Humhir of Parts \ or -that the Diameter of Jupiter fiould he projelied in Juch prodigious Me afire s as you [peak of. Sec. were enough to a-* mufe and amaze all the Mathematicians in Europe, and- may indeed be rather a Suhjdl of Admiration than Belief to any that hath not known your former Inventions to exceed Vulgar {Ijhad almofi [aid Humane) Ahiliiies- And. for my Part, I mujf confejs Modefly fi checks my amhithus Defires, that 1 dare [carce hope fich Miracles (hould ever he produced in real PraPtke to fich ExaUntfs. Then (to give the Society a further Tafte of thofe Letters^ follows an - Account of the Agreement of Mr. Horrox's Theory , of the Moon with Mr. Gafcoigne’s Obfervations ; and alfb very curious Ratiocinations, and a Difquifitiori about finding the Parallax of the Sun and Moon, and their Diftance from the Earth. In which he. cenfures Morinus% Braggs, ^c. and then faith, that no Man that hath written of the Diagram [of Hipparchus] underflood it fully,- or 'defer ibed it rightly, but only Kepler and our Hor- rox5 for whofe immature Death [|which was fuddenly* and about the Age of 25.] there is yet fcarce a Day - which / pafs without feme Pang of Sorrow. Thus, among many, I have related fome of the Paf- fages of Mi. Gafeoigne’s and Mr. Crahtrie's Letters rela- ting to Telefcopick Sights. From whence it is very ma- nifeft, that long before tht French Gentleman’s Claims,, our Countryman Mr. Gafeoigne had made ufe of thofe^ Sights in his Aftronomical Inftruments; particularly in two or more Sorts of Micrometers (as I plainly find) and in his ffiadrant and Sextant. And had it pleafed God to have given him a longer Life, we might have ex-< ( ^*0 ) ' peded greater things from his pregnant and fagacious Wit. For he was fcarce xo Years of Age when beheld thefe Correfpondencies with Mr. Crabtrie And at the Age of z3. he was killed at Marflori’H^oor-Eattle, on July X. 1644 fighting for King Chnrles]. His Father was Henry Gtfeoigne Efq; of Middleton, between Leeds and Wakefield. IV. An Attempt towards the Improyement of the Me^ thod of approximating, in the ExtraStion of the ^ots of Equations in Numbers. IBy Brook lor. Secretary to the %oyal Society. IN Phil, Tran No. xro. Dr. Halley, now Secretary of the Royal Society, has publifli’d a very compendious and ufeful Method of extrading the Roots of afleded Equations of the common Form, in Numbers. This Method proceeds by affuming the Root defired nearly true to one or two Flaces in Decimals f which is done by a Geometrical Conftrudion, or by fome other con- venient way) and correding the Aflumption by com- paring the Difference between the true Root and the affumed, by means of a new Equation whofe Root is that Difference, and which he (hews how to form from the Equation propofed, by Subflitution of the Value of the Root fought, partly in known and partly in un- known Terms, In doing this he makes ufe of a Table of Produds (which he calls Speculum Analyticum,) by which he com- putes the Coefficients in the new Equation for finding the Difference mentioned. This Table, I obferved, was formed in the fame Manner from the Equation pro- ( I ) propos’d, as the Fluxions are, taking the Root fought for the only flowing Quantity, its Fluxion for Unity, and after every Operation dividing the Produd fuccef^ fively by the Numbers i, z, 3, 4, Hence I fooii found that this Method might eaflly and naturally be drawn from CVr. 2. Prop.y. of, my Methodus Incrmento- rum^ and that it was capable of a further degree of Ge- nerality; it being Applicable, not only to Equations- of the common Form, {yi%, fuch as confifl; of Terms where- in the Powers of the Root fought are pofitive and inte- gral, without any Radical Sign) but alfo to all Expref- lions in general, wherein any thing is propoled as given which by any known Method might be computed; if vice versa, the Root were confider’d as given : fuch as are all Radical Expreflions of Binomials, Trinomials, or of any other Nomial, which may be computed by the Root given, at lead by Logarithms, whatever be the Index -: of the Power of that Nomial ; as likewile Expreflions of Logarithms, of Arches by the Sines or Tangents, of Areas of Curves by the Ahfciffds or any other Fluents, or Roots of FlUxional Equations, d‘c. For the i^kc of this great Generality, it may not be improper to fhew how this Method is derived from the forefaid Corollary. Therefore jss and a: being two flowing • Quantities ( vvhofe Relation to one another may be ex- preft by any Equation whatfoever) by this Corollary, while z. by flowing uniformly becomes z-\-Vj x will OC OC' X become x -| r v —7- v ^ — -- -|- drc. • "L . z X. i«2«3^' XV 'xV^ . or ^ A 1 J- for ^ putting i. I I Xz I .z.j Hence if y be the Root of any ExprcfTion formed of • y Jind -known Quantities, and fuppofed equal to nothing, and , ( <5ti ) ' and zhc ^ part of j, and x be formed of z and tlie ‘known Quantities, in the fame manner as the Expreffion made equal to nothing is formed of y ; and let jf'be equal 'toz~^V‘. the dilFerence v will be found by Extrat^ing xv X "the Root of this exprelEon -1- \ I I .X I . X . 3 ‘ -]- ^c. r= G. For in this Gale z being become z-\-v =j, xv^ AT, which is now become x xv -\ (jrc. z ' muft become equal to nothing. xvxv^'ic The Root V in the Equation x-\ 1 I I . X 1 . X . 9 ^ (^c. = o, is to be found upon the Suppofition of its being very fmall with refped: to z, fas it muft be, if z be taken tolerably exadl} by which means the Terms jf X ■. \- may be negleded, upon ac- 1.1.3 i.x.3.4 count of their fmallnels with refped to the other Terms, ^ xv xv"^ fo as to leave the Equation x -\ -P- =o, for I 1 .X finding the firft approximation of v, - By extracting the Root of this Equation, we have x“ ZX X That is, X X ^ je“ IX X . X V Firft, ~ — -rr, \i X xV • = o. ^ X X X X X* 2 X X . xv^ Sec. *r- ^ r — if — X XV — O. x"; X X 2i Thirdly I I t ^ 4* — — V— -] if — X — itv -\ , &c. •=. o. XXX 2, This approximation gives v exad to twice as many places as there are true Figures in 2;, and therefore tre- bles the number of true Figures in the Expreflion of y by z -\-v, which may be taken for a new Value of for computing a fecond v, feeking other Values of at, x, x, (jrc, Tho’ when z, is tolerably exadl (which it may be efteem’d when it contains two or three or more true Figures in the Value of y, according to the Number of Figures the Root is propofed to be computed to,) the Calculation may be reftofd without fo much trouble, 'z X 2> X only by taking V ~ — — X ^ X 2, X 2-. 3a; I, ^ . ^j.x inftead - X of — r x“ X taking every time for v its Value lad computed. SC X From the fame Equation x -\- xv -] -f- % I .z. 3 = o, may be gather’d alfo a rational Form, viz. 3 &c. V For negleding the Terms X X 1. 2.. 3 Z X X X we have v = r which is nearly — . , * X « -} V There- forejn the Divifor inftead of v writing r we have B b b b b more more exafUy v X ( ^14) X X 2. X that is I. 2. — X X V X X X X X when X it v~\ 2 o. X X V .XX X *~T 2 X X when — X x v 4 &c, — o. X • X X 2 X X xx X -| : 2 X • . X V when X — ic -y -| &c. = o. 2 when — X — i -v + - — &c. = o. This Formula, will alfo triplicate the number of true Figures in s. And the Calculation may be repeated, af- ^ter every Operation, taking for a Divilor + 2 ic , X X — ~\ 1- ^jrc. inftead of at -] 1.2.3 ^*^‘3 *4 ^ ^ Dr. HalUf has fully explain’d the manner of ufingboth thele Formulas in -Equations of the common Form; wherefore I fliall be the Ihorter in explaining two or three Examples of another fort. Ex. I. Let it be propofed to find the Root of this E- quation — 16 — 0. In this Cafe, for y writing 2, and for o writing x, we have -\- i\^'' ( ) i6=:x. Whence by taking the Fluxions, we have i, and i = 2 v' ^ X 8 — 4 ^ X i\'^ ^ For finding the firft Figures of the Root y, for v' z take f , and we have the Equation ih-j-y — 16 = 05 which being expanded gives y^ y^ z %z y — 255 = o. By this Equation I find that for the firft Tuppofition we may take z — %. Therefore in order to find v, let us now make 2 = (which is nearer than before) and we have x — i\^ z, 16 — 2^ 4. 14 — 5^ — 14= — 4,48 ; x=z 10, 66; it =4,72. Whence by the fecond rational Form v = = io^66 + 4j-7Jl.><-4>-1L, 2 X 10, 66 = o, 38 ; which mufl be too big, becaufe \84/9. Hence by the zd. irrational Formula v ■=. V ^4>934i9 j __ 5,18419" ‘ 5,^8419 ^5* i^!~9 “ oiyi6, which gives y =: z v 2,31516, which is true to fix Places. If you defire it more exadt than to the extent of the Tables of Logarithms, taking z. = 2, 31516 for the next fuppo» fition, the Calculation muft be repeated by computing of zz-\- to a fufficienc number of Places; which, mufl be done by the Binomial Series, or by making a Loga- B b b b b 2 rithm ( 6j6 ) rithtn on purpofej true to as many places as are necef- fary. Ex. II. For another Example, let it be required to find the Number whofe Logarithm is o, z9> Tuppofing we had no other Table of Logarithms but Mr. of 200 Lo- garithms to a great many places. This amounts to the refolving this Equation / 3/ =: o, 29, or ly — o, 29 = o. Hence therefoifc we have x —lx — o, 29, » = — ( a. T. being the Modulus belonging to the Table we ufe, vrz, ^ „ — a .. 2 .. — 6 a 0.4342-944819) X = x=— , •; = — &c. In this Cafe becaufe x has a negative Sign, changing the Signs of all the Coefficients, the Canon for v will be found in the fourth Cafe, which in the irrational Form . ^ Z X ZX gives — ^ . X X Z . 3 * 2 . 3 ■ 4>r zlz — 0,58 zv^ zv"^ '^C. z=z‘Z. -f- ————— — ' ^ 3^ ' 4^. 2 + — : &c. In this Cafe to avoid often dividing by z,. ic 5 -2^ . will be mofl convenient to compute ~ , which is got from this Equation = i — -v/ J + zl z — o, 58 2D- 3 2^ 2 D'l 4 z^ 2 D + , &c. The neareft Logarithm, in 5 the Tables propofed, to the propofed Logarithm o, 29 is o, 2900346114, its Number being i, 95. Therefore for the firfl fuppofition taking = r, 95, we have x {=: I Z — O, 29 = O, 2900346114 — O, 29 ) = O, 0000 o>ooco34^i^4>3nd C'diz) 1 I z — o, ^8 o, 0000692,2 2^8 434^944^19 . , ^ / z O, 50 oooi5'939i 39, and i + =1,000159- 59139. Whence for the fir ft approximation we have ly — — = I — v' I, 00C15939139 = — o, 00007969247, z and V = — o, 000 15 54003 and y = z -}- v ~ 1,94984459968. Which fs true to eleven places, and may eafily be -correded by the . Terms — ;■ which I 3 leave to the Readers curiofity. Being upon the Subjed of Approximations, it may not be amifs to fet down here-two Approximations I have formerly hit upon. The one is a Series of Terms for exprefting the Root of any Qoadratick Equation: and the other is a particular Method of Approximating in the invention of Logarithms, which has no occafion for any of the Tranfcendental Methods, and is expeditious e- nough for making the Tables without much trouble. gensrd Series for expeffing the Root of any ^adrM'ick Equation. Any Quadratick Equation being reduced to this Form XX — mqx-]-my=.o, the Root a; will ^ be «xpreft by this Series of Terms. ^ X = — -f A X — 1 B X C X TT~ q ‘ mq^ ‘ h" — % 0,5^ + D X &c. Which muft be thus interpreted. c — 2, I. The Capital Letters A, B, C, (jrc. ftand for the whole Terms with their Signs, preceding thofe where- I ( 6i8 ) -in they are found, as B = A x — , — • ~~y, “ 2, The little Letters a, h, c, ^c. in the Divifbrs, are equal to the whole Divifors of the Fradion in the Terms immediately preceding ; thus b — a^ — 2. For an Example of this, let it be required to find V2. Putting V 2 = X i, we have 2x — 1 = o, which being compared with the general gives — — 2, and m f — — i : therefore for m taking -—I, wx have ^=2, and y = i, which Values fubfti- tuted in the Series give at ^ y ^ ^ 2x6 2x6x34 I I 2 x6x34Xiij4 xx6x34Xii54Xi?3*7i4* ^c. The Fradions here wrote down giving the Root true to twenty three Places. A new Method of confuting Logarithms. This Method is founded upon thefe Confiderarions. 1. That the Sum of the Logarithms of any two Num- bers is the Logarithm of the Produd of thofe two Num- bers Multiplied together. 2. That the Logarithm of Unite is nothing, and confequently that the nearer any Number is to Unite, the nearer will its Logarithm be to o. 3^/y. That the Pro- dud by Multiplication of two Numbers, whereof one is bigger, and the other lefs than Unite, is nearer to U- nite than that of the two Numbers which is on the fame fide of Unite with its fdf ; for Example the two Num- bers being f and the Produd ^ is left than Unite, but nearer to it than which is alfo lefs than Unite. Upon thsTe Confiderations, I found the prefent Ap- proximation ; ( 6ip ) proximation ; which will be bed explain’d by an Ex- ample. Let it therefore be propcfed to find the Re- lation of the Logarithms of 2 and of lOa la order tothis, ItaketwoFradions^— and — , viz, and if 100 10 lor 10;', whofe Numerators are Powers of and their Denomi- nators Powers of 10; one of them being bigger, and the other lefs than i . Having fee thefe down in Deci- mal Fraedions in the firft Column of the Table annexe, againfl them in the fecond Column I fet A and B for their Logarithms, expreffing by an Equation the manner how they are Compounded of the Logarithms of z and 10, for which I write / 2 and 1 10. Then Multiplying the two Numbers in the firft Column together, I have a third Number 1,024, againft which I write C for its Logarithm, exprefling like wife by an Equation in what manner C is formed of the foregoing Logarithms A and B. And in the fame manner the Calculation is continued ; only obferving this Com^endium^ that before I Multiply the two lafl Numbers already got in the Table, I confl- der what Power of one of them muft be ufed to bring , the Produdi the nearefl: to Unite that can be. This is found, after we have gone a little way in the Table> only by Dividing the Differences of the Numbers from Unite one by the other, and caking the Quotient with the near- eft, for the Index of the Power wanted. Thus the two laft Numbers in the Table being o, 8 and i, 014, their Diflerences from Unit are 0, 2co and o, 024; therefore gives 9 for the Index; wherefore Multiplying the ninth Power of 1,024 by o,8, I have the next Number 99035^03 -9, whofe Logarithm is D = 9C-]-B<, In feeking the Index in this manner by Divifion of the Diflerences, the Quotient ought generally to be taken with ( 6zx) ) 'a^ich the lead : but in the pre(ent cafe it happens to be the mod, becaufe inftead of the Difference between o, 8 and I, we ought flridly to have taken the difference between the reciprocal i , and i, which would have given the In- dex 10? and that would be too big, becaufe the Product by that means would have been bigger than i, as 1^014 IS. Whereas this Approximation requires that the Numbers in the'firfl Column be alternately greater and lefs than I, as may be feen in the Table. When I have in this manner continued the Calcula- tion? till I have got the Numbers fmall enough, I fup- pofe the laft Logarithm to be equal to nothing. Which , gives me an Equation, from which having got away the Letters by means of the foregoing Equations, I have the relation of the Logarithms propofed. fn this man- ner if 1 fuppofe G =0, lhave 2136/ 2 — 643 / io = a Which gives the Logarithm of 1 true in feven Figures, and too big in the Eighth ; which happens becaufe the Number correfponding with G is bigger than Unite. There is. another Expedient Which renders this Cal- . dilation ftill fhorter. It is founded upon this Confidera- tion, that when x is very fmall i -|-xl'’is very nearly I Hence if i and i — are the two laft Numbers already got in the firft Column of the Table, and their Powers i -j-^rl^and i — are fuch as will make the Produtft i x i ^1” very near to Unite, w and » may be found thus : i -f- i -\-7nx, and I — z\" =.1 — ff Zj and confcquently* 1 xl”* x i ~ z\’* i -^-f»ix — itz, — X, orfnegleding 2; at) 1 -f- mx'—n/c- Make this equal to i, and we have zixi'.li — z: / I W hence a:/i — z-\- zl i -j-AT = 0. To give an Example of the Application of this, let 1,024 o»99035'2. be the laft Numbers in the Table, their Logarithms being C and D. Then we have 1, 0x4 Qo.^ O' H, O ( 6ii ) O k- o o « s ^ ’ so -> -• \o «JO ” SW C\ OS o Q-n ^ -fi. ws> I '*-» O' — ^ OO ' s*J --O 1-1 -f* N o o o o o N) OJ s-s Usj if N< V*s» O w '-o CO '•'1 oo K» *-0 ►h CO OS VD M ''J a:. o o so k-» SO o so O VD O 'O O <-i — ^ *'v) -fs OS ts' -fs " O *-i O CO (V 4- •-. CS O V o «>■> o l-l o N> SO VO VO Os OS SM SO QO *vj so o VO so O VO VO O ■'X VO I-. VC V»J CV'-^ CV hj VO h> 03-^ OOVO a-» *- -fv Os oo -1 >- OS O -p' -n ^ O SC' O O 'O M -P^ o O M w u CO N O OO V>>- J O' N v» o V>J 0'-p» Os t® -p- VO M il II II 1^. !>3 7"a; II II fl II oc^- ®i|l f) II v>J Os 4=. O H-' -*-» •^1 -P' o 0-^0 t® Q ^ M C:? o II II II II II ' -U I Os-P' N N> tS) II II SO 63 ^ oa^i ++■^++■^++1 II II II II II II II II II II I N I® o *'* oC'^ ^0-4'^ ^ J sj-i «»J W SO CO t® 4^ V OS ^ or VO ''O O ^ oc. _ v>o >^, O' N» N Os N t® N t® 1® ^ 1® N> 1 I I 1 I ^ ^ < v9 V>>) SM «>s> oo si® VK* o o O o o o 0 ►f h-« ►-( o o o o o o o 1® t® N N 1® N t® VC VC NO 'O so so VO >o VO NC so SO VO VD VO VC nO NO so VO VO '-S '-ri v-n —n '■f •vj Os Os -P* O 0\ ON Os S>vJ '■« ON W SO M ^ s« V A O O O o N uo so o SO ^ Os 0-» v*J y>0 ^ o o O O vij ►I •- o o o t® o t® V o N» oo C ‘cccc G- 2- o J? Si. crp ^ CO cj VO a 2. VC 3 ZL cc. g 3 s/» s» S®1 5 O n? ^ r* C ET O 5-0^ fT OP izr* - C® ^ 3 O u> C o CO :.ii CO r\ O O sz, ° O f6 65' p 5 O n- fi> ^21 ff r-i 3 o >1 o < o t« O .-vTO '* P' o v>® < t-T Q o- ^ o 0-0 3'^ ^ 3 <13 - O 7? a. o 3^ p v< p o o VO Cs oo a> s n n> O o 'H- n o (A sr o c S- ^ • CfQ 3 “o p G Err o’ “■ 3: o = o ; P rt IM ■ o H I 3 v^ O o a 3! 4^ -B-T3 ^0^ »® S o c =rS-° B*0 If P ■ fT (T) p < o o 3 3 ° fD — - g ® s; S s ^ « n ?s n Q 4 rs rs n> o o - II C? E3 *£X g irn oo “C2 ^ o c n n o* c o c_ Cu 3 p ?r o I— V 3t O o !=• - 3 ^ EhCna ??'44 3 • a. Cs o CO s o o pi) pm Pd c <-» 3 ^ 3" f V) >->< (A S®S I t® o lo O I»-| p 3 CP n O 3 7? |X5 C r» 3 r-r H O V* O t® p 3 Cu V N ( ^6ii ) rbave computed this Table fo far, that the 'Reader viuay fee in what matmer this Method Approximates ; this whole Work, as it appears, coding a little more than three Hours time. Y. Troprietates Jtmj)Uces Sedionum Coni- -carum ex natura Focorum deduSliC ; cutn Tl^eore-' mate gener alt de Vtnhus Centrij>etis 5 quorum ope Lex "Virlum Centri pet arum ad Focos Setiionum tenden- tium, yelocitate.s Corporum in illis reyolventiuniy Vejcriptio Orhium facdlime deter?ninantur. Ter Abr. de Moivre, R. S. Soc. Sit D £ Axis Tranfverfus Ellipfeos, AO Axis*alter, & C centrum Sedionis. Sic F pundum quodvis in circumferentia ejus ; P ^ Tangens curvsc ad P, oc- currens Axi Tranfverfo ad punda S, F Foci ; C P, C K femidiametri Conjugata: ; P H Semilatus redum ad diametrum FC; ? G normalis adTangenrem, cui oc- currac HG, perpendicularis ipfi F C in punda G, ut fiat FG radius Curvaturac Ellipfeos in pundo P,* fint etiam S F, CP, FF perpendiculares in Tangentem F ^dcmidae : Jungatur S'O, & demittatur in Axem normalis P L. His pofitis. Died quod, I. Re6iangulum [ub cP (I ant Us ab utroque Ellipfeos Focc, ■five S P xU F . Proinde P .S' eft ad iS TutC D in C A' ad C D X CO, five ut C A' ad CO. Ac pari argu- mento demonftfabitur P F efle ad FV in eadem ratio*- ne. ^ E. D'. III. In. eadem etiam eft ratione Semiaxis Tranfv'erfuc CD ad normalem e centre C ad Tangent em demiff am, five ad C R. Etcnim cum -reiftangulum CR x C.^asquale fit red- angulo C D X C 0, uti jam didium eft, erit dvd^oyov CDadCR ut CX ad CO. ^E.D. IV. Semidiameter qu£vis P C eft ad diftantiam puniii P a foco Sfive ad S P, ut diflantia ah altero Foco FP ad di- midium lateris refti ad Verticem P pertinentis, five ad P H. Hoc autem manifeftum eft ob Propr. I. cum nempe quadratum ex CA' aequale fit redangulo Pu\) S P xP F. V. ReUanguhm Semiaxhm C D xCO eft 'ad quadratum femidiametri conjugata CX, ut C X ad Radium Curvaturx w-punPio P, five . Ad P G. . Smt t ^ Sant enim Triangula PC R, PG H inter fe fimilia, unde C R efl; ad /’C, ut femilatus redum F H ad P G: C D X CO hoc e(l, per pr^Emiflam Propriecatemllf, CK C R eft ad F C ut F//ad c/r* CDxCO — proinde dvdhoyov C D xC 0 :C : \ C K : PG. ^E.D. THEOREMA GENERALE J. P'is cefftrifita ad idem fun^^um S undetis, in Curvis S P emnihus, efl femper proportionalis ^antitati -p-Q ^ 0 ^3 Hoc Tbeorcma ante plures annos a me inveftigatum & cum amicis communicatum, propriis demonftrationi • bus firmavere Geometric Clariflimi D. J. Bernoullius in Liplt£ ; 'D. J. .Keiilius- in harum Tranfa£i. N. 3 1 7. & D. Jac. Hermanrms iwPJooronomik fua pag. 70. quos vide. S P Scribenda autem C pto PG, per Propr.Y; & C K juxta Propr> II, pro S T ; (ob datas fciJicec Q D, CO) eric Vis centripeta tendens ad focum Ellipfeos S, fcmper ut SPxCK’ ,^SP,i . s CfO"x S^' hoc eft ut vel — „ nempe reciproce ut quadratum ex SP. Unde patet quod fi Sedio fuerit Ellip- lis UK«:u corporis defcriptaj erit Vis Centripeta ut quadra- tu'mdiftantiica centro Virium reciproce. Ex his Proprieta- cibusconrequunturCorollarianonnulla notatunonindigna. Coroll i« Velocitas Corporis in Ellipfi r evolvent is, ad panShtm cfuodlihet P, efl ad Velocitatem revolventis in circula ad eandem diflantiam S P a centro Viritm^ in fuhdupU ra- tione difiantia ah alter 9 foco PF, ad Semiaxem tranfverfum Sedlionis, five ut media proportionalis inter P F dr C D ad CD. Eft enim velocitas revolventis in Ellipft ad diftantiam F, ad Velocitatem revolventis in Circulo vel Ellipfi ad • • dift- C ) ' diflantiam Semiaxis C D vc\ S 0, uc C 0 ad 5 7* ; hoc eft per Propr, II. ut V P F ad a/S P. Velocitas aarem re- volvencis inCirculo ad diftantiam C D eft ad velocira- tem revolvencis in Circulo ad diftantiam S P, ut v'SP ad VCD. Ex ^quo igitur, Velocitas revolventis in El- iipfi ad diftantiam S P, eft ad Velocitatem revolventis in Circulo ad eandem diftantiam \\x.VPF ad V C />. CoroU, 2. Ex datis Velocitute in EWpfi, p o fit tone Tange n- tis, ^ centre Firium feu Foco^ facile efi determinare Focum nlterum. n Sit enim Velocitas Data R ; ea autem Velocitas qua deferiberetur Circulus ad datam a centre diftantiam S F fit ac per priccedens, R eft ad ^utV F Fad vC D, adeoque ^^eft ad R R ut C D ad P ^ — R R erit ad ut S P adP F : Datur autem S P ; data eft i- gitur P F magnitudine. Datur etiam pofitionc, ob angu- lum angulo S F /"xqualem. Datur igitur pundlum F alter Focorum ; Quo invento pronum eft Sediionem defcribere. Si vero ~RR majus fuerit quadrate ex 2 — RR fit quantitas Negativa, & loco Ellipfeos Trajedoria de- feribenda in Hy perbolam tranfit. Eritque RR — .2 ad RR ut S P ad P F diftantiam alterius Foci, ad alterum Tangentis latus ponendam, uc babeatur Focus F. Pro- prietates autem omnes quas in Ellipfi demonftravimus; mutatis mutandis etiam Hyperbolse competunr. Fig. II, Quod ft acciderit ^2„:rquale efte dimidio quadrati cx R ; evaneftente quantitate 2^^ — RR — o, quarta proportionalis P F fit infinita: proinde Trajedoria de- cribenda Parabolica eft, Foco fcilicet akero in infinitum abeunte. Axis autem Trajedorice pofitione datur; eft e- nim ipfi P F parallelus, exiftente fcilicet angulo F P V angulo dato S PT asquali. Coroll. 3. Velocitas revolventis in data SePiione Conic a ad diftantiam S P e(l ad Veiocitatemejufdem ad diftantiam alP am S JF, ut media proportionalis inter F P ^ S Jl adme- diafn proportionalcm infer S P ^ F JC. Velo*' ( ) F P Vclocitas cnim in P eft ut v' ('per pr^pr, II.; & per F candem, Velocitas in ut v' ^^-^.Undemanifeftaeft propofitio. Coroll. Ratio etiam Velocitatum duorum Corporum in eo‘ dem S)fiemate,fed in datis Clnife^ionibus diverfis, revolven* tmmy datis utriufqu: a communi Orb turn Foco di ft ant its, ope Coroltarii fiatim obtinebitur* Cum enim Velocicas corporis in P fit ad Velocitatem inCirculoadeandemdiftantiam^' /', ut v'f F ad i/C D. ; & in alia fuppofita Conifedione, cujus Semiaxis cd & FociS, f, ad diftantiamS^ Velocitares illse Tint utV pf ad V c d'.- Velocicas autem revolventis in circulo ad di- ftantiam SF fit ad Velocitatem in Circulo ad diftantiam S pntV Sp2idiV S P Compofitis rarionibus, ericVeloci" tas. in P ad Velocitatem in p,\xx.^^ 1 1 x c d x S p ad V pf X C DxS P. Quod fi Sedio ilia altera fueric Pa-' rabola, erunt cd, pf infinitae, fed in ratione i ad 2; proinde ratio Velocitatum erjt ut VPFxSp ad V.zCDxisP^ Coroll. Quod ft in Hyperbola punBum P aheat in infir nitum, ex pr^cedentihus manifefium eft, Velocitatem ultimam ac minimam, qua cum corpus in sternum afeenderet, aqualem ejfe ei qua, ad diftantiam CD Semiaxi tranfverfo £qualem, Circulum deferiberet. Coroll, 6. Ex data difiantia a Foco, datur quoque Pofitio Tangentis, five angnlus R FT, fub diftantia S P (jr. Tangent e F T contentus. - Eft enim fper propr. II.) P 5 ad S ^ ut C ad C 0 five nt VSP xP ^ ad CO, atque ita Radiusad Sinum anguli CPT. At in Ellipfibus Circulis aflinibus pr^ftaret angulum ^ S 7*,ejurdem complementum ad quadrantem,inquirere : Hujus autem Sinuseft ad Radium \xW ;s F xP F.^CO q ^dk\/SFxFF,r - Cftrefl,. ( 6^7 ) X^oroU. 7. Atcfue him confequuntur f^elocitates ^uihufcum difiAHtU S P srefcunt vel decrefcunt. Nam cum, ex Corollario pr^cedente, ^ S P xP F fic 2d d S P xPF — C 0 ^ uc Radius ad finum anguli PST, ac in eadem fit ratione Velocitas Corporis in P ad Ve- locicatem momenti ipfius S P ; Velocitas autem ilia in P F P fit (per frofr. II.) ut V cl*fis rupcrfluis, erit ^ Velocitati, quacrefcit vel dccrefcit difiantia S P, Temper proportionalis. THEOREMA GENERALE \l In omni TrAjeSforia CurvilineA Telocitates anguUres circa antrum Tirium funt reciproc'e proportionales quadrat is difian-^ tiarum a centra. Nam ob Sedorum minimorum Areas aequales, arcus angulis minimis Tubccnfi five Safes, funt reciproce ut Ra- dii; Anguli autem minimi quibus Bales xquales fubten- duntur funt etiam reciproce ut Radii. Proinde anguli Sec- torum minimorum Area jEqualium, funt inter fe reciproce in dupla rationeRadiorum, five ut quadrata diftantiarum. Coroll. 8. Hinc Telocitates angular es revolventium in di- ver/js Elltpfibus datis comp ar ant ur inter fe. Velocitatescnim angulares quibufcum ad difiantias Se» miaxibus Tranfverfis aequales circuli defcribereatur, funt reciproce in ratione felquialtera Axium, five ut Velocitates autem angulares has medias habent Corpora revolventia, cum quadrata diftantiarum sequanturredan- gulis Tub femiaxibusEllipfeon. Ideo Cpcr Theor. W.y ^iit quidem Quantitas eft ut Velocitas anguli ad centrum S, mptu redse S P, tempore quam minimo dato, defcripti. Coroll. 9. Velocitas angular is qua circumgyratur Tangens P 7, five re^ a in Tangentem perpendicuhris S'T, eft ad locitatem ( 6it ) kcifAtem angular m rc3a S P, ut SemUxis tra^fverfus C D 4,(1 dijlantim ab altero Foco F F, Demonprutid, In Fig* III. Sint punda F,p, quamproxima inter fe; dudiCque S P . S g, fine PT, pt dux Tangentes, adquas demittantur normales ST, St; iifque parallela! ducantur radii Curvacurje PG, />G coeunces in 6: ac deferibatur, centre S & radio S P, arcus minimus P E occurrens ipft Sp 'm E. Manifeftum eft angulum P 6p aqualem efte . anguIoT'5/, five angulari Velocitati norma'is 5 71 Eft autem angulus angularis velocitas redx S P ; quare angulus P G p eft ad angulum P Sp ut angularis VeJoci- tas ipfius S 7 ad angularem velocitatem redlx S P ; hoc eft, ut^ad.^. SsdPp.PExxS.P .Sr-.-.CK:CO r\j r o C K CO (per propr. II). Hx jgitur Velocitaces funt ut ad Pro P G r«ribe ^ CDxCO CDxCO Hinc CDxCO • j CO crit ad t:- —^ FSxPF PSxP f P five, deletis fuperfluis, C Dad P F, ut angulus TSt ad angulum PSp^ five Velocitas angularis Tangencis ad an- gularem Velocitatem diftantise S P : proinde Velocitas qua circumgyratur Tangca«, Temper proportionalis eft . .COxVCD quantitati — jttt • ^ P F X S P q ^leraque horum CoroUarlorurn ex aliis Conkarum SePiionum ^roprietatibus deduPia^ Vel facile deducen** da, inVeniet LePlor in Seifl III. Lib, I. Princip. Nat. Philofophiae. FINIS. LO ND G Nf Printed.-for W. Innys^ at the Princes Arms ifl ( 6t^ ) Number jyjv PHILOSOPHICAL TRANSACTIONS. For the Months of Jtdy^ Augufi, and Sef, 1717. I* A N Account of a ^iffeSlion of a ChiUy €om^ municated in ec Letter to Dr, Brook. Taylor, % S» Sec^ Dy 2)r.. Patrick Blair, % S. 11. De Seriehus infinith TraBatus, ^ars ^rtmak AuBore Petro Remundo de Monmorc. R.S.S. Und cum Appendice Additamento per D, Brook Taylor, % S*Sec, -jodrmiM ( ) JADIH'TO^O'JJH'T A r .>' A - t nr iOi-- ^l.'. ' !-N *> VrJ i, ly 1 A ■■ JooiU Vi \>"nA R l(\ ■ J~y ,'Vj' (. ’ ■■’ ' ' ■ • . . '' . ^ . . A 9 ^ . *- \ r-> ■ i » ; « *Aft • • •tsw^riQ li • iZ 'A- .11 .2 .j-i c::i-jcjioM v\i cb/L'jfT?>i o'n’AJ s'ic'ijift. o' i'^KV.V.V. , w f »v * < > ^ i - i -,^v> ? ljl/..l' \L: n I. h 0 4 I. Jn Jccomit of the DiJfeEllon of a Child, Com^ municated in a Letter to Dr, Brook Taylor, S. Seer, Dr, Patrick Blair, fi. 5. AS nothing is more apt to lead us to the Know- ledge of the feveral Diftempers which affedl the Human Body, and to acquaint us with the juft Prog- nofticks of the like Cafes, than the opening of dift* *. cmper*d Perfons. I hop’d it would not be an unaccepta- ble inftance of my Zeal and Readineft to ferve the Moft Honourable the Royal Society upon all occafions, : CO defire you to prefent them with the following ac' ; count of the Diftedion 1 lately made of a Child. This Child was five Months old, and was fo craa- : dated, that he appear’d rather to have decreafed, than CO have encreafed in Bulk, from the time of his Birth; his whole Body not weighing above five Pounds. 1 The Skin and Muftles of the Abdomen were vefy i thin, but the Peritoneum was preternaturally thick. ’ Tbe Ventriculus was more like to dn Inteftin than to a Stomach, its length being five Inches, and its breadth but one Inch. The Coats of it were thick and flelhy, and the Cavity very inconfiderable. The Pylorus, and almoft half of the Duodenum were Cartilaginous, and fomething inclin’d to an Oftification, lb that no Nou- rilhment could have pafted into the Inteftins, tho’the Stomach had been capable of containing it, which makes it no Wonder that the Body was fo emaciated. There were fcarce any foot-fteps of the Omentum to be'feen, even at the Bottom of the Stomach, to which it ufually adheres. The '( ) The right Lobe of the Lungs adhered firmly to the Ribs SSd h'a^ fhr€e ExuleefiflSfiS, WhRh c6titain*id pu- rulent Matter. It was fb very thin and compad, thaa it Ihem’d as if that Lobe had never been of life id Reipiration. The left Lobe was of a more florid Red^ fpongy, and free from any Adhefioft. Upon enquiring after the Symptoms this Child had been aflet^ed with, his Mother told me, he feem’d tO' be healthy till he was about a Month old, when he Was feized with a vidlerit Vomiting, and a Stoppage of Urine and Stool. Sothe time after« both thele became more regular, blit , the Vomiting ftill continued* ^e (eeni’d to have a great Appetite, taking, what Sutk,^ Drink, or dtlier ^dod was oner’d him, with a kind of eagerneis ; but he immediately threw it all up again* He bad all along breathed freely, and had no Cough, notwithfianding the Exulceracions above mention'd* "This confirm'd me in the Opinion that he had never, breath'd, by the right Lobe of the Lungs. , There could be nothing more emaciated than this Child was; ^d it ^ems to be worth confidering, ti^hether his lUhers might not be owing in a great nieafure to the want of the Omentum,, (for he ieem'd never to have had any) ; as alio, whence it is that cliis Part is generally confum'd in an Atrophy, and ip moft Hydropical Cafes, except where it feif is more. dTpeciaily concerned* I ! % ! I II. Vz Seriehus infinitls TraFhtus. Tars Trimal JuFlore Pecro Remundo de Monmorc. R. S. S. I Trop. 1. Troh, Nvenire fummam terminorum quot libuerit Seriei hujus axa-^n xa -\-xnx &c. xa-^ p — i » 4“ r}xa-\-^nxa -{-'^nx&c-xa pn a-\-% nxa-\--^nXa-\-^nx &c. xa-^p in 4 4" 3 nx&c, Ubi eft n differentia data, ram inter Fadores continues, 4, 4 -j- 4 -{- *■ »» &c ejufdem cu“ jufvis termini, quam inter Fadores homologos termino* rum diverforuni in Serie continuata ; atque defignat p nu- merum fadorum hujufmodiin quovistermino. &ol»tio. Fer x defignetur primus Fadorum in ultimo ter- minorum quorum fummarequiritur, atque fumma ilia eric xy.x~\~ n-<^c.xx-\rpn — 4 — ;; X X p in Proponatur ^EJ. Ex. I. Proponatur Series numerorum naturalium I ^ 4“ 3 4 -|- Sc invenienda fit fumma toe terniinorum quot funt unirates in numero z, qui in hoc cafii eft etiam ultimus terminorum quorum fumma requiri- tur. In hoc itaque cafu funt 4 — i , n= i, p — i,6t x~z. Unde Fitxxx-\-nx&c. xx ~\-p n'=:z,xz-\- i„ 1 n ox I, atque />4~^^ zyz,'\- i a — nx AX &c. xa -\- p ■=zzxi; adeoque fumma qusefita eft Ex- X. Invenienda fit fumma tot terminorum, quoc funt unitates in numero z, Seriei t -|- 3 6 -|- 10 -1- &c. Numerorum Triangularium. Numsri 1,3, <5, in hac E e c e e ' Serig ( ) Serieficfctibipoflunt^^, &(■ Hoc pado, fepofito diviforc dato i, Series revocatur ad foimam Propofitionis, exiftentibus a—i, n—\, & x — z> Unde fumma Seriei duplicata eft X X x-l-i XX 4- 2, -—ox t XX _ X X X -1- « X X -i- ^ ^ 3 ■” 3 ’ adeoqucliabit^ ratione diviforis 2, Summa Seriei ipfius efl i X 3 2- X 3 exiftente x eodem ac z. Ad eundem modum inveniun- turfummae cseterorum numerorum figuratorum, quosum ormulaejam vulgo innotefcunc. Ex. 3. Sine = I, » = X, p = 3. ut (It Series pro- pofita 1 X 3 X 5 -j- ? X 5 X 7 5 X 7 X 9 -1- In hoc itaque cafu formula fummae fir ATXX-l-XXX-l-4x.V-|-^ — 1 2^1x3. 4x X XXX 2 X x-1-4^x-|-6+i5 8 Verbi gratia, fi quae- ratur fumma decern terminorum, fit x = 19 (nempe ter- minus decimus in Serie Arithmetice proporcionalium, i» 3» 7» adeoque fumma eft ^ M _L£ = x868o. Propofitio vero fie demonftratur. Demonfir.atia. Sit Series quantitatum A, 5, C, D, quarum differentiae conftituant Seriem 4, h, c, d, (nemp uc fine 4 — 5 — A, b:=zC — B, c :z=: D — C, ) Hinc ftatim colligitur elle a -\-b-==.C — A,a-\-b-^ c — D — A, a^b-\-e-\-d~E — A: & in genere aggre- gatum quGtlibet terminorum Seriei 4, t, c, d, C'^c. sequale eft termino proxime infequenci Seriei A, B, C, D, Ey ^c. muldato termino primo A. Vio A^ B., C, fume terminos a — n a ( <^35 ) ft y. a 'x. &c. y/i-\-p — i « a y a pn p-\- If} p -f- I » •y a'i- in y &c- x 4 -I- p 4- i n , . n i , crc. hoc eft, valoo r ^ . r xy X -\-f}y ^c. x x -j- p res iuccemvos iplius ^ ; & eo- p-\-i n rum differencia:, pro a, I, c, <&c. fumendse, crunt 4 X /t - - n X &c. ^~a4p — * 4 »x 4 -f z » x ^f.x a~rpff, ^c. qui fume ipfiflimi termini Seriei propofitae. Sed comparando has Series, fi terminus aliguis Seriei pofte- rioris fit x Y^^-r-ny ^c. x x •+ p — i cohftac termi- num uno ulceriorem in Serie priori fore — 'ffT Summa itaque Serici pofte- tioris ufque terminum x x xJ^ny&c,^ x q- p i ^ m- clufive eft xyx-\>nx^c.yx4pf} — 4-*-»X4X^g.x gJ^p-^jn pHr i» ^E. D. Scholium I. In hie propofitione continetur particula qusedam Methodi incrementorum, de qui ante biennium librum edidit-D. Brook Taylor Soc, Reg. Lond. Seer, mihi amicitia conjundiflimus. Librum ipftjm adeat qui de ea methodo plura feire velit •• ad inftitutumnoftrum ftiffi- cit obiervare quanta interfit afSnitas inter Method um hanc & Methodum Fluxionum feu differentialem Nam ut in Methodo differentiali, ad inveniendum difterentiale ip- fius X dignitatis x”, unum latus x convertendum eft in differentiam 57.) faBorum maximus, & applicetur ortum ad nmnerum TaBo^ rum reliBornm cum figno negative. Exempli grati^ ©blato Incremento — ■■■ — : ; , fit primo X -K X n X 2 » — ==zz, deinde — =L=- , denique x\x-\-ny.x-^2n ■ xxx ft — ==, feu quod eft Integra:^ — . z '< X X ft z X % X ft qu^iitum. 4. In cafu hoc noviftimo Intcgrale invemum, cum figno contrario, xquale eft fumm^ omnium Incremento* rum in Serie in infinitum continuata<; v. g-, eft — — 2 x: X X -j- » xy.x-]-ftxx-\-zft x-\- ft X X -\~ 1 ft X X ^ ft + r---' -T'-T — .= — ■ . -}- Nam in hoc ca- X Z ft -a X ^ ft X X ft I fu, fadox' tandem infinite, evanefeit ==^j hoc Z X XX -[- ft eft, ultimus terminorum B, C, ^c. fit nihil ; & ob contrariecatem fignorum Integralis & Incrementi, vice — A exprimitur aggregatum per A. Lefftma i. Per X defignetur terminus quilibet in Serie quivis numerorum M, N, O, P-; ; per x defignetur locus termini iftius X in Serie ilia {y,g. utfit i, quando defignat X terminum primum M, fit x: — 2, quando defignat X terminum fecundum N, & fic de c^eteris) & fint terminorum N, O, P prima differentiarum pri- marum h, c prima differentiarum fecundarum, d pdma tertiarum, e prima quartarum, & fic porro. Turn eric F f f f f X=^M 4*^X ( 6)^ ) X T X — 1 X X — i X X — , X — f X’ X X 2 X — -\- e X- X X X X 3 i X 3 X — — 4. ' 1- Sequitur hoc ex tabula- a^quationum pag. 4 ^ 66. tra(^atua noUri Effay d'^Analyfe, 6‘c-. Lemma x. lifdem po(itis,per 2. dcfignecur terminus quilibet in Se- rie Arithmetic^ proportionalium a, a a^z», & fit jam A zx 2.Ar ft D z x z -j- rt Xz-\- ^ yt E zx"!^ nxz> -\-2.nx^ Turn ipforum Af BrC, D, B, &c. valores erunt. A=.M-\-h X — --\-cx — -X — i — n n . zn . . — a — a — n — a — 4“ « X X + X n n 2 n 3^ + , — a — a — n — a — zn — a — \n , , , 4- f X K ^x- X ■: B n x^ 4-^ X n zn — a — n -1-^ n n A — n — A~^zn — a — zn — X d'Anuljfe, &e, , ubi idem fufius explicatur. Ltmmd 4. 'lifdem pofitis, & Symbolb eodcm modo interpretato 'ac in Lem. z, Ci fit = A B z -\- C z, x z> ff .ut m Lem. erunt coefficiendum A, B, C, D, valo- res. I - — d I — — d — ^ 4 —1— fi .A — q r X — ^ + X n zn J~n n X B — —Xr-\-s I zn a — a — 4 — a n n a a X z n D — X — X j -1- ^ X 1- &€. n In n ' — X X — X t + &c. n zn Ordo coeffidentium in his valoribus eft manifeftusj -& demonftratur Lemma ad modum Lemmatis z. Cor, I. Ubi 4 — coefficientes, A^ B, C, D, d^c. pro- deunt per formulas fimplidores, nempc A=^q^r, Cz^— ^ — xi— ]f n zn j VC* j5 = — \ r — Si D n — X X — t n zn 3 » Cor, z. Unde ft generatorum q, r; s, f, tt, d'c* aliquot iint inter fe ^quales, exhibebitur X per formulam ftmpliciorem , evanefcentibus aliquot coe/Edemium A, B, C, Dy &c, ® Sic ( <54* ) Sic exempli gratia, propofita Seric numerorum 4» 6% J30, 2676, 10350, qui conftituunt lineam decimam cranfverfam in Triangulo Arithmetico cujus ge- ncratores tres priores func 54, — 18, 5-, & feptem pofte- riores (unt sequales 4; exiftentc 4=1 =z», Terminus exhibetur per formulam quatuor tantum terminorum. _ ± Z^ z±i ^ ^ I r 3 7 ^ ^ I z z-\-6 z -7Xy ,&c. Z’\"\ j z-^ 7 . z z~\~i J I J 8 z -4- 8 evaneicentibus coefficientibus fex primis B, C, ^ 9 Z), f- Invenire fummam M Trop. II. ^rok quotlibec + terminorum M Seriei a -x a -{- &c. a-\-»x &c» ^ a -\-pn 4- ' ■ — ■■ ■ + &c, ubi numeratores d -\-z &c. X 4 -f- p 4- I » Af, M, 0, &c. conftituunt Seriem quamlibet termino- rum, quorum difterentije, vel primae, vel fecundse, vel aliae quaedam dantur ; vel quod perinde eft, qui confti- tuunt lineam quamvis tranCverfam in dato quovis trian- gulo Arithmetico ; Denominatores autem conftituunt Seriem in Prop. I. exhibitam. Solutio, per X defignetur primus fadorum 4, 4 -j- xi, 4 -{- 2 ^c. in denominatore ejufdem termini, uc fine X 8iZ iidem ac in Lemm: praemiftis, adeoq iie deftgnetur X terminus quilibet Seriei per — -.-j zxz-^n^ &c. — n Per Lm,Zf vel per 4. Cprout magis commoduna G g g g g videatur ( ^41 ) videatur vel difTerentias,vel generatorestriangulr Arithme* tid adhibere,) refolvatur^ in Multinomiuno A^-\~ C z xz ^ z>-\- ^ 'i- ^ -|- Hoc pado (terminis multinomii ad denominatorem ^ ^ & 4“ ^ &C:. -X. z p — n, afpplicatis) terminus quilibec Seriei revocabitur ad.formulam B X -]- » X z. p — I « — . z-T»'>^&c,xz.-\-p — I » ai.-{-z«x Unde Cper Scholium 4 Prop. T.j aggregatum totius Seriei, a termino ===■ inclufi-^ 2, y. X » X ^£, xz. 4- p — I ^ ve in infinitum continuarse, eft' A p — I ZJ4 n X z -\-p — ^n^ p — z4~ ft X ^c. p — -2, n ■' ' ' ; ' — “H 3 X X z, 4- X X X z. p — i » re- ft demacur hoc aggregatum ab ejufdem aggregatii valore quando zr—a, refiduum erit fumma omnium terminorum ante terminum ^ , hoc eft, tot ter-? minoEum quot funt unitates in ~ — Q^E. I. Sit primum exemplumiaSerie ^ p u i ^ 41 ( <^43 ) 41 5-7-9-II -13 If + liL 7 . 9 . 1 1 IS . 17 473 9. II. 13. 15^. 17. 19 ' 11.13.15.17.59 x1 ^r. Sunt hie 4 r= 3, n f — 6, 7Jf — 5, & ca- piendo differemias numeratorum inveniuntut h = 36', c ==: 54, dz=iQ — e — ^c. Hinc in L^mmate fecun= X i£- 4" ?-CQ 4 do flint — 5 -|- 34 X — ^ -j- 54 X 5 = X 36 + 54 X— — X7 • := — , D—.o-=.E-=:^c, Summa itaque totius Seriei 4 C = — X — >*54 2. 4 109 eft •*4XfXiX3.5.7'9»Ai + :- ' - + 99 ^ X4 XX x5 -7 »9-i^ 183 atque 4 X3XxX7»9«^i 80 x3 • 5 • 7 -9 • fumma terminorum numero C= ") x8? X09 24 X 2i-|-4 . 2:, 4-6 . ^ -3 X - 80 X3* 5 . 7- 9 • 40 X ^ & "h 2- . Z-\- Z-\- 6 . I 99 27 1 6 y; z~\-z x 2i-H4 • ^ ^ ^ Quajrantur v. g. odto termini ; turn exiftente 8 fit 23—19, quo valore in formula ad hibito, prodic funama.— ’ , 2. 3 .3 . 3. 3 . 5 . 5 . 5 . 7 . II . 19 .23 lidem Numeratores occupant lineam tertiam tranfver-.' in Triangulo Arithmetico 54 . 54 . 54 . 54 . 5.4 • 54 ‘ — 1 8 . 3 6 . 90 . 1 44 . 1 98 . 5 -41 . 131 . 275 . ’( <^44 ) Unde in formula Lm. 4. funt generatores ^ = f , ~ 18 ; i = 54, t = o = & piodeunc qoeffi- ^cientes^ = 5 — i8 y ^ + 54 x ^ x — 18 + 54 X ^ C=r= — 4 ' a 2, X X X — X ^ 4 = — » D =?: o = B = iidem ac fupra» 4 4 i- £;c’. 2. Sic Series ii'X*.^ <4*5*^ •7*8«9*^o« II M ^9 _ . , no , . , ~ X . 3 . d'c. 1 X ^ 3 . 4 • M 4 . 5 • 14 ” + d'?* Ubi font 4 = 1, » := I, /) = ir. f . 6 . d'^^. 1 5 atqueNumeratores coflftituant Seriem in Coni. xo. Lem. 4. exhibicam. Applicando itaque valorem ^ in Ctfr»/. illo ad denominatorem 4 xd<^. x^+io, fk Serici propoficas Terminus — ,I i.x.3.4.5.6xs:,-|-6.z,4‘7’^4"^*^-}"9‘^+*o + I.2,3.4.5.6.7X;c + 7*^+8.;c + 9.x-)-iq 7^ iix.3.4. 5'^ *7* 8’t?i4-8,si4-^.x.4-io il Adeoque .] f-i‘2,3 »4*^*^*7*8*5^^'& ”j~ ^ ^ x> ~j * 1 o per hanc Prop fumma Serici a termino ilia in infinitum concinuatx eO: — I 4^^»a*3»4*J' 6 » Si 7 • ^ 8 • si -j“ 9 I + ( <^45 ) + 3X1 .^•3 *4 •5' •6.7X«-|-7 7^ 2Xi.2*3»4\5‘^*7*8^-2i4“2 54 I XI .2. 3-4-5*6^ 7- 8 . 9 x*i + 9‘ Itaque pro ^ fumpto i, fit fumma totius Seriei 305 iz XI. 2. 3. 4. 5. 6. 7. 8. 9. 10 ai — I . £c in genere fumma terminorum numero ^cft [2>z= g ^ X ^ ^ 1 a'* i >■» -■ • I ir ,j _■ ■.•!■■ . . .. Ukimus; aucem>:genesa«)i[ squalls refl Seriei termino pfimo * - . de -^nfvury -'Ahhs Orlactnfi^ mihi amidfli- muSj ruri yicinuSj poftquaiai’T&um eo hsc communf* ' caveram/ aliam invenk liujus Preblematis" Solutionem, cujus formulam ob ejus nnram fimplidcatem hie referre Juvac* Jtaque in Serienumeratorum fint <« terminus pri- mus, ^ pritna'differentiarum primarum, g prima fecunda- rum, d prima tertiarum^ & fic port 6 ; argue (it termini pipiiDenominatpri&xx-l-;? x^g.xai+f ^ j »; Turn fumma ^ ftfmma totius Seriei in infinitum contitiuat^ cxhibebitur pQt fotmulani + n •< p — - &c. xz,-\- p — 2 » + — I >c f — 2 ^ » X *- + p — ti^\ p—^i X ^ p — 3’ X 2i -f- 1 ^ &c. X z~\" p — • 2 -f- drc\ 4^ Sit exempiiim in Serie . 3'.5.Csr. *3 ‘ S.7.&c.i$ V -U d- 131- ■+ ^7$ . 1 > ■ &c. cuius fum- 7.9.e;-r. 17 9. ii.,v2r.i9 ^ ^ mam jam cxhibuimusj In hoc ^aiu func w — ,, .b,^. ^ 6^1 c = 54, d — or=: ez=^c\ Unde per forraulam/jfumma Seriei ihfegts fit" j^r-p ^ + d- _1 £ 4’. 5 . 4 X 5- .... I j - i8U . u^ra-fcr-^ z<»^ X3 • o =^-^r = y ^ ■ ut pbr for- 8.5 . 4. 3x7. ..II 80x3. 5... ii» , . ' ;/ '<•• ^ -■ \ \\ s i 4 ■•• mulam noftram exhibetur. Si quseratur fumma ejuf- dem Seriei incipientis a termino decimo — in *■ - - . r,*'3;=*’ . f-c eo cafu 6) = 22,73, ^ = 522, ^^54» & fumma eilet - X ——111— _| - ^4' . x*5x 21 . ..39 ^4,5 .4XXJ ...29~|~8.5.4.3 X2^....i9 Hsec fortbula bft'comraodifiima, & fummam exhibet nullo fer^' negotio, quoties quarritur fumrna Seriei inte- grsc, & difFerentice non funt nimis mults.' Sed ubi plu- res funt differentire, & quceritur non Series integra, fe4 _ termini tamfim initiales aliquammulti, formula: noftrs " comihodiores. . ... 3. Quando ( ^4« ) -3. Quando Serierum termini formantur tantum per ' Multiplicationem, nec afficiuntur diviforibus variabili- * bus, fummx Temper exhiberi poffunc per Methodum in Trop. I. traditam, fine ' licet formulae quantumlibec compofitae. Nam poflunc Temper revocari ad terminos in forma quam poftulat Propofitio ilia. Sic fi differentiae l ipforum*. Si xCintw & n, ^defignetur terminus Seriei per z x; hie terminus revocabitur ad formam a — »z-\- ~ t xsj w; cujus Integrale datur per Prep, I ; nempe - quoniam dx—n, .& d x, — m, eft ~ ; unde ' regrediendo ad integralia x — a (adje^o in- variabili a, ut habeatur ratio relationis inter ai & x in Seriei termino primo,^ quod fic feribi poteft 4 — X Si ut deinde in si dudJum induat formam re- quifitam. Et ad eundem modum- procedere licet .in aliis cafibus ejufmodi. Sed ubi formulae oblatae divi- foribus afficiuntur, eaedem ac in Calculo integrali, ut vo- cant, difhcultates occurrunt, eadem induftri^ Tuperan- dx, Nec tamen Temper Tuperari polTunt. Nam prxter- quam quod vix certo Tciri poflit q\jx debeat relatio in* fercedere inter Numeratorem fradionis & Denominato- rem, ut formula oblata ad Integrale revocari poftit ; fsepe etiam difficillimum eft explorare an adiit jam tails « relatio in formuli ift^, aut ft deftt, an introduci polftt.' Quicquid ego in hac materia potiflimum inveni, coii- tinetur in tribus Tequentibus propofttionibu£» Prop, III. Proh Crefeentibus, z, u, y, x, &c, per differentias da- tas n, /, 0, dre, invenire valorem numeratoris in- tegri ( y-^l ,&c.y ^ rlxx,x ~{- o &c. j 0 . ^c. Fradio ad Integrale revocari pofllc. Solutio. Fiat N=z-\-pn Xu -\- q m xy rl x ;c j &c. — zuyx &c. atquc Integrale erit frac^io, cujus Denominator g. . -j- » . &c» ^ -\-p — \n %u . u-\- m. €^c. t4 q — I m y . y I , ^c. y — x — \ l^-x o , ^c. X ^ s — 10^ &c. exiftente i Numeratore. Differentia enim hujus fradionis eft fradio cujus nu- merator eft ipfius N valor exhibitus, & denominator idem eft ac denominator propofitus, ut fieri debuit. Ex, 1. Sit denominator propofitus In hoc cafu funt n — 'i^ m=zS> P=^f t; adeoqueeft N = -}- 2 x»-|-3 6, & per — ^ reprefencatur terminus Seriei z,z xy. u . u-\- ^ fummabilis, cujus nempe in infinitum continuat^ Turn* tna exhibetur per Z H Sint verbi gratis, ipforum primus valor communis i, atque Series fummabilis erit I r 2.3 + 35 &Ci quip- mini cujufvis in h4c Seric, erit p 1. 3x1. 4 ' 3-5x4. 7 ’ 5.7x710 pe cujus totius fumma eft i. Per p defignetur ordo ter- % — r-f-2 u — 1 4-^ 2 i * adeoque z=^p — i, 8i u — }p — i; quibus valori- bus pro z & u icriptis, defignabitur terminus per for- mulam itp — t — ===-=. Summa 2/) — I xzp ^ xSp — ^ X3P -r * autem lerminorum omnium ante terminum ilium, hoc eft terminorum initialium numero =:p — i, eft I i i i i I — > ( <550 ) ^ ^ '' zu* zu re pro ^ fcripto p-]-U crir turn tot terminorum inicialiura quoc furrt unkates in f. Ex, r Tifdem manentibus js, u, n, m, fit denomina- tor 4" 2. • ^ ^ per formulam numerator eric z. -|-q x« -f- 3 — 3 z, -}- & fumma Seriei exhibebitur per formulam — — / , — , Sit ipforum a & » primus valor communis i, & hinc eii- i cietur Series j- ~ ^ ‘•S-5’^^-4 V^-7^4-7 5-7-9’^7.io + = i- . , ; i Scholium. In Seriebus jam expoiitis eadem itbique eft j differentia inter fadores continuos ejuldem cujuivis ter- j mini, ac inter fadores homologos terminorum conti- ! nuoraniv In fequentibus exempla qusedam liint Serie- { rum, quarum lummse in terminis numero finitis exhi- beri pofliint, quamvis ea regula non obfervetur. Crefccnte z per differentias datas ^1?, invenire nu.^ 1 meratorem integrum N, ut ad Integral e rcvocari poflic I ftadio, cujus Denominator fit ex certo numero /> ter- f minorum ai, z-\-z», Arithmetice propor- tionalium in invicem dudorum. Debet autem efle q numerus integer minor quam fadorgm numerus p. ^ Solmio. Erie N=: z-\-p^my.zJ^ p — % n\^c. ' x x ^c. x i Iiv z, Z-\~Z-Att Prop, IV. Proh, tegraJe < <^5 * ) tegrale exiftcnte — De- X X (^c. / — in mondratur ad modum propoficionis prascedentis. Sumptis ad libitum p, q, & prime valore hinc oriuncur infinicae Series fummabiles, cujufmodi funt Se- ries tres fequentes. tc <( 13 . i4 . 15 . I6 . 17 Has Series jampridem communicavi cum primariK quibuldam Geometris, a quibus minime contemni vi- dentur. Sic ad me fcribic periciffimus Geomecra D N/cs- Uus Bernoulli in epiftola dati if Julii 1716. “ Vous “ me ferez un extreme plaifir^ Monfieur, de me com- ** muniquer la Solution de voftre probleme, donn^ une fuitte des Fra^Hons dont ks Numerateurs foient dts nombres figures quelconque, ^ dont les Denominateurs ** f&ient formes du produit d'un mmhre egd de Fd^eurs “ qui foient en ProgreJJion Arithmetique, trouver U fom- *•' & principalement comment vous avez trouv6 “ ces deux fbrmules ■, , a4X4/>+i i2X3/’+‘X3?T-i Hae formulae fpedlant ad Series C & B, defignante p numerum terminorum, quorum fumma requiritur- Sic eciam ad me (cribit D. Taylor in epiftola data Augo 1716. “ Uc 6c qui ratione incidifti in fummationcni “ Serieium : a te exhibitaruna, pratfertim 4oquos> de Sene ( ) “ Serie ,-~tT~s + 4.5-^7"8 + 7. 8 '.9’ *0“'.. + quas videtur efle altioris indaginis. Sed ut ad exempla jam redeamus. In Serie func p = 4, ^ = <1 primo valore exiftentc i. Eft itaque z. 3 y.z,-\-% — i ==:xxi-z;-|-3 for* mula, unde frejedo dato numero derivantur nume- ratores 5, 9, 13, 17, Formula etiam furamx eft Quare habita ratione numeri 2, quern ex numeratoribus rejecimus, fumma totius Seriei, a termino in quo eft z, in infinitum concinuatie, exhibecur per formulam ; adeoque fumma Seriei integras eft I 1 3, X t xt 4 In Serie B funt » = i, /> — 5", ^ = 3, ptimo valore z exiftente i . Eft itaque z-\~% — X2i-|-2 = 6>t^:4" Ipflus autemsi-|-2 valores continui funt 3, 6, 9, &c. qui quoniam om- nes funt divifibiles per 3, ponendo 21 + 2 = 3;^, fit N = 6 ^ 3 = 6 X 9 r=: 54x% ipfius x valoribus continuis exiftentibus i, 2, 3, (jre. Rejedo itaque nu- mero dato 54, hinc prodeunt numeratores i, 2^ drc. hoc eft t, 4, 9* &c. Formula etiam Integralis eft ~^-q— ; quare habiti ratioas numeri 54 quern ex nu- meratoribus rejecimus, fumma Seriei a termino in quo eft 8k in infinitum continuatae eft Unde fui»- 54 ? r * ma Seriei Integra eft 108 In Serie denique C funt = r, /> = 5, ^ = 4, & primus valor z, — i .Unde dtN=z + 4 x % -|~'3 x ^+"2 XS-|-I — ^X^-r|-lX2;-]-2XSk^-3 ■— 4 ^ -|- I X ( ) z.-\- ^ x5^-f- 3* Valoresautem Nper hancformulam pro* deuntes femper pofTunc dividi per 4^ ix 3x4 — 5^5. Ergo hoc divifore rejedo prodeunc numeratores i, 14, S5,i^o, &c. Ec formula Summse, habita ratione nu- meri 96, eft Adeoque SummaSeriei Integra eft^.- i t I I Scholium I. Per Propofitiones has duas noviftimas nullo negotio inveniri poftunc Series quot iibuerit fummabiles. Et viciflim oblata Serie hujus fpeciei, fi fummari poteft, ejus fumma plerumque revocatur ad alterutram ex his Propofitionibus. In examine tamen folertia eft opus. Optime autem procedit fi termini Seriei oblata revocentur ad formulam Prop- HI. Sice.gr, Serie 2 .4. LI 1_ 3 . J . 7 .9 . II 7 . 9 . II . 13 . 15 propofita LJ J_ Denominatores fic fcribi pof- 11 . 13 . 15 • «7 • ‘9 funt 3. 7. 11x5’. 9, 7. II. 15x9. 13, II. ij. 19 X 1 3 . 1 7 • Unde Juxta Prop. IH. fitT^^q, m — ^, ^ — primus valor 2s— 3, primus valor 5. Hinc formula Nu- meratoris invenitur 4^z,-|-x»-l-8,Eft autem -f- 2, » -j- 8 femper divifibile per 3 ; quare rejedis diviforibus da-, tis 4 & 3, per hanc formulam prodeunc Numeratores 7, ii, iidem ac Numeratores in Serie propofi- ta, qu£E proinde fummabitur per illam propofitionem. 2. Cum Series illas B, C, communicaveram cum D. Taylor, refcripfit fe earum fummas invenifte primam quidem ^ & tertiam C, eas revocando ad cafus fim- plices Method! Incrementorum, tertiam C, e g. revoca- vit ad hanc formam ^ - d — ■ — h — 4- — ^ 24 1 . 5 5.9 9 . 13 * 13 . 17 ut habeatur fumma per praccepra tradita in SMio Prop, i- Kk k k k In ( <5j4 ) In Serie autcm fecundi cum hoc non (squo fucce/lit, fequenti ufus eft Analyfi, quam, ipfius venia jam im- petrata, ob ejus eximiam elegantiam hue transferre non piget. Seriei iftius terminus [in Stylo ejus] ex- hibetur per formulam =4= j pro 1 Xi[X;t+ I » / } in denominatorc feripto z, quoniam eft 2; = 3. "B B “ Pone acquale efle Integrali quaefito, hoc eft X I 1 X ^ ♦ ^ efle Integrale ipfius — == * -■ ■■—» fepolito divi- fore dato 27. Ipfius autem incrementum eft " Debet ergo idem eflo ac ^ cc ^ cc t •' I x;?.;?+l‘ ‘ #1 Comparando' denominatores inveni- “ tur C = » X I. Hinc itaque fumendo incremenr ** ta fit C= z zz, z (=zz zz ^Zi quoniam “ eft a — 3,^ His vaioribus in locum C & C fubftitu- " tis prodit B C — Be — zz-]- zy- B — % z>xz-\- z Bt ** quod debet efle idem 2iC z-]^z x z, SiiB—a-\-*v, exiftente a ipfius B parte invariabili, & parte va- “ riabtii. Turn fumendo incrementa fit B z=. 'o. Unde ‘‘ ad invenienda a (k v habetur aequatio zz-\-^"^ “ — 2!&-x2i-h2X4-j-'z;:?=2i-H2xfc,. quae fic feribi poteflz-ai + ai •o — % z%z-\- zv— X i+2-4> ** vei etiam C 'zf — C^ z -]-i Xz-\-z Turn appli- cando terminos ad Denominatorem novum z>^z-\- i xz, -\-x y. c^c. revocetur fradio ad hanc formam ^ — -4- : JL- h= ^ X ^ -f- * (3c. K~[' ^ ^ K "h i K (3c. + X (3c Unde denique quseratur Inte- grale per &chel. Prop. I. 3. Ratio Solutionis per le facis eft manifefta. Scholium r. Hujus Solutionis tota difficultas latet in revocatione numeratoris ad formam requifitam, quod tamen quomodo fit faciendum uno exemplo patebit. Proponatur icaque fadlum ?X^ + 7» quod ad formam propofitam fit revocandum. Terminos ita- que evolve gradatim ut fequitur. Faeftorem primum z-\-z fie feribo cujus terminum primum z duco in 3 unde fit 6j^\~zz>: Terminum fecundum z duco in z z. 1 f = z -j- 5) unde fit z ^ i. Dein fada in unam fummam colligendo, fit z -{-% x*^-l-3 =^ + ^+ * X '■+ ‘ = '5+4s + «ix Supereft ut hoc ducatur in & 7* Ttaqnc terminum primum 6 duco in .7 z. (= z. 4~ 7) unde fit qz 6 z; terminum fecundum 4 z, duco in 6 % 'j- i i~ z. -|- 7) unde fit 24 i?i 4 zx z i ; terminum tertium z. x z-f- 1 duco in 5 -f- z-^ z ("— 2^-4- 7,) un- de fit ^ zx i z-j-z. Fadis iraque in unum colledis ut prius, fitz.4-zxx z-'r^ rzr:4X-|-30Z.-|-92:,’«2i-|-I-|-Z.X!&-|-iX!&_^2. Ec ad eundem modum procedere licet in aliis cafibus. z, Sic ( ) z. Sit autem exemplum Propofitionis in fra(3rone Reftituendo faflores ^ + i, si + 3, z-j-4 in Denominatore deGcientss, fradlio fie l±_L21ljhiJLL±4 r> , :^x^i-ixK-h2x:( +1211.+ 4illi ^ ' ^^^afidus ita* que eft Numerator ?i-}-ix2i-j-3X«'-f4 ad formam requifitam. Itaque per mechodum jam tradiram fit primo z-\-i xz -[-3 — i x }-\-z -\- zxZ-\- -|-i ~ 3 -|- ^ -j- ^ ^ z, I — 3 -|- 3 ^ -j- g g I. Deinde z-^ i x^-j-3Xg + 4=z3 % z X 3 -\-z -]-l-|-2,xz,_|-i — ix-j-jg-j-qg -]-3!&X!5,-[-I ^ % Z X Z I -}- 2i X g. I Xg rzr: I 1 — j— Ix Z — 1~ ^ Z> "><■ z I —j" Z x z — I X g ~1“ ^ • Applicando hoc fadum ad Denominatorem x z. i x &c. ^ z-\- 5 fradio tandem revocatur ad hanc for- mam II + ^X^+iX^-hiX;i-f3X^+4X;?-f-5 4- ^ ^+»X^ + iX^4-3X;?-l-4X^-t-5 ’ + ^ + 2,x;?+ 3 X;? + 4X^4-5 Cujus denique Integrale eft + ^ -4- 3X3] Hr 4 ^ 'f~ ' — 1^ — 12 4.3' + iX3:4-2*‘;{+3 ^^4*4 — I 5;^X;^4-ix;?4'^X;?4-3X3;4-4 H- 3.;^4-2x^4'3''^^H-4 2.;?4~3^^H-4 3. Quando duo tantum lunt fadores a & g + I I exhibebitur etiam Integrale per formulam— . d’c. -4x2 1 — /jx2 — 4x3 — a 33[x;^4-i>^^4«2 45 ^^4“I>^^4-s. >«;?4-3 Seriem nempe continuando donee abrumpacur per eva- L I 1 1 1 neicentianai e 658 ) ncfcentiam tctminorum. Si Fadiores duo Tint — # cxhibebicur Inregrale per formulam — &c. Poteft idem Integrale — I -f> J ^ — r a 3 • ‘ • 3: — 3 exprimi ucroque modo, prout fradionis oblatai fador vel minor vel major fumatur pro 2:. 4. Si primus valor g. fit a -\~ t, migrabit formula pofterior in hanc ^X-7 ^ ^ ^ ufque inclufivc, qu^, cum figno contrario, cxhibctur fumma Seriei „ -4- ■ ,■ -1- , ^ ' 2X2“T4 3X3“T*« nitum continuarse. Sit r. g-/*, 4= 1, atque Scries eric + r^3 + F^4+^‘'- = T’'T = *-S'‘' = »>e- 1^3 2,x4 3><^5 * » g 4 Si «=3, Series erit ,-^+ril +T^ + + &c. in infi- J X 2 rit Series 3 1 ^ 3 18 + ■ <. Ex eadem Serie — === . ^ ■* lXI-t-4 2’^2-f~<* 3>^3“r<* '4 &c. pro diverft) valore a oriuntur Series plures forml fatis elegantes, quarum nonnullas Ledori ob oculos fiftere, credo, ingratum non erit. Si pro a fumantur fucceflive numeri pares, ^, 4, 6, 8, &c. Series erunt Si<*:=2) 4) 6) 8) + ■f ixi-^-2 2X2-p.2 3^3-t-» 4><4-i-2 L^4- — L=r--J. L=- 4- I X I 4-4 * 2 X 2 -r4 3 X 3 Hh 4 4x44-4 I , I j i I Wil im— _ ■■ L,— ■■■■—— ~j ■" ~ ■ I X I 4“ 2x2 4“ ^ 3^3 "i" 6 4^4 4“ 6 I » I . 1 J , I T'f' 3+ i X 4* 8. * 2 ^ 8*3X34“8 4X44-8 + ^c:. Vel ( <^5? ) JIT, +?~. + + 5^7 +:^, + pr — I L ^ _r _Jl L — L- 4- (^c. l6 — 9 ‘ 25 — 9 ^ ^ 49 — 9 v5-4 I 3^—9 I 49—9 ___i — f ? — 4_ r -I ! s- r^c. 25-16 ‘36 — i6~49— 16 ‘ 64 — 16 * 4" £^c. Vel — ^ -f* — ^ + -^— + 4 — I 9 — I 16 — I 25 — I .-1. , 44-1 94- 3~ 164-5 + + — ^ f * t I 44-3-94-7~‘ 164-11^254-15 C^c. 254-7 * 4" G?c.' 4 4_ y 4“^^ J , 4~ J54_iy 4" 254-23 Si pro a fumantur fuccelTive numeri impares i, 3 > 5“» 7» &c. Series erunt a = i) 3) ■r+. 4- h- + IX14-1 ‘2x24-1 ^3 ^3”t“i 4x44-1 “ ' f— =+ ' I X I 4-3~^2 X24-3^3 X 34-3^4^44-3 5) 7) i ^i4-y*^ax24-5~^3x34- 5^4 x 4 4“ 5 4~; ■+■ I . i x j 24-7^3 X3 4“7^4^44-7 Vel— X 4- 4- -- 4- - ‘6 ^10 -fx -i_ . ^ , _1_ 2- 3 — I* 6 — I 10 — I ^ I 5 — X ^ — L — L_ ^ 4_ L_ 2 6 — 3 I 10 — 3 ‘ IJ — 3 *^21 — — X L. 2 JO — ly — 6 3 • I? ' + 2-7^. ' Vel — X ' — -X --L 2 14-0* t 21—6 I 28 — 6 I r I — X — — 2 j-f. I I 4- * _L __i-_ ‘ 6 4- ° ‘ 1 ® 4" ° 3 -J- o T+ f+T + A — !■» o + ‘ 6 -i- 3 10 4- 4 II I j » ^ I Hh 2 3~4-1^ ^ 64-6 1 I — X - Z I I o — 3 j 1 _i ^ y I 4" 3 3 ri" 6 4- ^ _j_ ^ 4- ^ J2. -i“ ^c. 4" 4-0'c, 4- 4- 4“ C^c- 4" 4- 4-(^cr,- 4" 4 6 Ante 6, Ante aliquot annos D. Jac. Bernoulli Geometra infignis invenit rummam Seriei cujuflibet, cujus Name- , ratores conftitaunt Seriem aequalium, Denominatores i vero conftiruunt, vel Seriem quadratorum dato aliquo . quadrate 2jnioutorum, vel Seriem Triangulorum, dato ' aliquo Triangulo T minutorum. Haec invenit ille ob- fervando quod hujufmodi Series oriantur ex ablatione ' Seriei Harmoniee proportionalium truncatas ab e^dem ■ Serie Integra ; nempe ita ut numerus terminorum defi- ! cientium in Serie truncata, fit, vel du plus lateris dati 1 quadrati vel duplus unitate audus lateris dati Tri- • anguli T. Idem etiam obfervavit fruftra quaeri fum- mam Seriei reciprocal Quadratorum. Hoc idem etiam verum eft de reciprocis Cuborum, vel aliarum quarum* Ubet dignicatum numerorum in progreftione Arithmeti- ca. Ratio eft, quod nulla intercedit differentia inter J fadores denominatorum, quod ad hujufmodi fumma- { tiones femper requiri conllac ex Methodo fumendi > differentias in SchoUo Prop. jam explicata. Nam fi -j per formulam aliquam exhiberi poflet fumma quicfita, ' differentia iftius formula exhiberec terminos Seriei propofitae.* fed in tali differentia denominator femper ^ afficitur per fadores ab invicem diverfos, quod quo- niam in Seriebus pr.xdidis non obtinet, fumma: Serie- j rum hujufmodi in terminis finitis haberi nequeunt. Ad * eundem fere modum, argumcnco petito a Prop, HI. & IV. demonftrari poteft fummas Serierum exhiberi non pofle in terminis numero finitis, quarum Numeratores .J conftituunt Seriem a’qualium. Denominatores vero con- ; ftant ex certo numero terminorum in progreftione A- ; rlthmetica, maximo fadore cujufvis termini minore ex- . | iftente quam fador minimus in termino proximo in- | fequenti, cujufmodi eft Series 7. _Jam liceret regulas nonnullas tradere quas pro j cafibus quibufdam fingularibus concinnavij fed hare nos I ( 66 1 ) nos longius abducerent. Sufficiat itaque quas ; genera- liora ;funt explicafle, & fimul monuifle, ad nov^ hu jufce Serierum infinitaruni dodrinse provedionem ni" iiii magis facere, quam fi excogitentur formulse ge- neraliores fummarum, ex quarum diff^endis, .per re» gulas fupra traditas computatis, deinde conficiantur Ca- nones quantitacum fummabilium ; ica fere -uc jam fa- dum eft in Calculo Integral!, h. e> in Stylo Newtoniam^ in Methodo Fluxionum. _ '8. Reftituendo fadores in Denominatore deficient tes potuillet prsefens Problema revbcari ad Fropalftio~ mmW, Sed & in terminis generalioribus proponi po- teft, nempe pro Numeratore fumpti quavis For- mula, cujus differentia aliqua datur. Sub ea ramen conditione ut dimenfiones Denominator is ad minimum binario fuperent Dimenfiones Numeratoris ; alias enim fumma Seriei in terminis numero finitis haberi ncquit. Sit hujus rci cxemplum in Serie 777777^ + T. 4^6. 8 37177^+ ^70777 4- “b* I^utoeratores funt numerorum naturalium quadrata. Applicaiido turn Nu- meratores turn Denominatores ad numeros naturales, I 2/ Series revocatur ad forraam fimplkiorem ^ ^ 5T7~9'^6.8.'jo + ^^» Per P defignatis numeris na- luralibus i, 2, 3, 4, &c. terminus Seriei defignabi- tur per formulam — ; 7—^ — =f^ ; vel per formu- pro/> -f i fcripto z. Quo- niam progrediendo de termino iii terminum augetur z. per unitates, reftituendi funt fadores in denomina* tore dcficientes ^ pado revoca* tur terminus Seriei ad formulam — ^ j_=r- Per methodum in h^c Propofitione jam explicatam re- M m m m m vocatur ( ) 7ocacur numerator ad formam — 5 — — zxz-\- i* -|-xxz-+iX^4‘^’ Unde habitai rationr denomi-- natoris Terminus revocatur ad ibrmam . , - r * » X l + X X t.4- 8 X ^ + 4 ■ ^+2.X ^4" 3 X 4. 4- ===r-^-^«==. Adeoqufc Cumendo^ Imegrale fit. 6' 3.x? +i X?4-»X? + 35 — »== 4- J-r-r ; , quo, . Tub figno contra- rio, exhibetur. fumma. Seriei in’ infinkum continuaca?^ incip;ieatis . a . termino > ^ ^ itaque : Seriei integrae. incipientis a termino ~ eft‘ Si i per Pr»p, \h proeedere eflet animus, ex formula t z — i x.zi -\t 1 x 3^ colledii numeratoribus primis- a4, 70, i44i x52,.fiimendo eorum difierentias babe- rencur 46=^, 28 =r, 6=d, e=:o=i&c» exiftente M=z 24 ; unde perXfw. 2. prodiret formula — 6 — 6 z 1 — z X &-f" * X z- + qud defignatur Tet' minu&, eadem ac fupra ; acque pergendo per Prof. U.i baberecur fumma^ Frof. VI. Prohl Invenire fommam quotlibet terminorum Seriei Fra-» ' Sionum^ quarum Numeratores & Denominatores epn- fiituunt lineas duas quafvis tranCverfas in Triangulo> Arithmecico Pafchalir; nempe cujus generatores funt unitates. -Svlutio* Per*;? defignetur Ordo Seriei Numeratorum. in Triangulo Arithmecico, & fit f differentia inter ordtnem Numeratorum & Denominatorum, & per.^ defignetUcT numerus terminorum quorum fumma re- quirkur ( d6j ) qairicur. Turn (1 Deaominatores fmc plurium fionum quam funt Numeratores, Summa exhib^bitar per formulam primam' {equcntem j Ci dimenfiones- Numeratorum plureS/ fint quam dimenfioncs Deno minator um, . Summa. exhibebitur per formulam fecundam. Formula:. I. n 'T^p — I w ■ »-t~j .«>4- 2 « €^c. w «4~ P — » f — ^ ”” p — I ^ Formula IL n — f — I . \ — 1 ,^c.q~\-n — p — i P + * — i.« — — p Ex, I. Inveniendum fit aggregatum fex primorum? terminorum Seriei — + -i'4- ^ -f - ^ H ^ "F ^ ubi Numeratores conftituunt lineam quartam, Deno* minacores condituunc lineam feptimam in Triangulo Arithmetico. Sunt itaque. » = 4, f — y* quoniam dimcnfiones Denominatorum fuperanc dimeu- iiones< Numeratorum, dabttur fumma per Formulam < primami nempe — ; — T“ — ; dve ^ 3 — i 3,— I X 4 + 6X4 + 7 Ex, z: Quseratur fumma (ex primorum terminorum > Seriei +— -1“ ^ 4“ cuius ^ termini funt terminorum Seriei prioris reciproci. Sunt itaque » = 7, f = 3» adeoque per formulam ? fecundam fiimma fit — ^\‘xl \ ~ Scholium 1, Formulas in->hac propofitione exhibitas^ ante biennium communicavi cum Viris celeberrimis Molvreo & BermullHs, Facile autem derivarr polTuntr ex prxeeptis in Pro^, I. traditis. Sit exemplum in Se- rie priori "7 4"-^ + ^ + ? defignato loeoi* Tet?‘ ( rri‘Se46,^jic» exhibetuf Terminus per formulam • • .^_y ^ ' 11^0 Unde regtediendo ad Inregtale, 4- 5 .<$ fumma Ssriei incipiencis a cermino illo exhibetur : per formulam — -r^ ’4===» ; a4eoquepro/>fumpto f, Se- ^desr integra fit 'atque fumma primorum fex terminorum fit g ij-Lii- omnino ut per for- - X . IQ. . 14 . mulam jam. exbibetuf. , ^ ^ < 2. In formula prima fumma Seriei in infinitum con- tinuatse eft.” ? ~.d./ evanefcente jam parte altera for- mulae. Sed jn cafu formula: fecundae fumma bsec eft infinitum quid, , cujus fpecies, refpedfu numeri infiniti q, exhibetur per formula: partem alteram, qii£ in hoc p ~i~ I cafu fit -=~ — = ^ p-\- \ y.n—^ I ,n — X. (^c. n — p ^ V De hujufinodi Scrkbus in_ epiftolfi data 'menfc Mato 1716, fic ad me fcrrpfrjVir. lil. D. Le^mtius, quern magno Scientiarum damno nobis nuper ereprum lugemus. ‘‘ 11 me femble qu’autrefois jay aufii fomme quelqu'es Series ou- foktes coriilnr'~4''-^ + ^ + ^ « C( ^ -r ^ Lc ' termd de cette Tuitte exprime Analytiquement eft X . R X . a; I , X- 4- 2. X r • -i . 7 ^ On demande done ■tt <( x4-i-x-±x la Torn me d’une fuitte donned, dont un terme (bit XX ^ fignifie les nombres naturales ^ *' I, 2,, 3, 4, & / fignifie rUnite, ou la difterence y des X Suppofons que le terme de la fuitte fom- matrice ( 66y) ** matrice demand^e foie fx mx n I O Or DifT.2 2 ® J. o_Li® = : fed o ^f>lx; }) D -j- Da J) ^ ^ Sid D —mdx nftl m /; done la Dil?erence de — eft mmxx-\-imnlx n nil' -j- mmlx'\-mnll nfll Maintenanc il fauc faire mfl I . mm X X ^ i mm I x-\-z mm 1 1 m m X X -{- 1 m yi I x-\-n nil -j- m ml jf =-J-w3 nil “ e’eft a dire, il fauc identifier ces deux formules, ou la **'donnee eft Multipliee per done egalant les m m termes refpedifs, puifque les .vat conviennent, on “ aura par les x, z -f- w — 3 w, e’eft adire il y aura “ m — n.Si par les abfolus on aura nn -\-m n—'i.mra, ce <^ui donne encore w — »; done i’idencification “ reuftit, & nous pouvons faire n — m — 6c f— i (car / demeure arbitrairej & le terme de la “ fuitte fommacrice fera — — , car diff. — — donne X V .r I donne la fomme des X O ' Jf + I 3> 4’ —5 — j 5>— , Series Jummatrix, emus ter^ 2 J 7 ^ ■ 6 X X.X-\-I.X-\-ZXt.{.7 1 1 ^ 1 4 -1 CU‘ “ 4- X ^ . s tries fummsnda, i«s lermlms ^ ^ ^ Ec pout f’en fetvir aux fommations, les 5 termes, Ex. de N n n n n la' '( 6^6 ) " la fuitte donnee feront y — 3 — ment la fomme des termes jufqu’a quelque terme X - X ** — ^ — : excluilvemenc, fera — ; — X .x-\-^.x-\-^Xr^r.T . “ — 3 : Et pour la (bmme de la fuitte cnticre a 1 infi- “ nie, devient infini, & — 6 ; done la fomme “ de route la fuitte eft 6 — 3 = 3» comme vous “ I’avez trouve. “ Cette methode eft le calcul des differences ap- plique aux Nombres; & il faut vous avouer qu’a- vane que de I’appliquer aux Figures, & mcme avanc “ que d’avoir ete Geometre, Je le prattiquai en quel- que fa^on dans les nombres ; ayant trouve encore jeune gar^on que les fuiites dont les Numeratcurs fuflent des Unites, & dont les Denominateurs fuffenc ‘‘ les Nombres figures, comme Triangulaires Pyrami- daux C^c. etoient les differences 3^®“^ (^c- ‘‘ multipliees par les conftantes de la fuitte 7'”hy*l~Y -j- y & par confequent fommables, Mais quand je devins un peu Geometre & Analyfte, Je “ vis qu’il y avoir moycn de venir a bout de telles ‘V fommations par une Methode gegeralle, autant qu’il etoit poffible ; & que le calcul des differences elloic “ encore plus commode dans la Geometric quq dans “ jes Nombres, puis qu’il y a plus d’evanouiffements, “ & que les differences repondent aux Tangentes, les fommes aux Quadratures. Cette methode generalle “ de chercher la fuitte fommatrice de la fuitte donnee, “ quand elle eft poffible, reufffit toujours, quand le terme de la fuitte donnee exprime Analytiquement n’a “ point la quantite variable enveloppe dans une racine, ny entrant dans I’expofant; & aiors, on peut tou- “ jours V ( 667 ) ^ jours determiner la fuicte fommatrice, cu prcuver qu il eft impoftible d*en trouver. £c la chofe reullic meme bien louvent, iors meme que la variable en* tr§ dans TExpofanr. Mais comme il y a quelque- “ fois des Quadratures particulieres de quelques por- tions d’une Figure, done ou ne ftauroic donner Ja “ Quadrature generalle ou la Figure quadratrice ; de “ meme on peue trouver quelquefois la fomme de ** route la fuitte, ou d’un certaine partie, quoy qu on ne puifte pas trouver la fomme de cliaque partie ; & alors il faut avoir recours a des Methodes particulieres, “ dont on n’eft pas toujours le maiftre, noftre Analyfe n’eftaat pas encore port6e a fa perfedion. ProJ>. VII. Proh- Tnvenire fummam Seriei cujus Numeratores conftf tuunt lineam quamlibec eredam in Triangulo Arith- metico Pafeialii, Denominatores vero conftituunt li- neam quamlibet tranfverfam Soltitto. Delignetur ordo linea? erediE per />, ordo linese tranfverfe per q, &fit w aggregatuni tot fermino- rum primorum in linea ereda ordinis — > t quot (unt unicates in q — i , arque fumma quxfita eric 1 • 2 . 3 . (^C. q — t m X p rp -f- 1 . GJc. /) -f ^ — 2 ' Ex. I . Proponatur Series T '1' X + if + ^ + 56 Ubi Numeratores conftituunt lineam fextam eredam, Denominatores occupant lineam quartam tranfverfam. In hoc itaque cafu funt p — 6, ^ — 4, p — J ~ 9, q — I = adecque m—\ -p 8 --j- — 37 i e. tribus terminis primis lineae nohse eredx. Unde fit fumma quKfita — 37x5-^^=^- Ex. X. Conftituant Numeratores lineam cenrefimam eredam, & fint Denominatores Numeri Trigonales, qui occupant lineam tertiam tranfverfam. * Turn erunc P ( 66^ ) tft= loz. atque adco fumma quaefita fit X‘°‘ — 101 X — — lOO . i©x f Cor. Si'^rzzi, formula fit qua exhibetur ag- gregacum primi termini; una cum femifie lecundi, triente tertii, quadrante quarti, & fie porro, linex cu- jufvis eredf^e ordinis Trianguli Arithmetici Fajchdii, Sic r. . eft -1 A + X lO • Trop. VIII. Troh. Invenire. fummamejufdetivSeriei, quando te^inorum- , figna funt alcernatim -\- & — Solutio. Summa quxfita exhibetur per formulam fim- plicifiimam - . ? +“Z — ^ Ex, Invenienda fit fumma Seriei y — ^ ~ 1^5 — -4- -f— 1— , ubi Numeratores confiituunt li- “495 I2&7 * 3003’ neam feptimam eredam, Denominatores confiituunt nonam tranlverfam. In fornaula itaque pro p Si ^ ferip*. g tis 7 & 9, fit fumma — . Manente eadem Serie Numeratorum fnempe linea fep- tima ereda), fi pro Serie Denomipatorum fumantur fucedfive linex tranfverfx 1^*% 3"% 4*% &c, Summas • erunt , (jrc. quae fic pofiunc feribi, — > d“^- ubi tarn Numeratores, qu am Denominatores excerpuntur ex line^ tranfvers^ ordinis feptimi. Idem eveniret fi loco feptimx, Numeratores-- conftituifient aliam quamlibet lineam eredam ordinis />; Summae quippe orirentur ex applicatione terminorum linex- ■ ( <5^9 ) linese tranfvcrfe ejufclem ordinis p ad terminos proxi- me iequentes in eadern linea. Propoficiones hse dua: noviflim^ potius elegances funt quam utiles 5 quare Formularuna noftrarum demon- ftracionem LetSoris folercia inveftigandam relinquimus, ad Propofitionem ultimam jam properantes, quae ter- tiam continec Serierum fpeciem, ob ufum mukipliccm fads infignem. Lemma, 5:.- &c. cujus termino- e- c • . M N 0 P Sic Series quxvis j,, rum Denominatores conftituunt progrelTionem quam- iibec Geomecricam &c. Sint etiam Nu- meratorum primus A prima difJerentiarum pri- marum B, prima fecundarum C, prima tertiarum D, quartarum & fic porro ; Si fine refpedive, aggregata, Unius, Duorum, Trium, Qua- M N 0 j I’ h^’ tuor, vel plurium terminorum Seriei que fint Numeratorum primus a {— a) prima diffe- rentiarnm primarum h, prima fecundarum c,, prima tertiarum d, & fic porro ; & fit ^ — iz==.q. Turn ip« forum a, c, d, (^c valores erunc. a— A—a—M b— h A B c T=.q h A -\- h B -\~ C d = qH A 4- q b B h C D & fic porro. Demon^ratio» ' Satis conftac efie a — a,— A~M. ^ . . M M 0 P , ,, .9. r»1 Termini Numeratoribus 0, P^ O 0 O O G ^ ( 670 ) 6‘c. express pet A, B, C, D, dc, transformantut in A A jB a -|— 1 B C A -|— 3 ^ “]"■ 3 ^ ^ I’ “T" * terminos (^e. Unde colligendo fummas terminorum, inveniuntur Numeratores /3, y, T>- ) Prep. IX. Prth. Invenire fummam quotlibec terminorum Seriei cu- julvis cujus terminorum Denomina- tores confticuunc progreflfionem quamlibec Geometri- cam h, h^, &c, Numeracores autem func quan- titates difFerentil aliqua conftanti gaudentes. Solutio. Sunto Numeratorum /W, N 0, P, ^c. pri- mus A, prima difFerenciarum primarum 5* prima I’e- oundarum C, prima tertiarum D, & fic porro; & fit ipforum A, B, C, D, &c. numerus «, arque h — i — q. Turn fiat 4 (— M), h —h A -\- B, c =.q h A -\-h B -|- C, d'— h A q h B h C D, &c. ut fint tot termini 4, h, c, d, quot (unrunitares in Terminorum iftorum ultimus dicatur r, atque per /> -j- i 1 r • M N O F , defignetur numerus terminorum ‘juo- rum fumma requiriturj Dico fummam illam exhiberi per fradionem, cujus Denominatore exiftente ^ ^ % Numerator eft a-\-hp -y ^ ' — P ^ ~ ^ Demonjlratio. Nam (per 6.) per banc formulam leprsefeniatur terminus ordine P 4- i Seriei -y. ^,77, h h IF ^3- &C'. qui terminus (*per conftrueftionem Lemmatis 5’.) a^qualis eft aggregate terminorum numero p + i Seriei EiopoCtse j, ^ E. D. Ex* !• ( <^75 ) Ex. I. InvenienJa fit fumma novem terminorum Se- riei — , — , -f, 4* hoc cafu h=:z. a 2 ^ o lo ^ ( = ^ — l) ~I, p-\-l =:^, p=zS, A=J, Bz=t, C=:o, — P=&ct adeoque» = i, (quoniam funtduo •^yB,) Hinc fit a (r= A) — \,b (= h a\- B — ^ = 3, c {^ffh A h B ^C— o) = 4 = r, Adeoque per formulam fit fumma qusfica l+3X8-f i« — I — I x8 2’ fiz’ Ex. Quaeratur fumma fex terminorum Serici i x J + 3 X3^ 4- 6 X 3H" X X3^-l-2-i X3^+c^r. In hoc cafu funt ^ = y, q~ zi|, p -\- i z=:6, p = s, Az=i, B—z, C=r, D ~o = E=&c. adeoque » = 3, atque4=i, i=‘ +x = i. f==i+-|-|- 1=:—, d—-^ Unde fumma qux- 9 ^7 9 ‘ 3 27 fitai fit = 19956. five 2+f XS-f fx5X^+- II i 4 4 X^-^+ jX5-yX?X ^ 8 3 ' ^ Cor. I. Ejufdem Seriei, a termino primo y in infini- tum continuatse, fumma exhibetur per formulam fim* plicifTimam + ==^ -f ==3 -1* h — i h — i| b — ij h — l| Com, Si =: X , Seriei totius in infinitum continua- tae fumma habetur fbl^ additions terminorum A, B, C, D, ^c. Et base fumma eadem eft ac fumma line£e eredtas refpondentis termino primo A, in Triangulo Arithmetico, cujus lineam tranfverfam occupant Nume- P p p p p latoros ( 674 > rarores M, N~, 0, P, &c. (^od facile confl:at cx con- tcmplatione Trianguli. Si itaque fuerinc M, N, 0, (jrc. M Numeri figurati cujufVis ordinis n, fumma Seriei — M 0 P ^ -I L — 4-— -\- &c. a^qualis eric Numeri binari- ' 4 0 16 •* 1 dignicati z\"~ \ Sic Series -7 + ^ -K = 2 * " * = I, ut vulgQ notum ; Series — J- — 4. A -’p =: 1 ” ^ 1 ; Series*^ +‘^ + y "V ~ 2 ’ “ ^ = 4, & fic porro. Scholium. Celeb. D, Jac. Bermnlli, iti TracSlatu fuo de Seriebus infinitis, folvic illud Problema. ‘‘ Invenire “ iummam Seriei infiniras: Fradionum quarum Denomi- “ natores crefcunc in Progreflione quacunque Geome- “ trica, Numeratores veto progrediuntur vel juxca Nu- meros naturales, i, 2, 3, 4, vel Trigonales i, ** 3, 6, ro, d'c. vel Pyramidales t, 4, lo, 20, aut jaxta-Quadratos i, 9, 16, ^c. aut Cubes r, “* 8, 27, 64, ^c» eorumve mulriplices.” Ipfius folu- tionem confula^ Ledor. Aliam vero, & quidem mub to generaliorem invenic D. N/V. ^illius Nepos, eamque ( poftquam ei hsec miferam, fed fine demon- ftrarione) mecum communiGare dignatus eft, in epiftola data i8° Septemhris 1715’, miris quidem invencis refer* tiflima, quaiibus me crebro dignatur vir Dodiftimus. De hoc vero Problemace fic fcribic. Pour la fbmme “ d’un nombre determine « de termes de la fuitte de “ voftre Theoreme 7. [ Ccrcllmum primum eft hujus Propoiltionis] j’ay trouve cette formule x m — m — I i_j_ d 4_ 0^ Jes X-fiCtres B, If' pour m, h en raultiplianc tout encore par on a la iolucion de voftre Proh. “ IX'”'”. Ec me monuit Vir peririffimus hanc fuam formulam generalem in noftram pardcularem {Cor. i. hujus propofmonis) migrate quando » — oo ; quippe turn evanefcunc i, n • n . ^ ref- i 2 3 peduipforum m". A, B, C, ^c. adeo ut Series in eo . JpTi “ + fzTi ^ ^ 0“- " b c nino coincidit cum noflra —^-4- =.4-==, -1- ni — 1 ' m — 1 1 m — i { ‘ ^C. Ad hue aliam hujus Probicmstis folutionem, & qiiidem - ab hifee admodum diverfara, inVenit D. TA’^lor ope Method! fuce incrementorum. Viri dodiffimi rogatu, ad eum miferam formulam meam fecundam pro folu» tione Problematis item formulas alias fpectantes ad Propoficiones tertiam, quartam & quintam^ fed fine de» * monflrationibus : quippe non dubitabam quin Vir acu- tiffimus, atque ipfe Method! iftius Incrementorum In- ventor, hifce, yel fakem paribus inveniendis par effiet, Refcripfit fe harum foluciones invenifle, .& fimul alia qusedam communicavic ad hujus method! profeduni ' multum facientia, quae jam noftro horcatu indinihis hif cQ fubjungere dignatur. ( (>?(> ) APPENDIX Qtia methodo diversd eadem materia traBatur : AuBore Brook Taylor, LL» T>» S, Seer. ' HOrtatu Viri ClarifT, cui nos innumeris ofEciis da- vindtiflimos elle libenter'facemur, fequentes jam Propofitiones exhibemus, quasquidem in aliam occafio' ncm refervandas efle decreviflemus, ni xquum vifum fuifict parendum efle imperio amici qui, dum Propofleio- nes quafdam prjecedentes fuas olim nobis inveftigan- das propofuir, earum inveniendarum occafionem dedic. Definitiones. I. Quantitatis cujufvis variabilis valorem prxfencem . deflgno litera fimpliciter feripta, ut ^ j valores prece- dences diflinguo lineolis • eidem licere ex parte fupe- - riori pofitis, (equentes lineolis ex parte inferiori fcrip» , u / tis. Utvi hujus Definitionis lint x, x, x, x, e, ejuf- * t If dem variabilis valores quinqiie continui, exiftente va- lore prxfenti, x proximo prxterito, x fecundo practeri- to ; X proximcj atque x fecundo futuro. Et fic de aiiis. I II Ad eundem modum (unt interpretandee lineole qu* »i II t ^ •incrementis apponuntur. Sic funt x, x, x, x, x, ip- Xius X valores quinque continui ; ut fit ^ incrementum lecun- ( ^77 ) it i fecandum iplius Tit x incrementum fecundum ipfius f •4 X, Et fic de aliis. ’ ’ Cor» Vi hujus Definitionis, x -\-x=:x, x-\~x — x, • • / 3 X -\-x=z X. Et lie de aliis hujufmodi. Quando ufu venit ut varjabilis quantitas, puta x^ fpedanda fit tanquam Incrementum, ejus Integrale de- figno litera inter uncos [ ] inclusa, llb'us etiam Inte- gralis [a;] Integrale ('vel ipfius a: Integrale fecundum,) defigno numero binario uncorum priori fuperimpofito, z ut Iftitis etiam Incegralis Integrale Cvel ipfius at Integrale tertium,) ad eundem modum defigno numero 3 ternario, uc[a;]. Et fic deinceps. Unde vi hujus 3 ^ Definitionis conflituunt [a:], [at], [^], x Seriem terminorum, quorum quilibet eft ipCum immediate ‘ ^ 3 praecedentis incrementum primum, ut fit [^] = [a;], • z [jf ] = [x], x = [x], . : Lemma, Facfti a: 'z;ex Multiplicatione duorum variabiiium a" & V. incrementum x v xv, . Nam aueftis variabiiibus per propria incrementa, fit novum ' produeftum x ^ x xv ~\~ five xv ^ v x x hoc eft X X V X V (pro gs: + x fcripco * Def. i^.) Unde dempto priori produ'^o xt/'/ieftat increm^ntiVm X V X V. [ ■ Q.i', x, x, (jrc. X, 3 4 — i '—3"— 4 p:r [ AT ], [ If ], [x],^c. Series fit omnino eadera ac per Propofitionem praefentem prodit, ubi quxritur In- tegrale fecundum. z. Ex his autem formulis quaft fua fponte proce- dunc formula Propoiicionum undecimae aiq-ie duode- dmas i-ibri de Methodo incrementorum. Nam pro incre • ( <585 ) incrementis (cribe Fluxiones, atque evanefcentibus in- crementis fiant jam oranes x, r., inter fe ;e- quales, atqae migrabit ftatim h;sc Propofitio fecunda in ibam undecimam, acque pr.irens tertia in liiarnduo- decimam. Quod quidem exemplum iatis infigne eft Methodi l^errtonhn^, qua colligit ille rariones Fiuxio- num ex rationibus ultimis incrementorum evanefcen- tium, vel ex primis nafcencium. Rsecedentium impreffioni intentus dum Typoche- tarum erroribus corrigendis do operam, arque ed occafione in animo ilia fepius revolve, fubiic Artibcium illud quo jam olim ufus elt D Jac. Bernoulli in inven- tione quarundam Serierum, ope Progreftionis Harmo- nicse cujus meminicD de iMonmcrt in Scholia 6. Prof. V, prxcedente commode etiam appHcari pofle ad inven- tionem ipfius /^lonmort i i PropoCitionum 3**^, 4'®, 5- atque id genus aliarum aliquanco fortafte generalic-- rum. Hoc in fequentibus paucis oftendifte, credebam Ledtori non fore ingratum. Sit Progrcftio Aritlimecicaf, p n, p 2, n, ^c. cu- jus termini finguli fucccflivc dcfigneniur per x, & funto by Cy d, C'-c. quivis mukiplices ditTerentia; datts n terminorum Progrellionis iftius Arithmetica:. Sint B, C D, (^c. Numeri quillbet dati, ex fradione prima oritur Series — . -4—, —4 — • Dico quod agere- f ' p n p-]~2n ^ gatum quotlibet hujufmodi Serierura in infinitum con- tinuatarum in terminis numero finitis exhiberi poceft, fi modo fueric numeratorum A, B, C, D, aggrega- tum sequale nihilo. Duobus exemplis hoc fiec mani- feflum. ^ ^ Ex. Sint dux tantum fradiones — , atque ^ , exiftente h z=. Scribantur Series harmonicx ex his formulis ortx, eo ordine, ut termini, in quibus func denominarores xqualcs, fibi invicem refpondeant, & col- led:is fummis terminorum homoiogorum, prodibit ag- gregatum Serieruilti in terminis numero finitis, ut in calculo appofito videre eft. T‘+ — r~ H i -hn rn h (5c. = Scnei ortae ex — , -A . -A p -f- ? « ‘ — = Seriei ex — + p ' p ~j~ n^p -[-in Ex, 1, Sint tres fradiones — , -f &c.= Aggreg. Serieru. B C , exift- X x + iw’ X 3 a 2.n, c — ^n, atque ^ -}-B-|-C=:o. In entibus b hoc cafu Calculus fic f'e habet. ^ hy. _L oT +■ • • • — Seriei or:* ex — A A ■+ f ~^p + n~p -f - 2 w ' + 3 « / ^ 4 ~ "h • • • • ~t~ — Seriei ex — ^ — ' p f-2« .* p-\rin x-f-zn -f — 1- . . . i . -f- C^c. rrSeriei ex — — ‘ p-h'i» x-f-3„ A , A-[-B , A [~B [~C = o , ^ I 7+7^ St- rierum. Ubi ( ) Ubi etiam. prodit apregaram Serierum in termini’s numero finitis, nempe'4.4- — ^ ob Nume- P P ~r ^ . P~r i ” tatorum A, B, C, aggregacum acquale nihilo. Et ad eundem modum demonftratur Theorema in aliis cafi- bus quibufvis. Cor, I. Ex his principiis derivari poflunt innumerae Series in infinitum continuatce, in terminis tamen nu- mcro finitis fummabiles. ‘ Caf, I. Sint — & formulae duarum Serierum ' X X P harmonicarum quarum aggregatum prodit in terminis numero finitis per fuperius demonftrata. Turn, formulis iflis in unam fummam coIlecStis, fit == formula ' xX X \-b Seriei fummabilis. Sint v.^r. A=r, /'=i» atquc b z= '^n — 6. Turn formulae Serierum harmoni- carum erunt formula Seriei compofitae X ^ ■f~ ^ Serie ilia exifiente 1 X 7 fummabilis efit -L— i— 4--I \-&c. atque fumma Seriei, pec '3X9'5Xix*7xi3 - - calculum inpraemifiis demonftratum, erit -7^ Sint tres formulae Serierum harmonicarum . ' j i.. fexiftente A B uc fit Se- rierum a'ggfegatufo_ finitum'per^^p^^^ Turn for- "^6x5 A B mulis in unam fummam cgliedis fit A y( X b X c -V Bx X x X -4- c -f“ C X x X x 4— b, X X X 4" b y^x ^\-c , feu (ter- minis^ revocatis ad _formam fadlorum A-, j: A cb .q* /^c'4~g — bBXx-^A-^-B-^-CXxXx b XXx4-6xx4~c S f f f f Co ( ) for- (•pb ^ + B + g = ^ ^ ' jf X X 4-f Xx’+c miila Seriei fiimmabilis. Si (JuatuoE fine Frai^lioncs B D , 'exiftente^ -j- 4^ C -}-£>= o) i’ j: -f- c’ Jf -j~ ad eundem modum invenietur formula Seriei fummabilis Abcd-\-Acd-^'^Xo~b X d—h\ x x -YAd^Bxd~b-\^Qx4 — -C; "K x >iC xvj-^ X X X b X X~^c X X d . Et fic pergere licet ad formulas ad hue magis compo* fitas. Ca(, i. Et fi plures Tint formula Serierum hujufrao- di rumm^bilium,. qparum denominatorum fa<^ores ex* cerpantur p:x diverfis .prpgreirionibus Aritlimecjcis, ex ifiarum foirmularum quptvis in unam fummam addi* tione, conficiecur formula hova Seriei fummabilis. Sint e. gr, formulas dux Serierum fummabilium & . excerptis a:; ex Progreffipne AricbmeticAj^;, a.» 3, 4. &c* ex ProgrefTione Aricnmetica i, 3, Turn ex his formulis in unam fummam colledis ■V X X -j- 3 fiet formula, nova j vel, (expofi^ x>tx 4- 3 X? to z per X St numerosdfttdS^}'^^ — — — ; — ^ 'xxx-\~ix%x IX2X-|-I Cor. %* Hinc omnis Series in infinitum cominuata I. X z^sx-4- » jf:A? ><•■* -17 3 fummabilis eft, cujus termini defignantur per Fiadfio- nem, cujus, denominatoHY faeftores exeerpuntur ex da- ti-qualibet Progreflione Arithmetic^, numerator .autera eft multinomium, cujus <(im^i)fip;ie^.fu^^"^d minimum binario pauciores. quam funt dimenftones E>e^mina- tpris. omnis hujufinodf fra^io rcfplvi poreft in tot fradiones fimplices, quot funt dimenfion,es, {ho^ eft, quot funt faiiftores) Denorfiihatoris, qualriim nume- ratorum aggregatum, eft nihil. S^it^exempli gratis, , V ^ ' ^ .formula f ( 6^7 ) formula oblata Pons hancfor- X XJC-J-’^X-J»+CX .<71" ^ mulam arquan aggregate fradionum ~ q- -~y + f — ^. Turn fradionibus iflisinunamfummamcoiledis fiet Ah € d -\- A s d B c — b V, d — h y. X ^ ^ 5 X cL — b -\^C-=i ^ ~ c X XX X -f- ^ -j-^-|-^-[-C’-'rDxx^x-|-/>xx4-r applicatum ad — — , — i — — — ; — , a.-^^x-\-yx>ix-\-h c ^x-\-d^ — ' j!L= — =f=/ xX x-^bxx~\~c>(.x-\-d Unde per comparacionem terminorum homologorum Ah c 4^=: cc, A c d B xc — .bxd — h z=: A d -\- B X d — h — 1~ C "x d — c =: A — 1~ B — |— C — D — o» j yt ^ jj /3 A c d sdCOC^UC ^ • — ' ■; f ?' B — hed' c — bxd — b c=^ — Ad xd — b d — c , D— — A — B — C, Quo pado a, formula oblata refolvitur in fradiones fimplices t/ 1/ £/» ^ ^ ' B — A c d , y — A d — B X d — b *-p« ~ ~ . . — .nr: ■ ■■ — " c- — hxd-^hxx-\-b d — cxx-\-(^ ~~~~' ~x'^~d — qiiibus ortarum Serierum ag» gregatum, hoc eft, fumma Seriei ortx ex formula ob- , ^ tt 4" r}- ^ AT X at -t- ^ 1- lata ~~7 — r per jam dida prodic ■ X-^'4-r-xA: -}-f^ ■ in terminisiv numero finitis. Quod veto dimenfiones numeratorlv. in -formula oblat^, debeant ellc binario ad minimum pauciores, quam func dimenfiones Denomi=' natoris, hinc conftac, quod in redudione fradionum j^^.Viiibec numerator C, D, ' ducitur ( 6S8 ) ducicur in omnes denominacores excepto unoj nempe fuo ; unde prodeunc Numeratoris Dimenfiones unicace pauciores quam func dimenfiones Denominatoris. Sed per jequationera = perit altiilima dimenfio in numeratore ; Unde fuperfunt Numeratoris Dimenfiones ad minimum binario pauciores quam func • dimenfiones Denominatoris. Ad hoc veio Corollarium revocari pofliint D. de Monmort Propofitiones 5" Cor. 3. Item oblati formula juxta Ca[, z. Cor. r. adhuc magis compofita, ex iidem principiis perfpici poteft an fit Series fummSbilis. Sint progrcfliones du2E Arichmeticse i, 3, s* x, 4, 6, quarum termini homologi defignentur per <* & zi, & fit formu- * la Seriei oblata — , ^ ^ ^ ^ yel ( pro a X X~1~z ^ Z, Z. ^ fcripto AT -j- I, & fa(5toribus Denominatoris in ordi- _ A- X (Sx A-.y nr nem coaais) === — —-■•=-— — ==. Pone fdrmu- X* >< X "h * X ^ + X X a: + 3 lam hanc arquari aggregate formularum • « X * + ^ Serierum per fuperiUs di(3a fummabi- X + 1 x^T 3 lium, ut Cformulis his noviflimis in unam fummam colleau) x.x + v X X 3e 4- I ^ X -f- 2 X X -f" 3 3 P -1- 4 ^ “h 2 /3 y 4* ■ x_|_ ’ xx 4" ^’X<« 3 x-x:-|-i X J^4x.Xx~1“3* Hinc comparando terminos homologos oriuncur arqua- tiones3P— a, F + Unde eliminatis P &i ^ per debitas operationes, Analyticas, prodit ^quatio 2 a. -r- 3 ^ y — o, . qua idefinitur >re- latio quae inter coefBcientes oi. (B, y intercedere debet, a f3 w - -I- y Ut Series orta ex formula oblat^ xxx-|-ixx_|-2,xx-|-3 fit ( 6%9 ) f\t fummabilis. Ad eundem modum fi formulae obIat2e Denominatcris faClores excerpantur ex tnbus Progre* iJionibus Arithmedcis, invenientur duse ^equationes quibus definiancur relationes coefficientium Numerato- ris, ut fit Series fummabilis. Si quatuor (int ProgrefJio- nes Ariihmecicse, Coefficiendum relado definiecur per tres seqiiadones. Ec fic porro. Ec in hujufmodi for- iTiuIis uc fine Series fummabiles, hxc infuper obfer- vanda funt, Frimo ut Numeratorum dimenfiones Tint ad minimum binario pauciores quam funt dimenfio- nes Denominatorum, Deinde ut ex fingulis Progreffio- nibus Aridimedds excerpantur ad minimum duo fa(5lo- res Denominatoris. Denique, quod fi Tint duo vel plures fadlores Denominatoris inter (e sequales, ponendum Tie tot etiam Progrefiiones Arithmecicas, ex quibus excer- puntur, effe inter fe tequales. Pr^emiilis attentius per- penfis, hsec obvia erunt. Ad hoc veto Corollarium facile revocantur D. de Monmort Propofitiones 4^*, 'B 1 K 1 S. ) ERRATUM in N°. 3^2. PAge 586, after the end of line if, add llact Clotidf from behind which there ijfued a, L 0 M D 0 N: ^Printed by W. and J. I n n y s, Printers to the Royal' Society ^ 2Xt\\Q l^rinces^Arms in St. Church- Yard.. 1717- > ’ ' " ” ' 'Rp!. » r ' ■ : , ,ni ni 1 1 U T A 2 .1 3 ’ * ' V I f ^ • f • , V.Y M I ;C I onn r L' ) r>.'; s -1^, fi :’.j •.M 0 G Vi 0 ,a / ' Vv/\ i)i\i OT .7^'=' '■* ’ .( brc .V7 V"* .l;.oY-it:,:;fiO c\r*\ ' v:.v\^.*v,‘i-Av i oni :.: ,t' 1 ■/rjn/.u/u'n /K' jj4- IMPr^ARMANT«N¥S G^RDIANVSPTAVq tPRINaPlAETARMM imCDNPPSARE^Tl- rniRM(MMPs®m AVG-PR-eMTEMAAm QVIRIN0-IP-6HH.QCE Ui • rX M TF ±t ( 6^1 ) - Number 3 54.' PHItpSOPHICAL TRANSACTIONS. H'.JI— ■■T™^ — For the Months of QBob. ]SloV. and Decemh, 1 7 1 7. -ta/V’ Tfhc^ O N T E N T- S. ’ I. An Advertifentent fo 'Aftronomers, <>7 Advantages that Tn<*y accrue from the Ohfervation of the hA,o6n s fre<^ttent A’ppuljes to Hyades, during the-threemekt infumgTears.- II. Solatia Prohlematis d Dom. G. G. Leibnitio Geometris Anglis nuper propafiti. ; Per Brook Taylor, LL. £). ^ R. S, Seer. III. ! ExiraSlof a Lettet of Dr. Q.hf. Hunter, M.D. to £)r. J.VVood* ward, M.D. & K, S. S.from Durham, giving an Account of a, / Rojnan infeription, lately dug up in. the North (^England; , with fime Hifianicahand Chrondogical Retnarks thereon. ; -f IVi. A Genus 0/ P L A N T S, call’d Araliaftrum, of which the famous Ntn-ztn or Ginfeng of the Chinefes, is a •Species. Communicated by A/r. Vaillant Prademoti/lrat'or at . the Royal Garden at Paris, to the Learned Dr. Will. Sherrard, • LL. D. late Conful Smynia,! and by him to the Royal -Society. i c i, i V. ExtraPi of a o/" A/r. Ed w. Berkley /rew Naples, giv- ing Jeveral curious Objervationt and Remarks on the Eruptions of Fire and Smoak from Mount V E S U V I O. Communicated by. Dr, John Arbuthnoc, M. D. and R. S. S, VI. An Account of an extraordinary Tumour or Wen lately cut off the Cheek of a Perfon in Scotland. Communicated to the Royal Society by Dr. Thomas Bower, M.D. and F. R. S. VII. An Account of an Experiment to prove an interfpers’d Va- cuum,* or to jhew that all Places are not equally full. By the Reverend J.Theoph. Defaguliers, M, A. and R. S. S. T 1 1 1 1 VUE An CONTENTS. VIII An Account of a fm'ill Telefcopical Comet feen at London on the lotb of June *717^ ^7. £dm. UaUey, LL. D, R. Soc, Seer. IX. An Account of Bocks i I.'Joannls Poleni in Gymnafio Paravino Phil Ord. Prof. & bcienr. Societatum Re^alium, qu3c Londini & Berolini font, Sodalis, De Mutu rnixto, Libri duo, 4‘®. Patavii 1717. J. Apollonii Pergjei Conicorum Libri O£to Sereni AntifTenfis At SeBhno Cjlindri Coni Libri duo. Fal. Reg, E Tbtatro Oxoti. 1710. I. Jn Jdvertifement to Aftronomcrt, of the JJvajf tages that may accrue from the ObJerVation of the Moon’5 frequent Appulfes to the Hyades, during the Ihree next enfuing lears, OF all the Methods hitherto propofed for finding the Longitudes of Places for Geographical Ufes, none Teems more adapted to the purpofe, than that bv the Oeeultations of the fixe Stars by the Moon obferved in dillant Parcs: For thofe Immerfions of the Stars which happen on the dark Semicircle of the Moon, and their £« meriions from the fame, are perfe^ly momenianeous, with- out that Ambiguity, to which the Obfervacions of the Eclip- fes of the Moon and thofe of Jupiter s Satellites are fubje^. Befides, whilB the Moon is horned, and her weaker Light lefs daziing, an ordinary ftiort Teiefcope, fuch as bv Ex- perience is found to be manageable on Ship board, fuibces to obferve thofe vloments, even in the Occulta ions of ve- ry minute Stars: On which account, this way feems to bid fairelt for the defired Solution of the grand Problem of find- ing the Longitude at Sea. Bur fince it would be needlefs to enquire exa<5Hy what Longitude a Ship is in, when that of tlie Port to which fhe is bound is dill unknown it were to be wiflit that the P inces of the Earth would caule fuch Obiervations CO be made, in the ; ons and on the princu p4i Head-Lands of their Dominions, each for his own, as . might ( ^9} ) might once for all fettle truly the Limits of the Land and Sea. This Work however being likely to be left to the Care andCurioficy of private Perfons, it may not.be amifs hereby to give notice of the prefent Opportunity of performing itj in this our Northern Heroilphere, by help of the fiequent Appulfes of the Moon to the mure Southerly of the Hy^des^ many of which fhe eciiples in each monthly Revolution, and will continue fo to do, during the Years- 1718, 1719, and 1720. Thefe Stars are but Three or Four in all former Cata- logues, but the Britijh of Mr FhmfieeJ encreafes them to Sixteen ; to them we have added Three others fomewhae fmaller, 'viz. c, i, and n in the Figure of the Hyadet here- to annext. In it the principal Stars are markt with Bayer*s Marks, and the reft with the Letters of the Italick Alpha* bet ; their Longitudes are fitted to the beginning of the Year *718, and being truly laid down, may ferve to in- ftrud the curious Obferver, when and where to look for them, when the Moon is among them. It appears by this Scheme that the Diftance between a and « or Palilicium, is about Nine Hours Motion of the Moon, in which time fuppofing her to pafs from one to the other, (he muft eclipfe y and e, and Four or Five of thofe about 9, and muft apply very clofe, with her Southern Limb, to all thofe which have about Six Degrees . South- Latitude i which would be a very entertaining Sight for the Lovers of thefe Arcs. But if the Times of-the Occul- tations of any One of thefe Stars, or even of anv Two of tliem in the fame Night, be accuratel obferved under di- ftant Meridians, the difference of thofe Meridians may be truly obtain’d thereby ; efpecially fince the Mooni Parallax, and all orner parts of her Theory thereto required, are at prefent fufficiently ftared and known. For the fake of fuch as are willing to make ufc of this Method, we have added the Places ot all the Hyaiet fitted to the prefent Time, and chiefly i.aken from the Britifh Cata- logue, which being faulty in the Scars wc call k and/, we have here rectified them- Catahgns ( 6^1 ) ^ * i*.' - » ' * f Xatalogui ^Hy adum, immte Amo 1718. Steilarum NiOMIN^. 1 Long 31 ■ Lat. Au(V. Ma. I , pr£fedit y Tauri a 51 3 ,'5 50 *4 7 nartbus Tauri, Bayerc y ri 50 54 46 XX 3 fuh':*y :• — . ti frr , — b. 'I 56 31 6 19 57 7 ijft (J^igwe~Na/i TauVt —■ — : — • c IX 54 25 ,4 47 5 7 ^ Inter mtti ^ ociilum Tsuri 7 54 47 1 Eortnrn. — ‘ ^ J S' 1 4 0 34 3 \l^uic (ontfgun, 4d^ d 3' 10 33 4 9 4 6 \l:r. (Or R. S, Seen GU M Dom. G. G. Leilnitius nuper defun(5ius, in concroverfia jampridem orta circa Inyentionem Mechodi Jluxionum, ( quam is DifFerentiaiem vocarc maluic, fibique pertinacicer appropriari nifus eft,) nihil omnino refponfi dederit argumentis, qui- bus inclyci iftius Inventi gloria Neutono vendi- catur ; cn tandem, hortante Dom”® Job. Bernoulli, Pro- blema Geomecris folvendum propofuic ; quo fei- licec vires eorum in Methodo ifta experiretur; quad Problemacis iftius Solutioni fi cocteri iftius Nationis de- prehendantur impares, rede concludatur, nec ipfum t^eutonum, qui, fatente etiam Leibnitio, ab hujuimodi contemplationibus jam jure immunis efte debet, olim fuifle parem inventioni iftius Methodi. Sive Problema folvatur, five infolutum maneac, nihil exinde confeque- tur quod Neutonum afficiac ; nec iftis certe Leihnttii Fau- tonbus, qui I’roblematis folucioncm eriamnum conti- nenter efflagirant, jus ullum eft nos ad certanien ingenio- rum tanta cum licentia provocandi; adeoque Problema corum jure merito negligi poflet. Verum ne aliquando exinde occafionem triumphandi arripianc, fi hoc Pro- blema maneac ab Anglis omnino intadum, ipfe, Gco- metra longe non fummi inter noftrates fubfellii, inducor, uc folucionem edam qualern qualem Problemacis, nec ufu, nec difficultate adeo infignis. - Problema a Leibnitio primo proponcum, ita fuit in- telledum quafi nihil aliud reqaifitum fuiflet, quam uC fecarentur ad angulos redos Hyperbolce Conicse iifdem Centro & Vercicibus defciiptse Verum cum illi nuncia- V V v V ti m ■7 folutum, refcripfit, non (olutionem casus particularis, fed generalem requiri. Quo fadum eft uc folutiones iftre particularcs non editse fuerincs vcrum in Tranfadione Philofbphica N° 347.fubinde prodiic Solutio maximegc- neralis Sed nec ilia content! fuerunt Leibnititts & Fau- tores ejus, quin illam derifui habuere, quafi qui illam excogitaverat non potuiftec earn ad cafum (pecialem ap- ' ' plicate. Si nondum viderint quomodo ex illi icqua- tiones fine deducendsc, id profedd illorum iraperitiae tiibucndum erit. Paulo ante Luhnitn obitum prodiic tandem Problema (equens; quod quidem diverfimodc fbivi poteft, premendo veftigia Solutionis gsneralis mo* d6,citac£e, fed quod in pra^fentia folvimus uc fequitur* Su^tr re St a AG tanquam sxet ex funSio A educere in- CurvaSt qualis eft A B D, ejus naturee, ut radii Ojculif in Jingulis fun St is B ^ uhique ducti^ B O fecentur ab axe AG in C, in data ratione^ ut nemfe fit BO ad BC I ad n. Deinde conftruenda funt Tra^eStarl£ EBF primas Cur^ Problema. VAS A B D nor malt ter (ec antes* Solutionis £ A H C\ Q \ O ( <^P7 ) Solutionis Pars prinaa 5 Hempi Inventh Curvarum fccandarum A B D. I. ordinata axem AG normali, fine, Abfciila A H—z, Ordinata H B=x, Curva A Bz=.v. Turn per Methodum Fiuxionum diredam e- • * ♦ ' tit B C=^x, & fluente oniformiter B 0=^* Unde K , , K per conditionem Problematis fit £0 (■f) ; JSC ; I I adeoqus;c;f — ft 'zx=:0^ z. Collat,4 hac xquatione cum formula Fiuxionum fe- cund^* in cake Prop. 6. Methodi Increnientorum^ inve- nitur z x~^ =.v cc.'~'^ /; exiftente «- linea data, per cujus valorem poteft Curva ABD accommodari condiciohi a- licui Problemati annexse. 3. Pro v fcripto ipfius valors migrat ^qua- -« in banc z= X X Unde dacur tio zx-”ziz^>ya> z ex datd x, per quadraturam Curvae cujus abkifsa exi» - •X” flente x efl ordinata 4. Sint o- & '1- numeri int;^egri, yel affirmativi vel ne- gativi, tales ut fit Curvarum ifto modo provenientium fimpliciffimai ea cujus eft Abfcifsayj'St Ordinata')' z» ' ‘ 4: : - ^ „ * ; turn erit ea ojcnnium- Curvarum fimplicifE- ma, per quarum Quadraturam datur Abfcifla z, ex dat^ Ordina.ri x. 5. Eft Curva ABD Gepmetrica, qupties pro » fu- mitur reciprocum numeri cujufvis imparis> V V V V V ^ 6> In ( ) 6. In prscdicSlis Curvam A B D confideravimus uc ver- fus axem A G concavam, quo in cafu maxima ordinara X xqualis eft lines dans a, quam Parametrunr Curvs commode vocare licet. Et in hoc cafu Curva adlu oc- currct Axi. Unde flucnte ipfius -r=^^= debite fum* pd, hoc eft, ita uc ftmul evanefcant z ^ x, tranfibit Curva per piindtum- datum .^4, fieut poftulac Prpblcma. 7. Sed ft qusracur Curva A B D, qus fit versus axcm convexa, ad eundem modum pervenietur ad sq^jado- • rt’ X nem z--;==i. Vjf *'»_**'» ; qus eiiam ex squatione priori de- rivari poteft mutando ftgnum ipftus n, Et in hoc cafu eft curva ABD Geometrica, quories pro» fiimitur reci*- procum cujufvis numeri paris. In hoc veto cafu Ordi* nata omnium minima x aqualis eft Parametro a.; adeo- que Curva. nufquam occurric Axi. C^are limitatur Problema ad caiiim priorem. 8. Ex prsmiftis facile colligitur Curvas omneS/^^D efle inter fe ftmiles, & circa pundum datum A fimili- ter pofttas,. lateribus earum homplogis exiftencibu^ pro* portionalibus Paramctris Solutionis Pars altera 3. Nempe Invent io Curvx fecantis. 9. Ex $ i^ikv : z z'ycc." : x”. Sed BC : B H :: v \ z, Unde fit 5 C : 5// : : a’ : X". Ex conditione veto Pro- blematis eft B C tangens Curvs qusefits E B F. Qpare ft jam fumantur A H { z) 8^ B f/ ( x ) pro coordina- tis Curvs EBFy Curva ipsa EB exiftente r, eric, per Meth.Flux.diretft, r t — x '.'.^BC: BfF\\)oi":x^. Un- ^e fit - ■X- J f: 10. In ( ) 10. In Curva A B D finge aequationem z = ' ^A*a_ AT* transformari in aequationena fignis radicalibus non affe- fie tK f fiuxionalis eft primi gradus ad Curvam qu^fitam EBF. Revocacur autem ad formulam ftniplicioreni in terminis numero finitis, modo fequenti. II. Fluac uniformicer r, & exiftentC4 quantitate non fluente, fit Subftituto hoc valore ipfius ^ in xquatione noviflime invent^, atque duda iequatione in -7, transformatiir'ea in hanc^; X oillL J- ejc. Unde capiendo Fluxioncs fit --aV-~ -}-g Quod ultimum conftat ex Analogia Serierum Ax^—-\- pro s 8c s fubftitutis eorum valoribus ex eequatione — — colledis, elicitur xquacio nx^i^z — xxzz,^- -X r «••• .... . ^ -I > Quas ad Fluxiones primas. revo- catur modo Cequenrit .u *; ■ '"q ; ^’ ’.f V. X .V . fit f ( 700 ) . Tij Tn u^ipD. -7- vice 4: a: fcripto ip- frus valofc sec^uacione dcinde applicaca ad i, fit n z.-Lt x 'x x irdo.* Quai xquatio in duda eft Fluxio scquationis — x x~*' z.-\- x^~'‘ z, = 4‘“”r; cxiftcntibus a ^ r non fluentibus. Eft ergo — !&x — ;s x- X ^=rx x'' , scquatio fluxionalis primi gradui ad Curvam quarfitam EBF. 13. In ifl^ autem xquatione eft a valor Ordinara; B H, quando- incidit puncftam // in pumftum A. 14. Haud proclivc eft a?quationem %x zxy.d'-'^ — rx“, manente n in tcrminis gcneralibus, revocare ad sEquationem Fluentcs tancum involventem, vel ad quadraturam Curvarum. Sed puncfta curvae EBF po(^ I'unt commode inveniri pef defcriptionem Cufv:e A B £>, & ciiii}i^dam GeomeCric»E; Per Geometricam hie intelligo Curvam, cujus acquationem non ingrediuntur Fruxioii^s, nec fluentcs in Indkibus digniratum. Scce- tur enim Curva 4 B D, cujus Parameter fit ct, in B, a Cyirva, geometric^ cujus sequatio eft aoB^x^ — — x*-'; Qtque eric pundum illud interfedionis B ad upiana ex Xrajedoriis quseficis, nempe qua! rranfic per piindum C, cxrftente AF-=.a & nOrmali* ipft AG. 15. Hinc ft ABD fit Curva Geometrica, erit etiam ‘B F F gebmerrica. ^choUum, Poreft & alio tnodo inveniri xquatio xx—zx 'x^”'^’=^^''r qu^dam AHalyft quam nunc edare ftacup, invem xquationem —=—JLL . Qyj tKi- X X comparatS cum xquation,e ~=-4 C § P P eiiminando Si ct, tandem pervenitur ad prsedidam* xquatiPnem •j X— >z K X x” . Exmflum. ( 701 ) Exemplum. Ad demonftrationem Solutionis noflrie fuf- fecerit exemplum (impliciffimum. Sic itaque »— i ; quo in Cafu eft A B'D femicirculus diametro AG defcripcus, acque E B F item (emicirculus defcriptus diametro A E. Eft aucem in hoc Cafu .. Unde in ^ 3. fit adeoque z=a. — quas a^quatio eft ad Circulum diametro Gz=a defcriptum, ut fieri debuic. Item pro-» (cripto sequatio — z.x- ( § II. ) migrac in hanc 2.^ — zx — rx,. Unde extecminandOjr ope s^uationia f 2, fit — — = —X ; adeoque regredicndo ad Fluentes K K ^ a, qucE sequatio eft ad Circulum diametro AE^a deftriptum, ut etiam fieri debuic. III. ExtraSl of a Letter of Dr. Ghi*. Hunter, M.D. . to Dr. J. Woodward, (Z5; 5. 5. from Durham, gt- Vmg an Account of a Roman InfcriptioUi lately dug up in the North of England 3 with fome Hi- Jlorical and Chronological ^marks thereon». T he Infcription which comes herewith, {Ftg. II.) was dug up, two Years agOj in the Roman C AST RU M, LancheHer : The Infcription ^ is very legible, and gives me reafon to hope, a Search . after the firft Fortifying this Place will not be unnecef- fary ; eipecially, being able to fix the Time of Gordian s R-epair-"' ( 701 ) Repairing this Fortrcfs, to the i45d Year of Chrifl-. We may reafonably aferibe the Foundation to the pru- dent Adminiftration of Julius AgricoU,. in the Reign of Fl, Fefpafian, about 169 Years before. M Conlirmajion of this, I find the following Particulars very material, and think it not unbecoming to begin my Enquiry with Fefpafians firft Appearance upon the Theatre of Fame in Britain. fn the ^cond Year of the Emperor CL AXJD IV jAfin. Lorr. 44, the Romans invaded Britain^ under the Command of Aulus Plautias, in which Expedition Pe- Jf afian *, then Legate of the Second Legion, made a glo- rious Figure ; having been engaged in no left than thirty Battels, and reduced two powerful Provinces, above I twenty Towns, and the Ifle of Wight. All thefe Suc- cefles, tho’ continued with good Improvements in fomc of the following Years and Governments , could not frighten the Natives into an entire Submiflion ; efpe- cially, no Ad varree being made into the Country of the Bri^ntfs^ till the Advancement of Vffpajtan to the Im- peril'Th7on*e,‘‘libTur“i‘?r Years after, Ann. Dorn. 70. Then the w’hole Empire was deliver’d from the Miferies ‘ of Nero's, and the fhort but lamentable Devaftations of the three fucceeding Reigns : Fefpajian then refblv’d to pulh on his begun Conquefts in Britain-, dioice Armies, commanded by experienced Generals, arc lent over; and the XX Legion, having in the preceding Troubles adfed feditiouny, ( nor without Difficulty , vyas reduced to fubmit to P'efpaftan ( mofi: of the Offi- ^ cers as well as Soldiers having been advanced by Pi- Julius' A'grioola \s conftituted Legate, who, under the Govttnom'P etilius Cerealis, bore a confiderable Share * Suetonius f Cap, 4. in f 7°5 ) in the Succeffcs againfl: the Sed primo Cer^alfs modo labores & diicrimina; mox & gloriam communicabat: Ssepe parti Exercicus in experimen- turn, aliquando majoribus copiis ex evencu prjcfecir. Tacitus afterwards in a few Words Turns up the Whole of Cerealis his Acqiiifitions, f “ Terrorem ftatim incu- “-iit Petilius Cerealis y Erigantum Civitatem, quae nu- “ merofiffima Provinciae totius perhibetur, aggrellus ; VjPiulra praelia, & aliquando. non. incruenta'; magnam* ** a^^\Brtgamum partem aut vidloria amplexus;<^ auC *[ be)lo. Not withlianding thefe Advantages, I dare'not fuppofe Romans to have then penetrated* fo far into this Province as our Longovicumy which is i Tifuate fo near the Northern Bounds of the^Sr/^4;>/«, that at prdd l^nt it’s not diftlanc above'twelve Miles from the Roman the chief Town of the adjoining Peo* pie th^p/4i. I now advance* to my principal Mo- tive, ( I hope its Length may d eferve Patdon, being un- der no Obligation to account for the Government of Jul. Frontinus Succeflbr to Cerealis ) to fix upon the fe- cond Year of Julius Agricolas Government for this Work, which Tacitus thus defcribes, || “ Sed ubi y^ftas adve- “ nit contrado Exercitu — loca Caftris ipfe capere, ** scftuaria ac fylvas ipfe prxtentare ; & nihil interim ** apud Holies quietum pati| quo minus fubitis Excur- fibus popularetur 4 ^que ubi latis terruerat, parcen- “ do rurfus irritamenta Pacis ollentarc. Quibus rebus “ multse Civitates quas in ilium diem ex sequo egeranc, datis Obfidibus iram pofuere, & Praefidiis Callcllil^ que circumdatac, tanta ratione cur^ue, ut nulla an- “ te Britannise nova pars illaceflita tranfierit. This ex- cellent Condud Tacitus further confirms from the Ob- * Tacit, Ftt, Agrit, 8* t Cap. I7. Q Gap. 20. X X X X X fervatioft f 704 y n^adon of Others. Adnotabanc pcriti, non aliunt, Ducem Opportunitates locorum fapientius legiflc, “ nullum ab AgricoU pofitum Caftellum aut vi Ho '* ftium expugnatum, auc padione aut fug^ dcicrtum. Agricohy this Summer, having c^uieted to large a; Trad, and hnithed fo many Fortreffes, it cannot be ex- peded- all Ihould be built with the mod cxquifite Arc, fufficienc to perpetuate them. I proceed to GotdUns Repairs 9 whofe Bidorian Julius Cafitoliniu having ne« vcr once named Britain, yet giving fo many Hints of the excellent Oeconomy of his Government, under the prudent Adminidration of his Father in-Law Mifithttu, I dare not fixvthis Work till the Third Year of his Reign^ He having before been under the Direction of the Eu- nuchs and Officers of the Court, whom Capitelinus repretencs, in Mifitheus his Letter to Gordian, to have j^odituted all Employments to their own Covecoufne^ and mercenary Creatures. . JSurham, Julj.5.^ ' ■ m L '■rfnMi ' w. I .ij Ilf A IV. A new Genus of PLANTS, caWd Ara- liaftrum, of which the famous Nin-zin or Gin* feng of the Chincfcs, is a ^ecies. Communi- cated by Mr. Vaillant Trademonfirator at the H{pyal Garden at Paris, to the Learned Dr. Will. Sherrard, LL. D. late Conful at Smyrna, and by him to the Royal Society. ARaliaflrum is a Genus of Plants, whofe iFlqvper A * is complete t» regular, polypecalous, and her- maphrodite, (landing t>n the Ovarj B. The Ovar-j, which is crown’d by a Calyx cut into feveral Parts, becomes a Berry D, in which are, for the moft part, two flat Seeds, like a Semicircle, which both to- gether reprefent a fort of a Heart. Add to this the Stalk, which is finglc, ending in an Umbel of which each Ray bears but one Flower. Above the Middle of the Stalk come out feveral Pedicles, ( as on that of the Anemone ) on the Extremities of which grow feveral Leaves like Rays, or like an open Hand. Tbe Species of this Genus are, I. Araliaflrum ^luinquefolii folio, majus, Nin-zin vocet^ turn D. Sarrazin. 6in-feng. Des lettres edifiantes & curieufes, Tom. X- fag. lyi. 2. Araliaflrum ^inquefoUi folio, minus, D. Sarrazin. Plantula Marilandica, foliis in fummo caule ttrnis, quorum unumquodque quinquefariam dividitur, circa, marlines (err at is. N° 36. Raii Hift. IH. 658. * W, A R A 1 I A Inji. rei htrb. Tab. 154. t Coinplece, th»t it ta f*j, that bat 0 Calyx. X X X X X 2 3. AralU* w ( To6 ) 3. Araliaflrum Fragrarix foliot Vailknt^^- flurthmlifirUmm Anemones Jjlvaticx Joltts, enned^ fhjllon, fiorihus exiguis. Pluk. Manciff. .135# Tab. 45J-' Fig- 7- ■' , ’ I * , • - ■ ' ’ To fli€W wherein Arnliaflrupt differs from Anlia, ( from whence it takes its Name ^ 'tis co/ivenknc to give, aifo the Charader of this laft Gextu, fucb as Mr. yaillavt eftablifh’d it; in his Demonftrations of the Year 1^17. Aralia * is altogether like the AralUfirum^ as to the Strudfure and Situation of its Flower ; but its Berry confifts. of^ Five $eeds plac’d round an Axis. Moreo- ver, itsi-eavesare branched ^ almoff like thofe An^ gdka\ and its Stalks ( which in fbme Sfecies arc na- ked, and In othets have Leaves fet alternately ) bear each Several Uipbeis at their top, in the Form of a Bunch of Grapes. The Species of Aralia, are I. Aralia caule aph^llo, radice repente. D. Sarrazin. Chriftophoriana , Virginiana 2.arza radicihus furculo~ Jis ^ fungofiSf Sarfaparilla mjlratibus diCla. Pluk. Almag. 98. Tab. 238. Fig. ZarfaparilU yir- ghienfibus nojlratibus di£fa^ lobatis nmbelltferx foliiSy Americana, Ejufd. Almag. 39^ a.- Aralia caule folio fo Uviy~ D. Sarazzin. Aralia Ca- nadenfis. Inft. rei E5erb 300.1 3. Aralia caule folio fo & hijpido D. Sarazzin. Aralia arhrefcens fpinoja, ‘ D. Vaillant. Angelica arborefcensy fpinofa, feu Arbor IndicUy Fraxini folio, con ice fpinofo Raii Hid. II. 1798. Chriftophoriana arbor aculeata Virginienfts Plukv Almag. 98. Tabio. * vid. Injl, rti Herb, jco. Tab. 134.* All ( 7°7 ) All the Sfecie-s of thefe two Genera, except the lail: of each of them, are common in Canada, whence Mr. Sar- razi», Counfeilor jn. the upper Council, Phyfician to bis Majefty, and Correfpondent of the Royal Academy of Sciences, lent them to the Royal Garden firil in i'?oo. The Inhabitants of^ that Col ;n/, and thofe of Vir^ giiiia, call the firft Species of iiralla by the JS^ame of Sar- faparilla, becaufe its Roots have almoft the fame Figure and Vertues Mr. Sarrazin vvrites, that he had a Patient who had been cured of an Anafarca^ about two Years before^, by the ufe of a Drink made of thefe floors. Thac>able Phyfician aflures us alfb, that the Roots of the fecohd Species, well boyPd and apply ’d by way of Cataplapne', are very excellent for the curing of' old Ulcers;' as al* fo the Decoction of them, with which they bath ahd fy- ringe the Wounds. He does not at all doubt, but the Virtues of the third Species ( which i (hall briefly de- fcribe ) are the fame with thofe of the fecond. Its Roots creep, and' fend forth Stalks, ■ which rife commonly to the Height- of a Foot and half, and fomc- times to two Foot ; the bo:tom part of them is rough, with reddifh, ftiff and prickling Hairs Thefe Stalks are fet from the Bottom to almoft the Top ( which are divided fucceflTively into feveral naked Branches tharg’d with Umbels ) with branch’d alternate Leaves, almoft like thofe of Podagraria hhfuta Angelicat folh ^ odore D. Vaillanti which Plant is grav’d in the fecond Tome of Boccones Mufaum^ by the Name of Cerefolium ru^ofo Angdkx folio, Aromaticum. Tab. 19. 'and in Rivini by that of Myrrhis folto Podagrarid See the Account of the Chinefe Gin-feng, in Phil. Tranfa(ft. Anni 1713. p*237, V. ExtraB '( 70^ ) V. ExtraB of a Letter of Mr. Edw. Berkeley from Naples, federal curious Ohjer^ations and ^marks on the Eruptions of Fire and Smoakjfrom Mount V E S'U V I O. Communicated by Dr. John Arbuchnot, M. D, and R. S. S. April 17. 17 » 7. with much Difficulty I reach’d the top of Mount Pefuvius, m which 1 faw a vaft Aperture full of ^moak. which hinder’d the feeing its Depth and Figure. 1 heard within that horrid QuU certain odd Sounds, which feem’d to pro- ceed from the Belly of the Mountain ; a fort of Mur- muring, Sighing, Throbbing, Churning, DaOiing ( as ic were) of Waves, and between whiles a Noife like that of Thunder or Cannon, which was conftantly at- tended with a Clattering, like that of Tiles falling from the Tops of Houles on the Streets. Sometimes, as the Wind changed, the Smoak grew thinner, difeovering a very ruddy Hame, and the Jaws of the Pan or Crater, freak’d with Bed, and feveral Shades of Yellow. After an HouiV day. the Smoak, being moved by the Wind, gave us fhort and partial Profpeds of the great Hollow, in the flat Bottom of which i could dilcern two Fur- naces almofl contiguous ; that on the Left, Teeming a- bout three Yards in Diameter, glow’d with red Flame, and tlirew up red-hot Stones with a hideous Noife, which, as they fell back, caus’d the fore mentioned Clattering. May S. in the Morning, 1 afeeoded to the Top of Fefuvius a (ecood time, and found a dif- ferent face of things. The Smoak afeending upright, gave ( ) gave a full ProfpeA of the Crater, which, as I could judge, is about a Mile in Circumference, and an Hun- dred Yards deep. A conical Mount, had been formed fince my laft Vifit, in the middle of the Bottom. This Mount I could fee was made of . the Stones thrown up and fallen back again into the Crater- In this new Hill remained the two Mouths or Furnaces already mention’d ; that on oar Left Hand was in the Vertex of the Hill, which it had formed round it, and raged more vio- lently than before, throwing up every three or four Minutes, with a dreadful Bellowing, a vaft Number of red-hot Stones^ fometimes in appearance above a r hou» fand, and at lead 300 Foot higher than my Head as 1 ftood upon the Brink. But there being little or no Wind, they fell back perpendicularly into the Crater , incrcafing the conical Hill. The other Mouth to the ' Right was lower in the fide of the fame new formed Hill. I cou’d difeern it to be Hlfd with red hoc li.« quid Matter, like that in the Furnace of a Glafs-Houfe, which raged and wrought as the Waves of the Sea^. caufing a (hort abrupt Noife like what may be ima- gin’d to proceed from a Sea of Quickfilver dafhing a- mong uneven Rocks This Stuff wou’d fometimes fpew . over and run down the convex fide of the conical Hill, and appearing at hrft red-hoc, it changed Colour4 and harden’d as it cool’d, fhewing the firft Rudiments of an Eruption, or, if I may fo fay, an Eruption in Minia- ture. Had the Wind driven in our Faces, we had been in no fmall Danger of flifling by the fulphurous Smoak or being knocked on the Head by Lumps of molten Minerals, which we faw had fometimes fallen on the Brink of the Crater^ upon chofe Shots from the Gulf at Bottom. But as the Wind was favourable, I had an. opportunity to fuKvey this odd Scene for above an Hour and a h ill together; C 710 ) together ; during which it- ^as very obfervable, that all tli^^JiTolleys, of^^moak, Flame, and ^qrning Scones, c|Lii^,only oji^cipr the Hole to our LeS, while the li- quid- Stuff in the other Mouth wrought and overflow’d as hath been already defcribed. June .5, After a horrid Noile, the Mountain was. at t^aple^ to fp^w a little out of Crater, jThe fame condnu’d the^ ^th. The 7th, niching vyas obierv’d till within two Hours of Night,, when it began a hideous bellowing, which continued all ,tl)ac N)gh;t; gfd the ne^^, Day till; Noon, caufing the Windows, aq4^^ , tho; very Boufes m fJapl^Xo (hake ; From that time it fpewldi vaft Quantities of molten Stuff to the ISouth, which^ flream’d down the fide of the Mountain, like a great Pot boyliijg over. This Evening I return’d from., a Voyage thro* ApulU. iix\d wasjfurptifed, pafling by the North fide of the Mountain, 'to fee a, great Quantity; of ruddy Smoak lie along a huge Tcadt of Sky over, the River of molten Stuff which was, it delf out of, fight. The 9th, Vefuv'iuj raged lefs vjplendy ; that Night we faw from Napla a Column of fire, (hoot, between whiles out of its Summit. Thq loth, wl^n we, thought all wou’d have been over, the Mountain grevy! very outragious again, roaring and groaning mofl dreadr^ fully. You cannot form a jufler Idea qf this Noifc: in the mofl violent Fits of it, than by imagining a mix’d Sound made up of the raging of a Tempeft, the Mur- mur of a troubled Sea, and the Roaring of Thunder and Artillery, confufed all together. It was very ter- rible as we heard it in the further End of Naples y at the Diflance of above twelve Miles. This moved my Curiofity to approach the Mountain. Three or four of us got into a Boat, and were fet afhoar at Torre del Gw, a Town fi,cuate at the Foo; of Fejuvius to .the South- ( 7'« ) South-Weft, whence we rode four or five Miles before we came to the burning River, which was about Mid- Night. The Roaring of the VolcAno grew exceeding loud and horrible as we approach’d. I obferved a Mix- ture of Colours in the Cloud over the Crater^ green, yellow, red and blue; there was likewife a ruddy dif- mal Light in the Air over that Trad of Land where the burning River flowed ; Allies continually Ihower’d on us all the way from the Sea-Coaft. All which Cir- cumftances, fet oT and augmented by the Horror and Si- lence of the Night, made a Scene the moft uncommon and aftonilhing I ever law; which grew ftill more ex- traordinary as we came nearer the Stream. Imagine a vaft Torrent of liquid Fire rolling from the Top down the Side of the Mountain, and with irrefiftible Fury bearing down and confuming Vines, Olives, Fig-trees, Houles, in a word, every thing that ftood in its way. This mighty Flood divided into different Channels, ac- cording to the Inequalities of the Mountain. The lar- geft Scream feem’d half a Mile broad at leaft, and five Miles long. The Nature and Confiftence of thefe burn- ing Torrents hath been deferibed, with fo much Exadt- nels and Trudi, by BorelluSg in his Latin Treatife of Aloiifit Mim. that 1 need fay nothing of it. I walked fo far before my Companions, up the Mountain along tbs fide of the River of Fire, that I was oblig’d to re- tire in great hafte, the fulphureous Steam having lur- priz'd me and almoft taken away my Breath. Du- ring our -Return, which was about Three-a-Clock in the Morning, we conftantly heard the Murmur and Groan- ing of the Mountain, which between whiles would burft out into iouder Peals, throwing up huge Spouts of Fire and burning Scones, which failing down again refembled the Stars in our Rockets. Sometimes 1 ob- Y y y y y ferv’d ( 711 ) ftrv’d two, at others three Columns of Flame, and fometimes one vafl; one that Teem’d to fill the whole Crater. Thefe burning Columns, and the fiery Stones leem’d to be (hot a icqo Foot perpendicular above the Summit of thQ^olcano. The nth at Night, 1 obferv’d it, from a Terrafs in Naples^ to throw up incefl'antly ^ taft Body of Fire and great Stones to a furprifing Height. Thexith in the Morning, it darken’d the Sun with Alhes and Smoak, caufmg a Tort of EclipTe. Horrid Bellow- ings this and the foregoing Day were heard at t^aples, whither part of the Afties alTo reached. At Night I obTerved it throw up Flame, as on the nth. On the i3th> the Wind changing, we Taw a Pillar of black Smoak (hot upright to a prodigious Height. At Night I obTerved the Mount caft up Fire as before, tho’ not To 4iftindly becauTe of the Smoak. The 14th, A thick black Cloud hid the Mountain from Naples. The 15th, in the Morning, the Court and Walls of our HouTe in Na- fles were cover’d with Allies. In the Evening, Flame ap* pear’d on the Mountain thro’ the Cloud. The i6th, the Smoak was drivenby a Wefterly Wind from the Town to the oppofite fide of the Mountain. The i7th, the Smoak appear’d much diminifli’d, fat and greaTy. The 18th, the whole Appearance ended, the Mountain remaining perfe(3iy quiet without any vifible Smoak or Flame. A Gentleman, of my Acquaintance, whole Window^ look’d toward Fefyvius, aflur’d me, that he obferv'd this Night Teveral Flafhes, as it were of Lightening, ifliie out of the Mouth of the Volcano. It is not wmrth while to trouble you with the Conjedfures I have formed con-? cerning the CauTe of thcTe Phsenomena, from what I obTerved in the Lacm AmjanBi^ the Solfatara, ^c. as well as in Mount Vefuvius. One thing I may venture to Tay,. that, I, Taw the fluid. Matter- rife out of the Centre ' of ( 71 3 ) of the Bottom of the Crater^ out of the very middle of the Mountain, contrary to what BoreUm imagines* whofe Method of explaining the Eruption of a Folcana by an indexed Syphon, and the Rules of H^drofiaticks^ is likewife inconfiftent with the Torrent’s flowing down from the very Vertex of the Mountain. I have not feen the Crater fince tlie Eruption, but defign to vifit it again before I leave Naples. I doubt there is no- thing in this worth Ibevving the Society 5 as to that, you will ufe your Difcretion. E. Berkeley yi. An Account of an extraordinary TUMOUR.' or WEN lately cut off the Cheek, of a ^erfon in Scotland. Communicated to the ^yal Society by T>r, Thomas Bower^ M. D, and F. IT is generally acknowledg’d, that the exacSb Obler- vation of internal Difeafes, and the faithful Ac- counts of external Tumours, and extraordinary Cafes in Chirurgery, have contributed very much to the Advancement of Medicine. Hippocrates and Galen, and other ancient Fathers of Medicine, have fet us fait Copies of this ; and the Moderns, happily following their Footfteps, have illuftrated this Matter by many curious Obfervations and Reflections. The Royal So- cieties and Colleges of Firtuofi, that are now over all Europe, have taken much pains in this Affair, and have given us many Inftances and Examples of Extraordi- nary Cafes in Medicine, which are of great ufe to all the Pradifers of Phyfick and Chirurgery. Accordi^^g to thefe laudable Examples I fhall, for the Satisfadion Y y y y y 2 of ( 714 ) I of the Curious and Ingenious, give a true and faith- j ful Account of an extraordinary Excreicence cut off from the Cheek of a Man, which weighed Nineteen Pounds, and the Patient entirely recover’d in few Weeks time. I never before faw the like, nor never read of it in any Author, tho’ I have confulted ma- ny on the Head. This Excrefcence is preferved a- I mong the Rarities of the College of Phyficians at £• dinhurgh. The Phyfician concern’d in this Affair, was Dr. Alexander Rujfel of Elgine, a learned and ingenious Man, and the Operator was the ingenious Mr. George Cordon of Keithf from whom 1 had the following Infer. ! mation. I i Alexander Palmer, of the Parifli of Keith, in’ the ' County of Bamf, in the North of Scotland, now about | Fifty Four Years of Age, obferved, when about Twenty Seven, a little hard Swelling in the Mufcle of the lower Jaw on the Left Side, without any Hurt or mam'fefl: Occafion, which at firfl: went on flowly, but afterwards it proceeded more quickly, and the older it grew, it {till came on the fafter; until it increafed to a prodi- gious Bulk and Weight : From the fir ft Appearance of this Tumour to the total Excifion of it, there were a- bout Twenty Seven Years. He had exceflive Fains and Uneafinefs in it, and at laft it mightily extenua- ted and emaciated him, who was otherwife a flrong and robuft Man. This Excrefcence was of the natural Colour of the Skin, and feem’d to be an Atheroma being a glandulous Subftance with feveral big Blood-VefTels in it. and had j Hair growing on it, as on the other i arts of the !' Body, as may yet be feen. It was almoft round and ■ very hard, and was as fenfible as any other Parc of the j Body ; for, when the poor Man was working in the i Fields, I ( I- r ) Fields, feme fix or feven Years ago, he accidentally made a great Gafh or Wound in it with a fliarp Iron, which was very painful, but was cured by a burgeon, after the manner of an ordinary Wound ; the Cicatrice is flill to be fecn in it. This Excrcfcence having grown fo big, was attach’d to the Mufcle under the Left Eye, call’d Obliqtms minor or inferior^ to the Ear and its Mufcles, and to the Mufcle of the low’er Jaw, named De^rimens. By rea-^ fon of its great Bulk and Weight, it could not hang down freely without fome Support, therefore it refled on the top of the Shoulder, which made a confidera- ble Dimple in it, that is yet very obfervable; befides, it was holden up by the Man’s Hand in the Day- time, and laid on a Pillow in the Night* feafon. ' Some three or four Days before the total Excifion was made, the Patient obferved this Tumour begin to mortify at the lower end, which made him fo unea-. fy, that he took a Knife and cut off a good part of it. This occafion’d a great Haemorrhage; fo that he reckon’d there was loft a Scots Pint or four Pounds of Blood, before it could be ftopt. The Patient, after fb great Trouble and Pain, at laft applied himfelf to Mr- Gordon, Surgeon of the Place, who made a total Extirpation of it, on the 1 9th of Jnnmr% 1717. He made a clofe Ligature, taking in the Bafis of the Excrefcence, and all the loofe Skin, and contradf* ing it as much as poftible, he cut it entirely off with a (harp Pvafour. There gufhd out of the Excre- fcence, after it was cut off, and was lying on the Ground, as near as could be guefs’d, two Pounds of Blood; for it was nourifh’d by feveral large Biood- Veflels, perhaps by fome. Branches of the Carotide Ar- tery much iniarged, and other Blood- Veflels coming from ( 7\(> ) from tbc Ear, and the Mufcles of the Eye and lower Jaw abovementioned. When Mr. Gordon brought it to us, which was full three Months after it was cut off, we cut off with a Knife about a quarter of an Inch broad of the Bafis of it ; and in that fmall Space wc obferved four big Blood Vellels. The Bafts, as it now appears, is five Inches Diameter, which feems too large for the whole fide of the Face : So that after the Ex- fedion, I think the loofc Skin has turn’d backwards, which may make the Bafis now appear fo big. After all this Blood was loft, the Excrefcence was weighed, and was full Nineteen Pound Weight ; fb that before bis own Incifion and this Operation, it behoved to be feveral Founds heavier, which is a moft prodigious Weight to be depending on fuch a place. This Tumour was of a Spheroidical Figure, and when meafured, was Thirty four Inches about by the longeft way, and Twenty eight by the broadeft. The Haemorrhage, which was great, was flopped by the Vitriolic Powders and other Aftringents, and the ordinary Drefling w^as ufed. So this great Cure was completed in fix Weeks time, and the Patient entirely recover’d, and goes about his Bufinefs, to the great Admiration and Aftonilhment of every body. The Lid of his Left Eye continues ftill downwards a little, as does that fame fide of the Mouth, which was occa- fiond by the great Weight depending on that fide of the Face ; but it may be expeded they may come a- gain to their right Pofture ; for the Head, at firft af- rer cutting, enclined much to the Right fide, by rea- fbn of the great Weight on the Left Cheek having been removed ; but it now begins to ftand upright, •finee he is perfedly recovered. Tho’ the Skin, and e- ven a deal of the mulculous part of the Cheek and lower (. 717 ) lower Jaw was cut away, yet, according to the Infor- mation I have from Mr. Gordon the Operator, it is grown up again, and is of the ordinary Colour of the 5kia, and like the other fide of the Face ; fo that there grows Hair on that fide of the Face as well as on the other, which he ordinarily fliaves; and this is as furprizing as any thing in the whole Affair. I have given a true and plain Account of this ex- traordinary Cafe from certain Information; I have con- tented my felf to relate only Matters of Fadf, without making any Obfervations or Reflexions on it; for I leave it to the Philofbphers and Virtuofi 'to make their own Reafonings and Refinements as Teems beft to them- feives. yil. An Account of an Experiment to pro);e an incer- fpers’d Vacuum 5 or to Jhew that all Tlaces are. not ec[ualy full, This Experiment was made before the KING, and-^ HER Royal Highnefs the Princefs of Wales, at Hampton-Court, in the Month of September 17 17. afterwards before the R o Y A l-S o c i E T Y , on Thurfday, December^. 1717. and fince that, in Channel-Rowe, , Weflminfter, before [ome Members of the Royal-Society, by I. T. Defaguliers, M, A, F,R^S. as follows; Having had the Honour to make fome Experiments laft Year before his Majefiy and their Royal Highmfes the Prince and Princefs of Wales ; among others, ' lliew’d that of a Guinea and a Piece of fine Paper ; then oi a Guinea and a Feather dropt together ftom the top of an exhaufted Glafs Receiver about zo inches high ; both which ( 7«S ) wliich fell to the Bottom at the fame InBant of Time : Now fince the chief Refifiance of a Medium ( and in- deed almoft all of it ) depends upon the f Quantity . of its Matter 5 therefore this Diminution of Refiftance, whereby the Feather fell as Toon as the Guinea, fliew’d a Diminution of the Quantity of Matter, and conle- quently prov’d an interfpers’d Vacuum. Some time after this, I was inform’d that fome here in England objeded againft the i hormefs of the Glafs-Re- -ceiver; as if the Difference of Time in the Fall of the two Bodies, which they affirm’d to be real, could not be perceiv d in fuch a Glafs ; and that lome Philofb- phers from abroad affirm’d that in a Glafs Receiver 7 or 8 Foot long, there would be fuch a manifeft Difference in the Time of the Fall of the faid Bodies, as to fhew this Experiment no Proof of a ^ ncuum ; though at the fame time, Tome of the Objedors well knew that there - could be no Receivers of half that Length made at the Glafs Houfe, and therefore thought the Experiment impradicable. To obviate this, I contriv’d a Machine for the purpofe, which confifted of a flrong wooden -Frame 15 Foot high, that held the Air-Pump and four Cylindric Glafs-Receivers of about two Foot long each, and fix Inches Diameter Of thefe, having fet the firft upon the Air-Pump Plate, I laid on the Top of it a Brafs-Plate of feven Inches Diameter, that had an oil’d Leather fix’d to it above and below, with an Hole through the middle, of between four and five Inches Diameter; then on that Plate I fet the next Receiver, with a like Plate at top; and after the fame manner fix’d the other two with Plates between them : The upper Receiver being a little narrower at the Neck, t See Sir //i Brinci^ia, Book II- Prop. 4o. went ( 71? ) went into the Hole of a Board, whereby it was ferew’d down pretty hard on the ocher Glaffes, and fix’d, to the whole Machinei On the top'of .this upper Receiv-' er I laid the Brafs Plate, wet Leather, and Brafs Springs which contain’d the Bodies to be dropt ' ;; i Having acquainted His Majefty with what I had pre- par’d, he order d me to fhew him the Experiment wnth this long compounded Receiver, and when 1 made- it before him and her Royal Highnefs,: he was pleas’d f by pulling down a String fix’d to a Lea- ver at the top of the Machine ) to let loofe the Bodies himfelf, to fee that the Experiment was fair. :W-hen the Receiver .was^fuU of common Aimbefore Pumping, the Guinea, came w«?^^n 71 7^: being the Thur[day next after the Yearly Meeting focchoofing Officers on St, .Andrew's Day? x)n which Day an {an- nual Experiment is appointed to , be-maidd, in .Confor- mity to the. Will jof theiri late wenthy, Nleinber arid, Be? nefadlor Sir Coj^lej. . jUTiUL; , .. d I made the Experiment firft with two of the Rccei* vers:;, then iwitiKali the four ; : dropping afiGuinea.and a. fmall Piece of Paper together ; and the Succefs anfwer’d Expedation : But not being willing to try with a Down- Feather, becaufe I fear’d the Air might infinuate between fbme of the Glaile8,-by reafon the Number of Perfons prefent lhak’d the Room , the Society order’d me to make the Experiment at home before one or more of their Members. Z z z 2 z Martin 7 ( 7io ) J^arth Fffulkes, Efq; a very ingenious Member of th« Society, did me the favour to be prefenc when I made the Experiment at my Houfe ; where w'e made four Tryals in the following manner. The whole Machine being fix’d, as above mention’d, we firft let fall a Guinea and two Papers ; the one placed over, and the ocher under it, (before any Air was pump’d " out) and the Guinea came to the Bottom when the Pa- pers were only in the Middle of the fecond Glafs from the Topi Then having laid a Feather on the Brafs*- Springs clofe by the Guinea, we kc them loofe both together ; and the Feather was fallen only down to the 4th part of the Length of the firfl Glafs or ^ of the whole DKlance, when the Guinea was got down to the Bottom of the Receiver. We then laid two Papers and two Feathers, one of each under, and the other over the Guinea between the Springs ; and having drawn out (b much of the Air as to bring up the Mercury in tht Gage-Tube within a quarter of an Inch of the great* cR Height to which it could be then rais’d by the Prel^ Eire of the external Air, we caus’d the Bodies to fall all at once : And tho’ the Papers came down to the Bot- tom at the fame time as the Guinea, yet the Feathers, being much lighter, wanted about three Inches- But at lad, having laid the Papers, Feathers, and Guinea^ as before, we pampd out all the Air, and then the Feathers, as well as the Papers, came to the Bottom of the Receiver at the fame indant of time as the Guinea. yilf. Jn ( 711 ) VIII. An Account of a /mail Telercopical Comec feen at London on the loth of June 1717. by Edm. Halley, LL. D. R. Soc. Seer. « That the Number of Comets traverfing our So* lar Syftem is much greater than feme, on ac- count of the late rareneis of their Appearance, have fuppofed it, may be collected from feveral fmall ones which have within few Years been deferibed in the Memoirs of the fretfcb Royal Academy of Sciences.;; thofe diligent Obfervers alTuring us that they difeover’d one in Sept. 1698. another in Fehr. 1699. a third in ^prtl 1702: and again a fourth in Novemh. 1707. none of which, as far as I can learn, were ever (een ’m,E»Sr Und\ all of them having been very obfeure and with- out Tails, by means whereof Comets ufually firft Ihew themfelves. And bcfides thefe, two other Comets with remarkably long Tails> the one in Movemb, 1689. the o- ther in Febr. 1701. pad by unobfervable in thefe our Northern Climats, they having great South Latitude, and their Motions dire(ded toward that Pole. Hence we may juftly conclude that the Returns of Comets arc much more frequent than is vulgarly reckoned, and chat it is only contingent that for thefe ; 5 Yeats no one of them has been feen and obferved by our Adronomers. But there may be dill a much greater Number of thefe Bodies, which by reafon of their Smallnefs and Didance are wholly invifible to the naked Eye ; fo that unlefs Chance do dire(d the Telcfcope of a proper Ob- ferver, almod to the very Points where they are (againft which there are immenfe Odds^ it will not be poffible Zzzzz % for ( ) for them to be difcovcred : And that this is not barely a Conjedure, take the following Inftancc. On Mcnddjy June lo in the Evening, the Sky being very ferene and calm, I was dcfirous to take a View of the Disk of Mates ( then very near the Earth, and ap- pearing very glorious ,) to fee if I could diftinguifli in my 24 Foot Telefcope, the Spots faid to be (een on him. Direding my Tube for that purpofe, I accidentally fell trpon a fmall whitilh Appearance near the Planet, refem- bling in all refpeds fuch a Nebula as 1 lately deferibed in Philof. Tranja^. N° 347. but fmaller. It leemed to emit from its upper part a very lliort kind of Radia- tion difeded towards the Eaft, but Northerly withal '; ^jj^hich, confidering its Situation, was nearly towards the Point oppofite to the Sun. The great Light of the Moon, then very near it and alfo near the Full, hin- der’d this Phenomenon {torn being more diflindly feen ; bue its Place in the Heavens was fufficiently afeertained frbm the Neighbourhood of Mars, from whom it was but about half a Degree diftant towards the SouthwelV, the difference of* Latitude being fomewhat more than tbat bf Longitude and Mars being at that time in t 30'^ with 5°. 48^ South Latitude, I concluded the place thereof in .17®. 12' with 4°; Lat, South, or thereabouts ; the which may yet be more fecurely de- termined by help of two fmall fixt Stars I found near it, the more northerly of which I judged to have the“fame Latitude with it, and ito follow it at about the Diflance 'of>ft5C'Mihttires;' tKo^other Star was ilbouc- four Minutes more foutlierly chan. rhe former, and about one Minute ili-:conrequence rhereof ; the Angle at the Northern Star whsta httld ohtufe,, as of about lOp Degrees, and thie f)iftanpe pf'-okr Nebulaitxom iX 'fefquiaber to tliO Diff-anefe ibf?the)cwoi Stark; or rather a little more. “ The Re^er^id Mt, Alban Thomas, and my- ‘4 If, ;;l concern- ( ) contemplated this Appearance for above sn Hour, v/z. from lO:'' to near twelve, and we could not be deceiv’d as to its Reality ; but the Slownels of its Motion made us at that time conclude that it had none, and that it was rather a Neh'ula than a Comet, However, fufpedling that it might have fome Motion, I attended the next Night, June i ith, at the lame Hours and in the fame Company, when with fome Difficulty by realbn of the Thicknefs of the Air, we found the two little Stars, but the NehuLt could not at that time be feen, which we then imputed to the want of a clearer Sky. But on Saturda), June i$. the Moon being abfent, and- the Air perfedlly clear, we had again a diHind: View of the two Stars, with an entire Evidence that there re- mained no Footftep or Sign of it, in the place where we had firfl; leen this Phanomenon, which we therefore now found to be a Comet, and that being far without rhe Orb of the. Earth, and in it felf a very fniall Body, it appeared only like a little Speck of a Cloud, fuch as, would fcarce have been difcerned in an ordinary Tele- fcope, much lefs by the naked Eye. IX. An Account of ^ooks, I. Joannis Poleni in Gymnafio Patavino Phil. Ord. Prof. Sc Scienr. Socictatum Rcgalium, qux Londini& Bero- lini fuilt, Sodaiis, Ve Motu A^u^e mlxto^ Libri duo, ere. 4^®. PataVii 1/17. The Sub}ed;;herfi treated, of not having hitherto •fajleii under the Cpnfideration of Mathematical Writers, the Learned;iAuchor is obliged to make ufe of feverai XermSi which are either wholly new, or at r ' ' Isaft ( 7i4 ) lead are applyM in a fenfe fomewbat different from their common Acceptation; for which rea on he begins his Work with a Sett of Definitions. ^^tta mortua, or a dead Water is that whofe Surface being every where equally diflant from the viuWf no part of it can defeend any lower, without for- cing fome other upward, and confeqw-iitly the Whole is without Motion. viva, or a running Water is that which is put into motion by the Prefiure of the Incimibcnt Water, and whofe Motion is oppofed by no other Water lying in its way. The motion of a running Water is call’d Motus fim* flex, or the fimple Motion. If a running Water m )Vtng over the Surface of a dead Water, do, by its Prefiure, communicate part of its Motion to the dead Water ; the compound Motion with which the whole Body of the Water flows, is called Motus mixtus, or the mixt Motion. If a Water at different Depths from the Surface run with different Velocities, thewr^w is that, which being the fame at all Depths, will difeharge the fame Quantity of Water. Next follows a ftiort Hiftory of the Original, and Progrefs of the Dodrine of running W'aters, the Inven- tion of which our Author juftly afierts to the Learned Cafiellus, and defends him againft Fabretti, who has maintain’d that Cajlelluss fundamental Propoficion of the Quantity difeharged being cateris faribm in pro- portion to the Velocity, was known, and publickly taken notice of before him by Frontinus, The Author allows CafleUus to have been miflaken in determining the Velocity of Water running out at the bottom of a Veflel, he having aflerted that Velo- city to be as tlie Depth of ihe Water. Three 1 ( 7*5 ) Three Years after Cafiellus*s Book came ouri this Miftake was correded by the famous Torrkdlius, who was the firft that maintain’d, that the Velocity of the Water running out was in a fubduplicate Ratio of the Depth, but gave no Demonftration of it. This Propofition, fays our Author, .was confirm’d by the Experiments of Maggiotti, Mariotu^ and GugUdmini, and has fince been demonflrated by Mr. Varignoriy by Herman in his Phoronomia, and John Bernoutti, as re- ported by Herman in the Ada Lifftenfia. Here it may not be improper to take notice^ chat the Demonftrations of thofe three Learned Perfons are all grounded upon this Suppofition, that the Water running out from the Hole is preft upon by the Co- lumn of Water incumbent upon it, which may eafily . be demonflrated to be a Miftake. Likewife, if their Demonflracions be juft, it will follow, that the ftrft Drops of Water, which iflue out from the Hole, muft run with the fame Velocity, as after the Water has been running Tome time; the Contrary of which ap- pears to be true in Fad by the Experiments of the fa- mous Mr. Mariotte. The Author might have found a jufter Account of ^ this matter in the Writings of a Great Man, whom he - cites on another Occafion; the fccond Edition of whofe Book was come out fome time before Herman pub- lifh’d either of thofe Demonft rations, and had been feeu . by him, as appears by his quoting it frequently, and mentioning the Difference in this very Particular be- - tween the firft and fecond Edition. Our Author goes on to confider the fimple Motion of Water running out by a Sedion perpendicular to the Horizon, in the fide of a Receptacle, which is always entertain’d at the fame Height. He (hews, that the Velocities, with which the Water iflues out at different Depths, • ( ) Depths, being as the Roots of thofe refpet^iive Depths, may be rcprefented by the Ordinate- of a Faraho.n, whole Axis repteleiUj the entire Depth. of the Water. ConCet^ueiitly, fince. the C^ua;K,iiies of ^Vater, running bur at different Depths, are as thofe Velocities, th^ likew:j(e may be. reprefented by the fame Ordinates, and the C^anrity of .Water difeharg’d from the whole Sc- dibn, will be repceiented .by the Rsrabolick Space; and the! mean Velocity by that fame Spaep divided by the Abfciffe. The Times, being as the Qiiantities of Water dif- charged , may be reprefented in the fame manner as thofe Quantities. Hence he derives hi^ general Theorem, That the Qjaan- titics of Water difebaiged, are in a ratio compounded of the fe(quip!icate of the Depths of the Water, the ratio of the Breadths of the Section,, and of that of the times of the Efffux. The Author proceeds now to the mixt Motion of Water; in order to' ^ifeover the Nature of wliich he has made fbme curious Experiments, after the folloiving manner : - A large cylindrical Veflel, with a perpendicular Se- dion through the fide, of it, was placed upright in a dead Water ; fb that the bottom of the Veffel was a con* fiderable Depth below the Stirface of the Water; and the' Veflel was kept immovable in this fituation. Above this was Ext another Veflel, full of Watery whbfe Bottom was pierced >yith >6 Holes, exadly round, and of the fame Bore, and fb order’d,, as- to be open’d, or flppt at pleafure. The Water in this Veflel was al- ways kept at the fame Height, by means pf a third Veflel, Which fiipply’d the Wace^, . as fafl: as it.ran out at the round Holes, in the Bottom ; and a large Aper- ture^ in the fide, of the fecond, WefTel near' the Top. ' . ' ' ’ pre vented ( 717 ) prevented the Water in it from exceeding the due Height. To break the 'Force of the Water running in- to the two lowermoft Vcflels, they were each of them - divided by a Board , placed perpendicujar , but nor reaching the Bottom, which feparated the Part where the Water came in, from that where it went out. ' The j^pparatus being thus fixt, three of the round Holes in the Bottom of the (econd Veilel were un- ftopr, to let the Water run into the lower Veflel. Where not running out at the Sedion in the fide, fo faft as it came in from above, it rofe to a confiderable Height above the Surface of the dead Water ; after which, the Efflux of the Water becoming equal to the Influx, it rofe no higher. In other Tryals the Water being fuffer’d to run fiom 6, from 9, li, and 15 of the round Holes, the Water rofe fuccefflvefy to greater Heights, before the Sedion dif* charged it as fall, as it came in. The Experiment being repeated with opening other Numbers of the round Holes, with Sedions of diffe- rent Breadths, and at different Depths of the dead Wa- ter, rhe icveral Heights, to which the Water rofe in the Veffel, w'ere carefully obferv’d and fet down. Other Experiments were made by placing the lower Veffel on dry Ground, and the feveral Heights to which the Water rofe in the Veffel, according as different Quan- tities were fuffer’d to run in, were likcwife obferv’d, and found agreeable to the Heights deduced by Calcu- lation from the general Theorem above-mention d, con- cerning the fimple Motion of Water. The Learned Author comes now to apply thefe Ex* periments, in order to difeover the Theory of mixe motion, to which end he lays down thefe two Hy- pothefes. A a a I a a Firfl, ( ) Firft, he fuppofb, that the Velocity of the running Water is every where in a fubduplicate rafU of the Depth, and conrequencly the Quantities difcharged may be reprefented by the Parabolick Spaces, juft as in the cafe of the firtaple Motion of Water Secondly, that the Velocity of the dead Water, is the fame at all Depths, and equal to the greateft Velocity of the running Water. Wherefore the Quantity of dead Water difcharged may be reprefented by a Redangle, whofe Height reprefents the Depth of the ftagnant Wa- ter, and whofe Bafe is the greateft Ordinate of the 1 a- rabolick Space abovementioned. Having thus contrived a way of reprefenting the Quantities of Water difcharged by the mixt Motion, as had been done before for the fimpJe Motion of Wa- ter, our Author obfervcs that the Velocities of the Wa- ter iftuing out at different Depths, and confequently the Parabolick Spaces reprefenting the Quantities of W^a- cer expended, muft be lefs in the mixt, than in the fimple Motion. In order therefore to find a general Rule for deter- mining the Proportion between the Parabolick Spaces, which reprefent the Quantities difcharged by the mixt and fimple Motion, or between the Parameters of ihofe Patah/as, he draws fome Obiervations from the foregoing Experiments, by the help of which he hopes fuch a Rule may be found out. Firfly he obferves that, if the Depth of the running Water continue unchanged, a greater Depth of dead Water requires a lefs Parameter. Secondly y Thar this Parameter does not decreafe in fd great a Proportion, as the Depth of the Water in- cteafes- Thirdlyy That, if the Depth of the dead Water de- creafe, or the Depth of the running Water increafe in fuch ( 719 ) fuch manner, that the latter becomes infinitely gr^t in proportion to the former, then the Parameter of the mixt Motion muft become equal to that of the fimplc Motion. Fetirthly, That, if the Depth of the dead Water be- come infinitely great in comparifon of the Oepth of the running Water, the Parameter of the mixt Motion va- nifhes, or becomes equal to nothing. The Rule, therefore, which is to be found, ought to agree with all thefe Obfervations, and befides mufl: produce the fame Quantities of Water by Calculation, as were found by Experiment to anfwer to‘ the feveral Depths of running and dead Water, in the above mc*n- tion’d Tryals. Upon this Foundation the Learned Author proceeds, in a tentative Method, to find his Rule, and having difeover’d it, he fhews by Calculation, that it anfwers all the Conditions before requir’d. This Rule is expreft in a pretty high Equation, which, befides other Operations, requires the extracting the Root of the fixth Power From this Equation is derived another, ferving to find either the C^antity of Water difeharg’d, the Depth of the running, or that of the dead Water, the other two of them being given ; as likewife a third Equation, to find the mean Velocity. Our Author goes on to fliew the Ufefulnefs and Ne» ceffity of confidering the Doctrine of mixt Motion, in all Queftions relating to the Courfe of Rivers, the Quan- tities of Water which they difeharge, the enlarging or narrowing their Outlets, the fcouring and deepening their Channels, and ^ the Motion of the Tides in Har- bours. Thefe he illuftrates by feveral Deductions from the Equations above mention’d; to render which of grea- ter Evidence, it were to be wifiit, that thofe Equations A a a a a a z were ( 7?o ) were built upon a more folid Foundation than a ten- ' tative Calculus and that Allowance had been made for the Velocity impreft upon the preceding Water in Ri- vers, by the imf>etus of that which follows, which is omitted by the Author in his Theory, both of mixt and fimple Motion. In the Second Book, this Learned Writer propofes the State of the Laguna of Venict^ as a proper Exam- ple, to demonftrate the Ufefulnefs of his new' Theory. He confiders very minutely the feveral Caufcs of choak- ing up the Laguna, examins the Methods propofcd by various Authors for fcouring and keeping it clear, fome of which he rejcds as impradficable on account of the Expence, others as ufelefs, or prejudicial; and laftly de- livers his own Opinion. The principal Caufes, which he afTigns, of filling up the Laguna, are the Rivers running into it, and the Sea. The Rivers, which enter it, arifing out of the Alp, and running down with great Rapidity, carry with them, efpecially after Rains, great Quantities of Soil, which is eafily fufpended in the Water, fodong as that Swnftnefs of Motion continues. But w'hen they come into the Laguna, the Water, upon extending it felf over that vaft Surface, loofes almoft all its Velocity, and confcquenC'. ly the SoiLand Filth, which before it carry ‘d with it, fubfides in great Qiiantities to the Bottom. The Remedy our Author propoles for this Incon- venience, is either wholly to divert the Courfe of the Rivers and carry them, by another W'ay, diredfly in* to the Sea; or at lead, to fecure their Outlets with Sluices, (o as to fufTer them to pafs into the Laguna, when their Waters are clear ; but after great Rains, when they run foul and turbid, to flop* their PalTage that way, and let them out by the other Channel into the Sea. The ( 71 i The Tecond principal Caufe of choaking up the Ld- gftna, is the Sea Concerning which our Author ob- ferves, that the Tide of Flood iets into the Laguna from along the Coad of I(lria and Friuli, where it is per- petually walhing away the Land in great Quantities^ with which, and the Sand which it raifes upon high Winds in the Shallows near the Shore, it enters the Laguna excedingly turbid and foul ; efpecially, when the Wind blows hard at South- Ead, at which times the Tide of Flood is feveral Hours longer than the Ebb. This occafions very high Tides in the Laguna, and a great part of the Water, which enters by the Flood, not being carry ’d out by the fubfequent Ebb, has the more time to difeharge its Soil and Sand in the Laguna. This IS an Enemy very hard to deal with, however our Author propofes fome Works of flrong Piles, and large Stones thrown in between them, to be carried diredly forward into the Sea, in order to break th» Violence of the Waves, and prevent their ’wafhing and carrying away the Land. Fde feems likewife to favour a Propofal made by the late famous Guglidmini, and fome others, to let the Tide enter the Lai^una by more PafTages than it is to go out at, in order to make it run out with a greater Velocity, and thereby fcour and deepen the Channels. Bur he thinks this Contrivance will fcarcely perform all that is expeded from it; befides that, it will be attended with great Difficulties in making Works, and Flood- gates of a fufficienc Strength, to refifl: the Violence of the Waters. He occahonally combats the Opinion of Guglidmini, and moft other Mathematicians who have thought up- on the Subjedlf', that in order ro give a greater Velo- city to the Water of a River, thereby to fcour and cleanfe the Channel, it is proper to make the Outlet narrower. ( rji ) narrower. This our Author maintains to be ofcnec falfe, than true, and endeavours to (hew from his Theorem above-mention’d , that making the Outlet narrower, will frequently caule the rman f^elocitf of the Waters to become left than it was before. But whe- ther a Propofition of fuch Confequence, and fecraingly fo well rupported by Reafon and Experience, ought to be condemn’d upon the Authority of a Theorem founded only upon a tentative Calculation, mud be left to the Judgment of the Learned. II. Apollonii Pcrgaci Conicorum tihri OSio, Se- reni AncilTenlis de SeEitone Cylindn ^ Coni Libri duo. FoL B Theatro Oxon. 1 7 1 o. The worthy Curators of the Orfard PVefs having obliged the Publick with a very elegant Edition of the Works of Euclid^ Graeco- Latine, were pleas’d fur- ther to proceed in the laudable Intention of giving the reft of the ancient Greek Mathematicians in the fame beautiful Form; In this Delign they were chiefly animated by the late learned and beneficent Dean of Lhrifi Churchy Dr. Henry Aldridge, who pitching upon Apollonius, as moft proper to fucceed Euclid, engaged the two SavtUan PrefeHTors to take upon them the Care and Pains of the Edition ; Dr. David Gregory promtfing his Affiftance as to the fiift Four Books, which are fti’l extant in Greek ; and Dr. Edm. Halley under- taking to franfiate the Fifth, Sixth, and Seventh Books out of Arabick ( in which Language they were only to be found ) and to endeavour to reftore the Eighth, long fince wholly lort. But T>:. Gregory foon after dying, the Care of the Whole devolved on Dr. Halley, who hath fpared no Pains to render the Work complete. He in his Preface tells us what Helps he had to perfed the Text, That he had the ufe of two Greek MSS. of the ftrft Four Books, one of which was Sir Henry Savil's, and is in the Suvilkn Study at Oxford, the other is now in the Roy.al ( 7li ) Royal Society’s Mufeum, having been lately prefented them by that skilful Mathematician Mr. William Jones, F. R, S. That he had only one Manufcript of Commen- tary, out of the Bodley Library ; and two Greek Copies, from the Savilian Study, of Pappus’s Colledions, out of whofo 7ch Book he took the Lemmata, which ferve as a Comment on the more difficult Places of his Author ,• and that he was forced to revife and correct the Miftakes and Improprieties of the Latin Tranflation of Commandine. As to the latter Books, which were only in Arahick, he informs us, that he made ufe of the Boddey Txanfcript of a Manufcript that is at Leyden, which it felf is a late Co- py of that ancient Arahick Book of the Conickt, heretofore Gclius's, but fince purchafed by that great Patron of Uni- verfal Learning, NarciJJus late Primate of Ireland, who was pleafed to favour him fo far as to fend over into England this Original Book, whereby he not only amended feveral Faults committed by the Copyifts in a double Tranfcrip- tion, but was alfo affured that this Arahick Book was a ver- bal Tranflation from the Greek; the fame Schemes markc with the fame Letters, and the whole Context being the fame in the firft four Books of it, as in the Greek Apollo- nius This valuable Manufcript, with about 800 others, Oriental and Greek, has fince, by the Donation of that moft venerable Prelate, made a noble Acceffion to the Bodley Li- brary, wherein it is now depofited. It appears by an Epi- grapbe at the end, to have been written in the Year of Chrift 150;. and to have been a Copy of a Tranflation of the Conicks, made fome Ages before by Thehit Ben Corah, but ther) newly revifed by that famous Perfian Mathemati- cian Nafir-eddin, who flourifh’d about the middle of our thirteenth Century. Behdes this , the Editor tells us, that on occafion he confulted another Arahick Manufcript ( heretofore Ravim’s ) of great Antiquity, being an Epitome of the fame Books by Ahdolntelec of Schiraz, every where agreeing in the Order and Argument with the former, but abridg’d. So that ha- ving had thefe Helps, he is in hopes that he has fo far re- trieved thofe Three Books of Apollonius, that the Lofs of the Greek Text may henceforth be lefs lamented. The ( 7H ) The Eighth Book of theie Gonicks, was wanting in the Gruk Copies even before the Tradudion of them into Ata-- . bick lhebit: rf>wt it having been obferv’d that there was a very near relation between the Arguments of the Vllth and Vlllth Books, for that the fame Lemmata of Pappus were common to them both, which are different to all the reft, it feemed that the Tbmemata Diariflica of the Vllth Book were defigned to determine the Limits of the Yrobkmata Diorijmena of the Vlllth; and therefore fuppo- fing whac thofe. Problems might have been, and their Order from that ^of the faid Theorems, Dfj has.in XXXlil Propofitions given the Analyfes Synthefes of. them, after the Method of the Ancients, every where, following the Steps of Apollonius to be found in his Vllth Book. This he t calls Qonicorum Liber OBavus rejlitutus^ and may ferve the turn, till fuch time as the Original Eighth Book come to light ; if that be not now to be defpair’d of. Becaufe of the Affinity of the Subjed, he hath fubjoin’d the two Books of Serenus AntiJJ'en/ts, the Greek Text of which was never befoie in print. This was procured by the abovefaid Reverend Dean of Chriftchurcb, Dr. Aldrich^ in a collated Copy of three Manufcripts, extant in the King’s Library at Paris, and by him, according to his wont- ed Goodnefs and Generofity, freely communicated for the ufe of the Publick. To this alfo is added the Latin Tranflation of Commandine, which in many Cafes needed Caftigation. As to the Authors themfelves little needs be faid, they having flood the Teft of fo many Ages, and been highly valued by the Learned in all Times, efpecially the Conicks, juftly efteemed a Mafterpiece in the Geometry of the An- cients : So that it may feem ftrange, that a Book fo ex- celling in its kind, (hould not till now have been printed in its native a Tongue fo peculiarly adapted to Mathe- matical Purpofes. But this preient Edition may make am- ple Amends, the Paper and the Elegance and Corre..»C ( ^55 ) Number 35^5* PHILOSOPHICAL TRANSACTIONS. For the Months of Jan. Feb. March and Jpr. 1718. The CONTENTS. /""^Onfiderations on the Change of the Latitude j of fome of the principal fixt Stars. 'Ey Edmund Halley, R.S Sec. II. Jn /Account of fome Experiments fhown before the Royal Society , with an Enquiry into the caufe of the Ajcent and ^Sufpenfion of Water in Capillary Tubes. Ey James Jurin, M.D. and R. Soc. S. III. De Motu Jquarum fluentium. Authore eodeni T>. Jacobo Jurin, M. D. IV. An Account of the Sinking of three Oaks htto the Ground^ Manington in the County of folk. Communicated by Peter Le Neve, Efq‘j Norroy £\jng at Arms, and Fellow of the Roy- al Society. V. A ^eBifcation of the Motions of the five Satel- lites of Saturn j with fome accurate ObferVations of theWy made and Communicated by the E^Verend A/r. James Pound, R. S. Soc. Aa a aa a I. Conf^ / ^ ^ X \ V / L Conflderations on the Change of the Latitudes of tome of the principal fixt Stars. ^By Edmund Halley, R. S. Sec. HAving of late had occafion to examine the quan- tity of the Prcceflion of the Equinodial Points, I cook the pains to compare the Declinations of the fixe Stars delivered by Ptolomy, in the 3^;^ Chapter of the yth Book of his Almag, as obferved by Timocharis and Ari- fljUus near 300 Years before Chrift, and by Hipparchus about I/O Years after them, that is about 130 Years before Chriji, with what we now find : and by the re- fult of very many Calculations, I concluded that the fixt Stars in 1800 Years were advanced fomevvhat more than degrees in Longitude, or that the Preceflion is fomewhat more than j>er arm But that with To much uncertainty, by reafon of the imperfect Obfervations of the Ancients, that I have chofen in my Tables to adhere to the even proportion of five Minutes in fix Years, which from other Principles we are aflured is very near the Truth. But while I was upon this Enquiry, I was furprized to find the Latitudes of three of the principal Scars in Heaven directly to contradid the fuppoied great- er Obliquity of the Ediptick, which feenis confirmed by the Latitudes of moft of the reft; they being fet down in the old Catalogue, as if the Plain of the Earths Orb had chang’d its Situation, among the f«xt Stars, about 20' fince the time of Hipparchus. Particularly all the Stars in are put down, thofe to the the Eclipttek, with fo much lefs Latitude rhan we fmd, and thofe to the Souihvrard With fo much more Southerly Lati- Latitude. Yet the three Stars TaUUcium or the Bulls Eye, Sirius and ArEfurus do contradid this Rule di- rc(9:ly: for by it, ? alilicium hting in the days of Hip‘ parchus in about lo gr. of Taurus ought to be about Min. more Southerly than at prefent, and Sirius being then in about of Gemini ought to be xo Min. more Southerly than now ; yet e contra Ftolomy places the fird ^o Min. and the other xx more Northerly in Latitude than we now find them. Nor are thefe errors of Tran* fcription, but arc proved to be right by the dedinarions of them fet down by Ptolemy, as obferved by Timocharis, Hipparchus and himfeh, which (hew that thofe Latitudes are the fame as thoie Authors intended. As to ArEiurus, he is too near the Equinodial Colure, to argue from him concerning the change of the Obliquity of the Ecliptick, h\xi ^Ptolomy gives him 33' rooit North Lati- tude than he now^ has ; and that greater Latitude is like- Wife confirmed by the Declination^ delivered by the a- bovefaid Obfervers. So then all thefe three Stars are found to be above half a degree more Southerly at this time than the Antients reckoned them. When on the contrary at the fame time the bright Shoulder of Orion has in Ptolemy almoft a degree more Southerly Latitude than at prelent. What fliall vve fay then? ftisfcarce • credible chat the Antients could be deceived info plain a matter, three OblCrvers confirming each other. Again thefe Stars being the mofl confpicuous in Heaven, are in all probability the neareff to the Earth, and if they have any particular Morion of their owmi, it is mofl likely to be perceived in them, which in fo long a time as s 800 Years may fliew it felf by the alteration of their places, though it be utterly imperceptible in thefpace of a fin* gle emuvy of Years. Yet as to Sirius it may be obfer- ved that Tycho Brahe makes him x Min more Northerly than we now find him, whereas he ought to be above as much ( ) much more Southtrl'^ from his Ecliptick, (whofs Ohliqui- ty he makes 2 ' greater than we elleem it at prefent) di- ffering in the whole 4 f Min Cn . half of this difference may perhaps beexcufed, if refraflion were not allowed in this ( ale by T)cho\ yet two Minutes, in fuch a Star as Sirius^ is fomewhat too much for him to be mifta- ken But a further and more evident proof of this change is d.rawn from the Oblcrvation of the application of the Moon to ^ahlichsm Anno Chrijli 509 Mart, ii®, when in the beginning of the Night the Moon was feen to follow that Star v ry near, and femed to have Eclipfed it, lml2 Lth, VI. Prop. 35". II. An ( ) II. An Account of form Experiments [hown before the Royal Society 3 with an enc^uiry into the canfe of the Afcent and Sulpenfon of Water in Capillary Tubes, James Jurin, M.D, and fs,, Soc. S. SOme Days ago a Method was propofed to me by an ingenious Friend, for making a perpetual Mo* tion, which feem’d To plaufible, and indeed fo eafily demonftrablcfrom an Obfervation of the late Mr. Hdrvks^ hee, faid to be grounded upon Experiment, that, tho* 1 am far from having any Opinion of attempts of this Nature, yet, I confeft, I could not fee why it (hould not fucceed. Upon tryal indeed I found my (elf difap- pointed. But as fearches after things impoflTible in themfelves are frequently obferv’d to produce other difcoveries. unexpeded by the Inventer; fo this Pro* pofal has given occafion not only to redify fome mi- (lakes into which we had been led, by that ingenious and ufeful Member of the Royal Society above named, but likewife to dcted the real Principle, by which Water is rais’d and fufpended in Capillary Tubes, above the Level. Friend* s Propofal was as follows* Fig i. Leti4^Cbea capillary Siphon, compos’d of two Legs A B C, unequal both in length and Diameter, whofe longer and narrower Leg AB ha- ving its orifice A immerft in Water, the Water will rife above the Level, till it fills the whole Tube A B, and will then continue (ufpended. If the wider and Ihorter Leg B C, be in like manner immerft, the Water Bbbbbb will ] ( 74® ) I will only rife to Tome height as FC, lefs than the entire height of the Tube B C. I This Siphon being fill’d with Water, and the Orifice ! A funk below the Surface of the Water DE, my Friend i reafons thus. Since the two Columns of Water AB and FC, by the Supppfitiori, will be fufpended by (bme Power adling within the Tubes they are contain’d in, they cannot de- termine the Water to move one way, or the other. #3uc j the Column B F, having nothing to fupport it, mult j defcend, and caufe the Water to run out at C. Then the prefTure of the Atraofphere driving the Water up- ward through the Orifice A, to fupply the Vacuity, which would otherwife be left in the upper part of the Tube B C, this muft neceflarily produce a perpetual Morion, fince the Water runs into the fame Veflel, out of which it rifes. But the Fallacy of this reafoning appears upon making the Experiment. i Exp.i^ For the Water, inftead of running out at |i the Orifice C, rifes upward towards /^, and running all f out of the Leg B C, remains fufpended in the other || Leg to the height A B. Exp. 2. The fame thing fucceeds upon taking the Siphon out of the Water, into which its lower Orifice A had been immerft, the Water then falling in drops out of the Orifice A, and (landing at lad at the height AB, But in making thefe two Experiments it is ne- cefiary that A G the difference of the Legs exceed FC, [ otherwife the. Water will not run either way. ! Exp. Upon inverting the Siphon full of Water, it continues without Motion either way. i The reafon of all which will plainly appear, when 1 we come to difeover the Principle, by which the Water is fufpended in Capillary Tubes. Mr. f 74' ) Mr. Havphslce's Obfervation is as follows. z. Let A B F C he a capillary Siphon, into the which the Water will rife above the Level to the height CF, and let B A \>q the depth of the Orifice of its longer Leg below the Surface of the Water D E. Then the Siphon being fill’d with Water, if B A be not greater than C F, the Water will not run out at A, but will remain fufpended. ** This feems indeed very plaufible at fiirfi: fight. For fince the Column of Water FC will be rufpended by fome power within the Tube, why fliould not the Co- lumn B A, being equal to, or lefs than the former, continue fufpended by the fame Power ? Exp. 4. In fad, if the orifice C be lifted up out of the Water D E, the Water in the Tube will continue fufpended, unlefs 5 ^ exceed FC. Exp, 5". But when C is never fo little immerft in the Water, immediately the Water in the Tube runs out in drops at the Orifice Ay tho’ the length A B ho confide- rably lefs than the height C F. Mr. Hair kshee in his Book of Experiments has advan- ced another Obfervation, namely, that the fhorter Leg of a Capillary Siphon, asABFCy muH be immerft in the Water to the depth /^C, which is equal to the height of the Column*, that would be fufpended in it, before the Water will run out at the longer Leg. Exp, 6. From what miftake this has proceeded, f cannot imagine ; for the Water runs out at the longer 1-cg, as foon as the Orifice of the Ihorter leg comes to touch the Surface of the ftagnant Water, without being at all immerft therein. Having proceeded thus far in obedience tothe com- mands of this llluftrious Society, I beg leave to go a little farther, and to enquire into the caufe of the aicent and fufpenfion of Water in capillary Tubes. B b b b b b 2 That ( 74» ) That this Phafnomenon is no way owing to the prefllire of the Atmofphere, has been, I think iufficient- Jy prov’d by Mr. Havksbees Experiments* And that the caufe aflign'd by the fame ingenious and inquifitive Perfon, namely the attradion of the concave Surface, in which the fufpended Liquor is con- tain’d, is likewife infufficienc for producing this effed, I thus demonftrate. • Since in every capillary Tube the height, to which the Water will fpontaneoufly afeend, is reciprocally as the Diameter of the Tube, it follows, that the Surface containing the fufpended Water in every Tube is al- ways a given Quantity : but the Column of Water fuf pended is, as the Diameter of the Tube. Therefore, if the attradion of the containing Surface be the caufe of the Waters fufpenfion j it will follow, that equal caufes produce unequal effeds, w hich is abfurd. To this it may perhaps be objeded, that, in tW’O Tubes of unequal Diameters, the circumftances are di- fferent, and therefore the two Caufes, tho* they be equal in themfelves, may produce effeds that are unequal. For the lefler Tube has not only a greater Curvature, but thofe parts of the Water, which lie in the middle of the Tube, are nearer to the attrading Surface, than in the wider. But from this if any thing follows, it muft be, that the narrower Tube will fufpend the greater quantity of Water, which is contrary tb Experiment. For the Columns fufpended are as the Diameters of the Tubes. But as Experiments are generally more fatisfadory in things of this nature, than Mathematical reafonings, it may not be amife to make ufe of the following, which appear to me to contain an Expirmemum Cru- (is. Tig, ( 743 ) Fig. The Tube CD is compofed of two Parts, ifi the wider of which the Water will rife fpontaneoufly to the height B but the narrower Part, if it were of a fufficient length, would raife the Water to a height equal to C D Exp. 7. This Tube being fill’d with Water, and the wider end C immerft in the fiagnant Water d B, the whole continues fufpended. E^p. 8. Fig. 4. The narrower end being immerfl, the Water immediately fubfides, and ftands at lafl at the height D G equal to B F. From which it is manifeft, that -the fufpenfion of the Water in the former of thefe Experiments is not owing- to the attradion of the containing Surface .* fince, if that were true, this Surface being the fame, when the Tube is inverted, would fufpend the Water at the fame- height. Having fhown the infufficiency of this Hypothefis, I come now to the real caufe of that Pha:nomcnon,^ which is the attradion of the Periphery, or Sedion of the Surface of the Tube, to which the upper Surface of the Water is contiguous and coheres. - For this is the only part of the Tube, from which thC’ Water muft recede upon its fubfiding, and confequently' the only one, which by the force, of its cohefion, or at- tradion, oppofes the defeent of the Water. This likewife is a caufe proportional to the efTed, which it produces ; fince that Periphery, and the Co- lumn fufpended, are both in the fame proportion as the Diameter of the Tube. Tho’ from either of thefe particulars it were cafy to draw a juft Demonftration, yet to put the matter out of all doubt, it may be proper to confirm this afiertion> as we have done the former, by adual Experiment. ( 744 ) FJg. S'. Let therefore EDC be a Tube, fikc that made ufe of in the 7th and 8th Experiments, ex- cept that the narrower Parc is of a greater length ; and let AF and BG he the heights, to which the Water would fpontaneoufly rife in the two Tubes E D and D C. Exp. 9. If this Tube have its wider Orifice C im- merft: into the Water A and be fill’d to any height lefs than the length of the wider Part, the Water will immediately fubfideto a Level with the point G\ but if the Surface of the contain’d Water enter never (b little within the fmaller Tube E D, the whole Column D C will be fufpended, provided the length of that Column do not exceed the height AF. In this Experiment it is plain, that there is nothing to fuflain the Water at fo great a height, except the contadl of the Periphery of the Icfi'cr Tube, to which the upper Surface of the Water is contiguous. For the Tube D C, by the Suppofttion, is not able to fupport the Water at a greater height chan B G. Exp. 10 Fig. 6. When the fame Tube is inverted, and the Water is rais’d into the lower- extremity of the wider Tube CD, it immediately finks, if the length of the fafpended Column D N he greater thanO 5; where- as in the Tube D E k would be fufpended to the height A F. Erom which it manifeflly appears, that the fuf- penfion of the Column DH does not depend upon the actradion of the Tube D E, but upon the Periphery of the wider Tube, with which its upper Surface is in contad, For the fake of thofe. who are pleas’d with feeing the fame thing fucceed in dii^rent manners, we fubjoin the two following Experiments, which are in fubhance the fame with the 9th and loth. Fig. 7. ABC h z Siphon,: in whofe narrower, and fborter Leg ^ if it were of a fufficient length, might be ( 745 ) be fafpended a Columaof Water of the height E F; but the longer and wider Leg B C wilLfufpend no more than a Column of the length G H. Exf. II. This Siphon being fill’d with Water, and held in the fame Pofition as in the Figure, the Water will not run out at C the Orifice of the longer Leg, un- lefsD C, the difference of the Legs A B and B C, exceed the length E F. • Fig. 8. Exf. 12. If the narrower Leg £Cbe long- er than AB, the Water will run out at C, if DC the difference of the Legs exceed EF\ otherwife it will remain fufpended. In thefe two Experimentsit is plain, that the Columns D C are fufpended by the attradfion of the Peripheries at A, fince their lengths are equal to E F,or to the length of the Column, which by the fuppofition thofe Peripheries are able to fupport; whereas the Tubes F C will fuflain Columns, whole lengths are equal to G H. Tho’ thefe Experiments feem to be conclufive, yec it may not be improper to prevent an Objediion, which naturally prefents it felf, and which at firll view may be thought fufficient to overturn our Theory. Fig. 5*. For fince a Periphery of the Tube E D is able to fullain no j more than a Column of the length A F, contain’d in the fame Tube ; how comes it to (uffaina Column of the fame length in the wider Tube £)C, which is as much greater than the former, as the Sedion of the wider Tube exceeds that of the narrower ? Again, if a Periphery of the wider Tube DC be able to fuftain a Column of Water in the fame Tube, of the length BG\ why will it fupport no more than a Column of the fame length in the narrower Tube ED} Which ( 74 To thefe two worthy Perfons l am obliged for the following Obfervatioii,'’ That, what 1 call a Periphery, or Sedion of the concave fur^ce of the Tube, is really a fmall Surface, whole Bale. is chat Periphery, and whofe height is the didance, to which the aettadive power of the Glafs is extended. r IIL Tk • • C c c c< c i 748 ) * ' C I . III. De Motu Aquarum fluentiim, Authore fodetn. ’ 2). J^cobo Jurin, M. 2). O; vl'M’i 1 cri. ;.)ti ; ■ ,> ' , .•iA. Qu3Ci Motum 3£x imi yafis fora^'n^ de8ycutis/(k- pa v'idcmua, tftiov iii, ipfa re HydraUjic^ . turn in ejus Principiisad Oeconomiam Animalem applicandis, a- Iris ctt'm .CQ»Jpaiajci»i: r<2qjus Mot us quantita- tem cani)In^snus neino, qjiipdrficiatn^ re^^ie deter foienr 'Cjijts^rloQO'iferiptares Hydtaulict CojuoimajaqusaE pondijs^/oraijiioi itroimbentis ..Quod qui f^iBhb/lid fane ti^utiquatnlanimuln adVercuQii fieri ondningcindo poJilc; • ujiMotrisiaiiqqi^^univpwd^re flui^ efcente conferatur. Poteric autem Aqu^djefluentis Mot cu$fak:Hr4)pct^i!d:dbm ntcHfum. ■ i j fi^;. x(Q.i'Sk S H AHt^-^quae ruperficies infinita, C C foramen circulare in fundo fadum, AJ^ r^da perpen- d icM Itttls bpw I fiaranfltti lis eedt^Um,- .djuda, < ^ C C <5 ^ Co- lomdaj rosier, Catjamdai AqiiePiTpqijdwamfiBff C G decur- lentiSjt 5 GiljCuiii'a.-cujasieomiflQeici/ca ^x^m A B ge* ncratuc SiQljdiunh, zH/it rCaJafidasu Q C, QS. Aqua e> nith CDiOElibarQi'iiSd nnotu .aeceleiarorirdie^endai: :^d nor<> mam corporum omniunj. ;grayiumi;inqce(&rid. in mino- rem amplitudinem contrahitur, prout majorem velocita- tem acquirit inter cadendum. Sc profluic ex foramine CC ea cum velocitatc, qux cadendo ab altirudine^^ comparatur. , V^qcitas autem corporis gravis cadendo genica, ex demonftratis, ratiemeni obtinet fubduplicatam altitudinis unde cecidic. Quare, fi ducacur ad Curvam S6C Ordinaca qusevis D E, atque ipfa D E vocecur j, ^ AD ;v, exponetur velockas Aqux in fedione EE per ( 749 ) peryj^/fi?^Fadlwii tx -ea ?n feq-i tionem perVxx/. rr;:; r wpl: it: ^.yf i>ijji::. Quod Factum eft., u t . l»ol$Sj 4i^%%4^Co ^ qe^j^qris fpatio per earn fedtionem iranfeufltjs^i q^mque .e^denr* ;Aquae molea date iempjo^e;pqr|finiulao';p^^ia:^%(^^ nes tranfeac, proinde Factum iftud perpetuo fibi^pqn- ftabir, eritque Vxx y^-z-z: i , . Quie eft ^.^qyatio Curvsc S\GC, part^fp^- mtra datum vas comprehenfam, delinea^^^.^jufclgpique^^/^k- ^uacionem non obfeurg .ci^gnps , Frop,^6i .Lfh.ii Prhf.ip. qui primi^%5iqr5inj^rr»p>XSj-ara Aquae* efftuenris velocitatem, ex\gepuinis Prirf^ipuf^de- du(ftam, Orbi Literate expofuifi : - j ; ^ ,, •. Eft aucem ipfa Curva F3ypbrbolofiid§s quarci OrdP -ois^ cujus altera Afymptotos eft' re^a >4>S- ad-FJorizod*- tern parallela, altera ^.B eidem perpendiculafris. . Hujus Poteftas eft Quadrato-Cubus OrdinacGE ./^C7, dujSbs.ad pundum G, ubi reda^G, bifecan§ ;angulum ab Afympcotis comprehenfum, Curvx qccurrit* Spatium S A D BS, inter Curvam SQ E, Ordinat^m X)fi & Alymptotos A D,AS inclufum, ffquale eft qua- cuor panibus tertiis Redan^guli //£>* fubAbfeifla A P 8c Ordinata DE content!. Eftque proinde-Spatium •S’/Z.E -pars tertia ejufdem Redlanguli. , j Solfdum SG E EGS, convolutionei fpacii S A DBS, circa Axem A D, generatum, duplum eft Cylindri in- cumbentis fedioni E E, Unde Solidum cayum, quod gignit converfro fpatii S H EG S, circa eundem Axem, Cylindro incumbenti aequale eft. Quae omnia facili cal« culo inveniuntur per Methodum Fluxionum inyerfam. Theorem A L Aqui ex vafe amplitudinis infinicae, per foramen cir- culate in fundo fadum, decurrente, Motus totius Ca- taradae aqueae Horizontem verfus sequalis eft Motui Cy- C c c c c c a iindri ( 75® ) imdrt aquei* fiib ip(b foramine 6c alcicudine Aqux, cujus velocitas sequec velocicacem Aqu^ per foramen effluentis ; vel^qualis eft Motui' molis Aquae, qux dato quovis tempore effluit, cujus ea f»c velocitas, qua per- curratuf eodem dato tempore fpacium xcquale altitudini Aquie, , . Demonfiratio frim^e partis. Ducatuf ad Curvarn SGC alia Ordinata priori B E quam proxima. Gurva circa. Axem A B converse, generabunt Ordina^ ixD’E, dty Circulos duos, quibus incercipitur Solidum naicens EEee* Id folidum arquale eft Fa locicate Aquae in^ ea Seft^ione. Cumque fupra oftenfum fit, Fadum ex quavis Sedione Cataradae & velodtate Aquae in ea Sedione, quantitatem eftc conftantem, erk proinde Motus totius Cataradae aequalis Fada ex quai»> titate illa conftante dudaJn Summam omnium alcitddi- num Ddt fiVe in ipCam A B, hoc eft, Motui Cylindri fiib ipfb foramine & altitudine Aquae, cujus velocitas aequet velocicatem Aquse per foramen effluentis. ^E^ D. Corel. 1. Data altitudine Aquae, erit Motus. Cata- radae in ratione foraminis. X. Dato foramine, erit Motus Cataradae in ratione fefcuplicata alritudinis,- five in ratione triplicata veioci- catis, qua Aqua per foramen exit; 3. Dato Motu Cataradae, erit foramen reciproce in ratione fercuplicata altitudinis, vel reciproce in ratione velocitatis triplicata. Depionflratio fecund^e partis. Moles Aquae dato tempore effluentis eft ad Cylin* drum^ Tub iplo foramine & altitudine Aqus, ut longi- tude quam Aqua effluens arquabili velocitate dato. ifto ccmporcL ( 75* y t^ibpore p^urfura fit, ad altitudinem Aquae. Cumquc velocitas, quae tribuitur moli Aquae cfHuentis, fit ad velocitatem Cylindri reciproce in eadem ratione, erunt< Moruum quantitates utrinque a?qWales. E. D. Data aicieudine Aquae &. mole effluentc,* Mio^us Cararad^ae ell in ratione inverfa temporis quo> tfta tnoles efHuit. Data altitudine & tempore, Motus Cataradac itr moles Aquae tempore iQo edloentis. 0^3 i parosr rempore & mole Aqux efHuentis, erit Mo-^ tusCatara^^ in ratione altitudinis. 4- Dato Motu Catarat^x &>altitudine, moles efiluens e(l in ratione temporisV S» Daco Catarada: Motu & mole- Aquae cfflucntis/ altitude e(l ut tempus. 6.: Dato tempore & Motu Cararac^ae, erk Aquae - cfHuentis moles reciproce ut altitude^ , . TheoremA IT. . Figi II.' Si capiatur B A, quae fit ad B D, ut D 6^ ad< - D6+— AC+; Aqua decurrente ex dato vale Cylin^ drico femper pleno G GEE, per foramen circulare C C in fund© medio fadum, Motus Cataradae aquese Ho* rizontem verfus rrqualis erit Motui Cylindri Tub fora*' mine & altitudine AB^ cujus velocitas aequet veloci^i tatem Aquae per foramen exeuntis; vel erit aequalis Motui molis Aquae quae dato quovis tempore effluir, cujufque ea fit velocitas, qua percurratur eodem dato tempore fpatium aequale altitudini A B. Demonfiratio prima partis. ' Ducatur AS ipfi D G patallela, & Afymptotis AS^, . ABf per punda G, C delcripca coiKipiatur Curva New^ toniana SG C, Ut conftet Aquae altitude, fupplendus eft exeuntis > locus Cylindro aqueoj-^GG, defeendeme cum ea ve/* locitate . ( ) leckate uniformi, qu2 acquiricui cadcndo ad D, qucmadmodum docec Vir iiicompatabiiis PcopoOcione pc£edid:a. • . Motui bujus Cylindri a^quacur, per Theorcma fupe* i;ius, ^otus Catacadse S GGi Ergo Mocus Aqux def- oendencis.^ cuin.rit^coniporitus ex Mom Cylindri a<|Mei & Motu Cataradx GGCC, xqualis eft Moon , A. B% ctt)U3' Telo^itas.asqealis ftc veiocitaci Aq«z pec fo* ramcn dccurrentis. ^E*D» ' Pars lecunda iequitur cxpriorc. Carol. I. Oriuntur hinc omnia Pibpofitionis pracceden- (is Cordllaua* ftihlUcueado alcitudinem AM, pco Aqux akicudine. ^ 2, ‘ $i vas alia figura ffueric^ atque Cytindika ; auc fornminis ligura pro circulari fiieric quadraca, triaagu* Jaris, vel quaiilcunque ; auc ipfum foramen non fit in medio fundo fitum, vel'etiam in latere vafis fa(ftum; iidcmerit Motus.Cacart<9x^ fcit&ci acqualis Motui Pdf- macis aquei lub foramine altiiudinc A cujus ve- locitas par Ac velocitati Aqirx eiHuentis. Nam eadem Aqux moles, cum eadetn velocicace atque in priori Hy« pctheft,.ruTi per ipfum fdramcn, tutn pec finguias Ca-* ; taradse fediones traLufibit.' ■ * ' Si vafis Diameter permagnam rationem obtineat ad Diametrum foraminis, negligi poterk altitude A D, dc vafis .ipfuts akrrudo. pro altitudinc Cylindri, vcl Prif- . matis aquei, ufurpariai. .f-' Hadenus cafum ilium particularem, quo Aqua, Gra- Vitatis vi, ex i^afe deftuit, leorfim conlideravimus. Id eo fecimiis lubentrius, turn ^ quod ilium fere fplum adhi> . bere foleant Mathematici, quoties agitur de Fluidorum impetuy turn quod Gurva: Hyperbolioeiupra exporuam ; prpprietacemp,qua Cataradam Aqux defeendentis for' mat, ( 7f1 ) mac, non indignam ccnfeamus contcmplationc Gcome- cxarum Aiioqui pocuilTet ifte caHis nullo negocio de- duci ex Thcoremarrc general!, quod proximo loco pro- penemus. Theorem A Ilf. Fig, rr. Aqua fiuente per Canalem plenum qucn> cunque ABC D iecundum iineam E F, cui-fic perpendi- culare utrumque Canalis ofificium AS Sc C D, Motus Aqux verfus Orificium C ,Q, five Motus impedimenti, quod in ipfo orificio oppofiuim fiflat Motum tocius A- qux, xqualis eft Morui Prifmacis aquei fub qualibec 6edtionc Canalis C H Sa linea dirediionis, five longicu- dine Canalis E F, quod moveatur eadem cum Teloci- tate, qua Aqua fluit per iftam Seeftionem: five xqualis Mbtui molis Aqux, qux date quovis tempore effluic ex Canali, cujulque ca Tie velociras, qua percurracur eodem daro tempore fpatium xquale longirudini Cana* iis. ' Caf. I. Sit linea dirediionis reifta quxvis E F, Facile demonftracur pars prima eodem modo, quo Theorema primum. Eft enim Fadlum ex quavis fedlio* ne Canalis C H, h Aqux vclocitate in ea Sedionei quantitas conftans. . > 1 Pars fecunda fequitur ex prima. -! linea diredionis ABCDE, ex pluribus redis /f F, .FC, C E F, ad fefe invicem in- clinatis fit compofita, idem eric Aqux Moms. Nani Motus Aqux in toco Canali compofito A B C D E, con* ftcitur ex Motibus Aqux in partibus Canalis A B, E C, C D, D E‘ additis fibi invicem Stacuimus autem A* quam fluentem fecundum redam F, mutaw dba di* redione in aliam, qua feratur fecundum redam »F C, nihil ex Motu deperdere- Leges enim ilia?, qux in mo' ' tu. corporum folidorum obfervantur, quoties coruudem^ diredio < 754 ) 'xHrcdio mutatur, flu id a non fequuntur. Alioqui flui- ■dum, mutaca diredtione in aliam priori perpLndicula‘> rem, penitus fiftcrecut, quod Experimencis neuriquam depreh^nditur. Aqua porro ex Vafis foramine exiiiens, , five deorfum, five lecundum Horizontis planum, five reda furfum feratur, eandem obrince vclocitacem. Quod •fi aliquando vei raciocinio (ubtiliori/ ve4 Experimemis 'innoteicet, aliquam Morus imminutionem ex mutaca di- j 1 c ~ uncia:, Dia- metrum Globuli ^^anguinei parte tic.-ima-Uiametn Ca- pilii, five parte ~ unci« 5. Impetus, quern patitur inrcrr !'uImonum fuperfi. cies ab i^erc exfpirando, m nor ci‘ iOtu lemliimi loris c Csdo decidentis. Scholium. NeglccJa e(l in folucicnc Problematum d-uorum prarcedentium impcdimcnti confidt ratio, qu d /^eri ex Pulmone egredienti objkuur cx affndlu lareium ArreriteTrachxsc, cjufque ramorum 3 cum id perparvum iit, nequeiillo experimtnro fatis accurate aftiman pode Videarur. Ncc fuimus admodum follici i dc rationibus r.umerorum cxquifire fervandis, cum id unum nobis pro- ponium tueric, uc mcchodum exponeremus azRimandi, aliquanro certius quam vidctur antehac fadum, vires xas, quibus agit Aer inter cxfpirandum in vaia langui- nea fupernxicm Pulmonis internarn perrcpcanria. Unde dignolci porefl-, utrum pares fine bar vires effedis iflis producendi', qusciirdcm a Dodilfimis qujbufdam Scrip- torihus Medicis tribuuntur. Quod liberum eQo Ledoris Scieiitia Mecbanica &Anatomica inftrud:i Judicium. Trohlema 1 1 1. Dcunire impetum Sanguinis in Vena C^ava prope dextram Auriculam Cordis ; five motum Sanguinis per omnes Artcrias & Venas fluentis, prtster i ulmona* res. ’Sit q — Quancitas vSanguinis una Cordis Syftolc in Aor- tam projedi. I — Longiiudo media dudus integri ArteriO'Venofi, tacioiie habita ramouim longiorum& breviorum t ~ t = Tcmporis fpatium inter binos PulCus intercept turn. Inde, per Theorema 3. CaC 4. impetus quacfitus — li ■ • t Hoc eft. Impetus Sanguinis in Vena Cava aiquatur motui molis Sanguinex, qux una Syftole in Aortam pro- jicitur, cujus ea fit velocitas, qua percurri cjueat Inte- gra Arteriarum & Venarum longitude, temporis fpa- tio inter binos Pulfus intercepto. ^ E. /. Si in Corpore Humano ponamur ^ ~ X uneix Avoird* I ~ 6 pedes 4 Erit impetus Sanguinis in Vena Cava xqualis mo- tui ponderis ix librarum, quod uneix unius longitu- dinem conficiat fingulis minutis fecundis ; feu motui ponderis x librarum, quod pari temporis fpatio percur- rat pedem f. Qux eft fere Sanguinis velocitas in Ca- va fluentis. Ponimus autem, ex dimenfione Viri Doefti- ftimi fupra diefti, Cavx Sedionem dodrantem efle un- eix quadratx. Corel, Oriuntur ex hoc Problemate mutatis mutandis omnia Problematis primi Corollaria. ProhUma IV. Determinare motum abfolutum Sanguinis in Vena Cava; five motum Sanguinis, per omnes ^rcerias & Venas fluentis rd xter Pulmonales, fublata Vaforum reftftentia. Sit velocitas Sanguinis Naturalis, ad earn velocitatem qua Sanguis flueret, dempta omni refiftentia, ut 1 ad x, Cumque per CoroL fuperioris Problematis, & Corol r„ Eeceee PtohL « Pi oW f/ Mctus 'm U- m ratibne* ■ vclocifatis, ciit . in4e mot us quxliCu^ t=r ^ E, I. , , . Quod fi propottio per Exp-rimcntum a Viro CIoj- riffimo fijpra iaudaro inliuutuni inventa, ut verte pro- pinqiia, admictatiir, erit a; = i . 5. Unde, pofitis ii(dem qute in fuperiore ponuntur, morus abrolutus Sanguinis in Vena Cava tcquatur mo- tui pcnderis 30 librarum, quod minuio iecundo lon- gitudinem uncialem percurrat ; five motui ponderis z librarum percurrentis eodem tempore pedem i Qua fere velocitate Sanguis, omni refiftemia liber, per Ca- vam deferretur. Prohlema V. Motumi Sanguinis- invenire in Vena Pulmonali pro* pe finiftram Cordis Auriculam ; five motum totius Sanguinis per Pulmonem fluentis. Prseter notulas in Probl. 3. ufurpatas, fit AzrzCanalis ArteriO'Venofi Pulmortici media longitude. Unde, per Theor. 3. O/. q. invenitur motus quiEfi Hoc'ed:, motus Sanguinis per Pulmonem fluentis se- qualis eft motui molis Sanguineje, quae una Syftole in Arteriam Pulmonalem projicicur, obcinentis earn veloci- tatem, . qua percurratur longitude Arteriarum ac Ve- naruni Pulmonalium, tempore inter duos Fullus inter- cepto. Q, E. /. Si ponatur in Corpore Humane A =: i ^ pes. Erit motus Sanguinis in Pulmcne sequalis motui pon- deris 3' librarum, percurrentis uneiale lj3atium minute fecundo. Prohhmd ( 7^f ) ■ FroUema VL Definite momentum Sanguinis abrolutum in Vena Pulmonali. Eodem argumento, quod in Frohl. 4. ufurpatum eft, invenitur motus quarfitus = a . j x ^ E, /. t Pofitis veto iifdem quas fupra ponunrur, motus ab- fblutus Sanguinis Pulmonem prasterfluentis xquacur mo- tui ponderis 7 7 librarum, quod fingulis minuds fecundis uncix unius fpadum percurrac. Scholium. Experimento Keilimo definita eft proper- tio, quam obtinet Sanguinis per Aortam ejurque -ramos fluencis velocitas namralis, ad earn velocitatem qua Sanguis per eofdem flueret, fublata refiftentia Arteria- rum & Sanguinis prxeedenti?. Earn nos propoftionem ad Sanguinem per Arteriam Pulmonalem fluentem tran- ftulimus. Quia vel fublata vel imminuta fecund um quamvis rationem refiftentia, qu2s Sanguini per utram- que Arteriam fiuenti objicitur, neceflario Sanguis piri* ter acceleratur in urraque Arteria. Id enim nifi fiat, bini Cordis Ventriculi aut eodem tempore non contra* hentur, aut eandem Sanguinis quantitatem non ejicienr. Quorum utrumvis, abfque fumma totius Machinae per* turbatione & diferimine, fieri omnino non poteft. Ccrol. Ad tria Problemaca praecedenda. Sequuntur hinc Corollaria Problemati quinto fab- junefta, mutatis mutandis. Scholium ad quatuor Problemata fuperiora. Notandum Sanguinis velocitatem, turn per Pulmo'. nem, turn per reliquum Corpus fluentis, cum reipfa se- quabilis non fit, hie tamen talem fingi, uc motus San- guinis medius inveniatur. E e e e 6 e r Scholium < 766 ) Stholmm gentrde. Si cui numeri minus accuraci videantur, qui rparfim Chara(3eribus fpeciofis apponuntur, poterit illc facili o- pera, inventis per experimenta numeris qui propius ad verum accedanr, mocuum exempla fupra pofica, vel Pro- pofitionum ipfarum vel Corollariorum ope, corrigere. Ignofcat aucem nobis Ledor ingenuus, fi per viam ince- dentibus nullis prsecedentium veftigiis triram, adeoquc Erroribus in omnes partes opportunam, Human! all- quid forte acciderit. Damus h*nc venum^ p^timufqut vkiffim. IV. An Account of the Shilling of three Oaks inta. the Groundy at Manington in the County 0/ Nor- folk, Communicated by Peter Le Neve, Norroy ^ng at Arms^ and. Fellow Roy- al Society, ON Taefday July the 2,3/i of the laft Year, 1717, iir the Grounds, and near the Seat of Sir Charier FottSf Baronet, in the County of Morfolk, and Parilh of Man'mgtony (which lies about mid- way between the Market . Towns of Holt zwd Ayljham, and about (even Miles from theCoaft nczr Cromer daytime, to the great allonifliment of thole that were prefent ; firfl:^ one fingle Oak, WMch the Roots and Ground about it, was feen to fubfide and fink into the Earth, and not long after, at about 40 Yards diftance, two other Oaks that were contiguous, funk after the fame manner, into a much larger Pit ; being about 3 3 Foot Diameter, whereas the former is not fully 18. Theft, as they funk, fell a-crofs, fo that obftruding each other, only th« ( ?(>7 ) the Roots of one^of them reaches the Bottom> whereas? the firft {lands Perpendicular. When the firft Tree funk, it was obferved, that the Water boyfd up in the Hole; but upon the finking of the greater Pit, that Water drain’d off into it, from the former, which now continues dry. The depth thereof to the firm Bottom is nine Foot three Inches ; and the Tree that Bands upright in it, is 5 Foot 8 Inches in Girt, and its Trunk about 18 Foot long, half of which is now within the Pit. In the Bottom of the greater Pit, there is a Pool of Water about 8 Foot Diameter ; whofe Surface is ii Foot 3 Inches below the Ground, and the Trees that are in this Pir, are much of the (ame length with the other, but fomevvhat fmaller, the one being in Girt 3 Foot j Inches, the other but two Foot 9 Inches The Soil on which thefe Trees grew, is Gravelly; bat the Bottom is a Quick fand over a Clay, upon which there are Springs, which feed large Ponds ad- joyning ioSkCharUs Potts’s Houle, at about a quarter of a Mile from thefe Holes. , The Nature of the Soilfeems to afford us a reafonable conjedure at the Caufe of this odd accident, which Tome perhaps may be apt to reckon as a Prodigy. The Springs running over the Clay at the bottom of a Bed of very minute Sand, fuch as your Quickfands ufually are, may reafonably be fuppofed in many Ages to have walht away the Sand, and to have thereby ex- cavated a kind of Subterraneous Lake, over which thefe Trees grew: And the force of the Winds, on their Leaves and Branches, agitating their Roots, may well have loofened the Sand under them, and occafioned it to fall in, more frequently than elfewhere ; whereby in length of time the thin Bed of Gravel being only lefc> it might become unable to fupport its own w'eight and that (.76%) tint of the Trees it bore. That this is not a bare con- jediure, may appear from the boyling up of the Water at firll: in the lefler Hole, and its ftanding in the bigger and lower. And if it fiiail be found that it was a very windy day whereon this accident happen’d, it Will much add to the probability of this Solution I An accident not unlike this lately happened in 1 FUet’flreet^ London^ by the defcd: of the arched Roof of / a very deep Common-Sewer. The Earth gradually falling into the Sew-er, was carried away by it, fo as J not to obllrud the Water 3 and the continual tremour of the Ground, occafioned by the conftant palTing of ^ Carts and Coaches, by degrees (hook down the rarth, fo as CO leave a very great C vern, the Top wherqof at length grew fo very thin, that one day a weighty Cart having juft paft it, a great fpace of the favemenc ^ funk in, in the middle of the Street, not without hazard to a Coach then driving by. ] V. A ^eBification of the Motions of the five Satellites ^ of Saturn 5 with Jome accurate ObferVations of them, made and Communicated by the *^everend James Pound. R.S. Soc. IT is now above thirty Years fince that great Aftro- nomer Mr.CaJJini communicated to the World his difeovery of two new Satellites of Saturn, W’hich made their number Five ; and the account he gave of them to the Ropl Society, (of which he was a Member) is to be 4een in N°. 187, of thefe Tranfadions. Much about the fame time the excellent M. ChrifHan Huygens'ot !Zu- iichm, made the Society a prefent of the Glaftes of a XelefcopG ( 7h ) Telefcope of 115 Foot length, with the Apparatus for ufingthem without a Tube; by help whereof we might have fatisfied our fdves of the reality of rhefe Difco- . veries. But thofe here that firft tried to make ufe of this Glafs, finding, for want of Pradice, feme difficul- ties in the Management thereof, were the cccafion of its being laid afide for fome time. Afterwards it was dc- - figned for making perpendicular Obfervations of the fixt Stars paffing by our Zenith, to try if the Parallax of the Earths annual Orb might not be made fenfible in fo great a Radius, according to what Dr. Hook had long fince propofed : but in this we mifearried alfo, for want of a place of fufficient height and firmnefs, where- on to fix the Objedt Glafs, fo that it lay by negleded for many Years. In the mean time we could not but remark a great re- (erve in x.\\q French Aftronomers, in relation to thefe Sa- tellites, of which they have given us in their Yearly Memoirs no Obfervations till very lately, nor have they feetned willing to ihew them in their GlafTes to fuch as fequefied it: fo that rdimight poffibly occafion in fome Perfons a fufpicionof the reality of this Difeovery : And the Reverend Mr. William Derham having borrowed of the ‘■-ociety their long Glafs, could not thereby aflure - himfelf that the fmall Stars he fomecimes found about Saturn, were really his Satellites, their ficuatipn not a- greeing with their places derived from the Tables of their Motions exhibited in N°. 187. of fhil, Tranfa3. befides that he wanted a fufficient height to raife the Ob- jedf Glafs, fo as to v {c:\st Saturn to advantage, above the Vapour- of the Horizon But Memoirs for £714, publifhed bur about a Vtar fince M.CaJieni, the worthy SuccelTor ot his great Father, has given us fomeCbler- vations which clear up the i oinc, and by (licwing the er- rors of thole iirit Tables, has enabled us to be affured, that ( 770 ) ! that we have feen the whole SatdUtiam of Saturn out- felves. 'The Subftaiice of thefe Obfervations is as follows. Anno 1714 Matt 6. St N about Mid-nighc, Saturn being tlienStafionary in ’t? 4°; zy', the Fifth and ouccrmoft Satellite was in its fuperiour Conjunift on with the Planet, and at the fame time, the harth was nearly in the Plain of this Satcilic’s Orbit, lo that it appeared to pals very near the Center of Saturn : From hence and from fome other preceeding Obfervations. Mr CaJJini Concludes that the Nodes of this batellit s Orb are in 4 degrees of ’f? and X, and that its Inclination to the Ecliptick is not much more than half that of the other Satellites. Fience it fliould follow that the Elliples ic defcribes by its apparent motion about Saturn, when in ' It and t are much flatter and nearer to his body, than thofe of the other four, which he allows to move* in the plain of the and to have their Node^ in it*” | of and X, with an Inclination to the Ecliptick of 31 degrees To confirm this dificovery, he produces a- nother Obfervation of his Fathers, near Thirty Years before, viz. that. Anno i68y, Maii St. fT. about Noon, the fame Satellite was obferved in fuperiour con- junction with Saturn, with lefs than one Diameter of the Ring North Latitude, Saturn being then^in np 11° 48'. So that the Satellite wanted but 7°. ii' of compleating 134 Revolutions, in the Interval of time between them. i, From thefe Data it was eafy to fettle the Theory • of this Satellite. i As to the Fourth or the Hugenian Satellite; in the • Memoirs for but juft now come to hand, we find a very curious Obfervation of it, and the firft of its kindi viz- i\\2iZ Mart. z$°.S. N. about F. M, this fourth Sa- tellite, then in Afogeo, did immerge behind the Body of Saturn i ( 771 ) tu'n. Widvthts Fmendation the place of this Satellfte may for the fiirurc be computed witli a fufudent exat^- nefs. The Third Satellite by an original miftake in the Letters in N®, 187, is ail wrong* its dayly Morion being there printed 2\ 18°. 41'. ^o" inflead of z'. 41'. 50"; as may be perceived by the Period thereof being determined, in the_ aforefaid PArmoirs of 1714. to be 4''. \z’’* 25'. iz". that is, that it makes 400 Revolu- tions in 1807 days. This Satellite was obferved by Mr.CafJlnr, Apll 4”. St. N. lok P.M. to have newly pad its inferior conjundion with Saturn, and a perpendicu- lar from it fell on the extremity of the weftern Anfe^ fo that at about 5''. P. M. it was with the center of the Pla- net then in ’tP. j”. 23'. and confequently in X 5°. 23'. But ineunte anno Gregoriano 1686, Epochs thereof was n?9° 39'. So that from the Noon of the lad of De- cember 1685’, to April 4°. 6'’, 18'. anno 1714, that is, in 10320 Days 6'’. 18', there have been made 22847 Re- volutions of this Satellite to the Equinodial; from which Data, the Tables of its Motion are readily deriva- ble The Radix of the penintime or fecond Satellite, ac- cording to theaforefaid Letter, ineunte anno Greg. i685. was in 9°. I o'. But by the Oblervarions of Mr* Cajftni made the Nights before and after, this Satellite was in its iuperior COnjundion anno 1714 April 1 1' 7. St. that is, in 5°. 21', where Saturn then was: So that April 22''. 12', an entire Number of Revolutions were performed fince the Epochs of 1686, that is, in 10320 Days zz'". I2 : which Number can be no other than 371, according to the Period thereof given Memoire, viz. 2^ 17^41' 22". Ladly the innermod or fird Satellite, at the fame time, vizt 1714, April 30'. iSr. N. was in jcs Ffffff feiiuur ( 771 ) fcriour conjun(3ion fr oxime , and confequcntly in X But th^Efoche thereof for 1686, is >y 24®. 50!. which place the Satellite had paft 40^'. 31' at the time of the Obfervation. Tliis Arcbit movesin 5*. 6': Where- fore from the time of the Epoche to ^^pril 4*^. 16". 24^* 1*714, or in. 10320 Days 16'’. 24'. the Satellite has per- formed 5467 Revolutions, its Period being determined to be I Day, 2 1 hours, 1 8'. 27", in this Memoir e. Having by the help of thefe. late Obfervations cori* re<9^ed the motions of the Satellites, which it was not pofTible for their firft Difcoverer. to fettle truly, in the fhort interval before 1687 ; and having fixed their Epo- ches for the prefent *Year. we were enabled to know where to exped them with more certainty, and to di-, flinguifh them one from another, and from the fmall fixt Stars appearing with them- And the Reverend Mr. James Pounds (whofe indefatigable induftry is no way inferiour to his incomparable Skill in Aftronomical matters/, having, by means of his Steeple of Wan(ted, provided a Gnomon hig\i enough for the purpofe, and having fitted a very commodious Apparatus for ufmg the Society’s aforefaid long Telefcope, foon dilcovered, by it all thefe five*, Satellites ; and, lately communicated to them,. the following very curious Obiervations. 1718. April 21*'. id'’. 40'. The. third and, fourth Sate!* lies of Saturn were in Apog£o^2. little, pafi their Conjundtioa Vfiih’Saturn: A perpendicular from the fipurth to the Tranfverfe Axis of the Ring for Lioe of the Anf diflanc. from the faid Line about as far as the end of the Con- jugate Axis . of the Ring was from the Center of 'hyviz,^ nearly ( 771 ) nearly \ of Saturns Semidiameter h and it was about a Semiciia meter of the Ring from the Weftern Arifa. The fecond was a very little Southward of the Line, of the (and therefore in the Ptrig^cn Sen>kLc!e), above a Semidiameter of the Ring ("or about the ‘''emi- diameter of the Ring the Semidiam. of from, the Weftern /infa. And the Third, Firfl and Second were in a flrait Line. At lo^ 50'. A Perpendicular from the to the Line, of the Ar*[ril 5'. The four innermofl: Sarellits were, all Eaffward of T?. The zd and in the Afog^on, and the ift and in the Ferig Pofition. But by obferving the Motion of this fbme o- ther Nights, before, he was now fully farisfied, from the. Motions rediified as above, that there are five Satellits of Saturn, as Mr. Cajfini had long fince afTerted. In the bright part of each Anfa was a darkifh Ellipfe nearer to the.out fide than the in-fide of the Ring, as i£y it w'as compofed oE^two Rings near to one another. ■ ©n '( 774 ) • Oti i^e Bd'Jy of r? ,1yende the Ring on the fide, there appear^cl^on the f/tfr/Mfide a Zone not fo far frcm the Ccncer as the Ring, and not much unlike the fmall- efl: of Jupiter's Belts. Thefe appearances were firll taken notice of by as may be fsen in Phil. Trarf. -1 N°. Iz8 pag 690 Fide Fir. ir. t We fhall in our next give the Publick Tables of thefe Motions, corredcd from the atcrefaid Obfervations , j ioftead of thofe in N®. 187. 13ut it is not to be expc(5t- cd that thefe Satellites, exceedingly minute in them- felves, and fb faintly illuminated, flimild appear when the Air is but ordinarily Serene, they requiring not only the Medium to be fummo modo defecate and limpid but withal in perfedl Darknefs. For which reafons it may , well be underftood why the Gentlemen of the Varifian 1 Obfervatory may have fometimes made a difficulty to i undertake to flicw them upon demand. | F 1 N I S. Printed for W. and J. Innys, Printers to the Ro^al Society, at the Princes-Arms in St. Pauls Church- Yard, Ludgate-flreet, 1718. ( 775 ) Number 55 <5. PHILOSOPHICAL TRANSACTIONS, For the Months of and Jme^ 1718. The CONTENTS. I. TahuU Motuum quin^ue Satellitum Saturni, ad fidem nuperarum OhferVat'mum cornB'ie, Cosloque conformes reddiu, II. T^he refl of the Treatlfe of that Learned Anti- quary iDr.John Tabor 0/^ Lewes (whereof the Firjl Tart h puhltjh’ d in N° 351. of thefe Tranf^ actions ) concerning the Site of the ancient City of Anderida, and other ^(emains of Antiquity in the County of Suflex. HI. TraSlatus de Curvarum ConflruBione ^ Men- fura ; uhi plurimde feries Curyarum Infinitee Vel reSlis menfurantur vel ad fimpliciores Cary as redu-> cuntur. Autore Colin Maclaurin, in Collegia noyo Abredonenii Mathefeos Trofeffore. i'V* Tpmarky on a Fragment of an old Roman In- jeription lately found in the Morth of England, and tranferibed by the Curious and Learned Dr, James Jurin, M, D. and Reg. ^oc. S. Gggggg iTaMa T —T*' ( rr<5 ) Li TahuU Motmm quinque Satellitum Saturni ad fidem nuperarnm. Ohferyatmum coneSidy Caloque conformes reddiu, e'^frca finem Aiirti 1686. D.Jo, Dom. Ca^nl, Reg. Soc. Sodalis, & in Aftronomicisnemini fecund us> cum Societate noftri inventa fua de motibus quinque Satellitum Saturni communicavit, Epochafque fingulorum ad annum ineuntem i685. eorumque motus diuenos in Epiftola N°i87. harum Tranfa^. edita ex- hibuit.* E quibus dads motuum Tabulas concinnavimus, dida?que EpiRolae fubjundas una edidimus. Cum veto deinde per triginta fere annos nullas omnino Oferva- tiones eorum tradiderint, qui foli poteranr, ARronomi Galll ; cumque aliunde, ob intervallum temporis nimis breve, non nifi laxe periodos Satellitum, praefertim in- reriorum, definite potuerit praeclariflimus Inventor, non prius dicSarum.Tabularum defedus corrigere datum eR, qqam in nu peris Adis Academise Regise Pariftenjis Phy- ficis & Mathematicis, obfervata ea, quae fub finem prse- c^dentis Tranfa6}, N° 355., protulimus, prodiere. Horum veto ope fada aliquali Motuum caftigatione, rum demum Telefcopio Hugtniano omne Saturni Satelli- tium ipfi agnovimus ; adhibitifque accuratis Rev. D.Jac* obfervationibus, Tabulas fubfequentes caelo fatis CQnfonas obtinuimus. Addendo fc mocui annuo Imerio- ris, ^ 9 ' ; Fenintimi vero 3°. retentis Epochis D. •Caffmi ad Annumi686. Augendo etiam motum annuum Exiimi 9 min. fublatis vero 1 6 grad, ab Efocha, quae in Epiftola dida 187. perperam feribitur x 16°. 19', pro X p®. 16“. Hugenianum 6' annuatim tardiorem invemmus. Tettii 2L\Mtm Tabellas, ob motum diurnum falsd in tpi- ftpla ilia rraditum, de^integro recud, ere necefie habuimus, reijenta^ialtem. Tduh ( f?7 ) Tabula Alediorum Adotuum htimi SateUitis Saturni a Caffmo deteBi Anno 1^86. Aiinis Epoch iS Mot. Med. 5 A4o#, Mot.Med Motus Chrifii d Sti. 0 , I Medi. ineunt S 0 1 g 0 • s ® ' 0 « ?■ 0 § 1681 8 48 I 4 4 4? 1 6 10 42 1 0 7'S7 31 4 ■ -'6 1686 ^ 4 2 8 9 2J 2 0 21 24 2 0 ly 55 32 4 14 1701 n? 6 54 ; 0 14 8 3 '726 3 0 23 50 33 4 22 1714 9 5-7 4 lo 29 5; 4 I 12 47 4 051 47 34 4 30 17IJ 14 59' y 3 4 16 5 7 23 29 J 0 59 44I 3S 4 38 1716 31 19 21 6 7 8 J9 6 2 411 6 047 40 36 JL 46 1717 ^ 4 47 7 II 15 42 7 8 14 55 7 OSS 37 37 4 S4 1718 nX 9 JO 8 9 29 6 8 3S 8 I 3 34 38 s 2 1719 y? 14 I? 5 2 ; 49 9 9 6 17 9 I II 31 39 s 10 V 18 10 6 8^2 10 3 S9 xo 1 19 28 40 r 18 Menf Met, Med. II 10 ij ij 1 1 9 27 41 II I 27 24 41 s 26 Anni . 12 8 28 40 12 4 8 22 12 I 3521 42 s 34 I? I 3 2J 10 19 4 '3 I 43 18 43 s 42 Jan. 000 14 S 8 5 14 429 46 14 I 51 15 44 s Febr. f I 58 IS 9 12 48 I)' 11 10 28 IS I f9n 4S s S8 Mat. ; I 10 16 7 28 15 16 5 21 10 16 278 46 6 S April 8 248 17 025-6 17 0 1 52 17 2 15 s 47 6 13 Mail 62544 18 4 7?9 18 6 12 54 i8 2 23 I 48 6 21 Junti II 2^ 22 19 81221 19 0 25 16 19 2 30 58 49 6 29 Julii xo 16 19 20 6 27 46 20 7 3 57 20 2 38 55 SO 6 37 Aug. ; '7 51 40 I 25 52 21 I 14 39 21 2 46 52 S» 6 4S Sept., 8 19 55 60 8 25 19 22 725 21 22 ^ S4 49 S2 6 S3 ohcb 7 io 51 80 ; 21 5 ^3 263 23 3 245 S3 7 I Nov. 012 9 100 10 18 yi 24 8 16 45 »4 5 10 42 S4 7 9 Dec. II 5 s 120 S IS 37 2S 2 27 27 2S 3 18 39 55 7 17 26 989 26 3 3S S6 7 25 In Anno Biffextili pofi Fe- 27 3 18 50 ^7 3 3432 S7 7 33 bruarium adde unitis diei^° 9 29 3^ 28 3 42 28 S8 7 41 motum. 29 4 10 14 29 3 S© 2S S9 7 49 t. JO 10 20 56 30 5 58 22 60 7 S7 Psgggg i. ( 77^ ) Tahuta Mectiorum MotuumSatellius Saturnr J^enlntimiy a Cafliao deteBi Jnno 1686. Arnii Epochit Mot. p Med. Mot. \4ot,Med \t(TtUS Jtil. h V.x 0 « Medi. inemt s 0 i «* s 0 # • I: s 0 1 M 0 # 0 « 1681 X 3 2; 1 4 10 2 1 4 1 1 32 i 0 y 29 3J 2 y^ 1686 2y ■ 2 8 20 4 2 8 *3 4 2 0 10 j8 32 2 y6 1701 X 22 ? ■ 3 r o- 6 3 I 4 3 0 16 26 33 3 I 1714 7 y 4 9 21 40 M y 16 8 4 021 ss 34 \ / J715 17 7 y 2 1 42 y 9 27 40 y 0 27 24 3y 3 12 1716 n0 27 9 6 6 1 1 44 6 2 9 12 6 332 y3 3 >7 1717 n 18 43 7 10 21 46 7 6 20 44 r- / 258 22 37 3 23 1718 sa 28- 4y 8 7 13 20 8 ri 2 16 8 343 yj 38 4 28 171S X 8 47 C ✓ 1 1 23 22 9 3 13 49 9 049 19 39 3 34 172® s 18 49 lo 4 3 24 10 7 2y 21 io 3y4 48 40 % 40 • 1 i 8 1; 26 r 1 0 6 n ( ] 1 017 4 3 4y Menf Med. Mot. 12 5 y c 12 4 18 25 (2 r 946 4^ 3 yi Mi. —A— f 0 # - 13 '9 ly 2 ‘3 8 29 y7 13 r II 15 43 3 y6 'jan. JX 0 0 ■ I ly 4 H "I 1 1 29 14 r 1644 44 4 I Pebr. ■1 ^7 34 M 6 y 6 'y y 23 I »y ( 22 i; iS 4 7 Mar. 6 20 3^ If 2 26 4^ i6 10 4 33 i6 I 27 42 4^ 4 12 Afr. iO i3 6 i/ 7 6 4^ '7 2 16 y 17 I ;; ij 47 4 ‘7 Mali io 4 7 ' 18 ri 16 4. f8 6 77 37 i8 I ;8 ;9 48 1- 23 7unii I 41 19 '3 26 4^ 9 1 1 9 9 ‘9 144 8 49 4 2b Juki I 17 43 20 0 18 2C iO 3 20 41 2C ‘ 49 37 yo 4 34 Aug. s iy 17 40 I 6 4c i j 8 2 13 21 I SS 6 y 4 39 Sept. 9 12 yi 60 I 2y c 12 0 «3 4y 22 I 0 55 y^ 4 4y Qbt. 8 28. y3 So 2 13 20 ^3 •4 ■»7 23 z 6 t\ y; 4 y Nov. 0 26 27 ibo 3 j 4 9 6 ■49 24 ill 32 y4 4 y6 Dee^. 0 12 28 120 3 20 0 I 18 22 2y i 17 1 yy ) 1 26 y 29 y4 26 2 22 30 y6 y 7 In ,A^o EiJTextfli Vofi FehruA' ^7 lO II 20 .427 99 y? y 12 rintp aide miui, did r/totutn. 28 2 22 y8 28 2 33 27 y8 y 18 29 7 4 3c 2 38 ff. )'9 y 23 Li 30 i6 '2 3^ 244 2J 5b y 29 ( 779 ) Tahula Mediorum Motuum SatMtit Sacurni Medii^ ^Caflino deteEli Anno \6j\. Anyiis'' Efocha Mea 5 Motu H M Alo/ Med. Julia.' ineunt 0 $ •>' s 0 f «-» s 0 • ' iCX.o » * # / 1 M Met. i /# l68l 12 16 1 9 17 2 1 2 19 4' 1 D IS 31 1 43 1 686 nt 27 6 2 1 4 ? 2 f 9 2? 2 0 6 38 32 c 46 iJOl •rw I 17 5 4 21 f 3 7 29 4 3 D 9 f8 33 1 49 1714 II 4? 4 4 27 48 4 10 18 46 4 0 13 '7 34 f f3 I7I J © 28 4f f 2, 14 fo f r 8 27 _f 0 16 36 \S t f6 1716 V- 1 47 6 0 I f2 6 3 28 9 6 0 19 ff V 2 0 ,717 22 7 9 i8 f? 7 6 17 fo 7 0 23 If 37 2 3 1718 X 9 ?2 8 9 2f 8 9 7 31 8 0 26 34 38 i 6 1719 26 H 9 7 12 38 9 II 27 13 9 0 29 f3 39 2 10 1720 uTU 3f 10 '4 29 40 £C .2 16 f4 1 0 0 33 12 2 13 Menf. Med. Mol us II 2 16 42 1 1 f 6 36 ii 0 36 31 -M 16 dnni Com. s 0 12 2 0 2? 10 2f 26 (2 13 7 ; 0 26 If 17 fS 12 13 0 0 39 43 f ' 10 P 43 2 2 19 23 yan. •0 0 0 4 9 27 28 ‘4 I f 40 14 3 46 29 44 2 1\ 26I Pebr. ta 10 24 If 7 14 ;o 3 2f 2 1 15 0 49 48 If 2 29 Mar. 0 21 44 16 7 2 I 13 16 6 If 3 [6 0 f3 8 46 2 33 Afr. i i 2 9 17 f 8 If 17 9 4 44 «7 0 56 27 47 2 ?6 Mail 6 22 fi 18 2 2f 16 18 11 24 26 18 0 f9 46 48 2 39 lun. 5 ? 1 6 IS 0 12 18 ‘9 2 14 7 '9 3 f 49 2 43 Julii 0 f8 20 0 19 1 20 f 3 49 20 r 6 24 )'° 2 46 A'Ug. n 4 1 2? 40 1 8 2 21 7 23 .3^ 21 r 9 44 \ 1 2 49 Stft. 9 '4 47 6c I 27 4 22 to 13 1 1 22 1 13 3 •f2 2 f3 Ocl. S 50 8- 2 16 5 23 I 2 f3 t 1 6 22 f3 1 f6 Nov ? If 54'ioo ? f 6 3 22 34 24 t 19 4‘ f4 2 fS Dec. i r 6 ?7 120 14 7 Af 6 12 IC M 1 25 1 ff 3 3 In- Anno BiJJextili fofi Februa’ i6 ^7 9 11 I 21 f7 39 26 27 t I 26 29 20 39 f6 f7 3 2 i C num adds umus Viei ni-otum. v8 2 1 1 .20 28 i 32 f8 f8 3 13 ^9 f I j 29 « 36 17 fS 3 It ■> ' 7 20 43 3^ f 39 36 60 3 19 ( 78o ) Tahla Mediorum Motmm ^etiextimi Sa- tellitis Saturni ah Hugenio inventi Anno i<555. Annis 3uL ineunt Epocbx s ; , Amis Mea s 0 # 0 Mea s . Mol. 0 • a M Vio.Mo. » « f /I 5' Motus Medi. t H 1641 ^ 2 48 1 10 20 ;5 I 0 22 3f I 0 f6 31 29 10 i66i K i; 2; 2 9 II 10 2 I ly 9 2 I y3 32 30 6 1681 r 27 y8 ; 8 I 4y 3 2 7 44 3 2 49 33 31 3 «686 in 3 28 4 7 14 yy 4 3 0, 18 4 3 46 34 31 59 1701 n 12 s 6 y 30 y 3 22 f3 y 4 42 3y 32 yi 171^ 6 4 26 y 6 4 ly 28 6 y 39 36 33 52 1715 SJ5 828 7 ; 16 40 7 y 8 2 7 6 3y 37 34 48 1716 t 29 ; 8 2 29 yo 8 6 0 37 8 7 3* 38 3y 47 1717 ? 12 i; 9 I 20 2y 9 6 23 12 9 8 28 39 36 41 1718 m 2 48 10 0 1 1 0 10 7 ly 46 ^o 9 24 40 37 38 1719 25 23 II 1 1 1 55 1 1 8 8 21 1 1 10 2i!4* 38 34 ■ I72«. -Tb 13 5-8 12 10 14 4? 12 9 0 yy 12 II 1742 39 3» 1721 S 27 8 1; 9 y 20 ^3 9 23 30 «3 12 1443 40 27 . Men). Med. Mot, 14 7 2f yy 14 10 16 j «4 13 10,44 4' 24 An'Co S 0 , ij 6 16 30 ly IX 8 39 *y H 74y 42 20 Jan. 000 f 29 40 i6 0 1 14 16 ^y 3 [46 43 17 Peer. II 9 H 17 4 20 ly 17 0 23 48 17 16 0 47 44 13 Mar. i 8 12 2 18 ? 10 yo i8 i 16 13 18 16 5"6 48 4y 10 /ipr. 7 21 19 2 I 25 19 2 8 f8 «9 i7 f2 49 46 6 , Mail 6 9 14 20 I 14 ;y 20 3 I 32 20 18 49 yo 47 3 Junii y 7 40 2 29 10 21 3 24 7 21 i9 4y y^ 47 59 Julii 4 ^ 26 60 4 I? 4y 22 4 16 42 22 20 42 y2 48 f6 ■Aug. 3 16 18 80 28 20 ^3 y 9 16 23 21 38 y; 49 y2 : Sept. 2 26 12 100 7 12 yy 2^ 6 * yi 24 22 3f 54 yo 49 on. I I? 30 120 8 27 3' ^y 6 24 2J 2y 23 31 yy yi 45 r Nov. 0 23 24 140 10 12 y 26 7 17 0 26 24 27 y6 52 42 Dec. II 10 42 i6o II 26 40 27 8 9 3y 27 2y 24 y7 53 38 In Anno Bijfextili fofi Fehrua- rium adde unius diet motum. 28 29 30 929 9 24 44 10 17 18 28 29 30 16 20 27 17 28 13 y8 y9 6c 54 35 yy 3' f6 27 (>8i ) Tahnla Mediorum MotmmSapMtis Saturni Extimi) a Cafliao deteSi Anm 1671, Annii Julia. ivfunt\ 1681 f686 1701 1714 171^ Men/, Anni Com,. 1716 1717 1718 1720 yon. Febr. Mar. Mari Jun. Julii Sept. Oci. NiV. Dec. . E^ochce 8 Med. Motus s s e T 8 40 1 7 6 3^ r H t 3 V II 9 19 35 K 20 2a ■ 4 5 0 39 26 0 7 10 IE ? 6 7 n 42 yf 14 27 7 2 20 *3 '20 8 10 I 17 X 27 ;o 9 5 7 49 4 2 ro 0 14 20 Med, Motus 11 7 20 52 12 ? I 56 s 0 # 10 8 ,0 0 0 14 5 59 4 20 41 ij. 0 21 ;o 8 27 46 M 00 I 2 34 I 18 ^7 "Z( ^ 9 6 6 4 ?7 18 10 37 10 18 19 5 22 9 % 1 1 271 20 I ? 13 8 2 9 I 40 2 6 26 0 22 JO 60 3 9 38 S 8 59 8.C 4 12 5J 9 29 0 0 5. 16 4 2 1? JO 120 -6 T9 In Anno BiJJextili pojl Fehrua rium adcU uniuj Diet motum- \ded. Motus Mo. Me. Med. H 0 Mot, s ■ 0 • A4 i If M § II 0 4 32 1 0 II 31 5 5^ 0 9 5 2 b 23 32 6 3 0 13 37 3 0 34 33 6 14 0 18 9 4 0 45 34 6 25 0 22 42 0 57 35 6 37 0 27 14 6 I 8 36 6 00 I 1 46 7 I 19 37 7' ’ 0 I 6 18 8 I 31 38 7 II I 10 51 9 I 42 39 7 22 I 15 23 f 0 1 53 40 7 34 I 19 55 Ii 2 5 V 7 45 I 24 28 12 2 16 42 7 56 I 29 0 ‘5 2 27 43 8 8 2 3 32 ‘4 2 39 44 8 19 2 8 5 [5 2 50 11 8 30 2 12 37 1 6 3 1 46 8 42 2 17 9 3 >3 47 a 53 1 21 4-i 18 3 24 48 9 4 2 26 M '9 3 35 49 9 16 3 0 46 20 3 47 50 9 27 3 5 18 21 3 00 5 1 9 38 3 9 5' 22 4 9 9 5^ 3 23 23 4 21 53 ro 1 3 18 55 24 ■4 32 10 12 3 23 28 M 4 43 55 U) 24 3 28 0 26 4 55 56 lO 35 4 2 32 27 5 • 6S7 10 ' '46 4 7 5 28 5 17 58 10 58 4 ii 37 29 5 29 59 I !■ 4 1 6 9 ;o 5 40 60 II- 21 ( 781 ) Motibus mediis Sacellitum ad hunc modum cortftita- Tis, proveniunt Revoluciones eorum jam veris proximx, fcilicet - -- - D h > u Primt fivs Tnt 'mi I. 11. x8. ^6 Scemdi Penintimi 17. 41- 10 Tertii five Medii 4- 11^ 15. 10 ^arti Hugeniani If- 11. 41. ^inti five Extimi 79- 7- 46. 00 Pofito autem, juxta regulam Naturae C faltem in hoe noftro Syftemate) univeilalem quaequetam injovialiutn ac Lun« motibus, quim Plaaecarum Primariorum circa Solem, obcinet, Vires centrum Saturni petcntes eile in duplicata ratione diftantiarum reciproce, f>roinde Cu- bos diftantiarum a centre efle ut quadrata Temporum periodicorum ; ex data diftantia & periodo HugtniAnU hunt reliquorum diftantiae ut fequitur. Sernidiam, Semidiam, /int/uli Globi Dtfl. Primi 1.9189 4,3400 Stcundl 14708 5»5593 Tertii 5.4508 7*7643 Sludrtl 8.CO00 18 ocoo ^inti 23.3145 51,^573 Qtioe quidem diftantix cum D. Cajfini obfervatis fatis qua- drant. Quatuor autem interiores Satellites juxta planum Annuli Saturni orbitas fuas deferibunt proxime ; in pia- no, fc. ^quatoris noflri piano quoad fenfum parallelo, quicquid in contrarium proferant nonnulli. Quintum ve- to orbem fitu paulo diverfum a caeteris deferiberej nuper deprehendit D Jac.CajJims prioris filius &virtutum hseres, m videre eft in Aeftis Academise ScientiarUrtl Parifiends Anni 1714. Sed hsec autem omnia propriis oculis con- templari. atque penicius introfpicere jam ipfi accingimur. H. Tk C 78? ) II. The refl of the Treatife of that Learned JntU quary T)r, John Tabor 0/ Lewes (whereof the Firjl Fart is puhltJJ^d m 3 5 1 . of thefe Tranf- adlions ) concerning the Site of the ancient City of Anderida, and other ^mains of /Antiquity in the County of SufTex, TJFIB former Part of this curious Treatife having found a jttji Efleem among feveral vrorthy Members of the Royal Society, vfho are Lovers of Antiquity^ At Their inftance we have adventured to infert here the Re- mainder thereof; entreating our Pholofo^hical and Mathema- tical Reader, to indulge the Liberty we now take, of break- ing in upon the ufual SubjeLl of thefe Papers. Where 7rfc////j fpeaks of Britain and its Affairs, his De- Icriptionsarefo lively deliver’d, chat one would think him- felf had been here, with his Wife’s Father ; and where he mentions the Irijh ^ Prince, the ExprefTion by him us’d feems to give Strength tofuch a Suppofition. The gaining the Southern part of this Ifland, was the greateft, if not the only Acquifidon, made to the Ro- man Empire, from the Death of Tiberius to the Sixth Year of Claudius ; which we may well fuppofe was not pafs’d over in filence by chat excellent Hiftorian Tacit m : but his Four Books of Annals, which contain’d the Tranfadions of thofe Nine Years, we have reafon nough to fear, are irretrievably loft. From the mention Suetonius makes of Claudius his Expedition hither; *ds H h h h h h commonly ’Tac, Agric. cap, XXIV. ( 784 ) commonly infinuated his Conquefl: here * coft no Blood. ' Our Countryman Bedcy we may fee, was of that opi- nion ; becaufe, in the Account given by him of CUudim^ the Words of Suetonius ^ are copied- But Dio Cajfius^ from whom we have the moll particular Information of that War, gives a quite different Relation of the Mat- ter: He takes notice of at lead Four Battels, fought with the Britons ( before Claudius came over ) by Aulus Tlautitts\ who had Flavius P^efpaJjanus, Flavius Sahinus, and Hcjidius G^ta, that commanded under him.* In the firft Conflidf, Cataratacus was defeated ; in the fecond, Togodumnus, and, as may be infcrr’d from his Words afterwards, (lain. From the manner of his delivering the Story, all thofe Battels feem to have been fought, South of the River Thames^ and North of the Sjlva Anderida, except the lafl ; and that in the fir ft Cam- pagne the Conquefts of Flautius could not have exten- ded beyond Kent and Surry : For it s likely ^ that the Two firft Atftions happen’d about the Skirts of the Sjlva Anderida, Eaftward of rise River Medrray; and the Third, which held Two Days, on the Banks of that River ; becaufe, from the River, where they were rout- ed Two Days fucceffively, the Britons retiring, afiem* bled f their Strength again before their Fourth Over- throw, * Suet. Claud, cap. 17. Ac fine uUo prxlio aut fanguine, intva paucijfi- mos dies parte infula in deditionefn recepla, fiexto qnam profeRus erat men- f* Romam rediit 3 Beda Ecclef. Hi!l. Gent. Angl. Lib. I. cap. 2. + Dionis Caffii Hift. Rom. Lib. LX. Claud. V. p 768. A. Oj ^ Bfer- TfUo} fjti anrii c, auxilia ex Britannia, qua contra eas Regiones pofita ejl, accerfunt. Idem Lib. I-V. CEamen in Britanniam profieijei contendit, quoj, omnir kioffte Qallifis Belli sfiojlibus-nojiris inde fubminijlrata auxilia irHelligeb.at„. ( 78/ ) .'The Romans well knew, that thofe who were Scran-' gers to Civility, could not without great Difficulty be, kept in Obedience: As foon therefore as the Coun- tries they had conquer’d, were reduced to fome degree, of Quiet ; they endeavour’d to make the People in love, with their Government, by introducing their Arcs and. CuUoms among them : From that inconfiderable Inftance, recorded ^ by Plin), we may fee, how ready the Rc-^ mans were, to oblige the People under their Power,, with any Curiofuy that might entertain their Sences,, in order to endear them to the Authority they had o- ver them. ( He tells us. Cherries were not known in^ Ital'jy till the dSoth Year of Rome^ when L, Lticiillus- firft brou^TC them thither from Pontus ; and that in Hundred and Twenty Years, they were fo increas’d, that not only many other Countries, but Britain alfb^ was fupply’d with them; which mufl: have been about. Three Years after Claudius himfelfhad been here. The ufual Landing kom.Rome being then in the County of Kent ; that Fruit without queftion was there firfb planted ; and the Soil well agreeing with it, may, be the reafon that the bed and greated Quantity of it is. yet there to be had.^ Agricola, ir^the Second Year of his Lieutenancy hercK when in Winter-Quarters, purfu’d the fame Maxims^ ( which Tacitus terms Sal uberrima Confilia ; and, as. it may be inferr’d from an Expreffion of® Cafar ducive to the fame End ) to gain the Britons, by ma- king them acquainted with the Roman Manners : He not only in private perfuaded, but publickly help’d. and 5 Plin. Lib. XV. cap ^ De BelL Gallic. Lib. I. Hcrnm *mmum fortijfimi funt Belga : Propterea cjttod a cuHti atcjue humanitai-9 ProvittcU longijfime abfnnt, mlnimeque ad eos Jidercafores fape commewt^ atc^ui ea fi^4. ad effeminandgs animos pertinent, iniperSant.- ( 788 ) and incourag’d them to build Temples, Places for com- mon AlTemblies, and private Houfes after the Roman Mode : He took care to have the principal Youth in- ftruc^^ed in the Liberal Arcs; He ailur’d them to aflecfl the Habit of the Romans : And lafl of all, to engage them the more firmly, help’d them to a Taft of the Roman Luxury and Goodfdlovvftiip, by introducing the Ufe of lhady Piazzas and Barhs \ an J their way of 8an- queting. But here, Tacitus may be underftood to {peak of what was done in order to civilize the Northern Parts of this Nation, where A^r kolas Prefence was re- quired : The Southern was, we may fuppofe, fofcned and quieted by the fame Methods near Forty Years .before, when reduced by T'efpafian. *- From hence it may be infcrr’d ; that fliould never any other Tokens of the Antiquity of thefe Works be found; yet would the Bath denote the Age of the Pavement, and fet it near as high as the moft early Time, that the Romans had any real Authority in this Ifland. As by the Lofs of Lome of the Annals of Tacitus ^ ■\ve may have been depriv’d of the moft early Hiftory of this County ; fo likewife, for want of ancient Re- ligious Houfes; there has been little or.no Accounts left of its Circumftances, in the Times next after the Roman Authority expired here. Malmshury ^ fays, that in his Time, there were here only the Abbies of Bat- tcll and Le^xes, and thofe not long erecfted. The ear- lieft Mention made of it, is by ^ Bede, who informs us, that Bifiiop Wilfrid, in the Year 6; 8. being thruft cut of his Province of Northumbria by King Ecgfrid, reeled at Selfey in 68o. and ftaid Five Years, labouring in ’ Tacit. Agricol. cap.xxi. * Gul. Malmsb. dc geftis Pontific. An£^l. Lib. Jl. » Bed* Hift. Ecclef. Lib. IV. cap. xiii. ( 7h ) in the Converfion of the neighbouring Parts ; but of what elfe relates to the County, fave the miferable Ig» norance of the Inhabitants, and the Number of Fami- lies, he has left no Account. Bede (pent mofl of his Time in the Monaderies of Wiremcuth and Jarrow, and travel’d little ; fo, that confidering the Didance from thence to this County, and the different Govern- ments and Intereffs that lay between, he may well be. excus’d for the few Particulars he has left us of it. The next Records we have to view are thofe of £- theherdt the Chronicon Saxonicum, and Henrj Arch- deacon of Huntingdon, But that you may the more clearly apprehend the antient State of this County ; look int(T the beft Map of it you can get. At the Weft End, you will find iVefi-Harting and Stanfted, di- ftant from each other Six or Seven Miles; imagin ai ftreight Line to be drawn from Harting to Bourne near Fevenfef, and another to be drawn from a Point which ' muft he little South of Stanfiead to Brighthetmfiom \ . What lies North of thefe Lines is the Weald or Low- lands, formerly the S^jlva Andcrida'^ that which is com-- prehended between thefe Lines, and bounded by the' Sea, from Brighthelmflone to Bourne, is the Downs, fo* famous for their pleafant Situation and Fruitfulnefs. The Part South of thefe Lines, is a flat champaifii Ground, ending like a Wedge at Brighthelmftom. Thefe two laft Parts were thofe only that were inhabited Bede's Time; they contain not more than Two Fifths- of the whole County ; which muft be the reafon why-- Bede (aid,: Su[fex. ‘ confifted not of more than 7000 ;■ Families or Farms ; whereas in another place he com- putes to have 1 5000, Families. 1 04 I Be^dx Hift. Ecclsf, Lib. IV. cap, xiU, ( 790 ) In the three Accounts ‘ above-mention’J ’tis agreed, --that in the Year 477. ElU^ with his Three Sons Cj~ me)7, Wlencing^ and Cijfa^ landed his Forces at Cjmenes- Ora ( which from a Charter of King Cedmllas to the Church of Stlfe-^ the learned ^ Catr.bdetJ proves to be -about Witterir;^^ near S£lfejj) not far from which he routed the Britons y and drove them into the Weald - ( 3nt);eDfnetee ) : Their farther Progrefs is moft di- flindly and naturally deliver’d by the Archdeacon of Ziuntingdon y in thele Words; Saxones autem occuparunt littora Maris in aucrtjt, magis magifque fthi regionis fpatia capejfentes, ufque ad nonum annum advent us eorum. Tunc vero cum audacius regiomm in longinquum capeffe^ rent ; convenerunt Reges & Tyanni Brittonumjpud ■XCft)f|3bUtnC) & pugnaverunt contra File ^ filios fuos, ^ ,fere duhia fuit viZloria. Uterque enim Exercitus valde Ufus ^ minoratuSy alterius congrfjfum devovens, ad pro- ^pria remearunt. Mi fit igitur Elle ad compatriotas fuos au~ X Hi urn fag! tans. This County having been invaded in the moft Wc- ilern part of it by the Saxons ; if what they did after- wards, was to poftefs themfelves of it ; their Progrefs mu ft have been from Weft to Eaft. And fo much Henr. Huntingdon^ Words plainly imply. He fays farther, they were Eight Years about it; which, if we coufider the Circumftances of the Country, ’twill -be no great wonder it fliould take up fo much Time ; unlefs their Forces had been very great, which we have -no warrant from any Hiftory to fuppofe : For the Weald then uncultivated, muft have been moft difficult to pafs, even in the drieft Summers. The Downs y like a Wall X with a Terras-Walk on the top) have a very fteep Defeenc '■f Ethel ward Hilt. Lib.I. Cap. 5. Hen. Hunt, Hift, Lib. IT. Chronic. Saxon. Ann. CCCCLXXVII , * Camden Brit. Suflex. ( 791 ) Dcfcent into it, their whole Length 5 excepting! that every Ten Miles, or thereabouts, they have deep Chan- nels through them to afford Pallage for the Rivers into the Sea : Therefore, what was then habitable, being thus canton’d out into fo many Parcels by the Rivers ; nothing could be more difficult to gain, than thofo Cantonments ; were there any Forces to defend the Pafles that ffiould have been attempted ; the Rivers be- ing deep and muddy, and the Moralles on each fide broad and boggy .* Hence we may conceive, ’twas' no very difficult Task for the Britons to defend, nor an eafy one, for the Saxons to gain the Country. And in- deed, the many old Camps, Rill to be feen on the Dovrns, are an Evidence that fcarce any part effaped being a Scene of War. Mr. Camden mentions but two, Cifshury and Chenkhury. In the new Edition of his Works "Dr.Harris has added Three more ; 2l Roman Camp at the Brile near Chicheder, St. Rooks-hill, and Gons-hill near the Weft Limits of the County. It may not be improper here to infert an Account of the reft ; in which, I (hall firft take notice of thofe that are on the North Edge of the Downs, and overlook the Weald. Firft, Chenkhury, mention’d by Mr. Camhdcn, Two Miles Weft; of Steyning, and about Three Miles North of Cifshury ; ’tis circular 5 its Circumference about two Furlongs. From Chenkhury Eight Miles Eaft, over Foy^ ntngSy is a very large one, an Oval, not lefs than a Mile round s acceffible at one narrow Neck only, and that fortify’d, with a deep broad Ditch, and a very high Bank: 1 could never learn any other Name it has gone by, than Poor- Mans Wall; perhaps from its ha- ving been a Security to the diftrefled Britons. About Three Miles Eaft from thence, is Wolfenbury, on a Hill, projeefted beyond the reft of the Downs, like a Baftion ; it comes near a Circle in ftiape ; its Diameter a little liiiii mote ( 79» ) 1 more than a Furloiigi Near Three Miles Eaft of WoU finhurj, on the higheft pare of the Donns in that Quar* ter, is a Camp, near fquare, about 6o Rods long, and 50 broad ; much like a Romnn Camp ; the fide next the North is fecur’d by the Precipice of the Hill, which is both very deep and deep ; the other Three Sides have each their Porta after the Roman manner dill ve- ry vifible 7 the Ditch feems to have been not lefs than Eleven Foot broad ;but the Ground having been plough’d, the Bank, is but low : This is call’d Ditchltng^ as is the old Town under it. Near Seven Miles farther Ead, and a Mile and half Ead of Lewes, is the lad on the North Edge of the Downs , it goes by the Name of Cahurn ; which perhaps is but a Corruption of the Bri~ | 'ttjh VVbr<^ Cadir ; the Parilh below it dill retains its j| ^itiP) Naifie Glynd: This is a round Catnp, fcarce ! Three Furlongs in Circuit ; its Ditch very broad and i deep, and ,the Rampart within very high ; the Places ? where the Tertts were pitch’d are yet vifitle ; which, from the, Strength of the Out-Works, intimates that thofe wfthin held it no fmall time. Near a Quarter of a Mile Wed of it, there is a drong Work much larger, but pot fo perfed ; yet epough to flievv, it was made • to'lecure a Power, that might lie there to bridle thofe in the drong Carhp, and prevent their making Excur- dons towards Lewes. The Camps, on the Southern Limits of the Downs'^ me St. Rookfmzi Chichefter. High- Down, a fmall Square, Four Miles Ead of Arandeil, and in the Parilh of Goring: Cifshury, Four Miles South-Wed of Sieyning. Holling* lurj is the only one in the middle of i\\q Dow»s, Two Miles North of Brighthelmp one, and Three Miles South j| of Ditchiing ; ’tis a Square; the Porta dill remaining; !;| it contains about Five Acres. A Mile Ead of Bright- If helmftone da the top of a Hill, half a Mile from the. Ij : Sea, ( 79 ? ) Seai is a Campi which has a triple Ditch and Bank 5 this alto is a Square, only the Corners are bounding ; the outmoft Trench meafures about three Quarters of a. Mile. In the Parith of Telfcomh, about Five Miles Eafl: of the laft, are two^ but both imperfedb ; the. Cliff is a South-Fence to One; the Other is' a Mile diftaht from it; their Weft Sides are both finrfh’d with very able Works ; they were defign’d for Squares, and to contain 1 2 or 1 5" Acres. At Meeching or NewhAvcn, on the Point of the Hill, which overlooks the Harbour’s Mouth from the Weft, is a Fortification which they call ths Cafiley its Banks are very high, the Shape near half o* val, containing about Six Acres ; formerly it might be much more, becaufe the Cliff, which forms the Diame- ter, every Year more or lefs moulders away, and falls into the Sea. Near a Mile Eaft of Seaford is another call’d alfo the Caflle, bounded by the Cliff on the South ; its Figure almoft femicircular, the Trench and Ramparc large, inclofing Twelve Acres. Three Miles Eaft of Cukmere Haven is the laft, near a narrow Pafs coming up.frbm the Sea call’d Burlmg-gap ; it inclofeth a Hill nam’d Belli »ut of a half oval Shape ; the Works have the fame Figure, and meafure about three Quarters of a Mile? the Cliff here alfo makes the Diameter. Though neither Hiftory nor Tradition, has banded to us any Relation, when either of thefo Works were made or by whom us’d ( except Cifshury by Ciffa ) yec from this View we may conceive, the Calamity of War once rag’d in all thefe Parts .* that the Ground was difputed inch by inch : that in the Attack) a§ well as Defence of it, the Pick* Axe and Spade, Were as much made ufe of, as the Sword ; and laftly, that, unlefs the Aggreflbrs were very numerous, eight Years was no long time taken up, in difpofleffmg the Inhabitants of this faft Country. / I i i i i i ' ^015® { 7P4 ) Some may imagine, many of thefc Camps were made by the Dams ; but by what may be ob(ery’7i ) at lad forced the Place ; and by. reafon of the flout. Befiftance the Defendants made. Savage like, left not. a Soul alive, and raz’d the City, which, in Huntingdoti^, Time remain’d delolate. As to the Field where the Battel was fought; the. Saxtons extending their Power Eaflward, the Check- that was given them, in all probability muft have beem where they pulh!d on. their Victories; and it being- near ^CtCtC5f)3bunt> this Bourne near Pevenfey may b.e the Place meant, fince it founds like the iattet part of that Name ( for there not being a Weft Bourne that it relates to, the Name of it may rather be Es- hourne than ^z^-Bouine and likewHe that Anderida,, the Britons laft Stake and Support, was not far from? it. ’Tis probable therefore the Battel was fought on the. Dorvnst between the Camp laft mention’d at Burling^- Cap and Bourne ; for there are no where on. the; Dojrns, that I have fecn ( and there are few Parts of. them that I have not often view’d J, Marks of a grear ter Battel than there 3 becaufe, from the top of that: very, high ClifF, by the Inhabitants, call’d T/je Three' Charles. (. and by Mariners Bcachy-Head') to Willingr- ton Hill, which is four Miles, die Ground is 'full of? large. Tumuli or Places of Burial ; . and in many parts^, within that Tratft, where the Pofition of the Ground, feems to offer, there are deep Trendies and ^nks^^^, which one would irriagin were Breaft-VVorks made to de-> fend the Front of an Army ; and the on eacfeTidei ofthemdeem to ffiew, there was no fmalU Struggle, im forcing as wdl as defending’ thcOT Tte ( 79*5 ) The Learned and Judicious Mr.’ Somntr * diflikcs, that the Sira Andiridx fhould be fix’d at Newertde», and is inclin’d to aflign fbme Place in Sajfex for it : But from a modeft Deference to the Opinions of the Learned Camden and Selden, he drops the matBcr. But let us fee, what our more elder Hiftorians fay of it ; Hern*) of Hmtindon^ Words are, Et quia tot ihi detmna toleraverant Extranet, ha Urbem dejlruxe- runt, quod nurquam puflea readifcata e(t. Locus tantum, quaji nohilijfima urlisy tranfeuntibus ofienditur dejolatus, Matherv of Wefiminfier fays. Locus autem Civitatis ufque hodie tranfeuntibus oflenditur dejolatus. Manfit ergo ibidem Ella cum tribus Filiis fuis, Kegionem illam, qu£ u[- que hodie Anglice Lathe autemRegio Aujlralium Saxonum dkitur, colere ccepit. From the ExprefTions above*cited, it may be ftippos’d the Ground where that City flood was not quite forgot, in either of thofe Hiflorian’s Days. Henrj of Huntindon being the elder by zoo Years f had Nervenden been the Place liis Words might have been true, in faying it was defb- lare : But ’tis very improbable Mathew of Wefimin(ler Ihould have faid fo likewife; or at leafl, not taken notice of the Ad of Piety and Charity of Sir Thomas Alhuger, who, in his Time, had newly ereded a Mo- naflery at Mewenden ^ for the Carmelites who came from Ralefline : But let that pafs ; what Authority Mr. Camden had for faying ^ Hengift fent for Ella out of Germany, to help him reduce Anderida^ is not to be found. From the Accounts above flated, and others -that might be produced, it is clear, that Hengifl was dead Three Years before the Siege was laid to Ande^ rida. In the Time of Hengifi*s Life, we find, for Eight Years * Somner’j Roman Forts and Forts in Kent, p, zo6, 2 Kent ^it, i5p5. Cot, zii. ( 797 ) Years ElU had enough to do in Suffex ; and the Blow he had given him the Ninth Year at oblig’d him to be quiet the other two Years of Hen- gift^ and till his Succours { as above*mention’d ) came to him from German'^, Befides, we have not the lead; Hint from any of our Hiftorians, that Andtrida, was an Eye- fore, either to Hengift or his Son Esk after him ; or that Ella affided the Kcntijh Saxons, or the Kentijh Saxons E^lla in reducing it : Therefore this mufl: be a Suppofition only of Mr. Camden, in order to give Strength to the Notion of Anderidds being at Nervenden. Ta- king no notice therefore of that Suppofition, we may confider Nesvenden is on the Kent fide of the Limen ( for fo is the River Rather call’d ^ in the Saxon An- nals, and by Mathevp Weftminfler ; and the Mouth of it nam’d Partus Lmeneut, and CinUttE hy Ethelrverd and /denr. HuntindonO and that Kent having been fubdued by Hengif; and his Saxonr, near Forty Years before i the Town at the Mouth of the L'men, and the reft, if any, up the Stream on the fide of Kent, weiQ aUb > part of their Conqueft. Furthermore, after it had coft Ella fo much Time, and no doubt Pains too, in reducing the plain Ground of Su(fex, ’tis not likely he fhould call more Forces out of Germany, that he might lead them Thirty Miles, through the Difficulties of the great Wood ( which he muft have done if Netvenden were the Place, ) to be° fiege a City, fo far from his own, and within the Ken- tijh-Saxon Limits, efpecially if there’s any heed to be given to the Words of Math. V/ejlminjier before cited 5 who, after relating the fad Fate of the Inhabitants and City ’ Chron. Sax. A. Dom DCCCXCIII. Mat. Wcftm. Fl. Hift. A. Dom, DCCCXCII. ^ Ethelwerd. Lib. HI. cap. iii. A. D. DCCCXCIIL.:, Hen. Hunt. Hift. Lib, V, Alfr. Reg, an. 19, ( 79» ) City of Anderidd, immediately fubjoinSi Mdnjit ergo^i^t, Ella And his Sons refided there C that part of Su^ex where Anderida was ), and began to cidthate and improve the Country, In the laft place, from the Ufe made of Anderida by the Romans^ ’tis not likely ( as Mr. Somner ^ judici- oufly hints ) its Place was at Nervenden ; for being one of the Stations, under the Prafe6tus littoris Saxonici, where Forces were quarter’d, to have a watchful Eye on the Sea, when ever the Saxon Pyrats came to infeft the Coaft ; We may fuppole it, like the reft of the Garifons under that Officer, conveniently fitua- ted for the fame purpofe ; as were Branodunum ^ Bran- cafler at the North Point of l^orthfolk ; Gariannenum, '^on\\'Tarmouth^ or very near it ; Othona Ithanchefter in Dengy Hundred, in Ejfex, ibme Ages fince fwallowed up by the Sea ; Regulbium, Reculver in Rent 5 Rutupis, Richbororv ; Duhris Dover ; ^'Lemannis (which from the Saxon Chronicle ^ we muft look for. Four Miles Eaft of Apple dor e ) probably New Romney, all fituate near the Sea, on Ground which had a full Profpeeft of the Sea : whereas t^emnden lies low, at leaft Eight Miles within Appledore, on a turning of the River, where the Land Eaft ward muft have cut off any Profpedt of the Sea. To all this may be added, that the Romans having a Numerns, Cohort, or Battalion of the Tur- nacenfes, in Garifon at the Portus Lemanis on the Mouth of the Haven, we may fuppofe they knew how to husband their Strength to better purpofe, than to place another * Somner Rom. Ports and Forts, pag. 105. * Not. Imperii a Pan- cirol. cap. Ixxiii. pag. 162. 7 Chron. Sax. A. Dom. DCCCXCIII. ‘Turn appulerunt ( fc. Dani ) in JLimenioJHum , cum CCL. Navibus. Su- per eum Fluviiim traxerunt fuas Naves uf(fue ad fylvam, quatuer mtUariit ah exteriore parte afiuarii ; ibique expugnarunt quoddam mun'mentum ( fc. Apuidre. ) ( 799 ). another Garifon to watch the Motions of the Saxon Rovers, Twelve Miles up the little River, quite out of fight of the Sea, where they could be of no Service* Thofe who would have the Seat of Anderida to have been at Hayings ; let them look on thele Words of Hem. Huntindon ^ (Haraldus rex Anglorum, eadsrn die re*' verfus ad COUlttOlC cum fumma Utitia, dum pranderet, audivit nunthm dicentem fihi., Willielmus dux i^ormanntx. Uttora Ati fir alia oceupavit^ ^ caftellum conflruxit apud and they will conclude Hafiings was not a defolate place, in the Ages of the Hiftorians, who af- firm Anderida was : If at Pevenfey j that Place was fo far from being raz’d by Ella, that even after the Nor- man Conqueit it remain’d a ftrong Caftle, where Odo, Bilhop of Bay on and his Forces fullain’d a Six Weeks Siege ; and for want of Provifion were oblig’d to lur- render to K. William II. At this time there is I’o much of Pevenfey Handing, that perhaps 'tis the greated and moft entire Remain of Roman Building, any where to> be feen in Great Britain. From the Arguments on the foregoing Authorities, Anderida mull; have been fomewhere in Suffex, not in the Wed but Fall part of it, and not far from the Eaft End of the Downs, near the Sea. From the Bath, Pave- ment, Coins, and Bricks, ’tis fure the Romans had once an Abode, and not a lliort one, at this Place near Eaji- bourne : From the large Extent of Foundations about the Place where thefe were difeover’d ; that there was a large Town or City there 4 From the common Height thofe Foundations bare under the Surface of the Ground; that the Buildings they fufiain’d were effedua'ly levell’d or raz’d : And from the Coals dug up amongfl the Rub- bilh, ’tis evident that Part was burnt ; all which Cir- K k k k k k cumdances i Mtnr. Huntindon, Hift. Lib. VI. # ( 8oo ) cumftances well enough agree with the Account given us of Anderida, The Situation likewifc of a Town here, gives reafon enough to fuppofe, it was a Place of Importance, and whence it had its Name 5 no Part hereabouts being any way fo convenient, for a f'ecure Settlement ; or for fuch a ufe as the Romans might have occafion to make of it. We are inform’d by Cafar, that the Maritime Parts of Britain (fpeaking of what he faw, which was the South- Eaft ) were inhabited by People from Belgium ; and ' that they call’d their Settlements by the Name of the Places from whence they came. It was the Opinion of Tacitus alfo, that ^ thofe who inhabited next to Gaule, came from Gaule. And Bede fays, the Tradition in his Time was, that the Southern Part of the Ifle was peo- pled * from Bretaign. In the Third and Seventh Books of Cafar’s Commentaries, mention is made of the Andes, a City and a People belonging to it among the Celta, in- habiting on the Sea-Coaft. Time varying the Names of Things, near Two Hundred Years after Cafar, Ftolomj calls the City Anderidum : And near 250 Years after him, when the Notitia Imperii, now extant, was in ufe, the Clajfis Anderetianorum '* is regifter d ; and the Refidence of their Admiral fix’d at Paris. From whence ’tis to be inferr’d, that tho’ the Capital of the Andes might have been Angers near the Loyre, yet their Country had on the North the Britifh Channel ; and on the Eaft the Seine for its Bounds. The Britijh Coaft about Eafi Bourne is the neareft of any to the Mouth of the Seine ; Therefore, according * De Bell. Gal. Lib. V. omnes, fere its nominibus civitatum appel.. lantur, quibus orti ex civitatibHS eo pervenerunt. ’ Tac. Agric. cap. xi. la univerfum tamen xftinianti^ Gallos vicinum folum occupaffe credibile efi. 5 Bedoe Hift. Ecclef. Gent Angl. Lib. I. cap. I. In primis hac Infula ^ritones folum^ d quibus nomen accepit, incolaj habuit ; qui de traHu Armo.. vicano ( ut fertur ) Britanniam adveBi Aujlrales flbi partes illius vindi^ 0UTUH4. J Pancirol, Comm, ia Notit. Imp. Cap. XC. pag. i yp, i8o. ( 8oi ) according to the Ufage before C^efars Time, the Name of Anderida there, is readily accounted for. Moreo- ver, this Place feems moft naturally featcd, for giving an Appellation to the great Wood, to which it adjoin’d : For, as it felf is on the Shoar, fo alfo the Sylva Ande> rida here, came very near the Shore ; and a large part of it might be (een from the Sea before it : Indeed, on the Sea off of Ronuuy, it might be difcover’d ; but then the Diftance w’as great : At all ether parts of the Coaft, the Sight of it from Sea, is hinder’d by Hills, or high CliSs. Setting afide the want of a navigable River, the Spot of Ground where this old Town flood, yields to none in the County for Importance and Fleafure : For here, like a Wedge, ends the firm Soil of the Downs j Nature * has fhap’d it like an Equilateral Triangle, having each fide half a Mile in Length : Towards the Sea, on the Southern fide, ’tis fenc’d by a low Cliff, of 12, i^, and in fome Places zo Foot high ( in which Cliff is now to be feen a ftrong Foundation, that has acute Angles, which fhews it to have been for a Fort rather than a Dwelling-Houfe ^ On the Northern fide is a Morafs, with a large Rivulet of very good Water. Between the Weft fide and the Downs lies a fmall VaWey, by which Advantage, there was formerly a Harbour, ca- pable of a fmall Fleet ; the Banks on each fide of it arc an Evidence it was funk by Induftry; but by Weeds and Gravel from the Sea, and by Mould annually added, as is obfervable ’ in Valleys, it is now fo rais’d, that *tis never flow’d but at high Spring-Tydes, when a ftrong Wind forceth the Waves into it. This Harbour muft have been a good Security to part of the Weft fide ; what other Works might have been to guard it, from K k k k k k a the ‘ Philof. TranfaCl. An. 1701. N® S74. Pag. $i6. ( 8oi ) the end of the Harbour to the Morals, cannot be faid .; by reafon the Ground between has for many Ages been ijn Tillage. It is eafy to imagin of what importance a Town fortified at this i lace mud have been in ihofe Ages, when the only Pafs by Land from the Wed to the tad End of the County was through it ; for other there could not be, in many Miles North ; unlefs the Lands, in that Tratd, which are dill very owzy and ten- der, had been well drain’d. As the Situation deferib’d, render’d this Place drong; it is very pleafant withal ; for the Ground is high enough for a good Frofpetd of the Low Lands adjoining, and the Country towards Battell ; befides, it has a comman- ding View over that Bay,- which is between Beachy f/ead and Haftings, If the Ufe made of it by the Romans, was to guard the Coad, there was this Advantage be- longing to it ; that a Centjnel on the top of Bcachj, not Two- Miles from it, in a cleat Day, without turning his Body, might fee the J(le of Wight, the Hills in France near Bologn, and the Nir/r in Kent , fo that from the Nefs to. Selfey it muft have been a (mall Sail that could efcape his Eye. It was my purpofe to have added a Defeription of feven/ey-CMe ; together with an Account of Tome Rjcmains of Antiquity, difeover’d lad Summer towards the Wed End of the County : But having been too te- dious already, mud defer that for the prelent, and fub- dribe my feif Toftr moft humble Servant^ John Tabor. Tiewes, Jan, 26. x6 1 7..1. Ill, Trci^dtus ( 8oj ) III. T/'aSlatus de Carvarum Confl niH lone ^ yen- fura ; ubi plurimit feries CurVarurn hifinttd Vel reSlis menfurantur vel ad fimpUciores Cur^^as redu’* cuntur. Jutore Colin Maclaurin, in CoUegio noyo Abredonenfi Mathefeos Trofejfore. Ximise Mathefeos Theori^?, ob infinitam Propofiti- jW num Univerfaiitatem, .secernam ac necen'ariain ■* Veritacem, Evidentiam omni dubitatione majo rem, Idearum claritacem luculencifllmam, Demonftratio- num cleganciam, Theorcmacum nexus & mutual depea- denrias, pulclierrimis certe ac fummis humarii intdicdtus tepertis Tunt annumerandae ; inter eas vero eminent futn- morum hujus fxculi Philofophorum de Curvarum Loa- gitudinibus & arcis menfurandis ardua Theoremata^ Ad hos diffufos cognitionis campos diu alte latentes tanr dcm cruendos infinite fcienti^e portiunculam mutuari, vix libi temperare poilet quin pronuntiaret, qui ArithmeticJC Infinitorum vires in immenfb elegantiflimarum Verita- turn abyfTo eruendo, & bumani intelledus Horizontem infinite fere extendendo, paucis practeritis annoriim de- cadibus, ample fatis comprobatas, animo perpenderit ; Hujus vero methodi ( ficut nunc auda & exculta efl ) ope, incidi in rationem menfurandi' infinitas Curvarum feries, quam paucilTimis explicabo. Cum in omni linea curva fit aliqua curvarurx regula- ritas licet force implicata, fecundum quam figura detex- minatur; ideo Geometrce varias Curvarum charaderes ex if,quationc Ordinatarum relationem ad abfcifTas axis ali- cujus exprimente definiriinr. Cum vero idem fieri pofBt ex confideraiions Curvarum refpedu unius dati centri, iUIQ.!! ( 8o4 ) imo fimplicinTmia Nature uniformitas in ejus indagine id fieri fepe poflulet, ideo hanc Curvas confiderandi Me- thod um impra^fentiarum ufurpabimus, & imprimis often- demus qua facillima ratione ( fecundum hanc Mecho- dum Curvas detcrminandi ) ex fimpiicibus complexiores conftrui pofTmc. § I. Sint L & / punda quamproxima in Cutva B / L ; fit / 0 arcus centre S defcriprus perpend icularis in S L ; & erit L/ ut momentum Curvse & L c momentum Radii SL.* Ac fi detur ratio L / ad L o, vcl ad / o in diftan- tia S L, dabitur aquacio Curvx ad centrum S. ,Sint L P, / p Tangences Curvae in pundis L & /, in quas ex S de- miitantur normales S P S p iis occurrences in pundis P 'Sc pi fimiliter in omnes Curvx Tangentes dem^ttantur perpendiculares ex dato pundo S, & conftruecur Car- va tranfiens per omnes Tangentium & perpendiculorum interfedioncs. Hujus triangulum elementare P p fi- mile erit tiiangulo L , P L, & redos S S P L aquiangula erunt triangula Sp n, P » L, & ta ratione L/ ad lo, Sc reda S L, dari rationem P/> ad p jiSi redam S P, adeoque Curvam DP p. Eadem ratio- ne ex D P conRrui poteft Tertia, & ex ea dein Quarta, & progrediendo prodibit feries Curvarum infinita, qu^E • omnes ex uno dato innotefeunt. Quod fi erigantur L N proinde P : pn :: L n: S» :: L <7 : I o, adeoq; ob angulos P » />, S « L, hoi sequales, erunt tri- angula P»p, S;?L, Lei fimilia. Cum igitur ea- dem fit ratio hi ad qu£E P/>ad pn,ScSh ad S P, manifeftum eft, da- ( 8oj ) ^ 1 3^ perpend iculares in radios S L, S /, fibi mutuo oc- currences in » ; & per omnia fimiliter definita perpendi- cularium concurfuum pun6la defcribatur Curva E N: ca ? ipfa eric Curva ex qua deduci pocell B L, eadem ratio- ne qua conftruximus D P ex B L. Ex E N fimiliter conftrui poteft alia Curva, atque ex hac quoque parce Series infinita Curvarum conftrui poteric. ^ II. Curvarum vcro hac racione confidcratarum fimr pliciftimsE lime quarum L / eft ad L t? in rarione pore» ~ ftatis alicujus Radii, ita uc, ft a fjc data quanticas, r de- nocet Radium Curv^e, » numerum queracunque, fit L/ ' ad / (j ut 4” ad r” aequatio earum gencralis. Omnes ve- ro hx Apfidem habenc cum rz^zaj quoniam in eo cafu ; L /— / 0. Ut inveftigem aequacionem Curves D P, cum in 4 B L eft ut L / ad I o a" ad r”, ita r ad S Pr= — , ita ?. X S P^+T ad S P, ita ad S P"+q ita P /» ad , Proinde ft s reprefentet momentum Curvae, ^ ar- Gum circularem radio deferiptum a cencro S, 8c r radium > correfpondentem, qusecunque fit Curva cujus ^Equacio » inveftigatur, erit i^quatio Curvas B L, s y :: 4” : r”; Aquatic vero Curv:e DP, / : : 4»TT ’ Angulus ^ autem P S /> eric ad Angulum L S / ut || ad five ut ^ ad vel ( ft S Pdicatur a: & S L, ^ ) ut ad C ^ , hoc eft, ( ob ) ut ^ ad C,fiveut »-|-£ ad r, , Hinc ( vid. Fig. II. ) B S P eft ad B S L uc n-\-i ad i ; , unde facilius abfque Tangentium ope duci poteft Cur- va B P. Si fumacur angulus BSP ad BS L in rations • »~\~i ad I, & in S P demittatur perpendicularis ex Lt eric occurfus perpendiculi cum S P, in Curva B P prius > Tangentium ope deferipta. ^ ill. Oftea^^.^. ( 80(5 ) ^ ni. Oflendimus quo pado ex una feries Curvarum infinita deducicur; quo vero padto f'ngularum longitu- dines ex illius & unius altetius longitudimbus datis in- notefcant pergo demonftrare. Cum angulus S P S L /, atque L $/ fit ad P S/> ut i ad »+i, erit L / ad P/» uc S L ad n-\-i S P, (ive ^ ob S L : S l: LI : I o) ut L/ ad »-\-l 1 0, ac proinde P p=n-\-i / o : ted / g— / n — o n = / n — L N4"N n ; ergo P 1 x / n — L N-}-N », Sed I n — L N eft momenrum re Roherval, quatnque De la Hirt confiderat ^ ut Comhoidm Bafis Circularis, in Adlis Academism Pa- rifienfis Anni 1708. Perpendicularcs omnesLN, In concurrunt in pundo B, adeoque BNr=o: unde B P= tB L : Hinc Cutva tota B P S=^ B S, ac Ion- I — m ^ g\t\xdo Epcycloidis femperdupla eft chords arcus in cir- . culo correfpondentis. ‘Ex Eftqcloide defcribacuc Curva BnS, eadem ratione qua Epicjcloidm ex Cir- culo defcripfimus : In hoccafu>?=r» & 4-f* _ • • * f z=z\, ac proinde squatio Curvs BnS eric s : y :: a^:r^ BL-fLP Longitude Curvs eric — rBL-|-LP=^BL-|-LG, & proinde Bn eft fefquiplus fumms Arcus circularis ejuf- que Sinus redi. Quod ft fumatur C D^B D, & radio S D centre S deferibatur Circulus occurrens reds S P in H, & ftt H K perpendicularis in B S; quoniam D H= jBL, eric B n=D H-j-H K. Hinc arcus Bn neque lunt redis neque arcubus circularibus commenfurabi- les, differentia tamen arcuum Bn & DH eft reda H K. In pundo S evanelcit LG, adeoque Bn S=tB L S, unde tota Curva eft fefcupla femicirculi. Nulla vero pars hujus Curvs alBgnabilis commenfurari poceft toti, nee Integra Curva in data quavis ratione fccabilis eft, ita ut portiones rationem affignabilem habeant ad fe mu- tuo aut ad totam. Si hsc curva in data aliqua ratione Geomecfice fecari poffec, conftarec Quadratura Circuli, nam fi e.gr. eflet B n ad B n S ut i ad w, & BL ad B L S ut I ad », eflet Bn=--=— = = HT+lg „ unde eflet H & B L S=:^. L G j"' Ex BnS ft — M conftruatuj: explicata. methodo Curva B R, & quoniam ( Sop ) "i - i?~erit atque ^quatio Curv^ BR etk Yl ^1 » • 'L * - s : j i: afi : , Hinc longitude Curvae fiet |xBL-|-Pn, totalis veto Longitude Curvs BRS=:^ diametri SB. Si harum Curvafum Conftrudiones continuentur, prodi- bit, hujufmodi feries ^^quationum quse facile produd- tur ad libitum. « • iLquatio Circuli i. s : y : : a > r • * r I • Epicycle id is 2. s : y : : : r • • r r Secundi 3. s : j : : a’-' i • • J I Tercii q. s : y : • • It Cujufvis n. Sly : : i r ^ Cbfervare licet in genere, omnes quarumTndicum deno» minatores funt Numeri pares, perfedse redilicationis elie capaces ; cumque qujsvis fit ad penultimam ut i ad i — perpendenti nianifellum erit Curvse cujiifvis longicudi- nem fore : — m X I — 2»I 1— 4»» -6m l — 3»J ^ I— 5»i ^ I — 7»2- &c* X SB continuando feriem donee ad nihilum reducatur Fradio. Quod fi Indicis denominator fit Numerus impar, Curvae erunt perfedte rediiicationis incapaces, & earum arcus quicunque erunt fibi mutuo, ipfis totis, redis quibufyis & arcubus Circularibus incommenfurabiles : exprimi veto polTunt omnes arcubus circularibus & redis : At Cur- vac cujufvis totalis Longitude erit ad Semicirculum ut * X X ad unitatem. Denique fi Areo- I — m -3»j la a Corpore in harum quavis revolvente fumatur con- dans, hoc ed fi ry=.i, fubtenfa anguli contadus, cui femper ( ob datum data area tempus ) proportionalis ed FisCentripeta tendens ad S, eric reciproce ut potedas di- dantiae cujus Index ed % m-\-^ ; atque hoc ed non con- L 11 111 X temnenduni (^8iO; ) ' t^mnendum harum Curvarum privilegiujm, quod in iis . omnibus Vis centripeta tendons ad S fit uc aliqua reci- proca diftantise dignitas, quse^fimpliciflima eft, & utiliC- . iima in Naturse indagine, Virium Centripetarum lex. • • n H iT.,V. Curvarum quarum i : y .a : r proxime con* fiderandajcnic ( qqse Curva quidem improprie dicitur) ip(a Linea recfta, exiftence S extra redam. > In hac li- Jifa,, obrfimilia crianguia P /» », PBS erit C H B Srz= a & S^^r) / : y :.vr : 4. Ex linea reda mechodo diredi a nihil nifi pundum B conftrui poteft, Mechodo veto in- v versi>' perpendicularium nimirum P L,r pi concurfu. con- ftfui 4>Qceft .Cutva, cujus Index .( fi m fit Index Curvae B-P ) sequalis erit — ^ ; nam fi Index Curvse B L fit #, eric ac proinde Unde in hoc cafu, cum «i£= — I erit & ;^quacio Curvse B L eric . ^ . i , i ■ 5 : r‘ : 4*, quse xquatio eft Parabolse ad Focum. Ex hac P^-L N ; proinde hnsc Curva eft recftificabilis.. • Si Series cojicinuetur, prodibunt uc prius xquationes in - hoc ordine. ^quatio Re ■ ' tet dimidiam hujus fimilicer ac prioris Seriei efle recftis - menfurabilem *. alia vero dimidia pars in recftis & arcu-‘ 1 bus Parabolicis exhiberi poteft. In his omnibus Vis cen- : tripeta ad S eft redproce uc poteft as diftantiae cujus In-^ I dex 3 — zw, ac proinde femper inter duplicatam & tripli-. I catam racionem diftanciae reciproce. ^ VI. i£quatio- Hyperbolae aequilater^E ad centrum « eft J : jr : : r ; ex qua deducitur methodo dire • 2 2 I. : y : : ^ ' a- . . * 2 z, s : f .* : ^ • r . i. * 3. j :y :: /i’ '• • • 4. i : ^ : 4 5 ifT • ’ 2 2 S* S' y : : Ex bis Curvae, quarumbridicum denominatores funt in j progre/Tione— I, 3, 7, itt&c. exhiberi poflurir in redis ’ & arcubus Hyperbolicis ; reliquae vero in rediis & arcubus Curvae, cujus aequatio ad axem S B (fix fit abfcifta, f vero Ordinata ) eft x-]-yy quaeque con* ftiuitur . ( vid. Fig, Ml ) bilecando angulum B S L fumendo ( 8ii ) fumendo SN mediam proportionalem inter SB & SL.' Curv^ qux ex Hyperbola methodo inverfa conftrui , pofTunc progrediuntur in hac Serie, ■ : ■ . ' -2 2 Hyperbola i. s : y :: r : a • • . . * i a. s : j :: • • 2 a . 5. s : y : : ri : ' Ubi CtirvK quarum Jndicum denominatores funt in pro- .greffione i, 5, 9, 13, (^^c. exprimi polTunc in reiJtis & arcubns Hypeibolicis; reliqua; vero in redis & arcubus Curv^e modo explfcacx. Si ali;2 Curvae defiderentur quce alias exhiberent Se- ries, id facillime fieri potefl ope vel Circuli vel Redsc : h n ex eamm aliqua omnes, in quibus s : y'l a : r, conftrui poflunr, fumendo, fi o- pe Circuli Problema fit folven- dum, BSR ad BSL uc i ad »— r 1 &SNinipraSR=^ ” xSL”; quippe Curvae pet omnia pun- • • n n ^ua N dudiE ^quatio eric s : y : : a : r . Similiter ope • . n n Redse conftrui poflunt quarum icquatio s : y :: r : a-. Duas exhibuimus Series infinitas Curvarum redis commenfurabilium ; aliam arcubus circularibus, aliam Parabolicis, .aliam Hyperbolicis una cum redis menfu- rabiles demonftravimus : ex vero ad redarum menfu- ram arte fola infinica reduci pofTe videntur, ficut X- -^quatione fola infinica in redis exprimuntur. Cl. Author hrevitati fiudms paucis tradit, tlltm 'tern fknius rem pro dignitate ejus iUuflraturum fperamus, IV. ^mar^s ( ) IV. ^marks on a Fragment of an old Roman In* fcription lately found in the Morth of England, and tranfcribed hy the Curious and Learned I James Jurin, M D. and Reg. Soc. S. ^UR worthy Member, Dr. Jttrin, having refi- ded for Tome time at Neircafile upon Twe, had the Curiofity to travel the Country between that and Carlijle, in order to obferve what might oc- cur worth notice in the Remains of the Ruins of the famous Ti^isWally built by the Romans to fecure them- felves, againfl; the Incurfions of the Natives of that part of Britain they cared not to conquer, fn this Perambulation, befides many other valuable Obferva- tions which in- time he may be prevail’d with to bellow on the Publick, Dr. lurin faw and tranfcrib’d no lefe than Twenty Roman Infcriptions, fome of which we had formerly receiv’d from others, but many of them whol- ly new; among them the following, which, tho’ broken and in great part illegible, fuffices to fix the Name of one of the Ancient Nations of Britain, that has hithei- to been greatly mifcaird, ’Tis thus. CIVITATE CAT VV I L L A V A' ORVM- L- OC 6- C D / 0 ' and is to be feen on the Wall, about two Miles Wefl from Lenercrofs-Abhy, near the Confines of our two Nor- thermoft Counties. ,. ,; Here, ( 8i4 ) ' Here ’tis obfervable, that the laft A of the fecond | .' Line has a Mark that follows it, not unlike to the laft Stroak of an M ; and if inftead of we put N, we ^ dhall read it CIVITATE CATVVI LLAVNORVM, } which we cannot doubt to have been the true Name of that People which Dion. Cajjius, Lib. LX» calls Ka7«eA- * . AaroJ, and Ptolom% in his Geography, Lth.W. cap. | more falfly, Kccfveux^^ctyoi ; the firft A by producing the 3 tranfverle Stroak having been miftaken for This Na- rion appears by Dion to have been more potent than their ; Neighbours the Dohuni (whom he calls Boduni) and had, according to Ftolomy, f^erolamium for their Capital, which ’tis moft probable, was the Caj[fivelUuni oppidum of ^ ] far. So that it Ihould leem Cafftvellaunus King of thefe Catuvillauni when C$( (p triangulum squicrurum efficiebac, cum ab utraque 41 1 abefict Hoc mane duarum hcrarum fpatio vix dimidium gradum abfolvit; bora decima' vcfpertina cum Cajiepe^ & 9, Ferfei in iinea reda cernebatur, atque a priori 3° 38', a poftcriori 3° 9' dillabat. Dia- meter ejus erat $ min. nudoque oculo confpedus ftel- > lam quintse magnitudinis referebat. Die Z4'° Jdff. bora VI. mat nondum attigerat (p.Per- fei^ fed cum o ejufdem Afterifmi triangulum asqui-- crurum fiftebat, & ab utraque non plane 3r grad, ab-- erat. Plura ex obfervationibus docebit Aftrophilos Vic. accuratiflimus, in pleniori quam parat hujus Comette. Hidoria. H»5ienus Nova Litteraria pag- 43, qq. uhi defi^- derantur Ohfervatknes Dki 18''"', cum Cometa velocijfime mot us terr^ froxiims erat, unde ccrtius de Via ejus tarn, vera quam apparente judicium ferre poffemus. Mamfe^-< flum autem e(l eum Polo ^quatoris Boreo vicinijjtmum die ■ Januarii 19"° tranjtijfe, ^od ft cm liheat has Obferva*- tiones ad examen revocare-, calculoque accurate fubjicere 5 in illim gr at i am, loca Stellarum fix arum, quarum hie fit men^ tie, ex Catalogo Britannico excerpt a, fubne^untur : Unde - etiam patebit nonnulla in hac motm Cometa de/criptione baud I rite fe habere % qua tamen a Cl. Kirchio corrigi, in pU^:- niori ejus quam promifit hifioria, fpes tfi. Stellarum i ( Six ) SteOarum fxarum Loc4 inemte ^nm 1 71 8. BAYERO 'Long. 1 Lac. Bor. 0 ' "(o'." Ur [a minor i^ ^ 1 y fT. 9 18 072 58 1 0 17 3^ 13 15 C S' Qaffiope£ ■< g C

r II ^6 354f 4 5 c ^ Perfei J q> c ? b- 8 32 035 23 45 V 10 41 35 35 49 iq ^ iz 15 2c(35 18 37 £x iifdem Novis etiam ohinuimus dttplicem ohfervati(h nem Eclipfeos exiguA Solaris ^ currcntis a»/>i Feb. 19'“ ft. ver. wane celeb rat A '-i alteram Noribergce a CL £). W urtzelbau, alteram a prafato D. Kirchio Berolini hahitam, ' Noribergce autem Sol ortus efl aliquantulum deficiens in limbo fupcrioref qui quidem defeLtus ad tres flene digi- tos accrevit j Defiit Eelipjis 8'’ 8' 48'' circa 60 grad, d Vertice Solis ad Stniflras. Berolini veto Sol Jlatim ah or~ tu ccepit dtficere^ Hora ftil. 6 49^ '^il r» Circa me~ dium Eclipfeos, nempe 7^ erant Partes lucidA in Sole refiduA 24' 40", unde digiti ohfcurati 50'. Finis ' autem incidit S'* 28' id‘. ^ui pluta de his cupit, adeat Nova ipfa Berolini edita. II. A ( 8ij ) IT, A D/fcourfe occajtond Ij an Infer ipticn found, about Throe Tears ago, at Langchefler in the Bijhoprick of Durham, and communicated to the Royal Sociecy from Dr. Hunter hf Dr. Woodward, as it is printed in the Philofophical Tranfaliions, N'’ 354. By Roger Gale, Efq\ R. S. S, Dr. Hunter, who communicated this infeription,' having only given us his Conjedlutes as to the firft fortifying the Place where it was found, and the Time of its Repair after it had been deftroy’d, but faid nothing relating to the Explanation of the In- feription itfelf, tho* extremely curious ; it will not, 1 hope, be taken amifs, if I offer fome Thoughts that oc- curr’d to me at firft fight of it, and afterwards indu- ced me to put together what follows upon that Sub- jedl. I fhall not in the lead difpute or call in queftion the Time of its Foundation, as fix’d by the Dodor, but begin with the Place where it was difeover’d, name- ly Langchefier or Lancafter, in the Bilhoprick of Dur^ ham, which I am, ‘ with him, fully perfuaded was the Longovicus, where the Notitia Imperii places the Hume-* rus Longovicariorum. This place is feated upon a great Military Way, a- bout I % Miles diftance from Blnchejler, and 7 from Eb* chefter, the one the Vinovta, and the other the Findome- ra of Antoninus, as the Correfpondence of the Numbers may evince; Binchefter being 19 Roman from Bb~ chefler, as that is 9 from Corhridge, the exadl Numbers the Itinerary gives us between Vinovia, Findomora, and Corjlopitum. What is very ftrange is, that the Itinerary, which mufl: go upon the great Road dircdly thro’ this t Nnnnnn Town ’ Wilofepb, Travf, N® 2^5. p. ^57. * Not, Imp. fol. 17^. ( 8*4 ) Town of hongovicus betwixt Vindomon and VinovU, takes not the lead Notice of it, but meaiuresche Way at the whole Length and Number of Miles, fiom the firft to the latter of thofc Stations. If Lo>' decay, as the Word conlapfa implie : and not that it ^ was - • PtA. Leg. VI. Niceph . Eb»r heat, ® Anton, [tin. Not Imp. - p. i6i. J jintop. bin. IL ^ Camd. p. S35, ^io. thU, %rapj> N® ( 8jo ) was deftroy’d by any Fire, War, or other Enemy than Age and Neglect. Tho’ the Word conlapfa is wrote here with an iST, there can be no doubt but the Pronunciation of it was as we ufually find it fpelt, collapfa ; a certain Argument of the Letter N’s being filent in the middle of a W ord, before two Confonants, efpecially NS, and NT, when the T was pronounced like an S. To omit what ' ^intitian fays to this purpol’e, it is confirm’d by the Abfence of that Letter in numberlefs Infcriptions in Gruter^ Reine- Jius, ^c. and no wonder, fince the Workmen in thofc Days, as well as ours, ufually wrote as they fpoke their Words. 1 fliall nor trouble you with Quotations of any of them to this end, but as a Proof of what f fay, on- ly affure you from ocular Infpedion and a moft accu- rate Examination . that there is no trarifyerfe Line over the Letters tS belonging to the Word FABRIQESIS in the inferiprion of IVL. VITALI at Bath, whatever has been affirm’d to the contrary, but that the Letter N is totaly omitted there. Yon will alfo pardon my Endeavours, before I leave this Subject, to explain a ihort fnfeription belonging to fome of our Countrymen, tho* found at Amerhach in Germany \ fince it will be a new Proof of the foregoing Afiertion. III. NYMPHIS'^ N 9 BRITTON TRIPVTIEN SVB CVRA 9 VLPI MALCHU !>LEG XXII Nymfbis. l^umerus Brittonum Triputienjis, or — Sub cur a Marci Ulpii Malchi CenturionU Leg. 22. Trmigenia, Via, Felicis. PR. I. c. 7; * Cruter. p, xclil. { ) There is no Difficulty butrin the Word TRIPVTIEN, and that will prefently vanifh if you infert the Letter N. and read it TRIPVNT, /. e. Trifontienus or Trifontienjis, the Mutation of the O and V being fo frequent, that no body is ignorant of it. This will bring you to TVi- fontium ‘ or Dorvhridge in Morthamptonjhire-^ tho’ that ex- cellent Antiquary Dr. Battdy % in his Amicjuitates Ru- tQfin£, would read it RiPVTiEN, and fix’d the Place whence this Numerus took its Appellation at RichhurroTP in Kent. But to return where we left the Camp at Longovicus, it will be as difficult to affign a Reafon for its being repaired, as it was for its being deferred ; unlefs that the Frcpr^tors might judge it advifable about the Time of Gordian III. to fix their Refidence there, and confe- quently refortify the old Camp for their State and Se- curity. And that it was not refortify ’d upon any fud- den Emergency, but for Time and Duration, is evi- dent both from the Rrong Stone-Works that encompafs’d it, and a Body of Forces lying here, even at the Expira- tion of the Roman Empire and Authority in this Ifland, which from its Continuance in the fame Station, had got the Name of the Longcvicarii The Ferfon that under the Emperor gave Diredfion for thefe Repairs, was M^cilius Fufcus : As M^cilius is a Diminutive of M^cius, it is not unlikely that he was the Son of Maicim Fufcus, who was Conful with Turft- lius Dexter, A. D. 225 in the Reign of Alexander Seve» rus : By this Infcriptien it appears that this Meecilius was the Emperor Gordian's Lieutenant here and Prcpraitor 3 For tho’ in Phil. TranfaP^. N° 354, by the lnadver<> tency of the Engraver, we read only PR. infiead ef PR. PR ; it is right in the Original, and in the Tran- O o o o o o . feript * Antonin, hin. VI, ^ p. 21. \ Notit. Imp. fol. r~6. b, ( fcript fent up by Dr. Hunter ^ and accordingly in pag, Sx6. the Fault is amended. And as the Name of cus (lands in the fame Place in the fecond as that of LucHianus does in the firft, and with the fame Ad- junds both before and after, we may fairly conclude he was either his I’redecedbr or Succeflbr, but which, it is impodible to determin. And here, perhaps, it may not be amUs to re- mark5 w’e never meet with a Legatus Auguflalis in any Infcription in this llland, without the joint Title of Prepr^tor'-i and ’ Tacitus himfdf either makes them the fame Odice, or at lead unites them in the fame Perfon, when he tells us. In Britannia P. Ofiotium Propraio- rem turhida res excepere ; and having prefently after related the manner of the Fight with the keni, fliles him Legatiis, £lua pugna flius Legati^ P4. Oflorius, f:r- vati civis dtcus meruit ^ ; and a little after he gives both the fame Titles to A. Didius the SuccefTor of Oftorius. We are indebted therefore to thefe two Monuments, not only for the Account they have preferved of the Roman Arms and Magnificence at Longovicus, but for the indifputable Records of the Names of tw^'o Legates and Proprafors of Britain, that would otherwife have been buried in Oblivion, viz. Cneius LucHianus and Ma» cilius fufeus: For from Firius Lupus (who was Propra- tor and Legate here about the Year io8, under Seve~ rus, and juft before that Emperor’s coming into this Iftand repaired a Bath burnt down at Lavatroe, or Bovees ^ in Torkjhire) we have no where extant the Name of one of thofe Officers, till we come to Non-' nius Philippus, whom I take to have fucceeded the la ft of thefe ; the Stone which was found at Old Carlijte in ’ Tac.Lih. Ann. XII. c. 32. * Ibid. c. 39. I Camd. p 762* Edit. < C*md. An'Mw.'p. 830^ ! ' ( 853 ) in Cumkrldfj^, and has preferv’d his Memory, fetting forth that he*was Legate and Proprdtor when Attkus and PrdtextatMs were Confuls, which was A. D. 241. the very Year that our Gordian went upon his Perfian Expedition, from which he never return’d. And as that Emperor left Nonnius Philippus in that Poft, when he march’d into the Eaft, where he was murder’d about two Years after, it is highly probable that he was the lafl; Prcprdtor of his appointing, and confequently, that Mdcilius Fujcus was his Predeceflbr, and the Repairs be- gun at Longovkus before the Year 243 b I would not have troubled you with this Infcription, but that it is faultily tranfcribed in Camden^ and that I lhall have oc- €afion by- and* by to refer to it again, upon a material Point, which therefore I hope will plead my Pardon. IV. I. O. M. PRO. SALVTE. IMPERATORIS M. ANTONI. GORDIANI. P. F. INVICTI. AVG. ET. SABINAE. FvR IE. TRANQVILE. CONIVGI. EIVS. TO TAQVE. DOMV. DIVIN. EORVM. A LA. AVG. GORDI A. OB VIRTVTEM APPELLAT. POSVIT. CVl. PRAEEST AIMILIVS. CRISPINVS. PREF EQa.N ATVS. IN. PRO. AFRICA DE TVSDRO. SVB. CVR. NONNII. PHI LIPPI. LEG. AVG. PROPRETO. ATTICO. ET. PRETEXTATQ COSS. O 000 00 % The ‘ Phijof, Tranfdji, N° 554. p. 752. { 8U ) ThePerfon who had the Care of thefe Repairs both in Town and Camp, was Marcus Aurelius Quirinus, Pra- fePi or Commander of a Company of Foot ; another Ar» gumenc for the Propixtors Lucilianus and Fufcns fuccced« ing immediately one the other, he ferving in the fame Poft under both. I mud obferve however, that altho’ the two fird inferiptiens have been cut very near the fame time, and by the fame Hand, as appears by the Form of the Letters, and Manner of the Abbreviations in each of them, yet the Office that this Quirinus bore is fomething differently exprefs’d in the fird from what r it is in the fccond, if they have been accurately tran- feribed ; the Fird fliewing, after Qj^IR I NO the Letters PRE.GH. I. LG. R, which, before I had feen the Latter, 1 was induced to read Prdfe^fo Coherlis .friwA Longovica- riorum, the ' Notitia Imperii placing the Prerfeltus nume- ri Longovicariorum Longovico. That Numerus and Cu* hors WQTQ the fame thing, " Pancirollus^ in his Notes upon that Book, quotes St. Chr)fo(lome to prove, and fome other?, Cohors erat qui vocatur Numerus ; but I ra- ther take it to be an indefinite Number of Men, which might comprize feveral Companies, independent of a- ny Legion. ^ Negetius, fpeaking of the Legati Impera^ toris, fays, in quorum locum nunc illufires viros confiat Ma- gi(lros Militum jubjlitutos, a qaibus non t ant urn bina Legio- nes, fed plures Nwmeri gubernantur\ by which it is plain, the Numeri were no Legionary Cohorts. Neither was the Name fo modern as from the Notitia Imperii and Chr^- foflome it might appear to be 5 for we meet with a Nu- meras Britonum upon an Altar found in Tranfylvania, de- dicated to the Nymphs, when the Emperor Cemmodus and ' Glabrio vatiQ Confuls, A.D. 186. And ^ another Nume- ‘ rus upon an Altar ereded to Hercules for the Profperity ! of j b *fol,i6i,b 5 Lib, IIr.c.9. < Gf«^r, p.94. 4. ’id .46.9. j ( «55 )' ef Septimlus Scv;rns, when Laterams and Rufimts were' Confuls, A. D^ !Q7. Eui: after 1 had review’d ihe LeC' lers ac the end of the fecond Infcripcion, which are plain- jy tranftribed PR. CoH. i. L. GOR- I could read them no otherw ife than Trxficfo Cohorth pr'mu L^gionh Gordid- 7i£. Gordian III. was fo beloved of the Soldiery, that fevc- ral Legions complimented him by honouring themfelves with his Name, as the ^ Legio tertia linlica, w'hich took the Addition of Gordiana ; and the ^ Legio decima ge- mina, and ^ Decima terliA gemina^\<\ both give themfelves the fame Appellation. But which of the Legions quar- tered in this Ifland ib filled itfelf is not determin’d by this Infcription or any other that I know of. Howe-' ver, - as the Legio fexta ViBrix was all along quarter’d in the Northern parts of this Kingdom (" as i obfer- ved before) where thefe Infcriprions were ereefted, I make no doubt but it was that which call’d it felf Got- diana^ tho’ the numeral Diftineftion of Vi is omitted, only perhaps for want of Room on the Stone. We find by feveral inferiptions in Carnkn, that there was an Ah in thofe Parts which prided it felf upon its Valourj and' was therefore call’d ihQAla.Augujta; of the many Me- morials it has left us of its Title, I lhall only mention ^ one round ac Old Carlijle, and which is the ancientefl of them all, by any certainty of Date. I. O. M. AL. AVG. 03 : ; . RTVT. APPEL. CVI PRAEEST. TIB. CL. TIB. F. P. LING --N IVSTINVS. PRAEF. FVSCIANO. II. SILANO. I!. COS. that " • VeJf. Monum, Augufi& Vindd, p.431. » p._ 80. GrHtfTd’^^ p. 433..1. ^ ( 8r<; ) that is, Jovi Optimo Mdxtmo^ Ala Augufla oh Virtue urn apptliata, cut pr£ejl Tihtritis Claudius\Tiberii frovincid Lingoncnfi^ Ju(linus prafedus^ Fufciano fecund\ SiUno fecundo Confulihus. This Altar was dedicated when Fufeianus and SiU- Kus were the fecond time Confuls, that is, in the Year 188. under the Reign of Commodus, and Fifty Years before our Gordian came to the Empire. At the fame place was alfo difeoverd the Fourth infeription by me quoted, where we find this fame Ala Augujla filling itfelf alfo Gordiana'-, from whence I think it is not a little probable that the Legion to which this Wing ap- pertain’d was xhtLegio Gordiana mention’d in the Infcrip- tions found at Langchefler ; and that Legion to have been thQ^Legio [ext a FiSlrix, from the long Continu- ation of this Ala Augufla in thefe Northern parts of the Nation, the conftant Quarters of that Legion. if Ay 10. 1718. Ill, A ( ) III. A Letter of that curious Naturalifl A/r.Henry Barham, % S. S, to the ^uhlijJnr^ a %e~ latlon of a fiery Meteor feen hy him, in Jamaica, to ftrike into the Earth 5 with ^marks on the Weather, Earthquakes, See, of that Ifland. SIR, According to your Requeft I have colleded what I can remember, relating to a Meteor I law in Jamaica about the Year 1700, as I was riding one Morning from my Habitation fituaced about Three Miles North- Weft from St.Jago de la Vega: I faw a Ball of Fire, appearing to me of the Bignefs of a Bomb, fwiftly falling down with a great Blaze. As 1 thought it fell into the Town ; but when I came within a quar- ter of a Mile of the Town, I faw many People gather’d together a little to the Southward in the Savanna, to whom I rode up, where they were admiring at the Ground’s being ftrangely broke and plough'd in by a Ball of Fire, which, as they faid, fell down there. I obferved there were many Holes in the Ground, one in the middle of the Bignefs of a Man’s Skull, and five or fix fmaller Holes round about it, of the Bignefs of a Man’s Fift, and fo deep ( efpecially the biggeft ) as not to be fathom’d by what long Switches or Sticks they had at hand^ I did not hear that any was fo cu- rious as to make any farther Search : It was obferv’d, that the green Grafs was perfedly burnt near the Holes, and a ftrong Smell of Sulphur remain’d thereabouts for a good while after. Note that we had a terrible rainy Night before, with much Lightning and great Thunder-Claps, which we havp c 858 ) I liave very frequently in JamaicA, often killing Cattle in | the Fields. Mr. Henr) Lord, who lives at Dry-Riv:r, i had two Sons (big Boys) ftruck dead with Lightning, 1 in 1716, without any Wounds or /Appearance of Hurt J found about them. And as thefe Claps are much louder ”1 and Wronger than any I ever heard in Europe, fo are our 1 Showers of Rain, pouring down in a moR violent man- I ner. We have Lightning all the Year round, but oar I great Rains are in the Months of May, ^u^u/l, and 0c~ |j tokr. I knew May for two or three Years without Rain, 3 which was lookt upon as a great TVonder; and we paid dear for it in our Indigo; for a Catcerpillar appear’d and ^ wove a fine Silk about the Indigo-Flant, and deftroy’d it ® all, hurting nothing elle. May-Rzins us’d to deftroy thefe Worms. Auguft and OUohernQSQx: go out without a ^ Flood, we having then univerfal Rains, all over the Ifiand, jE coming from the Sea : For we have often Rains in the Mountains from the Clouds lodging there, when we have jl none in the Lowlands. ™ Our Ifiand is full of Mines, and, if fearch’d into, I j' ' queflion not but very rich. We are very fubjed to Earth- ' quakes, feveral happening every Year, efpecially after great Rains, which fill up all our great Cracks in theSur. ^ face of the Earth : For in a very dry Time, we have them 4 fo very large, deep, and gaping fo open and wide, that 4 it is dangerous to ride over Tome Parts of the Savannaes, for fear a Horfe Ihould get his legs into them. Our Earthquakes make a Nolle or Rumbling in the Earth, %: before we feel the Shake ; and feem to run fwiftly to the Wellward. This is all I can inform you of this kind at prefent, relating to the Ifiand of Jamaica, being ever • { ready to fliew how much I am, &c. Bmy 'BarhawJ: Decemb. 1 9. 1 7 17- ( 8^9 ) IV. An Attempt to pro^e the Antiquity of the Vene- real Difeafe, long before the Vifco'Very of the Weft- Indies ; in a Letter from Mr. William Beckett, to 2)r. James Douglafs, M.T>, and R. Soc. Soc. and by him communicated to the Royal Society. SIR, TH E Undertaking I am at prefent engaged in, has unavoidably obliged me to confult, among others, a great Number of ancient Phyfical and Chyrurgical Books, written by my own Countrymen .• From thefe I cook the Hint, that the Vsnsrsal Difeafe was known among us, much earlier than the ^ra^ which has been generally alTign’d for its Rife by mo- dern Authors ; for it’s believed it was not known, at lead in Europe., till about the Year *494. Not with- Handing which, I determin, in the following Papers, to make it evident, it was frequent among us fome Hundreds of Years before that Date. ! could men- tion feveral Phyficians and Surgeons of Eminence, who have been of the fame Sentiments with me, particular- ly, the Learned Dr. Charles Fatin, who has written a curious DifTertation to prove the Antiquity of this Dif- eafe, which is fufficient to excufe me from the Impu- tation of having ftarted a Novelty, or being at the trouble of quoting ancient Authorities before taken notice of, from the mod ancient Writers of Medicine; as the Great Hiffocrates, Galeri, Avicen, Cdfus,^c* and even the Holy Scriptures. I fiall in thefe and Ibme fol- lowing Papers, lay afide all thofe foreign Aids and Af- I^PPP.PP fiftances, ( 840 ) fiftances, and trace out the Sj^mptoms of the Difeafe, as they naturally ar ife, from the firft Infedion to the laft deftrudive Period, and (hew that, by learching in- to our own Antiquities, we may be furnilhed with In- ftances of the Frequency of the Diftemper among us, in all its refpedive Stages, before ever our Modern Au- thors dream it had its Appearance in Europe. I (hall begin with the firft Degree of this Difeafe, and prove from authentick Evidences, it was anciently call’d the 05?Cnmng or 'Burning *, and that this Word has been fucceffively continu’d for many Hun- dreds of Years, to fignify the fame Difeafe we now call a Qla^ 5 and that it was not difeontinu’d till that Appellation firft began to have its Rife. The moft like- ly Method to accomplilh my Defign, will be firft to examine thofe Records that relate to the Stevos^ which were by Authority allowed to be kept on the BAnk^Sid' in Southwark, under the furifdicftion of the Bp. of Win- chejler, and which were fupprefied the of //r» VIH. For it’s impoffible but, if there were any fuch Diftem- per in being at that Time, it muft be pretty common among thofe lewd Women who had a Licence for en- tertaining their Paramours, notwithftanding any Rules or Orders which might be eftablifii’d to prevent its In- creafe : But if we (liall find that there were Orders e- ftablidi’d to prevent the Spreading of fuch a Difeafe, that Perfons might be fecure from any contagious Ma- lady after their Entertainment at thofe Houfes f which were anciently Eighteen in Number, but in the F^eign of VII. reduced to Tw’elve^ we may then fecurely depend upon it, that it was the Frequency of the Dif- eafe that put thofe that had the Authority, under a necefiity of making fuch Rules and Orders. For the fame Powers that granted a Liberty for keeping open fuch: lewd Houfes,^ muft find it their Incereft to fecure, aS: ( 841 ) as much as poflible, all Perfons from receiving any In- jury there; left the Frequency of fuch Misfortunes fiiould deter others from frequenting them, and fo the original Defign of their Inftitution ceafe ; from the en- tire finking of the Revenues. Now I find that, as ear- ly as the Year ii6z, divers Conftitutions relating to the Lordlhip of Winchefler, f being alfo confirmed by the King were to be kept for ever, according to the old Cuftoms that had been time out of mind. Among which thefe were fome, v:z. No Stew-holder to take more fora Woman’s Chamber in the Week than ir^d. Not to keep open his Doors upon Holy Days. No Tin- gle Woman to be kept againfl: her Will, that would leave her Sin. No Tingle Woman to take Money to lie with any Man, except Ihe lie with him all Night till the Morning. No Stew holder to keep any Wo* man that hath the perilous Infirmity of 'BUtninQi. Thefe and many more Orders were to be ftridly ob- ferved, or the Offenders to be (everely punifhed. Now we are affured there is no other Difeafe that can be communicated by carnal Converfation with Women, but that which is Venereal, by reafon that only is con- tagious ; and it’s evident the 05Utnin3 'vas certainly fo : For, had it been nothing elfe but lome Timple Ul- ceration, Heat, or Inflammation, there would have been no Contagion ; and that affeding only the Wo- man, could not be communicated by any Venereal Con- grefs, and lo not inferr a Neceffity of her being com- prehended under the reftraining Article. Thefe Orders likewife prove the Difeafe was much more ancient than the Date above-mentioned ; becaufe they were only a Renewal of fuch as had been before eflablifiied time out of mind. But to confirm this farther, I find that in the Cu- ftody of the Bifiiop of Winchefler, whofe Palace was P p p p p p z fituated ( 842 ) fituated on the Bayik ftde, near the Steves, was a Book written upon Vellum, the Title of which runs thus j mu begrnne fte O;itiuiance0, Eulcg, ant) cu= Oimug, as toell fo? tlje ^altiatton of pannes itf, as fo;i to afctetoe ma;tp ^pfchicfs ano 3in= conbniieius tljat Oaplep be lik tbece fo.2 to fall otote, to be risbtfuUp liept,.anD owe Ctccution of them to be ooit unto any laerCoiiue toptbin tbe fame* One of the Articles begins thus ; De his qui cu^odiunt Mulieres h.ihentes Nfphandam infirmitattm. It goes on, Item, Cbat no Steto=boloci: keep noo man toptbin pis e;ous.tbat peUp anp S)pckneire of BRENNiNG. but tpit (pe 6e putte out upon tpe pepne of makeit a fpne unto tpe lo?t) of a pUnO^ell 0pplpn9S. This i« taktn from the Origi- nal Manuferipe which was preferv’cK in the Bifliop’s Court, fuppos’d to be written about the Year 1430. From thefe Orders we may obferve the Frequency of the DiQemper at that Time ; which, with other In- conveniencies, was oaplep lik tpere fo? to fall otDte^ and the Greatnefs of the Penalty, as the Value of Mo- ney then was, that is laid on it, proves it was no tri- fling or infignificanc thing. But the bare Proof of there having been anciently fuch a Difeafe as was called the 'BUCniUS? may be thought to be infuflicient, unlefs we were perfedtly aflured what it was, and how it was in thofe Times deferibed : I fhall therefore do it from an unqueflionai- ble Authority, which is that of 'john Arden, Efq; who was one of the Surgeons to our King Richard \\. and likewife to King Henry IV. In a curious Manuferipe of his upon Vellum, he defines it to be, a certain in- ward Heat and Excoriation of the Urethra-, which Dc- feription gives us a perfect Idea of what we now call ^Qlaf \ for frequeat Dif]e.(5fions of thofe that laboured undei^ ( 843 ) under that Difea(e, have made it evident, that their Urethra is excoriated by the Virulency of the Matter they receive from the infed:ed Woman ; and this Ex- coriation or Ulceration is nor confined co the OJHoU or Mouths of the GlanduU Mu[co[£, as has been late- ly thought, but may equally alike attack any part of the Urethra not beyond the reach of the impelled ma« lignant Matter. The Heat before deferibeJ, which thefe Perfons are fenfible of, as well now as formerly, is a Confequenc of the excoriated Urethra ; for the Saks contained in the Urine mud neceflarily prick and irritate the nervous FiJ?rillx, and excite a Heat in thofe Parts of the Urethra which are diveded of its natural Membrane ; which Heat will always be obferved to be more or lefs, as the Salts are diluted with a greater or lefs Quantity of Urine ; a thing I have often ob* ferved in Perfons that have laboured under this Infir- mity in hot Weather, when the perfpirable Matter be- ing thrown od in greater Quantities, the Salts bear a greater Proportion to the Quantity of Urine, and there by make its Difcharge at that Time fo much the more painful and troublefom. Thus we fee this very early and plain Defeription of this Difeafe among us, to be entirely conformable to the latcd and mod exacd Anatomical Difeoveries. , Here is no Tone of the Tefiiclcs depraved, according ioTrajanus ?etromus\ no Exulceration of the Faraflatx, according to Ror^dtUtius ; no Ulceration of the SemR ?ul Fejfels, according co P Uterus \ no Seat of the Dif- cafe in the Feficulx Seminales or ProfiateS, according to Bartholin-, not in thofe Parts and the Tedicles at the fame Time, according to our Countryman Wharton and others, who have falfly fixed the Seat of this Difeafe,. and whole Notions, in this refpedl:, are now judly ex* ploded ; but a fing|e and true Defeription of it, and- ( 844 ) Its Situation, about an Hundred and Fifty Years be- fore any of thofe Gentlemen obliged the World with their learned Labours. Having, I hope, fufficiently made it appear, the *BUtninS was a Difeafe very early among us, and given the Defeription of it, I lhall proceed to fay fome- thing of the ancient Method that was made ule of to cure it. We are not to expecS: the Meafures our Pre- deceflbrs, in thofe early Times, made ufe of, fliould be calculated for the removing any Malignity in the Mafs of Blood, or other Juices, according to the Pra- <5lice in Venerial Cafes at this Time; becaufe they looked upon the Dileafe to be entirely local, and the Whole of the Cure to depend upon the Removal of the Symptoms .* Hence ’twas they recommended fuch Remedies as were accommodated to the taking off the inward Heat of the Part, and cure the Excoriations or Ulcerations of the Urethra. The Procefs for the ac- complilhing of this, I lhall fet down from the before- mentioned John Arden, who wrote about the Year 1380. his Words are as follow. Contra Incendium. Item contra incendium Virga Fir tits inter ius ex calore ^ exco- riatione, fiat talis Syringa (" i. e. inje^io ) ienitiva, Ac- cipe Lac mulkris mafculum nutrientisy & parum zucariim. Oleum viola © ptifana, quibus commix t is per Syr ingam infundatur, ^ fi pradiHis admifeueris lac Amigdalarum me^ lior erit medicina. There is no doubt but this Remedy, being ufed to our Patients at this Time, would infal- libly take off the inward Heat of the Part, and cure the Excoriations or Ulcerations of the Urethra, by which means what illued from thence would be entirely ftopt; and this was all they expedfed from their Medicines, forafmuch as they were entirely unacquainted with the Nature of the Dillemper ; and did not in the lead ima- gine, but if the Symptoms that firft attack'd the Parc were removed, the Patient was entirely cured. I ( 84J ) I (hall now, as a farther Confirmation of what I have advanced, proceed to prove, that by this or 'BUntinS meant the Venereal Difeafe, by demon- ftrating that fucceeding Hiftorians, Phyfical and Chi- rurgical Writers, and others, have all along with us in England ufed the very fame Word to fignify the Vene- real Malady. In an old Manufcript i have by me, written about the Year >390. is a Receipt for ning of t^c pyntpl, pt men clepe ve apegalle 5 0alle being an old Englilh Word for a running Sore. They who know the Et'jmologk of the Word Afron^ cannot be ignorant of this. And in another Manufcript, written about 50 Years after, is a Receipt for *BUCn= ing in that Part by a Woman. Simon Fijh, a zealous Promoter of the Reformation in the Reign of Hen.VUL in his Supplication of Beggars, prefented to the King in 1530, fays as follows, Thefe he they ( fpeaking of the Romijh Priejls ) that corrupt the whole Generation of Man- hind in your Realm^ that catch the Pocket of one Woman and hear them to another 5 that he 'BUtnt tvith one Worn n and hare it to another ; that catch the Lepry of one Wo- man and hare it unto another. But to make this Matter fUll more evident, 1 am to obferve, that Andrew Boordf a Dodor in Phyfick, and Romifh Pried, in the Reign of Henry VIII. in a Book he wrote , entitul’d Ihe Breviary of Health, printed in 1546. fpeaks very par- ticularly of this fort of Burning ; one of his Chapters beginneth thus, 19th CtepUCC Cbcti) Of Burning of nn l^atlottc *, where lus Notion of com- municating the Burning is very particular. The fame Author adds, that if a Man be 'BUtUt with an Har- lot, and do meddle with another Woman within a Day, he fliall OBUlCn the Woman that he lhall meddle with- al ; and as an immediate P^.cmedy againft the 'BlltU- ing; he recommends the vvafiiing the Pudenda two or: three ( 84-5 ) K"* three times with White Wine, or elfe with Sack and Water ; but if the matter have continued long, to go to an expert Chirurgeon to have Help. In his 8id Chapter, he (peaks of two forts of Burning, the One by Fire, and the Other by a Woman through carnal Copulation, and referrs the ^Perfbn that is 05Unit of ^ a Harlot to another Chapter of his for Advice, what ^ to do, pf set a €>o?|[fr o? ttoo, fo called from its Protuberancy or bunching out : For I find about that Time the Word EuUco was moftly made ufe of, to fig- ' nify that fort of Swelling W’hich ulually happens in pe« flilential Difeafes. ■ ; , From hence it appears, the Burning,, by its Confe- quents, y^2LSveneria(, fince every Day’s Experience makes a*- it evident, that the ill Treatment of the firft Symptoms ii- of the Difeafe, either by aftringent Medicines, or the removing them by cooling and healing the excoriated Parts, will generally be attended with fuch Sw’ellings in f the Groin, which w’e rarely obferve to happen from a- ny other Caufe wiiatfoever. 1 fliall give a few more Inflances of this Difeafe be- ing call’d the Burning, and conclude. In a Manulcript «■ I have of the Vocation of Jckn Bale to the Bifhoprick of OJfory in Ireland, written by himfelf, he fpeaks of Dr. Hugh Weficn (who W’as Dean of Windjor in * but deprived by Cardinal Pole for Adultery ) as fol- lows, “ At this Day is lecherous Weflon, who is more pra£Hfed in the Art of 05UtninS than all ‘ the Whores of the Stews. And again, fpeaking of the fame Perfon, he fays, He not long ago bilCllt ^Beg- * gar in St Botelfh s Parifli. The fame Author fays of him elfewhere, “ He had been fore Bitten with a Win’. cheJierjGocfe, and was not yet healed thereof ; which \.- W’as a common Phrafe for the Pox at that Time , be- caufe the Stews were under the Jurifdidion of the Bifiiop of 1 ( 847 ') of Winchefler. Mich. Wood, in his Efiflle before 5tqh. Gardiner's Oration de vera Ohedientia, printed at Rhoan, i5’53* gives another Evidence of the ^Burning. And William Bullsin, a Phyfician in the Reign of C^een Eliz,, in a Book he poblifh’d, call’d The Buhark of Defence, d^c. printed in 1562. bringing in Sicknffs demanding of Health what he fliould do with a Dileafe call’d the French Pockes, Health anfwers, “ He would not that a- “ ny ihould fiflie for this Oifea'e, or to be bold when “ he is bitten to thynke thereby 10 be helped, but ra- “ ther to efehewe the Caufe of thys hifyrmity, and f filthy rotten BUnUnQl Harlots. I believe, by this time, I have fufficiently prov’d what I propofed, that the firfl: Degree of the Venereal Difeafe was very anciently known among us, under the Title of BUtning ; and that you may lofe no more Time at preient upon this Subjed, I fhall referve my Colledions, which (hew that the Difeafe, when it came to be confirmed, was no Novelty here dn thofe early Times, for a further Opportunity, and detain you no longer than to exprefs my Pieafure in profelling my felf, Tottrs, &c. London, Feb. 4. I7I7-1S« Will. Beckett, V. Jeeuratarum Ohferyationum Jflronomicarumj a\u no fuperiore zs* currente^ cum Societate com^ municatarum Sylloge. INterefl fane Sciential ne pereant Obfervata Aflrono- mica, debita curd hdifque Inftrumentis ab Artifi- cibus idoneis cielitus deprompea : Hoc enira fblo fundamento nicicur Urania pradica. Itaque in hisTranf 4449 (^^lonihus, ( 848 ) 0mihus, per plufquam quinquaginta annorum curri- culum, paflim {parguntur hujus generis Noras. Aufini tamen fpondere vix ullas unquam reperiri pofle Obfer* vationes quas certitudine cas quas nunc damus vincanr, ne dicam quae pares Tint, ucpote Tubis pradongis ac Micrornetris praeter folitum affabre fadis menluratas. Cape igitur primo. Tlanetarum Ohfervationes. Anno 1717. A^rilis 15°. 9'' 49" T. ccq. obfervavit D. P otitid Wanfled, Jovem jam reverium ad ftellam illam, quam Novemh.zz°. 1716. mane corpore fuo te- xerat, de qua vide N° 350. P^il. Tran{aPt. pag. 508, Jovis aucem centrum rum temporis diftabat ab ea Stella ( quae tcrtia eft Geminorum in Catalogo Britannico ) 13' xi" boream verfus ; fimulque ab alia vicina, qux quarta eft Geminorum in dido Catalogo, 37' n''. at- que huic fere conjundus erat planeta. Jprilis 25'° fequentc, eodem obfervatore ac loco, 10’’ 3' T. xq. Jftpiter apud quatuor Fixas exiguas vi- fuseft, eas omnes praecedens, & in ipfo quafi principio Cancri. Centrum autem planetse diftabat ab e 12' 00", ab h 13' 50", ab / 19' 5-3", & a ^ 9' x;". Poftridie veto Apr. 16°. 9'’ f Jovis centrum difta- bat ab e 8' 35", ab/ 9' 00", a ^ 4' 5", & ab ^ 13' 50". Jamque prceterierat omnes praeter / ad quam tendebar, quamque parum admodum die craftino infra fe relin* quere debuir. Eodem fere momento, bora fcil. nona, Londini vila eft ftella g in vertice Trianguli Ifofcelis ac fere Ifopleu- rt cum Jovis centro ac tertio Satellite, turn fex Jovis diametris ad occafum diftante, nifi quod parum admo- dum bafe longjora crane crura; ac intra quadrantem hora:. C 849 ) horx, angulus ad Jovis centrum, qui prius major erat angulo ad Satellitem, fadus eft eo fenfibiiiter minor. Tres autem StelJas h, g, e, funt ii'“% & 12'^V Geminorum in Catdl. EritAn. juxra quern turn temporis fttum habuere, h 'm s- 0° 55", cum Latic. Borea o^iirs". Et^ in s- 28' 25". Lat. Bor. 0° 3' 40'' ; e veto in s o° 29' cum Lar. Auft. 0° 8' oj". Di- ftat autem quarta / a Stella g ii' 40", ab 5 i% 50", ac denique ab b 20' 36", unde conftabic locus ejus. Ex his manifeftuoi eft Jovem Latitudinem habuifte par** vam admodum Borealem, nec femiminuto majorem, faltem ft didis ftellarum locis habenda fides. Hxc pofteris ufiii efle polTunc definiendo Nodorum Jovh motu, ft quern habeant- Ejufdem anni Junii i8'’° 10'^ Londini^ in xdibus So- ’ cietatis Regiae, vifus eft SAturnas Stell^e fixse Telefcopi- cx admodum propinquus, a qua vix diftabat ad Au- ftrum una Annuli diametro, & normalis in lineam An- farum a Stella demifta incidebat in medium Anfas ori- entalis. Fixa hsec parvula nullique Catalogo adfcripta tunc habuit 12° 58' r cum Lac. Bor. 2° 33' proxi- me,; comitemque habet ftbi adjundam ac luce sequalem, quatuor minutis ad orcum diftancem, ac paulo auftra- liorem, unde facile dignofci poterir, loculque ejus fi cui libeac veriftcari. Eadem node lo’^ yJ Mats vifus eft prope Stellam quns prsecedic 35'. Scorpil, a qua diftabat Tubo 24 pe- dum menfurata 7' 1 6" ; idque in reda per claram in pede Ophiuchi G & didam Stellam produda. Hsec autem Stella prtecedit 35-. Scorpii 30' 27" Afc- Red. ea- queAuftralior eft 2' 28 ', unde fit locus ejus turn tern- iporis SAgitt. 15° 24' 20" Lar. Auft. 3* 59' .25". Sed 6 Ophiuchi tunc habuit 17° 28', & Lac. Auft. 4° 47' 38". MArs itaque Stellam prcEcedebat Longi- tudine 4' 58”, auftralior ea 5' 30". Q.S1 S ft ^ ^ 2, Deinde ( 850' ) I Deinde Sept. 13® S’’ 5'. T. seq. Mars vifus eft a Dom; Fcu/3^ prscedere claram in humero Sagittarii o- 11' 54" Afc. Redt. fimulque borealior erat Steilliz' 56"* Hora ^ i 8’’ z^' erat diftantia Planetx a Stella 25' co" accurate.* * | Decemb. iS** 30'. T. xq, confenfu fxpius repetita- £ rum oblervationum, invenitD. Pound Saturnum prxcedere- I Telefcopicam claram fibi vicinani xj 19" Ale. Red:. f Stellaque auftraliorem efte i' 59". S\mu\ Sat urnus^tx- r cedebat x in Syrmate 1° ^5* x\'\ eaque au- T ftralior erat 4' 05". Hinc Saturni locus Libra 19°. „ 16' zi'\ Lat. Bor. 1° 21". Telefcopica autem tune ^ habuit Libr. 29° 40' 5'6". Lat. Bor. 2° 33' 43". j| Anno 1718. Jan.y, 5'’ 30'. T. xq. apud duas X Stellas in Catal Britan, omiftas obfervata eft. Erat au^ m tern Planeta utraque Fixa Borealior, diftans a prxcc- jj dente 32' 30", a lequente 17' 30". Stella prxeedens « tunc habuit / ifc. 14^42' 20", cum Lat. Auft. 0° 40' 10"; 1 altera \ero fequens Fife. 15° 21' 55", Lat. Auftral. 0° 3 ‘ 5"> prout ex obfervationibus D. FUmflidii collige- * ff2 licet.. Jan.i^. 8' 00', T. xq. Jupiter prxeedebat r\ in pe-i .ji dore Cancri 3° 30' 50" Afc. Red, fixaque Auftralior erat 14' 15". Hinc provenit locus 28" 20' cum Latitudine Borea 0° 36' 45'". MartJi II. 10^ 36', T. xq Saturnu' prxeedebat jc in Syrmacc. iS' 51", eaque Fixa auftralior erat 5' 23. Hinc fit Locus Saturni Scorp^ o i8' 34'^ cum Lat. Bor. 2. 44' 8 Poftto fcilicet, juxta CataL Britan, jc Virgtnis occupare m o. 34'' 10'', cum Lati2. 55' 40". Eadem node i,'’ 00' PVejlwonaflerti obfervarunt DD. F>i[aguliers & Cray Saturnum prxeedere Stellam oo^j cum dedinatione majore in Auftrum 4' 45". ^pril 8,>iL 30' Londini \ Xus ci\ Saturnus nupet A- ' ccon^chus parum admodum occidentalior Telefcopica . clara, eademque 5 minutis borealior. Unde Fixx locus Lihr rs . ( 8ji ) hilrdi%%. 1 8' 30^' Lat. Bor. 2.. 41'. Circulus autem magnus per banc Stellam <5c Saturnum dudtus dirigi videbatur ad Stellam 5^* magnitudinis in Catal. Brit» omiflam, fed qu2C Htvdio efl: in cufpide AU Bore/e Vtr- ginis, cuique locum affignat Lihr. %6. 10', cum Lat. 14. 43' Bor. Eadem node 13^ 10', apud Wanfied, perpendiculum a dida Stella Telefcopica in lineam Anfarum Saturni demiflum prtccedebac centrum planetoc quafi fefquial- tera diamecro annuli ; aberat autem Stella ad Auftrum ab Anfarum axe 4' 30". Simul Anfe orientalis extre- mitas deprehenfa eft in linea reda inter banc Stellam & aliam eidem quafi longitudine conjundam^ quse tunc a Saturno diftabat 14' 48" verfus Boream. Locus- autem prioris Stella tunc fuic Lihr. i8. i8' 30" cum Lat. Bor. x, 41' proxime* Sept, 7. circa meridiem incidit conjundio “Jov-h & Vc-- mris ardiftima, cujus quidem fpedaculum Aftronomis. noftris inviderunt Nubes. Die autem (exto prtccedsn- te mane, vel 5"^ ix*' 57' 30" T. arq. apud IVanficd, Ve- mi occidentalior diftabat a Jove i. 3' x8". Die autem 7. 21', Venus jam fada orientalior a Jove aberat 43' 18"; ac 17^34', auftralior erac 'jove difle- rentia declinationum 14 Et 17'’ 39.' capca eft di- ftantia Planerarum 44' 4". Hinc calculo accuraciftimi Obfervatoris conjundi funt Sept, 7. 9' T. xq. Vc- neris cenrro turn Jovis auftraliore non nifi i' 4x". Denique Sept. 18. mane, apud Wanfled, Jupiter vifus eft prope - or Ler>nis, quocum die praecedence conjun- dus fuerat. Sept, 17. 16'’ 51' 1l .xq. Jovis CQnimm ab» erat a Corde Leon, 24' 2.2"; & 17'’ 6' io"erat diff. DecJin.; 12' 43". Dein poll Horam, nempe 17'’ 54', fada eft diftantia 24 44"; ac 18*^7' differentia Declinationum > inventa eft 12' 35". Hinc fupputance Dom^ i ound^ fit Sept I/. 18 go' T. teq« Jpvh locus 2.6 ii' 7" cumv= Lac, Bor. 45' 39''- Objerv at tones j ( 851 ) Obfervationes Lmrima Hyadum in Naribus Tauri ( y Bayero ) vifa eft in re£l^ per cufpides Lunx, adeoque propemodum con- junda; diftabat autem a limbo Lunx Auftr. 5' 51". LJiameter Lunx 3 1' .4 j" meniuraca Micrometro. n •1 V r '4 >• ij ( ) . Feh» 2S. ;6'T. app. etiam Weflmnaflertlt vifa eft Immerfio Stellse in Poplice Vollucis ( a Geminorum Bayero ) fub limbi Lund obfcuri ea parte, quse paulo Borealior erat macula quara Hevelius Cretam vocat. Emerfio ipfa ob ccelum minus purum non confpe(^a eft .* fed ad 9'' 51' cgrefla erat Stella e limbo lucido, a quo diftabat 3 rain, drciter, e regione Boreae partis Infulac Majoris Ca/pii. Aug. 8. Luna orta eft paulo infra Tdiltcium, cum quo tamen ob nubes conferri non potuic. Apud W^n* jied autem 13” x' 00" T. app. vifa eft Prarcedens conti- guarura ad o- Tauri Bayero, ( five Penultima in noftro Hyadunt Cz^2\ogo, in Num° 35"4. TrunfaB, litera (\ no- taca ) in linea re. Geo. Graham Automatoposi pr^eftanfis, obfervavic D. Martinus Folkes Armig. cum aliis quibuidam Regte Societatis Sodaiibus, uc lequitur. <538 o Luna per fumum Urbis & Vapores ^gre vifa^ 6 54 I 3 Chorda inter Cufpides utcunque, xj" y X o Immerfio Totalis in umbram. 7 qx 1 5 Stella fixa fatis clara diftabat in limbo Lunae orientali 19' 21". 8 3 5" 18 Eadem fixa occultata eft, 10' circiter minu- tis centro Lunse Auftralior. 8 '45 50 vel, ut quibufdam vifum eft, uno minuto tardius Luna coepit emergere. 8 49 38 Palus Mareotis primo margine emerfir. 8 50 14 Integra Palus extra Umbram. o 5 Montis Fcrphyritidis medium emerfir. 7 39 - Er^us margo emerfir. 9 8 Mons Sinai totus extra umbram. 10 35 Umbra per medium yFtn cat juxta quamyis Totentiam diflantid d Centro ; i data nempe imo Cury<^i punSlo ad datam diftantiam C A. Oportet invenire pun laudatam, non folum rejice- re, fed aliam eidem infinite prope diferimine minorem numeris difertis exprelf'm fubftituere. Hunc autem cenfemus, prteterquam quod primum il- lud Boreli/anx [biin'wnls vitium imicatus fir, in fequenti- bus etiam a vero aberrafic. Qiiod Corollarium Newtoniamm, quo utitur ad Cor- dis vires definiendas, auc male incellexerit, auc cerce nod fatis apte ufurpaverir. Pond us enim illud ab Archtmc’ de Britanmeo decerminarum, quo Motus aquas ex vafe eftluentis generari potefl, ncquaquam gencrat Motum a- quse ; quippe quio gravuacis vi cadendo ipfa Motum ' fuum acquirac. Sed h c pondus per datum tempus ca* denuo, Viotum concipic Motui aquse eodem daco tempo-' re effluenris ctquaiem. Prastcrea ponit Vir Clariffimus velocitatem Sanguinis > ex Cord e effluencis pprpetuo sequalem per totamSyfto»* isS-J ( S68 \ Ics durationcm, quam nos infigniter inaequalem fieri in fequcntibus oftendemus. In Mechedoilla fimpliciore, quam poftca adhibet Vir Dodiflimus, prxcer dclidta hadtenus reprehenfa alia e- tiam bina admittir. Adfumic enim Vires Cordis in -diverfis Animalibus ^ earn inter fe rationcm obtincre, quae efl: inter pondera ' corundem ; quod infra falfum efle demonftrabimus. Turn ; ponic velocitatem Sanguinis ex feda Iliaci Arterii pro- fluentis, eandem efle qua ex Corde in Aortam emittitur. i Arqui cum omnis fere languis ex Corde expulfus per Ilia- j cam alteram refedam emittitur, patet ejus velocitatem tanto efle majorem in lliaca quam in Aorta, quanto fee- tio Iliacae circularis a fedione Aortje fuperatur. Praeter- » quam quod velocitas aequabilis, qua Sanguis per Aortam fluic, longe diftet ab e4 veJocitatc, quicum exit ex ipfo | Corde. f Similiter fere redargui poteft & ilia Methodus, qu^ u- t fus eft Vii Cl. ad rationem definiendam inter velocitates f diverfas Sanguinis, refiftentia nunc oppofica, nuncfubla- f la, per Aortam profluentis. Sed cum ifto Experimento ?! non altera folum, fed utraque velocitas major sequo re- ? periatur, unde ratio, quse eft inter ipfas, non magnope- re pcrcurbetur, poteric Tatis tuto proportio ab ipfb ex- pofita, tanquam verae propinqua, ufurpari, Curfu hadenus expedite, fcopulifque decedis, in quos impegerunc Viri egregii fupra laudati, erit modo nobis ipfis, uc in via difticili & erroribus plen^, fumm^adhi- ^ biia cautione progrediendum. Et primo quidem loco .Jt' ad ambiguitatem prsecidendam necefte eft, ut id, quod I quaeritur, quale fit, accuratius paulo declaretur. v Cordis Virium, five Potentitc, nomine fignificamus vel ipfum Cordis Motum, dum in contradionem agitur, •• vel Motum ponderis cujusliber, quod Sanguini cbjedum ‘ ex ( S6p ) ex Corde proruenti & velocitate idonca delatum in par- tes concrarias, Sanguinis efHuxum, adeoque ip'ati Cor- dis contradiioncm, squali vi librare valet & fiftere. Potentiam idam, cum a priori vix fperandum fit ut dennire poflimu’3, quod neque fabricam Cordis interiO' rem, neque caufre contrahentis nacuram, auc vires fatis I habeamus exploraras, relinquicur, ut eandem per eiieda, five a poderiori, a’dimsmus. Cordis adio in Ventriculorum ruonim contradione omnis conddit. Ventriculi autcm inter contrahendum in fang.uinem impingunt, eique Moius lui partem com- muiiicandoj eundem magna vi, qua datur porta, urgent, & expellunt- Sanguis hoc modo in Artcrias, Aortam & Pulmonalcm, protrudis, impetu in omnes partes fado, partira in tunicas Arteriarum ex Sydole fua pragrefia coJlapfas & fiaccidas, partim inSanguinem priorcm tar- dius fluentem impingit. Unde gradatim cxurorfum tru- duntur Arteriarum tunica, ^ Sanguis antccedens curdi celeratur. Quod fi animo concipiantur Arteri^ fedio- nibus tranfvcrlis minimis didindx, prima San'iuinis por- tiuncul^ ex Corde in primam fedionem irruente, partim didenditur ida (cdio, partim Sanguis eadcm ancca con= tencus in fedionem proxlmani detruditur, earnque did- cr.dit, arquc idaadio per (iiccedentes Arteriarum' fedio- nes continuatur. Deinde fccunda, & tertia d>nguinis portiuncula, & ccetera! deincens, in primam Aiterire fe- dionem incidunt, earnque paulo niagis dilatant, & fan- guinern eadem contentum in proximas fediones fuccef i?ve propellunc ; idque fieri pergir, donee omnis fangiiis ex Ventriculis fuerit ejedus, Ca^terum id auique ebdr- ■ vandum ed Arcerias, quo magis contradre flaccida: fuerinc, eo minus dilatatiom obfidere, quanto autem magis fuerint diiatatte, tanto fortius ulteriori didradio- 2u reniti ; arquc idcirco Vim Sanguinis ex Corde pro- lumpcntis primo m?g!S impendi ii didendonem Arte- z riatym,.. ( 870 ) riarum, quam in Sanguinis prsecedentis protrufionem’ * Tub finem vero magis propclli Sanguinem antecedentem quam diliendi Arterias, quippe qux jam rigidsc h&x majorem dilatationem vix admictanc. Sanguis autem ex Corde profiliens, cumj uti didlum eft, Motus fui partem Arteriarum tunicis, partem San- guini pracedenti communicat, ipfe neceflario de prifti- na celeritate remittit; adeoquedum Ventriculorum con- tract jonemmoratur, novum abiis impulfum excipit, ejuf- que partem, eadem ratione atque antea, tunicis Arteriarum & prascedenti Sanguini impendir, unde iterum retarda- tur, & alium Ventriculorum irftum fufcipit, & fic dein- ceps, donee omnis ex Ventriculis fuerit expulfus. Prater caufam (upra expofitam, fupereft alia, qua Sanguis ex Corde effluens gradatim retardatur, adeo- que novos fucceftive impetus excipit ex Ventriculis fefc contrahentibus. Nam Sanguis in Arteriam Aortam infiuens, etiamft nulli omnino reftftentice occurrere ponatur, adeoque nullam pati Motus fui imminutio- nem, tamen, cum ex lato in anguftum fertur. Ion- gitudine perpetim crefeit, donee totus in Aortam perve- nerit; cumque fedtio Aoftse non minuatur, neceftario rainuitur Sanguinis velocitas. Motus enim Sanguinis eft in ratione compofita, ex ratione SeCtionis Aorcse, velo- cicate in eadem, & longitudine Columme Sanguinese, per Theorema noftrum 111. De Motu Aquarum fluentium. Cum vero ea Sanguinis portio, qu^e jam pervencrit in Aortam, gradatim retardetur, retardabitur inde San- . guis ifle qui adhuc Ventriculo conrinetur, & hinc re- tardabitur ipfius Ventriculi contradio. Unde Ventri- culi perpetuo aliam atque aliam Motus fui partem Sanguini contiguo, his de caufts perpetim retardato, communicabunt. Patet vero ifthinc, ut id obiter note- mus, aiium efte Motum Sanguinis ex Corde erumpentis, ahum ejufdem jam ex Corde expulfi, & intra Arterias ftuentis. ( 8/i ) fiuentis. Item idum. five impulfum Ventriculofum in Sanguinem imprefTum, qui alioqui unicus eflet futurus, & pundo temporis tranfigeretur, tamen caufariim (u- pra didarum vi, quibus Sanguis perpecim retardatur, per cotam Cordis Syftolen continuari. Ventriculum itaque alterucrum Cordis Sanguinem impellentem licebit fpedare, ut datum corpus cum data celeritate impingens in aliud corpus quiefcens, cui Motus fui parte commiinicata ambo corpora com- muni velocitate deferuntur. ^quatur autem Potentia ejufdem, vel Fac^o ex pondere Ventriculi Sc velocitate ejus initiali , priufquam in Sanguinem impingat; vel Sumniac Motuum ipfius Ventriculi ac Sanguinis ex eo- dem profluentis, & Moms qui tunicis Arteriarum & Sanguini prsecedenti communicatus eft; vel etiam, ft abcfte ponatur omnis Arteriarum & Sanguinis prjeceden- tis refiftentia, Summce Motuum ipftus Ventriculi & Sanguinis efHuentis. Theorema I. Motus, Machina cava inaqualiter contra^ His in contraSiionem agitur^ II. That the Houfes in which thoie Sick Cows have flood be Waflied very clean, and then fmoaked by the burning of Pitch, Tarr. and Wormwood, and be kept three Months at leaft before any other Cows are put therein. III. That the Fields where thofe Sick Cows have Grazed, be kept Two Months before any other Cows are FufTered to (land or Graze thereon. IV. That the Perfons looking after fuch as are III, fliou’d have no Communication with thofe that arc well. V. That the fame Methods be Obicrved if any o- ther of the Cow-keepers fhou’d get this Diftemper a- mongthem; and that they be all Summoned and told, that as foon as they perceive any of their Cows to re- fufe their Meat, or have any other Symptoms of this Diflemper, that they immediately feparate them from their others, and give notice to fuch Perlons as your Excellencies Ihall appoint, that they may be Burnt ; and the places where they have flood or Grazed to be ordered as before* VI. That the Cow- keepers be required to divide their Cows into fmall Parcels, not more than ten or twelve in a Field together; and that they be allowed fuch fatisfadion for complying with thefe Propofals, as your Excellencies fliall think fit ; all which is moft humbly fubmitted, The next day their Excellencies confulted the four Gentlemen before-named, and gave them Orders to com- ply with the preceeding Propofals, and to allow Forty Shil- lings for every Sick Cow which they Burnt, that be- longed to Vit. Ratcliff, Rufford, Pullen \ but the free intercourfe which both Maflers and Servants had had with each others Cows (before we were appointed^ ^ 2 had (^75^ had fpread the Contagion , and the Difeafe began foon to appear in feveral other Neighbouring places. The Gentlemen then fummoned all the Cow- keepers in the County, and acquainted them with the above- named Propofals (to mofl: of which they readily Com- plyed, as being vifibly their interefl:) and offered them Forty Shillings for every Cow which they Burnt, that had not been Sick above twenty. four Hours ; but for fuch as had been longer 111, or were Dead, they wou’d allow them only the value of their Skins and Horns. Some of the Cow-keepers appeared not content with this Regulation, and believing that the Difeafe wou’d become general, defign’d to have fold their Cows at fome diftant Market; which the Gentlemen having no- tice off, appointed feveral Butchers to Watch near their Grounds, and count their Numbers every Morningj, with Orders to follow fuch as they fent to any Market, and prevent their being fold, by telling the people what they were. Another great Obflacle at the firfl was the Cow- keepers not owning the Difeafe, till they had loft fe* veral of their Cows; for fo foon as it was known that: any Man had but one Sick, none wou’d buy his Milk ; and to thofe who kept many Cows, that lofs was eonfiderable. Nor was there ever wanting one or other who gave them hopes of a Cure. To obviate thefe three difficulties, the Gentlemen encouraged them to hope for a Brief, but aflured them that fuch only as complyed with thefe Oiredions, fliou’d have any benefit by it- Accordingly they ordered a daily account to be taken of the Condud of each Cow- keeper, and allowed or difallowed their pretenfions to this Brief, as well as to, the. Forty Shillings per Cow, as they complyed qr difregarded thefe Ditedioiis: This.. ( 8/(5 ) This had a pretty good effcd ; but here in England^ where every Man is at liberty to difpofe of his Cattle as he plcafes , nothing but making them fenfible that it was each Mans particular intereft to comply with thele Methods cou*d do ; this, tho’ true in fa Green Colour., Their Pancreas's were Shrivelled and Contratfied, many of their Glands very large and hard, and of a black Colour, The Glands in their Mefenterys . were niany of them..diftended to eight or ten times .. their natural bigneis, were very Black, and in the Pelvis ^ of moft of thofe Glands in two Cows, there was a { yellow Pctrefa fanna, lays down for a certain mark of a Roman City, and takes to have been a Compoficion of the Clay of Sagitntum, often mentioned among the Romans* Fi^a Saguntino pcuU malo luto. Mar. Lib. Vllk Ep. 6. Sume Saguntino pcula fi^a luto. Lib. XlV.Ep.io8. There are remains of a rude Semicircular Building, raifed on Arches, which defcends gradually into an Area, and Teems to have been a kind of Theatre. I brought away with me a Marble Pedeftal of a Statue, dug up near to the Square Tower. The Marks where Bbbbbbb th« ( ^04 ) the Feet and the extremities of the Drapery were fatt- ened to it, are ftill to be feen, and the following Let* ters finely cut V A R I A M A R C E. It was given me by the owner of the Ground, who faid he had read upon it formerly three other Letters L L A fince bro- ken off There are other Infcriptions, but fo Defaced and ill Cur, that they do not deferve a particular mention. I have a confiderable number of Medals, that were found among thefe Ruins ; moft of them have a Caput turritum with C A RT E lA in very le- gible Charaders. The Reverfe is generally a Fijh, a Neptune^ or a Rud/^er, Towards the Weft there is an eafy Defcent to the River Guadarranque, which takes its Source at Caftdkr, about four Leagues in the Coun^ try, and is very deep at Rocadillo. There is a Bar where the River falls into the Bay; but it does not hinder the entrance of Veffels of 1 5 Tun, to load Charcoal and other necefTarie^, that are Shipt off from thence for Ceuta. Along the fide of the River there is ftill a great deal of Stone Work and vifible remains of an Ancient Key. At a fmall diftance to the Eaft, upon an Eminence, there are confiderable ruins of a Square Caftle, which appears to have been an ancient Building of very great Strength The Country People now call it Cajitllon^ but the Corrigidor of that Diftrid told me he remember’d it called Torre Cartagena. The Situation agrees exadly with the Tower of that Name, mentioned in the and -^i6th Chapters of the Chronicle of Alphonfo XI of Ca(li[et A Book of great Authority among the Spaniards, who are generally of Opinion that it was formed upon the Memoirs of Fernando Nunnez de P'alladolid, a Favourite and Mini- fter of that King, tho’ it goes under the name of a- nother Perfon. All ( 9°5 ) All the 3p4fihrds who live about the Ruins I have been defcribing, fay they are the remains of a City of the Gentiles called Cartago. The corruption of CarteU into a name fo much more talked of, might eafily hap- pen in an Oral Tradition of fo many Years ; and I cannot help thinking that, where other Circumftances concur, an account deliver’d down from Father to Son is an evidence not to be flighted, in matters of fo much obfcurity. Frequent mention is made of C^rteia by the Ancient Geographers and Hiflorians. I build fo much on two Pafl^ges of Livy, that I am obliged to infert them at length. The firfl is Lib. XXVlll. C. 30. ( Livy does not mention from what Port Letlius failed for Carteia, but by what goes before, it feems to have been from Cartagena, at that time Scipio's Head Quarters) Lidius interim, freto in Oceanum eveoius, ad Carteiam cU^e ac» cejfit, (Urhs ea in ora Oceani fit a eft, uhi primfem e fauci- hit anguflis panditur mare ) Gades fine certamine prodi^ tione recipiendi (ultro, qui earn rem pcllicerentur, in cafira Romana pervenientilus) fpes, Jicut ante a dititim eft, fue- rat. Sed patefa^a immatura proditio eft, comprehenfcfque omnes Mago Adherbali Carthaginem devehend&s iradit. Ad herbal, Conjuratis in quinqueremem impofttis, pr^miffaqne ea, quia tardior quam triremis erat, ipfe cum oBo triremihus medico intervallo fequitur. Jam /return intrahat quinqueremis, cum Ledius ipfe in quinquere- mi, e portu Carteiae, fequentihus f/ptem triremibuSy eve^ Bus, in Adherbalcm triremes invehitur; quinqueremem fatis credens deprekenfam rapido in freto, in adverjum reftum recifrocari non poffe: Pcenus, in re fuhita parumper in- certus^ trepidavit utrum quinqueremem [equeretur, an in hoftes roftra converteret, Ipfa cunBatfo facultatem detre- Bandre ptigna ademit: jam enim fuh iBu teli erant, ^ undique inftabant hoftes, ^Lflus quoque arhitrium moderan- Bbbbbbb 2, M ( 9°o ) M nnvzs admerat\ mque erat navali fugna ftmiliSi quippe ubi nihil vcluntarium, nihil artis aut confilii e(f(t. IJns natura freti aflujquc totius ccrtaminis potens, fuis^ alienis navibus, nequicquam remigio in contrarium tendentes inve-> hebat ; ut fagientem videres retro vortice intortam vi^ri* clbus illatam, [equentem, fi in contrarium traBum inci- dijfet maris, fugienth modo Jefe avertentem. Jam in ipsa fugna h£c, cum infefto ro/lro peteret ho(lium navtm, ohli* qua ip[a Hium alterius roflri accipiebat: ilia, cum tranfver^ fa objiceretur hofli, repente into.rta in proram circumage- batur. The other Pailage is Lib. XLIII. C. 3. Et alia novi generis hominum legatio ex Hifpania vsnit : Ex militibus Romanis ^ ex Hifpanis mulieribus, cum quibus connu- hium non effet, natos fe memorantes, [upra quatuor millia hominum, orabant ut fibi oppidum in quo habitarent dare- titr. Senatus decrevit, uti mmina fua apud L» Canuleium frofiterentur, eorumque fiqaos manumifffet^ eos Carteiam ad Oceanum deduct placere ^i Carteienfium domi ma- nere vellent, pot eft at em fore uti numero coionorum cffent, agro ajjignato. Latinam earn coloniam fuijfe, Libert ino- rumque appellari. The bed Spanifh Authors, and Ortelius and Cellarius trufting to them, take this Carteia of Liv^ to be diffe- rent from that which was the next to Calpe^ and place it generally about ConiL Rodrigo Caro in his Qonvento Juridico de Sevilla C. 2^. applies the Carteia in the XLIII Book of Liv) to Rocadillo , and in Cap. to Car^ taia near Lefe. It is furprizing he takes no notice of the Paflage in the XXVIII Book, For the particular mention of ad Oceamm, and Urbs ea in ora Oceantfita eft, implies they both relate to the fame place ; perhaps it was becaufe he could not reconcile it with his CartaU near Lepe. Cellarius makes Bsjippo this Carteia of Livy, c. Ba/ippOf qu£ videtur Carteia Livii eft'e, extra (return. ( 9^7 ) fretunf columnas fofitA. Aliam pro Livio Carteiam non invcnh 5 tho’ in all the ancient Geographers B^fippo is mentioned by it felf as a diftant Town f am To far from feeing any necefficy of ereding a oe ’ Cartcix in the Ocean for theie Faflages in Livy^ that I take that in Lib. XXVIll. to be rather a proof that the City there mentioned, flood diiRccitdillo. m, certainly agrees much better with that Situation, than with Conti or Cartaia near Lepe. It is not to be reconciled with the latter, b caufe that lies North Wefi of Cadiz, from whence Aclh^rhal fet out for Carthage, and is a good way up the Country, on the fide of a River, and not in ora Qceani. Neither can Conti be faid properly to be Situated Uhi primtim e faucilus angttflis pandit f/r mare ^ for the Sea widens confiderabiy before it reaches the Capes Spartel and Trafalgar, and becomes an Ocean where that Town (lands It is obfervable that Mela applies words of the fame import with thofe of Livy to the Sea between Calpe and AhiU. BarhefuT, Aperzt deinsU anguftijftmum pelagus* There is no Harbour at Conil, or any other place between Cape Trafalgar 'awA Cadiz, If th<^ Carthaginian ^iinejtteremls had only been going into ( intrahat ) the Mouth of the Streights between Capes Spartel and Trafalgar, L^elitis could not have be- lieved it fatis deprehenfam rapido in fteto, in adverfum flum reciprocari non pejfe, for there is no fuch flrong Current there; and the adion between him and Ad? herb ah Triremes, which were at fome diflance behind the ^inqueremis, mud have happened fVeflward of thofe Capes ; which is inconhflent with the defeription Liv/^ gives of it ; bccaufc in that part of the Ocean there are none of thofe Eddies, that appear to have had Co particular an effed on both the Fleets, during the Eri’ gagement, and are peculiar to the Middle of the Gut, ( ?o8 ) This general miftake feems to have been occafioned by giving too eafily into the opinion, that Liv^ un- derllood by the FrcUtm all the Sea between the Gapes Spartd and Trafalgar, and the Rock of Gihrdtar and Apts-Hill\ when it is more probable that he termed flridly fo only the narrowed Fart, which was general- ly reckoned to be between the two latter : Mda.l’roximt Africa & Europe littora monies efficiunt Calpe AhiU. Plin) takes MellarU to be neared to A/rick, and there- fore places there the Eretum ex AtUnttco mart Lih. 3, which is an argument his Freium was not the fame with our Sttcights, and that he carried the Atlantick Ocean much farther Eafi th^a the Capes Spartd and Tre- falprar. Other Authors feem to make the Pillars of Hercules the Boundary of the Mediterranean and the Ocean. Marcianus Heracieotes. <7re^« rvs BcuIck^s la-'TPxvloc.s TO TO TO-frl)(^y •srccp \)s^Ti^i i^v Slyaoivoy. Baiica qui- ekm pars maxima pratenditur nofro^ mart, Herculeas intra cdumnas, pars vero qu£dam occidentali Oceano. Polybius L. III. KaA«TO^ ^ to yav Try r facts 7rapVJ(fiy eoos Hg^jtAawj' ?jjAwj/, to H TVy e^ca ^ faeyd?\./iv 'zxrQpaity>p€uofatv>u> if^ivTiv fx)y oyojxccoixy vie TtT^a-ipciTws i{^TV7rTiveSzif porrigifur Jecundum mare mil rum port to ad column as ufque Herculis Iberia nominatur ; qu£ (eenndum mare externum quod ^ magnum appdlatur, communem appellationem nondum tnve- Mzi, quia non diu efi cum fuit fxplorata. Appian ( pop ) AfpUn //. ’E/t4(pyA- tos sr^as 'ms 'Hg^tjtAaas TdV s'Tri^y. TrajeBo ad Columnar Hercalis Oceano. florus Lib. IV. C ^ Jn ipfo oftio Oceani Varus Didiuf’ que legAti conflixere ; [ed acrius fuit cum ipfo mart, quam inter fe navihus helium : Siquidem vdut furorem civium cafligaret Oceanus ^ utramque claffem naufragio ceeidit. Qttin&m tile horror, cum eodem tempore fiudus, procell£, viri naves, armament a confligerent ? Adde }vus ipfius for- mtdinem, vergentia in unum hinc Hifpani:2 inde Mauri- tani:E littera; Mare dr inleflinum externum, imminen* tefque Herculis [peculas ; cum omnia undique ftmul pratllo tempeftate J^virent, Here the Pillars of Hercules are made the very Mouth of the Ocean. If you underftand the Fret urn of Livj in this Senfe, and reckon it to fig- nify only the Sea between Calpe and Ahila, and the Ocean to begin from thence 'Weflvrard, the Paflage in the %%th Book is an accurate defcription of Rocadillo. LseUus Interim freto inOceanum eve6im ad Carteiam claffe accejjit. Urbs ea in ora Oceani ftta e(l, ahi prirntm c fait- cihus angufiis panditur mare* And allowing Lalius to fet out againft Adherhal from thence, every circumflance mentioned by Livy is fo eafy to be accounted for, that it is needlels to make Application. A Paflage in V/o^ Cajfius Lib. XLHI, induces me to believe the Veflels an- chored in the Guadarranque, and that that River, and not the Bay, was properly PortusCartei£ ''OuotpQ* Si \zod S’ 'c%/? KQ^r>lca,y evccuasscrri^, ^ fad) (pvytiv es Tvii' ywi', ay^vj^jis es ro S ?\.ifjidv©^ aMas aums 01 (r(p(xs, ua-'TnjSj} i^'nrixeiQ.v, omv oiv ro yecvky(}v amAcoAexei.. Varus vero d Didio apud Crantiam navali fralio juperatus in terram evafit, conjedifque in introitum portiis anchoris, ltd ut una ah alia, teneretur, cum ad cas, tanquam ad feptum - qmddam, prints infeqmntium - naves i ( pio ) tJAnjes offendiffentt pericalum totius clajfts amittenda declina- v'lt. 1 his cannot be underftood of the Bay, becaufe that is three Leagues over at the narroweft part, and much too deep for a work of fuch a Nature which might eafily have been efFeded upon the Bar of the Ri- ver Guadarranque. There is no room to doubt of the emendation Luts Names, in his HifpnnicA, has made here of KapTnU for Kepivno.; for no ancient Author mentions any other Town or Harbour thereabouts of a name like that ; and Cartcia was the place which held out the longeft for the younger Pompey, and wl>ere he kept his Fleets. Floras in the Paflage I have already quoted, relating the fame Affion between Didias and Varus, reprefents in very lively Colours, the very Scene near Rocadillo. Adde fitus ipfius formidimm^ vergenth in anum hinc Hif’ par,t£ inde ManritanidS littora ; mare inteftinam ^ exter- nam, imminent efqae Herculis fpeculas mvja. ^ gtp>'7rc. ?a(hoif, cc^ioAoyt^ ^ vecugx.'^^i croTi yivo/Mvn ’'Evioi fs 'H^xAeye x.lio'fJia, Afyniaiv ccvrr.y ^ d)y tc^i Qo£ 0 ^ Ex Demarunte autem natus e(i Melcarthus qui & Her- cules. MgAxapr^Ds autem eft Melech Kartha. Rex Urbis, i. e. Tyri. Idem Gnccis Melicertes five Pa- l.'cmon Maris Deus, quern Cad mi nepotem e([e fingunt. H'tnc Hefyehius rurfus MaA/>ca rov *Afjt.x%v near Carteia, and are ftiU taken in great quantities near the Shoar of the Eaft Sea, a {mall diftance from Roeadillo. Bernardo Aldrete an Author of fuch Weight, that Bochart does not difdain to copy him on feveral ocea- fions, in the fecond Book and fecond Chapter of his Antiguedades de Efpanna, accounts for the Addition of eia to Cartha; which in the Sjriack and Chaldean fignifies Tulcher, Fermofus, and was affixed to the Name of this City to diftinguilh it from the Cartha in Syria, men- tioned in the zi/? Chapter and 34?^ Verfe oijo/hua*^ By all accounts, the Fheenicians founded moft of the Cities on this Coaff, and probably Carteia was one of their earlieff; Settlements j for it lies very near Africk, in a mod inviting Situation, having on one fide a Bay, and on the other a. River, which waters a rich Country. Its height gave, it ftrength and a very beautiful ProTpedl ; circumffances which, (eem to juft ifte Aldretes interpretation of the latter part of it’s name. In the Itinerary of Antoninus, it is Calpe - Carteiam, not tanquam dm urhes diverfa, 2.S Cafaubon intimates in, his Notes on the third Book of Strabo, for then it would be Calpen Carteiam', nor, according to Suritds Comment on that part of the Itinerary, ut JigniJicet non re£ha iUr ex Suel Carteiam deduct , fed paultdum ad Calr ^tndejteSiiy becaufe (lands at the end of a nat' row neck of Land,, which projetds to the Southward a great way from.. the reft of the Continent; and confe- quently is qnite. out of the Road from Suel to any o- thet place Wefiward o( it ; probably Calpe -Carteia is Carteia, ad Calpen, to diftinguilh it from die other Cmeia itSk CeltiherMy mentioned in. the.z.1 Jt Book and ^th ( ) ^th Chapter of Livy : for, as Caro obferves, there is no neceffity for the alteration Sigonius has made in that paflage of Althaa for Carteia, from the Text of Polj- lius\ becauie Livy never mentions the other Carteia without adding Oceanum, l/rhs ea in ora Oceani Jita efli which diftintJ^ion were needlefs, hacf there been only one City of that Name. Strabo in his thiid Book mentions a City called KccprnbxUs, and places it near Saguntam, which is agreable to«the Situation given this Carteia by Livy, I am very much furprized that Mariana, and feveral others, fliould take the prefent Gibraltar to have been the ancient HeracUa ; when neither Fliny, who reiided fd long in thofe Parts, Mela who was born there, nor any ancient Geographer or Hiftorian that I have met with, makes the lead mention of fuch a City thereabouts, ex- cept Strabo ; and he places it 40 Stadia from Calpe^ at the Foot of which Gibraltar is fituated. The Spanijh Hiftorians give good ground to believe there was no Town upon that Mountain till the Moors invaded Spain under Tariff, who gave it the name it has retained ever fince. I ftiall not enter into the detail of the reafons of thofe Authors who place Carteia at Tarifa or Alge- zeira : the true one (eems to have been their not know- ing any other place which agreed better with the old accounts of Carteia, or where tlie ruins of a City, which made fo great a Figure, could be buried ; the common praSice of Authors who deicribe pla- ces they have not feen. This appears to have been the cafe of mod of thofe, efpecially Mariam ; who, had he been in thefe Parts, would not have been guilty of the overfight he has committed Lib. XVI. C. 9. where he places two Bays in the Streights, one at Gi- braltar* and the other at Tarifa ; which error he Was' probably led into (as it often happens) by another. Ccccccc % For, ( 9'4 ) For, giving into the Opinion that Tarifa was the an- litmCarteia, and finding that City placed in a Bay by MeUf he concluded there muft be one at Tartfa^ which is an open Road, and fo much expofed, that in the leaft bad Weather, the fmallefi: Veflels muft be haul’d afliore. Which Circumftance alone is a fufficient proof of its not being Cart eh, by all accounts, a famous Harbour. Tho* there are very great Ruins at Algezeira, they are not fuch as give any room to believe they are the remains of a Roman City. For neither pieces of Marble, nor Infcriptions are found there, nor any Roman Coins. The Circumftance of f^arus his fhutting up the Mouth- of the Harbour of Carteia, and the diflance ef 40 or 50 Stadia from Calpe, are not applicable, either to Ta- rifa or Algezeira , and if one of thofe Towns was Car- teia, to what City belong thofe Ruins I have been de- fcribing? fince all the ancient Geographers make Car- tel a not only the neared Town to Calpe, but the only one in that Bay. There is better ground to believe Tarifa dands on the Ruins of an other Town, as 1 fliall endeavour to fliew prefently. But before I proceed to a Defeription of the Coad, it may not be improper to mention fome Ruins I law at Ximena; an inland Town, about five Leagues from Gibraltar, fituated on a Rocky Hill, at the bot- tom of which to the Eafirrard is a very plentiful Coun- try, waflied by the Jofgarganta, a fmall Branch of the River Guadiaro. On the top of the Hill is the old Town, which by the Arches and Vaults, appears to have been built by the Moors. On the right-hand Corner of the fecond Gate of it, there is a courfe Stone with Mouldings on the Edges, which has tlie follow- ing Infcription^ L. HE- ( P»5 ) L. H E R E N N f O RE R E N N I A N O L. CORNELIVS HEREN; NI VS R VST I C V S NEPOS EX TESTA MENTO POSVIT NONIS MARTIIS SEX. QVINTILlOtCON: DIANO SEX. QVIN TILIO MAXIMO GOSS.. Rodrigo Caro in his Convento Juridico de Sevilla C. 13=.^ fays he faw the beginning of this Infcription in E^fer de la mkl\ but when I was in that Town, I was inform- €d by a very intelligent Perfon, that there is no Ro<^^ Infcription in any part of it. The Author Ca~ . diz el Emporio del Orhe, when he inferts this infcrip-, tion, makes itSEXOViNTILIO CONDIMIO; ; But the Dafti of the CL is very plain, and the other word Teems rather C O N D I A N O. The Latin Fafi , in A. U. C. 903. place Confuls- SEX. QUINTILIUS GORDIANVS. SEX. (QUINTILIUS MAXIMUS, But the very learned Dr. has obferved to me ■ that i\\Q Greek Fafti and Dio call him which . reading is confirmed by this Infcription. I have brought with me from this Town a piece of Marble with the following Words upon it,^ AVCTIN VS CLEMEN TIS SI-BI ET SVIS BRITTLE MATER AN LX H.S.E, SIT T.T.LE VIS; I fe,'V ( 9»6 ) I (aw another on the Wall of the great Church which (eems to have been the Bale of a Statue ; the Jnfcription is as follows. RESP VBLICA OBEN' SISE..LO DATO DEDI...VIT CVR AT LIBE..OR H..REN NIO RVSTICO H.M. SINILO RESTITVTO II VIR. 'The manner in which the Moors have placed thefe Infcriptions plainly Ihews the little value they let upon them, and there is fo great a plenty of Scone on the Rock where Bands, that it is not to be thought they would fetch them for fuch an ufe, from any di- Rant place ; which induces me to believe a Roman Town formerly Hood there called O B A. I do not find any Town of that name in tlie ancient Authors. Strabo L. 111. mentions McuVoiSa ^ cT^&iss, which may polTibly comprehend Oba. The6V^>« grafhia Nubienjis, in the fourth Climay makes a Town called Rothan^ the firlt Station from Algezeira to Seville, which perhaps may have been this Oba ; for it is about a Daysj journey from AlgezeJra, zod in the diredRoad fronii thence, to Seville. Mariana places Lib.ni, C. z. the Cave vthetQ Craffus hid himfelf, near JCmena ; the Marks of it, given by Plutarch, are common to moll others. I went three Leagues in fearch of it ; but the Country People having a notion that there is a Treafure in it, and not being to be perfuaded that I would take fo much Pains out of pure Curiofity, would not (hew me the Way, tho’ ^they acknowledger! there were feveral fuch Caves thereabouts. I cannot help taking notice of one very ( ) odd tho’ trifling circumflance. The name of the^ Perfon who owns the Land where thofe Caves are, is Pachmo, which is very near the fame with that of the ' Spaniard, who is faid by Plutarch to have entertained C rajf us Co courteoudy, Ua,->uctt(ps. . f/irtius in t\\Q begin- ning of his Book de hello Hifpanico mentions a Spaniard of Note, in provincia B£tiea, called Patiecus. ^ibus frafecit hominem ejus provincU notum ^ non parum fcientem, L. Julium Patlecum, which was probably the Roman Name ; and therefore .1 am furprized the Latin Tranflator of Plutarch makes it Pacianus. Moft of the antient Geographers defcribe the Caad Weftward of Carteia in the following manner. JulU Traducia, Mdlaria^ Balo fiuvius ^ oppidum^ Portus Bajippo^ , Tromontorium Junonis, &c. The Itinerary of Antoninus, . makes no mention of Julia Tradu5ia, and Pliny places iton ; the African Coaft, which Hardouin endeavours to account for Pag. 227. in his Nummi Uluftrati.i Straho c^\h it Ju- - Ham Jozam, which as obferves Lib. I. C. 24. fig- * nifies the fame in the Phanici an Language as TraduPtam in the Latin.: Ptolomj calls it LranfduBao He places s Barhejula between that and Carteia. But all the other old Geographers put both the Town and River of that Name Eaftward of Calpe. I faw fomd Ruins on the Eaji fide of the River Guadiaro, four Leagues oi Gibraltar which I take to be the remains of the ancient Barhefula. For I find in the Cadiz Emporio del Orbe, mention made of two pieces of Marble, brought . from thence to Gibraltar on one of which was M M ' BARBESVLANI. I was credibly informed they ' were ufed for the Fountain on the Parade. The Letters - probably were either fa wed off, or turned inwards; for r they do not appear. This Barhefula is probably ^ the^ placed' in the Itinerary X. P* Bafciiom \ Carteia,, 1 (pi8) "Pmpomus Mtla, who was born in thofe Parts, and therefore is moft to be depended on» gives the follow- ing account of the Coaft, according to the Edition of '^ronovius. Sinus ultra efi, in eoque Carteia, ut quidam putant, aliquando Tartcflus, ^ quam tranfve^li ex Africi ‘ PhxnicQS /jahitani ; atque unde nos fumus^ Tingentera. Turn Mellaria & Bcelo, & Bacfippo ufque ad Junonis pro- ‘fnontotium or am freti occapat. The Text of MeU in this place has occafioned great dil'putes among the Learned. Cafauhon in his Notes upon Straho, fays, lego autem — atque unde nos funsus Tingi contraria Mellaria^ aut Tingi e tegione jita Mellaria. Nam Tingis fa6iam hie d Mela mentionem mihi efi perfuafijfmum ; primiim quidem veterem UBionem fpeBanti, qu£ efi^ ut dixi^ Cingentera- tum ; aut etiam ut in Juts libris doBijfimus Elias Vine- tus reperit Tingentera ; ut jam de eo dubitari non pojfit. Deinde autem 'video morem Mel:e hur\c effe^ ut locorum in altera ora oppofitorum mentionem facial. Sic alibi; Ma- jorem Sabcei tenent partem, oftio proximam, & Car- mariis contrariam Mac^c. Nec moveri quifquam debet quod alii Tingin Bedoni non Mellariae faciunt contrariam. Nam Bcelo & Mellaria it a funt vicina, ut mirari hoc ne- mo debeat, Saknafius, whofe opinion is approved by Bo- charts makes it Tingis altera, turn Mellaria, &c. and takes the preceding tranfvecli to denote Julia Tradu- Ba. Cafaubon feems to have been once of the fame Opinion. Sed a Strabone fiare Ptolemseus videtur, qui in hac HifpanieS ora oppidum quoddam memorat cui nomen Tranfduda, in quod jcilicet collocati fuerint ifii, de quh bus nunc loquitur Strabo ; & de quibus dubitavi aliquando, an hac Melx verba effent accipienda. In eoque Carteia, ut quidam putanr, aliquando Tarteflus, & quam tranf- vedii ex Africa Phsenices habitant. Nam videbatur fatis aperie Tranfdudlam Ptolomsci a^(pfci^€iv. Nunc iis afi fentior qui ad Carteiam ea referunt. The -opinion of * Salma* ' ( 9*9 ) Salmajjui feems to be the moft probable ; for B<£lo and not Julia Tradu^a is faid to be over againft Tingis, Marciams Heracleotes makes the two former about zfo Stadia diflant from one another, and Mellaria is generally placed between them ; therefore they could not be fo near one another as Cajauhon infinuates. Tho’ Carteia was originally founded by the PhcenicianSf it had been eredied into a Roman Colony long before Mdas time, and therefore he could not very properly fay Carteia, quam Phaenices habitant ; and had be intend- ed to take notice of the Founders of that City, it is probable that one whofe Stile is fo pure and accurate, would have made ufe of another word, or at lead another Tenfe. Befides, if Julia TraduPia, according to Cajauhon, is not meant by that paflage, it muft have been entirely omitted by Mela ; which is very unlikely, confidering he was Born in or near it ; and that it is mentioned by Strabo, who lived before him, and Pto- lorn) and feveral others who were after him ; and ap- pears to have been remaining at the time the f^andals were in poflefTion of Spain ; for Greg. Turcn, Lib. If. fays Profequentibus Alamannis ufque ad Tradudfam, tranfito mart, Vandali per totam African! ac Mauritaniam funt difperf. The Letters of Tingi altera come nearer the Tingentera of Elias Vinetus, and the Tinge Hiera of Cronovius, than Cafaubons Tingi contraria or Tingi e re» gione fita. The © and the atque, by making the flop at Tarte(fus inftead of Habitant., may very well relate to the fame place; and it is not improbable that Mela was defirous to illuftrate the obfcure place of his Birth by a PeriphrafiS, and a name of fome Eclat ; tho’ k has happened, the method he took to do Honour to it, has been the occafion, that we are in doubt even of its Name. D d d d d d d I ( 5>20 ) I met with two Medals of Julia TrarluCia among the Brafs Spanijh Coins; but as I cannot alcertain where they were found, I will not pretend to form from thence any judgment of the fituation of the Town to which they belong. But I prefume in matters fo dark, a con. jetfure n?ay be offered. It does not ieem very im- probable, that Julia Trada6la flood where Tarifa is at prefent. The Spanifh Authors reckon that Town to have been built by Tarif at his fecond coming to Spain. I cannot fee what could invite him to fettle on a Spot which has neither the convenience of a River, nor a Harbour, and is commanded by a rifing Ground ; un- lefs he found fome Tenements (landing, or Ruins to ferve for Materials to Build. I have feveral Roman Coins that were found there after great Rains, in the Common Sewer ; which is fome flight inducement to believe it was formerly a Rowan Town. About a League and half to the Weft of Tarifa^ is a place which goes now by the name of Fal de Vaca, The Country People have a Tradition among them, that it was once a confiderable Town, fince fwallowed. up by the Sea. There is a fmall Brook called el Ar- roffo de Juan Francifeo, which ferves to turn fome Mills, that a Pried of that Name was encouraged to build there, by finding an antient Stone Channel for the Water. I faw fome other fmall Ruins, and was credi- bly aflured there are vifible remains of an old Town a good way under Water. There is a Shoal almod off this place, that runs pretty far in the Sea, on which a Hamburgher was loft fome Years ago. Per- haps Mellaria flood hereabouts. Wherever it was, the Ruins of it muft be a confide- rable way in the Sea, if credit is to be given to Rliny, who upon the Teftimony of one Born there, reckons only five Miles from thence to Afric. Lib. III. whereas ' ( ) whereas it is at preftnc five Leagues over at the nar- row Parc. Cnjauhon is miftaken in that Note on Strabo L. H. where he fays. At Maris Mediterranei cftium vix LXX Stadia latum e(l y I cannot help oblerving that the beft Hony in all Spain is made in thefe Parts, and that the fame caufe to which the ancient Mdlaria ow’d its Name, dill fubfifts, and has given a modern Appellation to feve- ral places hereabouts, as Playa de Orimd, Rid de la Midt Bejer de la Miel. The latter of thefe is generally rec- koned by the Spaniards to be the old Mellaria, for no other realbn, that I can fee, but the Name. For it is at lead two Leagues from the Coaft of the Streights, and, by what I could judge when I was on the Spot, as near the Ocean, and therefore may as well be aferibed to the one as che other. Whereas Mdlaria, according to all the old Geographers, wasfituated on the Sea fide in the Streights, and is reckoned by Vliny the nearefl Town to A^ric , a plain proof that it was not what is now Bejer de la Mid. About a League and half further Wefl, in a fmall Bay, there are very great Ruins, which appear evi- dently to be the remains of a Roman Town. A League Eaftvpard from that place, upon an Eminence, are to be feen the Quarries from which the Stone was fetch- ed for building it; and all the way from thence are large remains of an Aquedudf, of which in fome pla- ces there are entire Arches dill danding. Among the Ruins of the old Town, I faw the Body of a Roman Statue of fine Alabader, fomething bigger than the Life. Our Guide faid his Father had feen it entire ; but as it was an Idol of the Gentiles, they, like good Catholicks, had broken ic to pieces. He likewife cold us that Urns of old Coins had been found there ; Ddddddd x but C pii ) but not being Current in Spah^ they had thrown them away. The place is called Balonh. ft is over againft: Tangier^ and frequently infefted by the Moors from thence; on which account it is uninhabited. A fmall River, called Alpariate, runs by it : all which circumftances correfpond with the ancient accounts of Bdlo, I have a Medal that was given me at Tarifa^ with the following Letters upon it B A I L O, which probably belonged to this City, called by Ftolowij BfluAwv Martianus CapdU i^ib. VI. mentions it under the name of Velomnfis B^ticaCivitas- The Itenerary of Aniomnus places VKM. P, Wefi Mellaria, which is about the diftance of thefe Ruins from Val de Faca* About five Leagues farther is the Cape of Trafalgar i i the fight of which immediately brought to my mind ^ Melas delcription of it. Idud jam in Occtdentem (jr ft Oceanum ohliquo jugo excurrens, atque f/, quod Ampelnjium t effe dixeramus, adverfam, &c. Near the Capes Point are ^ the Ruins often mentioned by the SpaniJJ) Authors, un- ^ der the name of Aguas de Mecca, I was not there, but was afiured at Bejer de la Mid, that there were fiill fome Ruins on the Shore, and more in the Sea, that run all along under the Cape ; particularly remains of a Mole, which muft have made it a tolerable Harbour. Thele Ruins feem to be the remains of old B N. B. Mr. I’Abbe Conti /pent fome Hours alfo in , looking over the old Letters and Letter Books kept in the Archives of the Royal Society, to fee if he could find " anj thing which made either for Mr* Leibnitz, or again/} Mr, Newton, and had been omitted in the Comiaercium i Epiftolicum Coliinii & aliorum ; hut could find nothing of that kind. A Letter of M, Leibnitz to M.U Abbe Conti, , in An/wer to the former. Monftear, Hanover ce 14. /x\vril, 1716. POur ne vous faire attendre, je vous dirai par advance : que j’ai repondu d’abord a I’honneur de votre , Lettre, & en meme terns a celle que Mr. Newton vous a ecritej & j’ai envoys le tout a bAt. Remond ^ Paris^ , qui ne manquera pas de vous le faire tenir. Je me fuis fervi de cette voie, pour avoir des temoins neu- tres & intelligens de notre Difpute : & M. Remand era ; fera encore part a d’autres. Je lui ai envoye en meme j terns, i ( 91i5 ) terns une copie de votre Letrre & celle de Mr. Nevpton, Apres cela vous pourrez juger, fi la mauvaife chicane de quelques uns de vos nouveaux Amis m’embarraflc beaucoup. Quant au Probleme dont quelqaes-uns parmi eux ont voulu refoudre des, cas parciculiers, pour en fixer, difent-ils, les idees; il y a de I’apparence qu ils (e feront .jettez fur des cas faciles : car il y en a dans les Cour- ^bes Tranlcendantes, aufii- bien que dans les ordinaires ; mais il s’agit d’une folution generale. Ce Probleme n’eft point nouveau. M. Jem BermuilU fa deja pro* pofe dans le mois de May des Adies de Leipfic 1697, p.%i\, Et comme M. Fatio meprifoit ce que nous avions fait ; on en repeta la propofition pour lui & pour fes femblables, dans les Ades de May i-joo.p. 11 peut fervir encore aujourd’hui a fair connoitre a quelques- uns, s’ils font allez aulTi avant que nous en Methodes ; & en attendant qu’ils trouvent le moyen de parvenir a la folution generale, ils pourront efiayer ce qu’jls p^uvent, en fixant les idees fur un cas parti- culier, qu’on leur propofe dans le papier cy joinr. Sa folution vient encore du meme M. Bernoulli. Ainfi vous aurez la bonce de ne pas vous rendre crop tor aux in- finuations de ceux qui nous font contraires ; comme lorfqu’ils vous font a croire que notre Probleme leur etoit aifd. Je fuis avec zele, Monfieur Votre Prohlema continens cafum fpecialem Prohlematis genera- Its de invenienda Serie Curvarum, quarum qualibet fit ad aUam Seriem Curvarum perpendicularis. ( 9^7 ) Suptt rtciA A G tAn" quAm AXCy ex fun^o A con- ftrucris Curvis quotcm^ttc qualis ejl A B D , ejiis nature ut rAdtus cfculi ex fingulis (ingularum CurvArum punHis B edu6lus B O ^ece- tur ah axe A G in Q in Da- ta fefnper confianti rat tone : ut ncmpe fit ^ Q ad ^ C nt M ad N. Conflruendx jam fttfjt Traje^ortA qualis ejl ENF, priores Curvas ABD fecantes ad angulos reBot, Thus far this Letter. Mr. Leihnitz firfl; propofed the general Probleme to M, I'Ahhe Conti in ihefe words; Trouver une ligne B C \y,qui coupe a angles droits toutes ies courhes d' une juite de- termine d'nne rneme gcndre\ par excmplcy. toutes Us H)- perholes A B, A C, A D, qul ent le meme fommet & le neme centre; ^ celapar une her, i6>i8. />. 4/0, 471. he calls the Curves in this determinate Series, Curvas ordinatim datas, & pofttione datas, & pofitione ordinatim datas. And by all this, the Series of Curves to be cut is given, and nothing more is to be found, than the other Series which is to cut it at right Angles. But Mr. Leihnitz being told that his Probleme was folved, he changed it into a new one, of finding both the Series to be cut and the other Series which is to cur it. And the.particu- Eeeeeee lar ( ?i8 ) 1 lar Probleme propofed in this Letter is a fpecial Cafe, | not of the general Probleme firft propofed, as it ought I to have been, but of this new double Probleme. And I the firft part of this double Probleme (viz. by any I given property of a Series of Curves to find the Curves) I is a Probleme harder than the former, and of which a I general Solution is not yet given. Mr. Leibnitz in a / Letter to Mr. John Bernoulli, dated i6 December, 1694. f and publiflied in the A^a Eruditorum for October 1698. ^ />. 471, letdown his Solution of the Probleme, when j the given Series of Curves is defined by a finite Equa- | tion, exprefting the relation between the Abfcifs and 7 Ordinate. The fame Solution holds when the Equa- tion is a converging Series, or when the property of the Curve to be cut can be reduced to fuch an Equation, by the And)(is per Series numero terminorum infinitas. But Mr. Leibnitz was for folving the Probleme without, converging Series. IV. ^ars ( 9^9 ) IV. reli^ua 'Dijfertatlonis De Potentia Cordis. Authore Jacobo Jurin, 6c R. Socie- tatis Soc. ThiormA II, SI ex Mdchina cAvk inaquAliter contrAlHUt A B C D, aquA per MAchina contrAlliomm expriwAtur, Motus a- qua ex orificto A profilkntis aquAtur Summ = f, Qtiisx — q. Hinc Potentia Ventriculi xy~]-~ ( 951 ) Simili ratione itivenitur Pocentia dextri Vcntriculi # S ' ' Literis autem Grsecis eadem fignificantur in dextro Vencriculo, quse Latinis in finiftro. Hinc tora Cordis Potentia Si ponatur p = S unc. Avoird = 13.118 unc. cub. 7T=4 =6. J64 S = 10 unc. quadrat. S = 10 / = ^ unc. A =17. ^=1 unc. Avoird. = 5.181 unc. cub. j = o . 41 8 f unc. quadrat. 1 Ex Kdllianis Experi- 0- = 0 . 583 ^ mentis. ? = o . 1" Erit Potentia Ventriculorum srqualis motui ponde- rum fubfcriptorum, nempe, lib. unc. Ventriculi fmiftri ^ 9 • i Ventriculi dextri — — ^ ^ Cordis totius *5” • 4 Quorum ponderum ea eft velocitas, qua percurratur longicudo uncialis fingulis minutis fecundis. Cor. I. Quoties Pulfus fit celerior ; aut minuitur refiftentia, aut Potentia Cordis augetur, aut minor foli- to Sanguinis copia fingulis contradtionibus ex Corde expellitur. 1. Si Pulfus folito tardior fiat necefie eft, vel auge- atur refiftentia, vel Cordis Potentia minuatur, vel ma- jor Sanguinis moles ex Corde ejiciatur* 3. Au(fta ( 955 ) 5. Auda refiftentia, neceflario vel Pulfus retarda- bitur, vel augebitur Cordis Potentia, vel Sanguinis quantitas folko minor ex Corde exprimetur. 4. Imminuta refiftenci^, vel Pulfus acceleratur, vel major Sanguinis copia quaque Syftole ejicitur, vel Cor- dis vires minuuntur. 5. Audtis Cordis viribus, neceflario vel augebitur re- fiftencia, vel Pulfus accelerabitur, vel plus Sanguinis ex Corde ejicictur. 6. Viribus Cordis imminutis, vel minuatur necefle cfl: refiftentia, vel Pulfus tardier fiat, vel minus San- guinis ex Corde exprimatur. 7. Cum minor Sanguinis moles ex Corde projicitur ; vel acceleratur Pulfus, vel Cordis vires minuuntur, vel augetur refiftentia. 8. Gum plus Sanguinis ex Corde exprimitur; vel Pulfus tardior fiet> vel augebitur Cordis Potentia, vel refiftentia minuetur. SchoL r. Ventriculorum fuperficies internas, cum fadilu difficillimum videatur, ut accurate determinen- tur, aut etiam ratio habeatur imminutionis, quam in- ter contrahendum patiuntur, contenti fuimus pra:ter- propter ceftimare : cum five eafdem ix, five 8 unciis quadratis fingulas rcquales ftatueris, perparva repe« riatur Potentiarum fada mutatio. Quod etiam obfer- vari poterit de longitudine media filamentorum Sangui- nis. Prasterea difterentias, qua Arterice ambx, earum- que rami proximi a Corde progredientes, feeftione au- gentur, ut xftimatu perdifficiles & pene infenfiles, negligimus. Alioqui eftet Cordis Potentia tantillo minor ftatuenda, quam qux fupra definita eft. X. Determinavic Vir Celeberrimus, Jaeohus Kdllius, velocitatem Sanguinis, refiftentia fubmota, ex Corde cf- fluentis, eam'circitcr, quS percurrantur pedes 6~ fingu- bs minuds fecundis. Ponic veto illc celedtatem San- guinis ( ?54 ) guinis per totam Syftolem a:quabilem, quam nos infig- niter inxqualem fieri, & perpecim a Syftoles initio re- tardari fupra oftendimus^ Hanc fi cui definite libue- ric, fubftituenda eft, in quartd i^quatione iupra pofita, Potentia Ventriculi proxime inventa, & ipfi x valor quivis tribuendus, ut eliciacur v, five velocitas eidem refpondens. Ita, cum initio Syftoles fit x = o, fub finem vcro x = ^, determinarur inde ea Sanguinis ve- locitas initio Syftoles, qu3 pedes 14^ ; in fine autem qua 4 minuti fecund i (patio percurrantur. Pariter in dextro Ventriculo : velocitas Sanguinis initialis pedes circiter 1 o ultima veto 3 pedes eodem temporis fpatio conficiet Adhibuimus hacftenus earn Hypothefin, qua Mufculi Cordis Veniriculos conftituentes Motum omnem, quo adjguntur in contradionem, Momento temporis conci- piunc Quod fi ponamus Motum iis communicari non unico quidem Momento, fed tantillo tamcn temporis fpatio, quod cum tota Syftoles duratione comparatum rationem obtineac admodum exiguam 5 erit Cordis Po- tenria paululo major ftaiuenda, quam qux fupra deter- minata eft. Si veto ftatuatur ifte Motus, procedentc Syftole, in ratione temporis augeri; erit totus Motus in fine Syftoles acquifitus duplo major quam fupra pofu mus, ubi nulla rcfiftentia Sanguini ex Corde pro- fluenci objicitur: Ubi autem folita adeft refiftemia, e- rit idem quintuple major ; quod inftituto calculo facile patebit* Pari ratione potent calculus nofier ad aliam quamlibet Hypothefin, qua Ventriculorum Motus in duplicata vel fuperiori quivis ratione temporis augea* tur, accommodari. Potentia veijo in fine acquifita fu- prapofira elicietur longe major, nempe ex ratione du- plicata Potentia tripla, tx triplicata quadrupla, ex qua- druplicata quintupla, & fic in infinitum. Nobis ( ) Nobis autem videtur fecunda Hypothefis, qu^ Vett= triculi parvo admodum temporis fpatio Motum om- nem concipiunt, cseteris longe verifimilior. C^uum ne- cefle fit, ut aliqiiid temporis impendatur ad Motum quemlibet generandum ; nequs videatur adeo tarde in- crefcere Ventriculorum Motus, ut non celerius augea- tur, quam fecundum temporis rationem. Motus enim Mufculorum impetu folo Fluidorum quorumcumque, qus ex Sanguine proveniunt, perfici nequic ; quumBra- chio alterutro Motum exerere poffimus Motu Sangui- nis per vala Corporis univerfa profluentis longe majo- rem. Relinquitur ergo, ut MufculorUm fibrce Ventri- culos Cordis conftituentium, rarefcentia qu^am liquo- rum in eafdem influentium, in Motum impellantur. H^ec autem, quoties vim magnam concipit, plerumque fubita eft, & fere inftantanea. Adde quod Ventricu*- Jorum Motus fecundum hanc Hypothefm longe minor efficitur, quam in tertia. Non folet autem iapientifli- mus Artifex, Rerum Conditor, in operibus fuis plus Virium adhibere, quam quantum fufficit ad finem pro- pofitum confequendum. Caeterum five admittatur ifta Hypothefis, five alia qu^cunque ex fupra didlis verior cenfeatur, poterunc omnia Corollaria noftra eodem jure ex Problemate de- duci. Quae utrum aliquid adjumenti afferanc ad Mor- borum Hiftoriam explicandam Medico fagaci confide- randum permittimus. Facile autem ex Morbi cujufque Nacura fciri poterit, utrum autfta fit vel imminuta re- fiftentia. Augeri vero credibile eft vel imminui Cor- dis vires audis vel imminutis Mufculorum reliquo- rum viribus; quamvis aliter ftatuifte video VirumCc' kberrimum, Laurentium Bdlimm, F f f f f f f Thcmmti Theorem A III. Totus Motus refiJlentU, ofua Sanguini ex Corde erum- fenti duranpe Syftole obpeitur, five totus Motus, eyul San- gutni .'pracedenti ^ /4rtersarum tunkis eommunicatur, toti Cordis PetentU quamproxime aqualis e(i, Dem. PeradlS Cordis Syftole, quae pars Aortae & Arceriae Pulmonalis Cordi psoxima eft, perftat plena Sanguine per cotam Syftolem Arteriatum. Nec enim patitur carum fabrica & nexus, quo Cordi conjuneftre func, ut cunicis in fefe penicus collabencibus totae oc- cludancur, neque poteft earum cavum Sanguine vacare. Alioqui enim, contrahentibus fefe reliquis Arteriarum partibus. Sanguis iildem concentus retro in vacuum im- pellerecur motu, & inutili & motui Sanguinis naturali contrario. Turn etiam Valvulx Semilunares non ten- derentur verftis Ventriculos, adeoque Sanguis ex Auri^ culis in Ventriculos expreflus, etiam in Diaftole Cordis, in Arterias protruderetur. Hinc patet Sanguinem proximo ex Corde expulfum Syftole perad^ immotum in Arieriis perfiftere, adeo- que turn omnem Ventriculorum Motum excepifte, turn eundem rotum parcim Sanguini antecedenti, partim tu- Bicis Arteriarum communicafte. ^ E. D, Theorema IV. Motm, qui in Syftole Cordis communicatur Sanguini pracedenti^ eft ad Motum tunkis Arteriarum communka- turn, ut iempus Syftoles Cordis ad tempus Diaftoles quam proximo. Dem. Quum Sanguis per vafa Corporis univerfa, fi partes Arteriarum. Cordi propiores exceperis, a^qua- bili curfu deferatur ; necefle eft, ut cum Motus affntJu Sanguinis ad valorum latera deperditus, turn Motus Sanguini redditus a Syilole five Cordis five Arteria- rura ( 957 ) rumi sequalibus temporibus ^qpalis fit, Qui autem Motus a Syftole Arteriarum Sanguioi communicatur, idem eft prsecife, qui prius a Cordis Syftole Arteria- rum tunicis fuerac irapreflus, cum Arteriie eodem im- petu quo diftrate fuerint eciam reftituantur. Et Syftole Arteriarum cum Cordis Diaftole duratione coa- venit. Unde patet Propoficum. E. D. Cor. Si ponamus cum Viro Dotftiftimo Jacoho Keillh^ Syftolen^ Cordis peragi tertia parte temporis inter Pul- fus binos intercept! ; erit Motus Sanguini prsecedenti communicatus totius Potentise Cordis pars tertia : Mo- I tus vero Arteriis communicatus prioris duplus, fiv,e du£ partes tertian totius Cordis Potential. Theorema V. In diver fis Animalihus Votenth Cordis rationem ohtinet I compofitanty ex ratione qmdruplicata Diametri cujujvis ho- mology AnirndiSy ^ ratione inversa temporisy quo Cor ! (ontrahitar: vel rationem compofitamy ex ratione fonderis I vel ipfius Cordis vel integri AnimaliSy ratione ponderis^ ejufdem fuhtriplicata, d>* ratione temporis reciproca, Facile demonftratur vel ex Corel, j. Theor. i & z- vel ex Potentia Cordis Problemate prxeedente definita, Cor. 1. Si ponatur Cordis Potentiam rationem obtinere ponderis vel ipfius Cordis, vel integri Animalis, vel Sam- I guinis copiae in toto Animali ; erit. Animalis longitado in ratione temporis, quo Cordis Syftole perficitur, five in ratione inversa frequenti^ Pulfuum. ! z. Si ratio longitudinis integri Animalis major fuerit ratione inversa frequentias Pulfuum , neceffe eft ma- jor fit ratio Potentise Cordis ratione ponderis ejuldem, , Schol. Quum conftet Experimentis Puerorum Pulfus non elTe tanco frequentiores Pulfibus Virorum, quanto Pueri Virorum longitudine fuperantur, concludendum Fffffffz eft. { 9j8 ) eft, vi fecundi Corollarii, Potentiam CorcKs Virilis ma* jorem obtinere radonem ad Pocenciam Cordis Pueri» quam eft ratio ponderum. Et par eft ratio in cazeeris Mufculis. Nam fi Corporis robur rationem ponderis iequeretur, poflent Pucri sequalia icinerum fpacia eodem tempore cum Viris conficere. Simili ratione ac Motum Sanguinis cx VentricuKs Cordis erumpentis ope fecundi Theorematis determina- vimus, poterit quoque Urinse Motus ex Urethri pro- fluentis deternfinari. Nempe ft ponacur Urethra & Vc^ ftcaz iongitudo i £ unciis xqualis, & bin£ uneix Urioae minuti fecundi fpati& emtccantur. erit Motus Urinae effluentis sequalis Motui ponderis librae i f , quod ua* cialem longitudinem ftngulis minutis fecundis percur* rat Quoniam veto Urina non folis Veftes LJrinarise viribus contradivis^ led etiam Diaphragmatis & Muftu. lorum abdominalium ope in (ubftdium vocati, expelli- tur, nequit Veficse Potentia ex Mocu Urinae profluentis aeftimari. Haec tu, VirDodiflime, squi boniqueconfulas rogo: ipfe autem uc diutiftime valeas» utque exiftimationem tuam, & iplam Artis ^fculapiae dignitatem uique uc badenus fecifti, inftgnirer tueri pergas, ac magis in- dies magifque extendere, idcirco ex animo voveo, quia, publicam ad falutem peccinere arbitror*, Galendis fanuaril^ tyih V*. ( 9i9 ) V. Nova Methodus Unherfalts CurVas Omnes cu- - ju/cunque Ordinis Mechanic ce defcrihendi fola dd- torum Angulorum cunque Ordinis, licet pundo. duplice aut multiplice. quoyis deftitutae, conftruuntur, non fore Geometris in» gratam. I. Linese primi Ordinis ipfae funt Redae ; qtjae in ^ uno (bio pundo fibi mutuo occurrere pofl’unt. Lineae : fecundi Ordinis funt Sediones Conicae,* quae in pluribus r pundis quam duobus a reda quavis fecari non polTunc. vero omnes lecundum Lemma zi. Lib. I. Princif^r D,. Mevptoni fic ,conftrui pofFunt, Circa data duo punda ( P40 ) C & S moveantur AngtiH daci MCR,LSN; icaucCrurum CM S’ L concorfus femper ducacur per red^am indefini- cara poficione dacam A £; tunc crurum aliorum CR & SN concurfus in P defcribet Li-‘ neam (ecundi Ordinis (eu Se- d^ionem Conicam. IT. Moveatur ut prius Angulus MCR (v-Fig.z.) circa datum punc^um C; Angulus vero datus L N Temper percurrat Angulari fuo pundTo N redTam datam A E, ita ut crusN QJem- per tranfeat per datum pundum S. I. Si con- curfus crurum C R & S N, turn pundum Q^ducatur perr^am infiniram A B, concurfus crurum CM N L deicribet Curvam lineam Tertii Ordinis pundum duplex haben* tern in C. z. Reliquis manentibus, fi crurum C M & N L concurfus {vide Fig. I’) ducatur per redam indefinicam A B: S concurfus crurum G R & SN in P defcribet Curvam Tertii Ordinis t^undum duplex habentem in S. TH ( P4» ) B £ Exemplum Cafus i. Sine anguli M C R. L N S re6li, (vide Fig, 4)&AE, DB, CS parallelse ; fine quoque S A & 5 D normales relpedive in re- <5las A E & DB;fitque SD = 2 8 A. Hifce pofids, fi SD fit minor redla CS, Curvafecun- dum regulam Cafus primi deicripta, erit Parabola No- data cum Ovali, Speciei 6Zva Curvarum D. Meuteni; Quod fi S D = C S, Ovalis evanefcic & nodus evadic Cufpis, atqoe Curva deferipta erit Parabola Meiliam feu femicubica ; Si vero fit S D major quam CS, erit Cur- va Parabola pundata Campaniformis Speciei 6^na* III. Moveantur Anguli da-, ti R M T, K N L, ita ut pun- da M & N percurrant redas indefinitas B M, D N refpedi- ve ; & crura R M, K N Temper ^ tranfeant per data punda C 6 S. Si primo Crurum M T & NL concurfus Q^ducatur per redam indefinitam AQ^; tunc concurfus crurum M R - & N R in P deferibet lineam Quarri Or* dinis punda duo du- plicia habentem, alte- rum in C alterum ^ vero in S. Sed fe- cundo fi crurum MR & N K (vide Fig. I. De Maximis Minimis in motihus Cor* forum Calefiium occmrmit. NTE Keplerum Aflronomi aniverfi, per tot re- tro fecula, rianetarutn motum circularem non aufi funt in dubium^ocare, ex prceconcepr^, ut videtur, in figura Circuli nefcio qua perfcdionis Ide3. Keplero autem Inventori debetur ea qua nunc utimur Theoria, nempe quod Corpora cceleftia Solem ambiunt incommuni orbium Ellipticorum Foco fitum, ea lege uc Arese Temporibus proportionales radiis ad Solem du- .^iis defcribantur. Sublimiorem vero poftulat Geome- tfiam, ad ollendendum quam ob caufam hoc ica fe ha- beat, quodque aliter efle non poflTit. Hoc in fempiter- nam celeberrirai D. Nevotoni Prscfidis noftri gloriam re- fervatum eft. Hujus veftigiis infiftens, CoroIIaria quasdam exhi- buit eximius Mathematicus'D. Ahr. de Moivre R. S. S. in PhiUf.Tranfa^, N° edita; Thcoremata fcil pa- rata, quibus determinantur Velocitatcs five Momenta Motus tarn veri quam apparentis circa Solem, ficut e- tiam accefsus vel recefsus a Sole, in dato quovis datq- ;um Orbium pun(fto. Deinde ut I'heoriam lyftematis Pla'netici pehitius excoleret, ope eorundem Theorema- tum, duftorum Momentorum Momenta perfcruiatus eft, ofteqdirque quibus in orbium puneftis fiant Mdx'mA harum Velocitatum mUtat^nes, idque Soludoriibus .ci|tcWe,&!c6ncinnitate.pr^ ^ 'Si^ AdP Orbis Pldfiftce ElhptfCuSj AP Axis Tranf^ yerrus,' C B Jemiaxis ccbjuga'tu^,"; S Sol^ Q_ Focus alter . V I y y/ V 1 i-i I'd jvio w V* I j ^ ^ ^ ® ^ ^ ^ ^ j a w V i4 ^ oaa V * ElJi|>reos. Per S dUcacuF S'M ^pfi C B p^r^llela : & ;^n^ pan«ftura M iA 4^p tftm- ( 95‘i ) fcit veldecrefcrc didanda a Sole, & S M±=:AC^~ . AC® oi vero capiatur SL media proportionalis inter S®- miaxes AC, CB, erit pundlum L in quo Maxima fie. so quatio Centri, uc vocanc ; five ubi motus anguiaris fit xqualis medio Motui : Quod fi Eccentricitas non ma*> jor fit quam in plerifque Planet is. BL—BM quam proxime ; • Eft vero S L=\/v^ A C"— A C*S C% ' Si quxratur pundum N, in quo fit Maxima mutacio Velocitaris motus realis in Curva, Problema Solidum eft. Eft enim ^ N S=:4 A C — z N ad ^ N Qj— A C uc AC^ — CS^zrzCB^ ad NQ^; adeoque ft, ponatur AO— a, CB— &NQp=y, habebitur squatio — . ia'j’j~\-\cq—\acc—o. Qua refoluta eric y five NQ, diftantia pundi quaefiti N ab alcero Ellipfeos foco. In Orbibus autem parum Eccentricis, quales funt Planeca- rum, fi fiat CD^rSQ,, & jundas AD sequalis ponatur A K, eric reliqua pars Axis K P— N S diftanticC pundi N a Sole quamproxime. Si veto Orbis fuerit Parabo’ica eric SN ad SP uc 5 ad 4, angulufque NSP eric 53®. 8' fere, cujus Sinus eft \ Radii. At Pundum O, in quo motus apparentis five angu- iaris acceleratio Planecas defcendencis, vei rerardatio * afeenden* ( P54 ) afcendentis Maximifii, hoc modo ohtinebicur. In AC capiatur CGr=?AC, ac fiat angulus CSF 30 du- dicque SF squalis ponatur CE, ipfique GE fit GH aequalis. Dico, fi diftantia SO fiat sequalis ipfi P quod in pundo O proveniet Maxima muratio motus an- gularis Planetas in Orbe Elliptico A BOP gyrancis; eo fcilicet in Orbis loco fecundx ditferencise scquatio- num centri Planctae repericntur Maxima, Eft autem S 0=rr A C— Vi A S Q*« Quod fi Orbis Parabo- lica fuerit. ut in Cona^cts, fiet SO ad SP ut 8 ad 7, angulufque OSP fiet 41°. 2,4'r, five cujus Sinus fit ad Radium ut ^ V7 ad i. Denique Minima cum Veiocitate mutatur diredio Tangentis Orbits in pundo R, fi fiat SR xqualis dua- bus tertiis Axis majoris A B. Quod fi Eccentricitas SC minor fuerit quam fPC, Minimum hoc non locum ha- bet, led decrefck fempet hsec Velocitas quacum revol- * vftur Tangens, ufque m ipfum Aphelion , quemadmo* duni leies hahet in omnium Planetarummotibusi Ne- que eciam in orbe Parabolko obtinet, ob Axem e)us in infinitum protenlum. Haec omnia demonftrantur, juxta praecepta Dodri- nse de Maximis & Minimis^ ex Theorematis prjedidis in N° 35X exhibitis, quas quidem hac oc^fione revi- fere Ledorem rariolum non pi^ebit. IL JfologU ( 955 ) II. Jpologta T>, Brook Taylor, J V T>. 8c %S.Soc. contra C J. BernouUium, Math. frof. Bafilea:. [uam odiofas contehtioties obi- ic uitiitciiuu. verum cum patientia noftra pro ignavia habetur, filentium pro confefljone criminis, 8c nuperam calumniam jam nova fequicur concumelia, om- nino refpondendum eft, ne npbis ipfis deefte videa- mur. In Epifiola pro emin:me Mathemattco D. J Berno- ullio, A(fris Lipfienfibus An. iyi6- inferta, plagii reus ftftor fequentibus verbis : “ Hoc nihil novi eft in qui- “ bufdam Anglis, qui fibi folis licere putant, aliorum ‘‘ inventa tanquam fua impune afurpare; quando ipfi Ho- minefque Deofque invocant, ubi vident, vel laltem ** videre arbitranrur, Excraneos in fixorum Inventa ma- nus inferre. Exempla funt quorundam, uc Chey- ** nxi, Des Hayes, Taylori, aliorumque, qur pa(Jtm in- “ ventis Bernoullti funt ufi alienifque, vel nulla prorfus fa8l a mentione Autoris, vel — Palam eft abipfo Ber- noullio promanafte hanc accufationem. Nam in Acftis Lipfienfibus An- 1718. ‘ per filium fuum fatctur le res ipfas tn ilia epiflola contentas quoad maximam partem ami- CO alicni perfcripfiffe. Invidiam equidem praediift^ ca- lumnia! a fe amovere follidte ftudet, atque transferre in vicarium ilium fuum, cum ipfe profitetur, Je non ap- frohare qu£ in alios durius di^ta cenferi pojfunt \ Sed admodum imperfecfta eft hxc purgatio. Nam calum- ni£E funt qure durius dida vocat. Ait le di^a ilia non approbare : Sed improbafte necefte fuit. Teftimonium 1 Pag. i6i. ftudiofb fatius eftet injurias I i i i i i i i Pag. 262. denique ( 95^ ) denique eft pro fe teftantis : Autorem ilium anonymutn citafle opoctebat, ux cum ipfo agere liceret.* Sed is ad- huc laticac. Quam vere autem & ex animo fe durius S^a. non approhare yid&zzwTt couftace quodammodo po- teft ex fequentibus, qux de me ipfe proferr, proprio fuo nomine, nulla ulus peribna ; “ Taylorus Geomerra “ inftgnis & acutus, qui ad profundiora mftra felicicer penerravic, tefte ipfius libro de Methodo incremen- “ torum, probe fenciens impeditam nimis Analyfeos “ fraterniE prolixitatem, eamque in compendium contra- “ here, ac limul generaliorem nonnibiL reddere volens^ tancam. rei affudic obfcuriratem ( qua in aliis quoque “ brevicatem afiecftans impense deletftari videcur) uc du* bitem quenquam fore etiam inter perfpicaciores, qui “ ubique & hie imprimis mentem viri affequatur, imo etiamfi aliunde rem cognitam habeat. tJr jam nihil dicam de ipfo calculo, pro more- ejus, concifo qui- “ dem & contrado, fatis tamen adhuc longo & intri- *'* cato, ft quis fingula ejus capita minutim perfequr ** velir ; praeterquam quod cum Fratre meo ad certias “ quoque fluxiones excurrat ” ^ ' Sit fane liber rile meus nonnihil obfeurus : Difficile eft in re fere nova, & ab ufu communi aliquantulum remota, non efie ob- feurum, Sed maxime obfeurum oportet efle librum, in quern ilia omnia vere dicantur- Et ft vere dicantur, tamen fine ullS. omnino causa talia dixifte, ab inge- nuis moribus prorfus alienum eft, & mera contumelia. Sed audio Bernoullium de exordio conquerentem quo nuper ufiis fum, in folutione problematis Leibniciani in Tranladionibus Philofophicis editi. Stylum acriorem reprehendit quam virum bene moratum deceat, item iilmium contcraptum Extraneorum. Quse liberius ef- fttus fum, h£EC funt : Si nondum viderint [ fautores 3 Aa. Leipf. An. M. Jan. p.-iS- Leibnitii \ ( 957 ) Leibnicii ] quomodo ex ilia ’’ [ ex anteriori nempe fe* lutione general!] ^equationes fine deducendiE, id pro* “ fe£to illorum imperitice tribuendum eric ” Hxc fateor paulo durius fonant ; fed fi ad caulam attendas conturaelia vacant. Faurores Leibnicii ( non omnes in- telligo, fed Bernoullium tantum, & Socios ejus anony- mos nobis infenibs, ^ univerfos Anglos indigne trada- runt. Solutionem illam generalem cum non intcllige- rent, derifui habebant : In injuriofos & deiifores me liberius explicui; contumelia non eft. Sed ubi ille contemptus Extraneorum ? Neminem ego nominatim citavi: De Faucoribus Leibnicii fum fo)um locutus. Sed abfic ut omnes defignatione ilia omnino intelligerem quocunque modo caufe Leibnicii favences ; canquam ipfe caufe Neuconianse eftem tarn percinacicer addidus, ut alios omnes odio habeam. Sed concroverfia ifta Neutonum inter & Leibnitium nihil ad me. Solos in- tellexi Faucores illos qui in Anglos eftenc infenfi, qui me nominatim calumnia provocarunt j Bernoullium ice- rum dico quem Frincipem agnovi caufx iftius, foci- ofque ejus anonymos vel veros vel fidos. H^ec a- percius dico, ne alii de noftra in alios contumelia im- merico querantur. In immerentes injuria eftet, in Ber- noullium non eft. Sed ad fuperiora ilia redeo. Plagii accu(br,tanquam inventa Bernoullii, aliorum, u- furpaflem ut mea. Exempla proferat, dabitur refponfum. Plura fane tradavi cum aliis communia; fed inventis alienis fum minime ufus ut meis. Propria ubique fum ufus Analyfi, ( fi Ifoperimetrum excipias, de quo po- ftca dicetur ; ) ut nullo modo dici poftic me alios frau. dafte. At Autores nominafle oportebac, unde artem hauferam. Tanta me quidem tenet reverent ia illu ftrium nominum, Hugenii, Hofpicalii, Varignonii, Leib A Tnnf. Phi). N° 354. I i i i i i i z nitii. C ) nitii, aliorum, ut nerciam an ex hac parte non p€cca-> verim, cum mihi ipfi deelTe videar, cui tamos viros citafle (emper fuiflec ornamento. Nimia fortafle igna- via erat, quod de rebus cum eflem maxime follicicus, hiftorias rerum penicus neglexerim. Sperabam tamen me in tantse fraudis fulpicionem incidere non potuifle, cum illuftriflTima tantorum virorum opera earn faci!c detegerent. cum Bernoullio communiter trada* vi problemata, funt, de Funicularia, de Centro Ofcil- lationis, & de Ifoperimetris. In duobus primis fum propria omnino ufus anal)Ti; in Ifoperimetro ufus fum analyfi Autoris Jacobi Bernoullii, Viri k rebus Mathe- maticis optimc meriti, cui debitos nunc perfolvo ho- norcs. Solutio noftra problematis de Centro Ofcilla- tionis, cum amicis meis communicata eft ufque ab ini- tio Anni 1712. ut teftes pofliim citare epiftolas auto- graphas Keillii noftri; Liber item nofter erat penes So- cietatem Regiam, & cum omnibus fere noftris Mathe- maticis communicatus, ulque a menfe Aprilis Anni 1 7 14. quod hie monicu neceflarium duxi, ne Solurionem iilam fibi vindicec Bernoullius ; cujus Solutiones ^ dux extant eodem Anno editx ; quarura pofterior cum no- ftra, quoad principia, tarn mire conftntit, ut jurares ab eodem homine efle ucrafque inventas. Materia de Ifoperimetris excogirata primum eft a Jacobo Berno- ullib, ficiit jam innuimus. tjus extac Solutio cum Ana- lyfi, in Adtis Lipfienfibus Anni 1701. Extat Analy* fis fratris in Conimentariis Regix Scientiarum Acade- mix Anni 1706. Extat & Solutio in Lihro noftro. De eadem materia Commentarium nuper edidir Ber- noullius in Atftis Lipfienfibus Anni 1718, proxitni 5 Altera m Aft. Lipf. M.Jun. In Comm. Reg. Sc Acad. MAugjkeia. ^ P. 16. & Has igitur afiafque ob rationes, aftum a'gere miaime vi- debor, «c. p. iS, ' Ibi, ( 959 ) Ihi, tje aiSum agere videatur, non meis folummodo, \^rum edam fraternis folucionibus malevolus derrahere aggrediturj fratri prolixitatem \ mibi obiiuritatem ^ objiciens. De novis iliis inceptis nihii non magnum ^ poIHcecur ; & ofe cujufdam princif^iiy ah miformitatis le- ge, qu^nt nems hucttfque ohfervavlt, pet it i, rem totam pene fine calculo, nullo labore abfolvet. Sed nefcio quo faco fit, ut in hac materia de Ifoperimctris, 6er- noullius Deos omnes Temper offendac iratos, Nam pri» mo, prifiina ilia Analyfis ejus a capite ad calcem quafi imum aliquod vicium maximum conftituic : Secundo, quod tamum jacliicat Principium, a lege uniformitatis, quam nemo hucufque obfervavic ( fic enim ftrenuus af- firmac) peticum, a me olim obfervacum eft: Denique quam hie tanquam novam cxhibec Analyfin, cota me- ra fraterna eft. Analyfin enim conftituunc Prsccepta, juxta quas deinde inftituitur calculus; qui non Analy- 7, Nullos hie ofFendet 'LtSlor jeopuks, quos^bjicit operofa Fratris anaiy- fis-, atque difFtfrentiarum tertiarum tncas ac fpinas, quibus undique oi/Jip- ibi fentit viam, in noftra methodo nullas percipier.— — Nec fratris calculi prolixitatemi nec Taylori obfeuritarem aeque ingiatam ac moleftam fibi metuendam habeat, />. 18 quam Frarer per operop.JJim^m fuam analy- fiu eliciii% p- 23.— —non tanrum ea, quae a fratre meo quondam propo- fita magna pempa, nec minor i cmatu & l»bore foluca fuere, ego ex fola lege Uniformita is folvi citra calculum analyticum, &c. S Fide Not. prated- item ejua ex p. 18. j/tm funt deferipta. 9 -publictim ei gratinm h»bitu'f»'7i, quod occafio mi“ hi extucrir, taiia nunc divulgandi, quae forte cum mulris aliis in fehedis m«is psrpetuo manfiflent fepulta, quamvis recondita Geomciria fines non pa- rum prolatura, p i7. quod ibi ex incuria prrerervifum reparabo hie «eie folvndi modo„ qui fingulari facilirare expedic problemaC', non tantum omnia qUE de-Ifo-pctimetris propolUcrat Frater, fed & innumera alia iliis affinia, tb. ope cujufdam principii ab unifor nitatis lege, qua7n nemo hucuf/jne eb- fervavif, penri, ex ibU Figurae inTpsttiore, ac line ullo pene calculo lequa* tfones pro cufvis quailitis fponce veluc fe off:rentes I'.arim eliciam , &c. uc in Not, 7. aftum agere minime videbor, fi in hoc arguinenro per fe difficili viam monftfsm & rationem brevem, platiam, elaram, & facilem, qua qui(- que medio. ri quoque inge- io prtedicus ad veritates I'las ablfiuliores ( non ^dealiorum, fed) propriis oculis fpe£tandas per venue poUitj ita nempe, uc, &c, ut in Not. 7. ( ) fis eft, (ed inftrumentum Analyfeos. Praeceptis ftmel pofitis, quivis facile calculum inftituit, more quifque fuo, hie prolixius, ille magis concinne, prout unicui- que faveric Minerva. Negandum non eft, Bernoul- lium calculum tandem concinnafl’e, & reddidifte clegan- tiorem 5 (ed tamen in Analyfi fraterna fecit, non liia : Nec dubicandum quin frarer, adhuc ft vixiftet, rem red- didiftet non minus illuftrem Analyftn diximus in prae- ceptis contineri ; praecepra verb lunt omnia fraterna. Nam quod curvac quasfttx arculum minimum, tanquam ex tribus lineolis elcmentaribus compoftcum contempla- tur, vel ipfb fatentc a fratre eft ; quod ex data Ion- gitudine arculi iftius minimi quxrit rationem differen* tiarum Ordinatarum in Lemmatis fuis, a fratre eft : quod rationem eandem denuo quaerit, faciendo ut fit areola nafeens, ex FuniHonibus ( ut vocat ) compoft- ta, vel maxima vel minima, a fratre eft : quod deni- que ex duplici ilia expreftione ejufdem iftius rationis arquationem colligit qua curvae quaefitae natura definia- tur, a fratre eft. S'ed hxc Solutionem conftituunt. Er- go vSolurio mera fraterna eft. Dixi me olim ufum efie Principio illo, quod tanta cum oftentatione ftbi arro- gat Bernoullius *. Ex eadem una pagina, en duo exem- w m pla. In pagina 113, Libri mci haec funt — =^..Sed m * “ eft — novus valor ipftus unde eft ^ quantitas “ data Luce clarius eft me hoc loci ex obfervata lo Ltar pro hoc, ut ipfe fecit in fua Analyfi, contemplatione arculi minimi, &c. ?• iS. uniformi- f p6i ) tn uniformitate inter formulas, — , — , conclufifle quod A. ‘A t fit ^ quantitas data. Idem feci in fequentibus. ‘‘Pone V mn m^n m nn hoc eft &c ubi ut unifor- ^ > m nn mn n // y / micas appareret inter formulas -y, scquationem transformavi' Videtis, credo, quam feliciter penetra- verim ad profundiora Bernoullii. x\n hrec obfcura dicet ? Ad primam jam pattern promifti pervenio, uc o- ftendam priftinam illam Analyfin Bernoullii efle omni- no corruptiftimam.- Primo per fubftiturionem fatis rir- diculam, ex profundiorihus juts nefcio quibus petitam, sequationem FJ \ A BO=(pco x Apw transformat in hanc FO X F—(pu) X i quod in cafu particulari ( nem- pe quando funcftiones Tunc ut quadrata ordinatarum ) hue redir, ut Tint fimul /^O x A 0— Xfw & FOx P F-(poaX'n-(p h unde confit P F : RO :: 7r(p : pea Sed hoc impoftibile eft, quoniam eft vel P F-i Pk0~^p(>}- ’^7T(p, vel P Fc-ROzrpatC-^tp'^ quorum neutrum cum analogia expofita conciliar! poteft. Nam ft P F~:^R0 -ypca^it.x;5 inleito. rc^ijfioefe habere ” Errores ergo fuos jam denuo adopta- vic. Unde fortafte nunc qucrrec aliquis. Quo jure hie primas fibi in fublimiori ilia Analyft ram obftinata am- birione arroget ? Uc nemo fit qui in ilia aliquid profe- ceric. quin continuo acculetur ad frofundiora Bernoullii per/etf'rffe Unde conftec verum efte, quod quidam nuper afErmavic, regulas extantes in libro de Analyft infinite parvarum a Bernoullio emanafte Quod lau- des Excellentiflimi Marchionis Holpitalii ftnt fuo Pr^- ceptori cribuendae ? An hie fit idoneus qui alios do- cuerit regulas differentiandi differentias ? Cum multis aliis qu.T ftgillatim enumerare non eft opus. Sed iftis refpondeat qui volet : nos in hifee diutius non moramur. II Pag l6. 12 Pag I7» 13 Pag. 18. vid^ ttiam €p. pro Em» Math. ^ feripta ipfins BirnoHlhi p»Jj[im, 14 Concedit Dn. Mafchionem de I’Hopital cakulum iftum intellexiflej nec ignoiat, il!uftri(fimum hunc virum eundem a Cel. Bernoullio didicifTe: trque n.inime ipfom fugit, regulas in di&o libro [ de ^nmlyfi infintte peerva^ rum ] extantes a Cl- Bernoullio ptomanafle- aB. Lipf An. 1718. p. 4^4- 15 Dum irrerea conjici poteft, ilium enm Dn, Newtono ab initio in ifto eirore baelifle, donee tandem liberati fuillent ufu calculi differcntialis, ^ regulas differentiandi different ias d Cel. Bernoullio edeUi ejfeut. ib. p. 465* * Res '( 9^1 ) Res ipfas expofui. peroratione non utor • fiarum e- nim tceder. Nec fi quidquam regellerit Bernouliius, ukerius refpondere neceflo habebo. A contumeliis nos femel vindicate & jus & ratio poftulat ; ulterius non expedic. III. An Account of the ImpreJJion of the almofl En- tire Sceleton of a Urge Animal in a Very hard Stoney lately prefented the Royal Society, fro7u Nottinghamfliire. By Dr, William Scukely, M D. and R. S. Soc. Having an Account from my Friend, Rohert Darwin^ E(q; of Lincoln’s-Itm, a Perfon of Curiofity, of an human Sceleton ( as it was then thought ) imprefs’d in Stone found lately at the Rev. Mr. John South's^ Re(3or of Elfton near Nejvarkt Nottinghamjhire, I was defirous of a Delcription of it, for the Entertainment of the R o y a l Society, and have at length procured the Stone it (elf for their Re- pofitory, where fuch remarkable Appearances are befl: preferv d, and delervedly valued. It cannot but be mat- ter of Regret, that fo confiderablc a Rarity, the like whereof has not been obferv’d before in this llland fco my knowledge ) (hould be maim’d and imperfedi, yet we may content our (elves if enough be (lill vifible to favour a Conjedure of what it has been. The Stone it felf is a blue Clay Stone, the fame as ( and un- doubtedly came from ) the neighbouring Quarries of Fulheckf or thereabouts, upon the Weftern Cliff of the long Trad of Hills extending quite through the ad- jacent County of Lincoln, k lay, time out of mind, Kkkkkkk ac at the Tide of a Well near the aforefaid Mr. Scuta's Farfonage- Houle, where it had ferv’d for a Landing* place to chofe that drew Water ; but upon removal, the Under fide exhibited this unufual Form, and was accordingly taken notice of by that worthy Gentleman, and laid up in his Garden for Curiofity-lake Where the remaining part of the Stone, which contain’d the Upper-part and Continuation of the Sceletoft, or that which was the other fide, and tally’d with it, may be, is now utterly unknown : but upon view, I am per- fuaded, it cannot be reckon’d Human, - but Teems to be a Crocodile or Forpoife. There arc Sixteen rerte- ht‘£ of the Back and Loyns very plain and diftind:, with their Procefles and intermediate Cartilages, Nine whole or partial Ribs of the Left-Tide, the Os Sacrum^ JUum in Jitu, and two Thigh-Bones difplac’d a little, the Beginnings of the Tibia and Fibula of the Right- Leg ; on one Corner there feem to be the yefli^ia of a Foot with four of the five Toes, and a little way off an entire Tod> now left perfed in the Stone: there are no lefs than Eleven Joints of the Tail, and the Cartilages between them of a White Colour diftin- guifhable from the reft We fhould impofe upon our Senles, to quefiion, whether thefe be the real Reliques of an Animal ; for the very Bones themfclves are now to be feen as plainly, as if prelerv’d in an Egyptian Mu,mmy ; a .very little while ago, the Society had a Draught of a Crocodile, tho’ a fmall one, found af- ter the like manner inclos’d in Scone, from a Quarry in the Mountains of upper Germanj. I fuppofe the fame Reafbn accounts for both and all the reft of thefe kind of Fofiils, and 1 pleafe my felf in an ocular E* vidcnce, and fb great a Confirmation of what f had the Honour to prefenc to the lio^al Society, in a late Difeoutfe, where I hinted ac_a Solution of fome ob- vious ( 9<55 5 vious and remarkable Pbxtiomena, in the externa! Face cf the Globe, confequenc to its Formation, as fee forth in the Mo fuc Account; and of fome Changes it fuf- fer’d at the univerfal Catacljfm, and Proofs of chat great Cata/irepbe of the animal and vegetable World in Plants, Shells, and Parts of living Creatures found in Rocks and Qiiarries. Its remarkable, that all the Stone Pits about the Country whence this came, abound with prodigious Quantities of Shells, and the like, and the greaceO: part of the Subfiance of the Scone is a Compofition of them. There are many Account'' of them in the Tranfa^ions, and this Stone has many Shells of dif- ferent kinds in it. S'r Hans Sloan has a Fidi-Sceleton, amongfl his immenfe Treafure of Curiofities, found near this Place, given by the Duke of Rutl-n-^ If we look upon a Map of the Coun.ry, and obferve the Lincolnfhire Alfos which 1 fpoke of before, how they run 50 Miles North and ^outh, and on the Well fide are fleep and rocky, we may fee the Reafdn why thefe Quarries (liould be fo fluft with them ; for it is juft to conceive, that upon retiring of the^ Waters of the Deluge from the Superficies of this Country, into the Eaftern Seas, tliele heavy Bodies met a full flop, and were intercepted by thisCiifF, which has re- tain’d fuch vaft Quantities of them ever fince: whflft thofe which fell upon common Mold are moftiy rotten, and now loft. Sir I^aac t^evoton^ DocSlrine of the Attraction of tne Particles of Matter, according to the Quantity of its Solidity, Proximity, and Surface, efpecially that it is irs- finitely greater in the point of Contaft, upon which depends its Cohefioii and all- the Varieties of Phyficat Adiod, will eafily direct us to a Notion of PetrifJ (tion. We karn how a proper Degree o-f Heat or Cold, Kkkkkkk 2, Moifturs, ( ) Moidurc, Motion, Reft; and Time, promote tlii? Prin- ciple, from the common Experiments of Chryftalliza- tion and Freezing even before the Fire, and in many Chymical Mixtures. Whence we cannot be ignorant of tone growing in the Quarries gradually, not by any fancied Vegetation, tho’ there is fomething like it in Corals, but generally by Appofition of Farts to Parts, as is notorious in the Fluors of fubterraneous Grotts and Caverns. So that we have no reafon to doubt but what was Clay, Sand, or Earth 5000 Years ago, may now be Stone or Marble, according to the Proportion of Concurrence of fuch mentioned Caufes. This will perfuade us that the now barren and rocky Plains of the Countries of Syri/t, India, and Arabia, are owing to Natural Caufes, as well as an immediate Curfe of God for the Difobedience of irs ancient Pof* feflbrs his peculiar People, becaufe the fame is obfer- vable of the famous Countries of Gretce and Africa, warm Regions fo renowned for Fertility in antient Au- thors. Wherefore there may be fome likely hood in the Opinion of thofe who think that in many Ages the whole Face of the Globe may become one great Rock. Dr. Plott, in his Natural Hiflory of Oxfordfldre, gives an Account of a Tumulus, now a perfedl Mount of Stone: and upon St. VincenPs Rock near Briftol are Fortifica- tions now become Folid Cliff I remember, about fix Years ago, Vix.. Ralph Widdrington, Brother to the Earl of that Name, Ihew’d me many human Bones taken from whole Sceletons, with Brittifh Beads, Chains, I- ron Rings, Brafs Bitts of Bridles, and the like, which were dug up in a Quarry, near the Seat of the Fami- ly, at Blanknej, Lincolnfhire ; which very probably was plain Mold when thefe old Corpfes of the Britons were interr d ; and fince then I faw many human Bones and Armour, with Roman Coins, Fibula^ dre, found in a Stone- ( 9^7 ) a Srone pit in the Park at Norfolk ; belongs ing to Sir Nicolas V Eflrange, in whofe Ciiflody they no'.v arc, which were conjediircd to have been buried in Earth after a Battle- From whence we may judge it a vulgar Miflake- when in the Ruins of old CaBles and Walls, wc admire theTenacity of the Mortar, and arc apt to praife our Ancefiiors, .for an Art which we fuppofe now loft; when doubtlefs the otrength of the Cement isowing to the Length of Time : and in future Ages our Modern Buildings may obtain the fame Judg- ment. From all which IniJances, I only defire to infer the antient Bate of thefe ClifTs, where thisSceleton was, and Shells are daily found, intimately mixt in the Subfiance of the Stone, to have^been formerly of a fofter Con- fiflence, capable of admitting them into its Bowels, and to have immur’d them as part of it felf; and that Earth which is now manageable by the Plough, may pofTibly in time afTume the fame Denfity, at lead: very little below!' the Surface ; for in this very Cliff the upper Strata are yet Clay, growing harder as deeper. VVhac Creature this has been, for w^ant of a Natural Hiflory of Sceletons, W’dl worthy the Endeavours of this So- ciety, we cannot pofitively determine; but generally find the like to be amphibious or marine Animals. Why fuch rather than many others, fliould chance to be thus entomb’d, may be thought, becaufe they Were able much longer than Terreflrial Animals to live in that World of Waters, even till they began to abate and fall away into their deflin’d Receptacles; fo that while the Bodies of the reflToon perifhing, were cor- rupted, and their Bones feparated and difpers’d much earlier; thisSceleton, with others of its like, fell entire into the Fiflures of this Bed of Clay, which has fince turn’d into Stone, and made this noble Monument and ■ pregnanE ( 9^8 ) pregnane Teken of that general rmiudation, durable as the vain glorious Monarchs I'yramids ar Mmpkis; to be perpetuated in the lading Records of this Society. See the Figure of this ImprejUion, in Tab, T, IV. J curious De/crlftion of the Strata ohferVd in the Coal-Mines of Mendip in Somerfet- (hire, being n Letter o/John Scrachey Efq-^ to Dr, Robert Welded, M.D. and R. S. Soc. and by him communicated to the Society, I Now fend you the Obfervations which f fome- time fince promifed you, relating to the different ttrata of Earths and Minerals found principally in the Coal-Mines in my Neighbourhood. For the bet- ter Illudration whereof, 1 have inclofed a Draught, wdiich you mull fuppofe the Setdion of a Coal-Coun- try, and to take in about Four Mile from the North- Wed ro Soutl>Ead, and may be applied to the Veins of Coal as they lye at Faringdon-Gourny, and likewife at Bifiop-Sutton, W'hich lad Place is near Stowy, but in the Pariili of Cherv Magna in this County of Somerfet. For Difeovery of Coal, they fird fearch for the Crop, which is really Coal, tho’ very friable and weak, and fometimes appears to the Day, as they term it. ; or elfe for the Cliff, which is dark or blackilli Rock, and always keeps its regular Courfc as the Coal does, ly»> ing oblicjueiy over it. For all Coal lies flieiving like the Tyie of a Houfe, not perpendicular nor horizontak unlefs it be broken by a Ridge, which is a parting of Clay, Stone, or Rubble; as if the Veins by fome vio- lent Shock were disjointed and broken, lo as to let in in Rubble, between them. The Obliquity or Pitch, as they term it, in all the Works hereabout, is about Inches in a Fathom; and when it rifeth to the Land is called iXxQCrop, but in the North Baffsthg, In the Works near Stowy, and likevyife at Fartngdon it rileth to the North Weft, and pitcheth to the South Eaft ; but the farther they w'ork to the South Weft, the Pitch enclines to the South ; and e centra, when they work towards the North Eaft. So likewife they obfervC: as they work to the South Weft, when they meet with a Ridg it caufetli the Coal to trap up, that is, being cut off by the Ridg, they find it over their heads, when they are thro’ xhtRidg: but on the con- trary, when they W’ork thro’ a ridg to the North Fajl, they fay it traps down, that is, they find it under their feet. Coal is generally dug in Valleys or low Groundso The Surface in thefe parts is moftly a red Soyl, which under the firft or fecond Spitt degenerates into Malm ot Loom, and often.yields a Rock of Reddifli Fireftone, till you come to four, five, and many times to twelve or fourteen Fathom depth, when by degrees it changeth to a Gray, then to a Dark or Blackifti Rock, which they call the Coal. Clives. Thefe always lye ftielving and regular as the Coal doth But in thefe parts they never meet with Fire ft one over the Coal, as at Nmcaflle and in Stajfordjhire. Thefe CZ/Wj- vary much in Hard- nefs, in fome places being little harder than Malm ot Loom, in others fo hard as that they are forced to fplic them with Gunpowder So likewife in Colour, die top inclining to red or grey, but the nearer to Coal the blacker they gi%!b; and wherefoever they meef:' with them they are fure to find Coal under thenio. But to their difappointment ’tis not always worth the the digging. The firfl or uppermoft Vein at ^Sutton ( P70 ) is called the Stinktr^g Vein» It iS hard Coal fie for Me* chanick ules, but of a fulphurous 6mell. About five Fathom and half, fddom more than feven Fathom un- der this, lyes another Vein which from certain Lumps of Scone mixt with it like a Qafux monnum not Infla*> mable, called Cats-head, they ca l the Cathead Vein. About the fame Depth under this again lyes ihtThree Coal Vein, fo called becaule it's aivided into three dif- ferent Coals ; Between the firfl and fecond Coal is a Stone of a foot, in fome places two feet thick ; but the middle and third Coal feem placed loofe on each other, without any feparation of a different viarter. Thefe three Veins before- mentioned arc fomeiimes work’d in the fame Pit: But the next Vein which 1 am going to mention is generally wrought in a feparate Pit ; for tho’ it lyes the like depth under the other the C7/j^ between them is hard and fubjed: to Water; whe' fore i have reprefented a Pic funk thro’ the three Upper Veins at A. and another funk upon x\-\tjhree od i^eins only acB. and fo if they fink on any of the lower Veins they go more to the North Weft. See Fig Tah II. Next under the three Coal Veins is the Peaxv Vein, fo denominated becaufe the Coal is figured with Eyes re- fembling a Peacock’s Tayl, gilt with Gold, which Bird in this Country Dialed is called a Fea'x. The CUjf alfo over this Vein is variegated with Cockle-jh -lls and Fern Branches, and this is always an Indication of this Vein, which, as I before hinted, is always fearched for about 1 5 Fathom to the North Weft of the former. Under this again between five and fix Fathom lies the SmitVs Coal Fein, about a >%rd thick; And near the fame depth under that again«the Shelly Vein: And. under that a Vein of 10 Inchd^ thick, w'- ich being little valued, has not been wrought to any purpofe Some fay there is alfo another under the lafl, but that Taht-JT: ^7o . ( 97* ) that has not been proved within Man’s Memory^ At Faringdon they have the fame Veins, which, as I am informed, agree in all Parts With thofe of Bi(l36p-Sutton before-mention’d. But as Faringdon lies four Miles South-Eaft {tomBijhop-Sutton, fo, in the regular Courfe, they would lye a Mile and deeper than thofe at Sm^ ton. But as in faift they are dug near the fame Depth, it follows there mull be a Trap, or feverai Traps down, which in all mud amount to that Depth between, the faid Works; Between Faringdon and High-Littleton tht fame Veins feem to retain their regular Courfe ; but at Littleton their undermoft and deeped Vein is the bed Coal, which at Faringdon proves fmall. On the other hand, in the Parilh of Stanton^Drew, to the North* Ead of the Coal- Works at Sutton afore- faid, about a Mile didant, and in the true Courfe with thofe at Sutton, the fame Veins are found again. But here they wind a little, and their Courfe or Drift runs almod North, and they dip to the Ead ; which Winding is attributed to Ridges, which the Workmen have met with on both Sides, and have occafion’d them to difeontinue the Work that way. At Stanton they have little of the Red Earth or Malm on the Surface, but come immediately to an Iron-Gritt or grey Tile- Stone, which is a Fore-runner of the CoaUClives ; in all other Matters they agree with the Works near Stowy: In the fame Parilh of Stanton- Drew, a little to the Eadward, they have another Coahwork, but the Veins are in all refpe, on the ixth Day of ^ugufl, a large Turnip was plucked up ( though probably not fo big as feveral others then growing upon the fame Ground ) which, together with its Top and long defcending part of the Root, weigh- ed above Two Pounds and Fourteen Ounces. At the fame time alfo was weighed an Ounce of the fame fort of Turnip'Seed, that the Gardener had fown his Ground with ; and afterwards a Thoufand of the Grains were counted fmgly out of the Ounce fo weighed ; and the reft of the Ounce was divided into Heaps, as near as could be guefled, equal to the 1000 Seeds firft fevered and laid together : And it was found that the whole Ounce contain’d above 14600 fingle Grains ; which Number multiplied by 46 ( viz. the Number of Oun- ces that the Turnip Weighed ) produceth 6yi,6oo,viz„ the Number of fingle Grains of Seed required to equal the Weight of the Turnip. From whence may be ga- thered, that ( upon fuppoGtion, that the Increafe of the Turnip was ail along uniform ^nd equal, from the Time Time ic was {own till it was pluck'd up ) the Grain of Seed which it fprung from, weighing when ic was fown but ,7^, of an Ounce, was increafed in Weight ac- cording to the following Proportions, vlz^^ In Six Weeks time ^ ' Some time after, another Ounce of the fame fort of Seed was exadly weighed, and the Grains were found , to be in Number 14673. Another Turnip of the fame Crop was plucked up on the 21/? Day of O^oher; and being put into a Scale, j: was found to weigh above Ten Pounds and an half 5 which unufual and truly wonderful Bulk it acquired i ( it being fuppofed, as above, that the Growth was all along alike ) by increafing the Weight of the Seed it was raifed from, ly times in every Minute of an Hour from the Sowing to the Drawing of it. The Gardener negleded to thin his Turnips in due Time, elfe probably their Growth had been more con- fiderable. At anotherTime, in two other forts of Turnip-Seed, it was found by counting, that an Ounce of one fort contained i47oz Grains-^ and an Ounce of the other fort no fewer chan E490J Grains. It’s credibly reported, chat of late Years, Turnips have been prcrry frequently found growing in feverai Counties of this kingdom that have v/eighed above twice as much , one of v, hich was fsen at Birmingham about the Year 1710. Every < Hour JMinute of C an Hour Week Day times its own Weight. VL An VI. Mcount of fome Experiments tried with Mo7if.Y'i\\cttes'Burnin^Con£aVe^ mjune 1718. (By the ^ev. Dr. J. Harris and Dr. J.T. Defa- HIS Miroir is a Concave 47 Inches wide, and ground to a Sphere of 76 Inches Radius ; fo that its Focus is about 38 Inches diftant from the Vertex of the Glafs. Ihe Metal of which it is made is a Mixture of Copper, Tin and Tin-Glals, whofc Reflexion has fomething of a yellow Caft. The Concavc«Surface has Icarce any Flaws, and thofe very fmallj but the Convex fide, which isalfo polifli’d, has fome Holes in it. Having held feveral Bodies in the Focus of this Mi- roir, we obferv’d what happen’d to them whilft expos’d to this great Heat ; and with an half Iccond Pendulum took notice of the Time in which any material Change happen’d to them. The Experiments were as follow, and made from Nine till Twelve in the Morning. I . A red piece of a Roman Patera^ which began to melt in 3 Seconds, was ready to drop in lOo. X. Another black Piece melted at 4, and was ready to drop at 64 Seconds. 3. Chalk taken out of an Echinus Spatagus fill’d with Chalk only, fled away in 13 Seconds, 4. A FoITil e-Shell calcin’d in 7 Seconds, and did no more in 64. 5. A piece of Pompeys Pillar at Alexandria, was vitrified in the Black Part in 50 Seconds, and in the White part in 54. 6. Cop- guliers, %eg, Soc. SS. r ( 977 ) 6. Gopp^r-Oar, that had no Metal in it vifiblc, vitrified in 8 Seconds. 7. Slag, or Cinder of the ancient Iron-work faid to have been wrought by tliQ Saxons, ready to run in 29 Seconds and an half. the Glafs grovsing hot, burn d wit h much lefs Force. 8. Iron-Oar Bed at firft, but melted in 24 Se- cond:. 9. Talk began to calcine at 40 Seconds> and held in the Focus 64. ic. Calculus humanus in 2 Seconds was calcin’d, and only dropp’d off in 60. ]j. An anonymous Fifh’s Tooth melted in 32 Seconds and an half. 12. - The Ashejlos feem’d condens’d a little in 28 Seconds; but it was now fomething cloudy : MonC Vilktte fays that the Glafs ufually calcines ic. 13. -A Golden Marchafite broke to pieces, and began to melt in about jo Seconds. 14. A Silver Sixpence melted in 7 Seconds and, an half. 15. A King rT/7/;^««s Copper Halfpeny melted in 20 Seconds, and ran with an Hole in it in 3 1. 1 5. A KmgGeorge*s Halfpenny melted in 16 Se-. conds, and ran in 34. 17. Tin melted in 3 Secondsi 18 Cafl: Iron in 16 Seconds. j 9. Slate melted in 3 Seconds, had an Hole in 6i 20. Thin Tile melted in 4 Seconds, had a Hole and was vitrifi’d thro’ in 80. 21. Bone calcin’d in 4 Seconds, and vitrifi’d in 33. An Emerald was melted into a Subftance; like a Turquois Stone. A Diamond weighing 4 Grains loft .i. its Weight. yik ( 978 ) VII. Account of the Extraordinary METEOR feen alt oW England, on the i ^th of March 17 if. With a Demonflration of the uncommon Height thereof, Edm. Halley, LL, D. and Secretary to the Royal Society. HIS wonderful luminous Meteor which was feen in the Heavens on the 19th of March lafl:, as it was matter of Surprize and Aftonilbment to the Vulgar Spedlator, fo it afforded no lefs SubjeeJt of Enquiry and Entertainment to the fpeculativc and cu- rious in Phyfical things : Some of its Phanowerfa being exceeding hard to account for, according to the No- tions hitherto received by our Naturalifls ; fuch are the very great Height thereof above the Earth ; the vaft Quantity of- the Matter thereof; the extravagant Velocity wherewith it moved ; and the prodigious £x- plofions thereof heard at fo great a Diffance, whole Sound, attended with a very ienfible Tremour of the fubje6t Air, was certainly propagated through a Me- dium incredibly rare and next to a Vacuum. In Num* 341. of thele TranfaBions, I have colle(3ed what I could find of fuch-like Meteors, and fince, turn- ing over the Ephemerides of Kepler, I accidentally hit upon another, prior to all thofe there deferibed, and which was feen all over German'^. Of this the Words of Kepler are.* Die ~ Nov. 1623. Meteorwm ignitum, Clohus ardens ah occaju in. ortum volans tota pajlfim Ger- mania fuit cortfpeefus. In Auflria etiam fragorem exau- ditum affirmarunt epuafi a fulmine ; ^uod vanum tamen puto : nihil enim talc confamant defer iptienes epum extanu Yet neither ( 979 ) neither this, nor any of the other hitherto defcrihed, feem to come up in any Circumftance to this late Ap- pearance; of which I am in hopes to give a fatisfa* ^ory Account, being enabled by the very many Re- lations thereof communicated to the Royal Society, from moft parrs of the Kingdom ; tho’ it was not my good Fortune to fee it my felf ; and tho’ very few of our Countrymen who befl; know the Stars, had better luck. Some of the moft perfed Defcriptions we have receiv’d are the following : /v>/, Our very worthy Vice-Prefident S\x Hans Sloans Baronet, being abroad at that time, happen'd to have his Eyes turned towards it, in its very firft hruption j and the next Day he was pleafed to give me in Writing what he had with great Exadnefs noted about it, in the Terms following : “ On Thurfr/ay, March 19. i7[|, “ pafting along Eaftward by the N E. Corner of Sou- “ thamfton-jireet in Bloowshury-Square, London, at about “ a Quarter after Eight at Night, I was furpriz’d to “ fee a fudden great Light, much beyond that of the “ Moon, which flione then very bright. 1 turn’d to the Weftward where the Light was ; which I appre- bended at firft to be artificial Fire-works or Rockets, The firft place I obferv’d it in, was about the Pld- ** ades Northerly, whence it moved after the manner, “ but more flowly than a falling Star, in a Teeming “ dired Line, delcending a little beyond, and withal “below, the Stars in Orions Belt then in the S, W. “ The long Scream appear’d to me to be branched about “ the middle, and the Meteor in its way turn’d Pe^r- fafhion’d or tapering upwards. At the lower end it “ came at laft to be bigger and Spherical, tho’ it was “ not To big as the Full Moon. The Colour of it was “ whitifh, with an eye of Blue, of a moft vivid daz- “ ling Luftre, which Teem’d in Brightnefs very nearly , 7 M to { p8o ) ro refemble, if not furpafs that of the Body of the Sun in a clear Day, beheld by the naked Eye. This Brighcnefs obliged me to turn my Eyes ( which had “ their Pupils adapted to the Light of the Moon ) fronr “ it feveral times, as well when it was a Stream, as “ when it was PearTafliion’d and a Globe; tho’ I had “ a great Curioficy to obferve it with Attention, ft “ feem’d to move in about half a Minute or lefs, about “ the Length of and to go out, as I guefs’d, about “ as much above the Horizon. There was left behind it, where it had pals’d, a Track of a cloudy or faint “ reddifli Yellow Colour, fuch as red-hot Iron or glow- “ ing Goals have, which remained more than a Minute, “ feem’d to fparkle, and kept its Place without falling. “ This Track was interrupted, or had a Chafm towards its upper end, at about two Thirds of its Length. I “ did not hear any Noife it made, but the place where “ the Globe of Light had been, remain’d after it was extind^, of the fame reddiOi Yellow Colour with the “ Scream for fom^ time, and at firft fome Sparks feem’d “ to iffue from it, fuch as come from red-hot Iron bea- “ ten on an Anvil. The Surprize, Brighcnefs of the “ Light, and Noife of the People upon the Variations “ of the Appearance, calling to one another to obferve “ what they never had obferv‘d in* their Days, and thought to be prodigious, hinder’d me from taking “ notice or remembring any thing farther about it. • It were to be wiiht that Sir had more efpedal- ly regarded the Situation of the Track of this Meteor among the fixt Stars, and let us know how much it part above the Pleiades, and how much under the Belt of Orion, that fo we might with more Certainty have determin’d its Pofition in refjped: of the Horizon of London \ for which purpofe the whole Number of Spe- dacors there has not furniihed us with one fuiHcicnt Obferva- ( 5>8i' ) Obfervation. But all the Relations, however otherwile differing, agree in this, that the Splendour was little inferior to that of the Sun; that within doors the Candles gave no manner of Light, and in the Streets nor only all the Stars difappear’d, but the Moon then Nine Days old, and high near the Meridian, the Sky being very clear, was fo far effaced as to be fcarce leen, at leaft not to caff a Shade, even where the Beams of the Meteor were intercepted by the Houfes : fo that for Tome few Seconds of Time, in all refpeds it refembled > perfedt Day, The Time when this happen’d was generally rec- koned at a quarter paft Eight; but by the more ac’ curate Account of the Rev. Mr. Pound ( who only law the Light J agreeing with what has been lent us from the Pariftan Obfervatory, it appears to have been at 8*^ 8' apparent Time at London. And the Sun being then in 9r gr. of ArkSt the R^ht Alcenfion of the Mid-Heaven was gr. qy', whereby the Pofition of the Sphere of fixt Stars is given. Hence the Lucida Pleiadum will be found at that time to have been gr. high, in an Azimuth 6 gr. to the Northward of the Weft, and confequently the Arch the Meteor moved in, was inclined to the Horizon with an An- gle of about z7 gr, having its Node or Interfedion therewith, nearly South South Wefl ; as will be more evi- dent by what follows. At Oxford five Minutes earlier, Mr. John Whitefidel R. S. Soc. Keeper of the Ajhmole Mufeum, and very skilful in both Mathematical and Phyfical Matters, immediately alter the Extindion of the Meteor, made hafte out to fee what it might be, and well confider’d the Situation of the Track it had left in the Sky : He found it to have paft about i r Degree above the preceding Shoulder of Orion, and about 3 r above 7 M X the { p8i ) the middle of his BelPy where there appear’d a lumi- nous Nubecula of a rcddifh Lighr, being a Dilatation of the Track, feemiog to have been occafion’d by fbme Explofion there; and by'what he could learn from thofe that faw it, it was thereabout that it broke out, and 6rft began to efface the Scars. Hence it proceed- ed as to fenfe in an Arch of a great Circle, and pal^ fing in the middle between the Tail of Lepus ( 6 Baj* ero ) and /3 in the Fore-Foot of Cauis major, it termi- nated about § in the Breaft of the fame, nearly in gr. of Right-Afcenfion, with gr. South Declina- tion: and at the place of its Extindlion there remained a large whitilh Nebula, much broader and of a Wronger Light than the reft of the Track, which he took for a certain Indication of a very great Explofion made there. By Computation it will be found that the An- gle this Track made with the Horizon of Oxford was neareft r\ogr. and its Interfedtion due SSPV; and that the place of its Extinffion was about 9 gr. above the Horizon, in the Azimuth of ^^gr. to the At Worcejler Mr. Nicola! Fatio, a Perfon greatly skill’d in Aftronomical Affairs, faw this Meteor defcend obliquely towards the South, making an Angle with the Horizon of about 65°, and interfe^ling it about S SJV ~ S, as may be colleded from a Scheme thereof Pent up by him, and communicated to the Royal So- defy, Teeming to be defign’d with fufficient Exadncfs. By this the Track left all Orior! and Caais major to the Wcftward, and divided the Diftance between Sirius and Procyon, To as to be almoft twice as far from Pro- tyon as Sirius. The Time here was one Minute before Eight, this City being about 9' of Time to the Weft , of London, and confequently the Right-Afcenfion of the Mid-Heaven 118 T gr* Now ' (9^) Now the Situation of the three Cities London^ Oy- ford, and IVorcefter being nearly on the Point, whereon the Track of die Meteor had its grea* reft Altitude above the Horizon, equal to the Angle of its vifible Way; if we fuppofe it at London to have been 17 ^i*gh, and at the fame time at Worcefter to be 611 gr. high, in the Plane of the Vertical Circle palling through London and IVorcefier ; fuppofing like- wile the Dillance between them to be 90 Geographi- cal Miles, or one Degree and half of an Arch of a great Circle of the Earthy we lhall by a Trigonometrical Calculus, too obvious to be here inferred, find the per- pendicular Height to have been 64 fuch Miles ; and the Point over which it was then perpendicular to have been 30 fuch Miles W.N.W. from Worcefter. And the Geographical Mile to the EngUjh Statute Mile being as ^3 to 20, this Height will be no lefs than 73 En^lilh Miles. The place alfo direoUy under it, will be found to be about Preftain on the Confines of Hereford and Radnor^hhkti. Nor can we be much out in this De- termination, the Oxford Obfervation concurring nearly in the fame Conclufion. This Altitude being added to the Semidiameter of the Earth as Radius, becomes the Secant of Eleven De- grees, fo that the Meteor might be feen above the Ho- rizon in all Places not more than 120 Leagues diflanc from it. Whence it will not be flrange that it fhould be feen over all Parts of the Iflands of Great Britain and Ireland, over all Holland and the hither Parts of German'^, France and Spain, at one and the lame inllant of Time. This fuggefts a very great ufe that might be made at thele momencaneous Vheenomena, to determine the Geogr^t^ fhtca' Longitudes of Maces. For if in any two Places two Obfervers, by help, of Pendulum Clocks duly coircfted by ( 984 ') \ by Coeleftial Obfervation, do cxadly note at what i Hour, Minute and Second fuch a Meteor as thii blows ^ up and is extinguilht, the Difference of thofe Times Will be the Difference of Longitude of the two Places, as is well known. Nor does it require To much as the Ufe of a Telefcope, as in the Methods hitherto put in practice for that purpofe : fo that if thefe Appearances could be predidted, and Notice given of their coming, that we might know when to exped them, I lliould make no Difficulty to prefer this way of fettling the Geography of a Country before all others. Having thus fixt one Point in the Line of its Mention, let us now confider what courle the Meteor took from thence. And firft at th^ Town of Kirkhy- \ Stephens y on the Borders of Torkjhire and WeflmoreUnd, in a Meridian very little to the Weflward of fVorce/her, but about z r more to the North, it was obferved to break out as from a dusky Cloud, diredly under . the Moon, and from thence to defeend, nearly in a Per- ! pendicular, almoft to the Horizon. Now the Moon, be- ing at that time in the third Degree of Leo, was about ■ half an hour pad the Meridian, and confequently much about a point to the Weft, ot S bW : and the Situation of Preftain from Kirhy-Stevens being fufficiently near upon the fame Point, it follows that the Diredion of the Track of the Meteor was according to the Great Circle paffing over thofe two Places. And this is further confirm’d by the Obfervation of ; Sam. Cruup, Efq; Reg. Soc. Soc. who at Tiverton.^ about twelve Geographical Miles nearly due North from Exe^ i ter, obferved the firft Explofion of this Meteor exad* 1 ly in his .Zenith, as he was aflured by applying his Eye to the fide of his' Door, which he took to be per- pendicular, and looking upwards.* And from thence he i law it defeend to the Southwards diredly in the fame : ^ Azi- I ( 9^1 ) Azimuth, without declining either to the Right or Left: Hence it is plain, that the Track likewife pafs’d over this place, which by our beO: Maps is found to lie in a Line with Frejiain and Kirbj-Stevem with Tufficienc Exatlnefs ; fo that we fhall take it for granted that this was the very Courfe it held. On this Suppofition, that the firfi: Explofion, at- tended with the reddilh Nuhecnla, was diredly over Tiverton^ we have the Oxford Obfervation to compare with it, in order to determine more nicely the per- pendicular Altitude there At Oxford this Nubecula W’as found to be 3 gr, above the middle Star of 0- rio»s Girdle^ at 8*^3', and was therefore gr, a- bove the Horizon ; and the Diftance between Oxford and Tiverton, being i°. or 115 Geographical Miles, it will be as the Sine of 61°. 35' to the Sine of 63° 30' So the Semidiameter of the Earth being 3437 r fuch Miles, to 3498 Miles the Diftance of the Meteor from the Center of the Earth ; from W'hich deduding the Semidiameter, there remains 60* Geographical Miles for the Height of the Meteor above Tiverton : And that this was fo is confirmed by the Obfervation of the Revc Mr. Will. Derham^ who at Windfor faw the afore- faid Nubecula about two Degrees above the moll Sou- therly of the Seven Stars in the Shield of Orion \ that is { the Time being 8*^6'^ in the Altitude of 13 \ gr* whence, the Diftance between Tiverton and Windfor being 150 meafured Miles, or 130 Geographical, by a like Proportion we fhall find the fame Height of the Meteor 60 fuch Miles wanting only one Quarter. So tliat in a round Number we may conclude it to have been juft 60 Geographic or 69 Statute Miles above the Earth’s Surface. Nor is it poftible to come at a precife Determination of this matter, by reafon of the Coarfenefs and Inaccuracy of our Data, which were (9^6) I only the Notes of Perfons under the Surprize of the I fuddennefs of the Light, ►and no ways pretending to I Exadnefs; how^ever, fuch as they are, they abun- | dantly evince the Height thereof to have exceeded 6c i Englifh Miles, not to fay 38 or 40, as fome would * fain have it. I was unwilling to leave off, till I had pitcht upon fome Hypothefis that might fubjedi the Motion of ; this Meteor to a Calculus, that the Curious might be > uble to compute the vifible way thereof, either in re- fpedl of the Horizon, or among the fixt Stars: This I found might be done with tolerable Exadinefs, fup- f pofing that it mov’d in the Arch of a Circle concen- trick with the Earth, but 60 Geogr. Miles without it; j- and that the Point of the firfl Explofion was over the i Lar. of 50° 40' and 3® 40' to the Weft of London', and 5 that of the laft Extinction over Lat. 47°. 40' with 4°. 5'o' Longitude: The Time being iixt to 8 ? Minutes paft Eight at London, Hence it will be eafy, ; by a Trigonometrical Procefs, to obtain the vifible Al- ^ titude and Azimuth of the Meteor at either of its Ex- plefions, as feen from any Place whofe Longitude and • Latitude is know^n ; and from the Time given, the Points in the Sphere of Stars anfwering to thofe Azi- muths and Altitudes are readily deduced. Let thofe ! that contend for a much lefs Height of this Meteor try ; if they can on fuch their Suppofition reconcile the feveral i Phanowena before recited with one another, and with ' the Obfervation of the Rev. Mr. William Ella, Redior | of Famfton in Nottingha'mlliire, between Gainsborough | and Bedford, which for its Exatftnels I muft not omit. j Here at 8'^ f the Meteor W’as feen to pals precifely in | the middle between Sirius and the Fore* Foot of Canis j major, moving obliquely to the Southward, in a Line ! whofe Direction feem’d to be from the middle between ] the ,| I ( 9^7 ) the two Shoulders of Orioff, The Latitude of the place being nearly %o', and Longitude fTr/? from London o°. 45'. Let them try how they can account for its being (een five Degrees high at Aberdeen in Scot- land, and near as much at Peterhead half a Degree more Northerly : and then they will be better able to judge whether it did not exceed the reputed Limits of our Atmofphere. Laflly, if the apparent Altitude of the Meteor at Parts was not 5r but ii gr, on the If' Point, when it muft have been in its greatefl: Luftre, there will be no pretence to bring it lower than 1 have made it, efpecially if it be allowed to have follow’d the Track I have allign’d it, over Prejlaln, Cardijf, Minhead, Tiverton, and Breji in Bretan'j. Allowing this to have been the Path it mov’d in, it would be eafy to aflign the real Magnitude and Velo- city of this Meteor, if the feveral Accounts of its ap- parent Diameter, and of the Time of its Paflage from one of its Explofions to the other, were confident with themfelves. But fome of them making its vifible Ap- pearance nearly equal to the Sun’s, w'hich in the Opi- nion of many it far exceeded, we may fuppofe with the lead that, at the time when it fird broke out o- ^*er Tiverton, its Diameter was half a Degree, And its Horizontal Didance being * yo Geogr. Miles from Lon- con, and its Altitude 60, the Hypothenufal or real Di- dance from the Eye will be more than 160 fuch Miles; to which Radius the Subtenfe of half a Degree will be above an Englilh Mile and half, being about 2800 Yards quamproxime: After the fame manner it is dif- ficult to aflign its due. Velocity, whild forae make tc half, others lefs than a quarter, of a Minute, in paf^ dng from its fird Explofion to its lad Extindion: But the Didance it moved in that time being about 3 gt, or 1 80 Geogr. Miles, we may modedly compute .7 N it ‘ ( J>88 ) j it to haVe run above ^oo fuch Miles in 2 Minute; which is a Swiftnefs wholly incredible, and fuch, that if a heavy Body were projeded horizontally with the fame, it would not defcend by its Gravity to the Earth, but would rather fly off, and move round its Center in a perpetual Orb, relembling that of the Moon. Of feveral Accidents that were reported to have at- tended its Paflage, many were the effed: of pure Fan- cy ; fuch as the hearing it hils as it went along, as if it had been very near at hand : others imagined they felt the Warmth of its Beams ; and fome there were that thought, at lead wrote, that they were fcalded by it« But what is certain, and no way to be difputed, is the wonderful Noife that follow’d its Explofion. All Accounts from Devon and Cornrval and the neighbour- ing Counties are unanimous, that there was heard there, as it were the Report of a very great Can- non, or rather of a Broad fide, at fome diftancc, which was foon follow’d by a rattling Noife, as if many fmall- Arms had been promifcuoufly difcharged. What was peculiar to this Sound was, that it was attended with an Uncommon Tremour of the Air, and every where in cliofe Counties, very fenfibly Ihook the Glal^Win- dows and Doors in the Houfes, and according to fome, evert the Houfes themfelves, beyond the ufual Effed of Cannon, though near ; and Mr. Cruvpjs at Tiverton^ on this occafion, lofl a Looking-Glafs, that being loofe in its Frame, fell out on the fliock, and was broken. N&rvjdo We yet know the Extent of this prodigious Sound, which was heard, ^gainft the then Eafterly Wind, id th^fe Neighbourhood of London^ as I am inform a ; and by the Learned Dr. who difliodly heard it be-, yond Lems< in .Sujfex : So that I cannot help thinking, a Meteor.as jthis might hav.e oecafion’d that : F arcus Pfcrum cnUor, &c * — ■ "Nam^ut I ( 9^9 ) ' ' Namcfue DiefpHer Igne corufco nuhiU dividtns TUrumqne^ per purum to»antes Egit equos volucremque currum^ ^0 hrula tellus, (jrc. Concutitur. But whether the Report heard near Lervis were of that Explofion right over Devonjhire, or rather of that latter and much greater at the Extinction over Br/tany, I (hall not undertake to determine, till we have fome further Accounts from France, whence hitherto we have only had, that at Paris the Time of the Appearance was at 17 Minutes pad Eight. It remains to attempt fomething towards a Solution of the uncommon P/j^nowena of this Meteor; and by comparing them with things more familiar to us, to fliew at lead how they might podibly be efFe(ded. And firft the unufual and continu’d Heats of the lad Summer in thefe Parts of the WorkJ, may well be fuppos’d to have excited an extraordinary Quantity of Vapour of all forts; of which the aqueous and mod others, foon condens’d by Cold, and wanting a certain Degree of Specifick Gra- vity in the Air to buoy them up, aicend but to a fmall Height, and are quickly returned in Rain, Dews, whereas the inflammable fulphureous Vapours, by an in- nate Levity, have a fort of f^is centrifuga, and not only have no need of the Air to fupport them, but being agi- tated by Heat, will afeend in Facuo BoHeano, and fublime to the top of the Receiver, when mod other Fumes fall indantly down, and lie like Water at the bottom ; the Experiment whereof was flrd fliewn me by the Reverend Mr. Whitefide ^x.Oxford, and was very lately made before thz Royal Society. By this we may comprehend how the matter of the Meteor might have been raifed from a large Tra(d of the Earth’s Surface, and afeend far above the re- puted Limits of the Atmofvhere being difengaged from all other Particles, by that principle of Nature that congregates Homogenia vifible in fo many Indances, its Atoms ( 9P<^ ) Atoms might in length of time coalefce and tiih * firtuU toujlj together, as we fee Saks fiicor in Water; and gradu- -ally concrading thcmfelves into a narrower compafs, might lie like a Train of Gunpowder in the Ether, till catching fire by feme internal Ferment, as we find the Damps in Mines frequently do, the Flame w’ould be communica* ted to its continued parts, and To run on like a Train fir’d. This may explain how it came to move with fo uncon- ceivable a Velocity; for if a continu’d Train of Powder were no bigger than a Barrel, it is not eafy to fay how very faft the fire would fly alongft it, much lefs can wc imagin the Rapidity of the Accenfion of thefe more in* flammable Vapours, lying in a Train of fo vaft a Thick- nels. If this were the C ale, as it is highly probable, it was not a Globe of Fire that ran along, but a fuccelfive kin- dling of new: Matter : and as fome parts of the Earth might emit thefo Vapours more copioufly than others, this Train might in fome parts thereof, be much denfer and bigger than in others, w'hich might occafion feveral fmaller Ex- plofions, as the Fire ran along it^ befides the great ones -which were like the blowing up of Magazines. Thus we may account for the rattling Noife like fmall- Arms, heard after the great Bounce on the Explofion over Tiverton ; the Continuance of which for fome time, argues that the Sound thereof came from Diflances that encreafed. What may be faid to the Propagation of the Sound thro* Vi Medium, according to the receiv’d Theory of the Air above 300000 times rarer than what we breath, and as I faid before, next to a Vacuum, I mufl confefs 1 know not. Hitherto we have concluded the Air to be the Vehicle of Sound ; and in our artificial Vacuum we find it greatly diminifh’d t but we have this only Inftance of theefletS of an Explofion of a Mile or two diameter, theimmenfi- ty of which may perhaps compenfate the extream Finc- nefs of the Medium, F I N 7 S. * Dele fjrtuitoujt/. / f 99* ) Kumb. PHILOSOPHICAL TRANSACTIONS. For the Months of June, '^uly and Auguft, 1719* The CONTENTS I. \ N Ohjcrvation of the End of the Total Lunar Jf\ EcUfje on the ^th of March 1 718. ohfrved ■near the Cape of Good Hope, fervtng to determine the Longitude thereof. With Remarks thereon By E. Halley, R. S, Seer. II. D. Jacobi Keill, Medicina. nuper DoLloris eruditiffmu De V iribus Cordis Epiflola. HI. An rtccount of fome Experiments relating to the Specifick Gravity of Human Blood, By James Turin, M. D. Fellovp of the College Phyficians, and^. R. S. IV. Bn account of the Sunk Lfland in Humber, fome Tears fince recover'd from the Sea., Being an Extract of a Letter Communicated to the Royal Society by John Chamberlayne, Efep^ R. S. S. V. A Way for Myopes to ufe Telelcopes Eye^Glaf- fes, an OhjeLL^Glajs alone becoming as ufeful to them^ and jometimes more, than a LLombination of GUffes. Commu’» micated to the Royal Society, by the Reverend J. T. DeC- aguiiers, LL. D. and F. R. S. VI tdlerc and accurate Tables for the ready Computing of the EcUpfes of the of Jupiter hy Addition only. By the Reverend Mr.]^mQS Pound, R S. S. 9 o I. An ( 99* ) I. An Ohfer^^atlon of the end of the 'Total Lunar Eclipfe on the ^th of March 1718. ohJcrVed near the Cape of Good Hope, JerVmg to deter^ ynine the Longitude thereof. With ^markj thereon, E. Halley, ^ S, Seer. I S no A^ better than thirty Years fince 1 had a .1 Difpuce with fome of the French Geographers about the Longitude of the Cape of Good FJope, faid to have been obferv’d by the Religious Mifllonaries fent to China in the Year 1685, By an Emerfion of the firft Satellite of Jupiter, they determined that Cape to be 11' or I?! grad, more Eafterly than Paris, i\\^i is xograd. from London ; Which for the reafons I then gave, \ concluded could not be more than i"] grad, ^ See Phil, Tranfa^. 185. Very lately I have fallen upon an Obfervation which I believe will determine the Controverfy in my favour: for I had accidentally a Journal of an O dicer of the Ship Emperor put into my Hand^, who in his re* turn from India, on the fifth of March 1718. obferv’d the End of a Lunar Eclipfe, when the vifible altitude of the Moons Centre was i}°. x5', he being then in the Latitude of 34°. 23' South, and as they found afterwards, juft 1 80 Leagues to the Eaft wards of Cape Bonne Efperance. By Calculation J find that in that Latitude the Moon had that height at yh, iy'~ P. M, and by comparing this Eclipfe with that we obferv’d with great exatftnefs on Fehr. i\°. i68z. (which agrees perfedly well without .Numbers^ I conclude the middle of this to have been ijt London at 3^ 48' P,M. To which adding I*’. 46' for f 99} ) the Semiduration (this being very certain from the ob- fcrv’d Continuance of the Edipfe of l6Sz.) the End will be found to have been at London at 34'- The Ship was therefore in a Meridian to the Eaftwards of London : But (he was at that time i8o Leagues to the Eaftwards of the which diftance in that La- titude gives eleven Degrees of Longitude ; this there- fore being deduced from the Longitude of the Ship, leaves juft or one Elour, for the difference of Meridians between London and the Cafe. So that by this account the Cafe is yet nearer our Meridian than I had formerly made it, and nea fix Degrees nearer than M. De la Hire places it in his Talks. This Edipfe was attended with all the Circumftances requifite to make the Conclufion as certain as the na- ture of the thing will admit of: For the Moon was near- ly in Ferigdo and the Edipfe almoft central ; for which reafbns (he emerged out of the Shadow as fwiftly as poffible ; The Sea was very fmooth, there having been little Wind for above 30 Hours before; and the Moon was not too high to be well obferved with a ForeftafI' .Nor were they long at Sea before they made the Land, for in lefs than five Days, on the tenth of March at Noon, they had paft d' Agulhas the moft Southerly Promontory of Africa, which then bore from them l^orth Eafl, about feven Leagues diftant. The End of this Eclipse, though not vifible here, might have been feen in Germany, both at Narenhurg, Leiffick and Berlin, but we cannot learn that it was any where obferved there ; however our Numbers in this Cafe may be fecurs- Jy relied on. On this occafion it may not be amifs to infert an Ob- fervation or two I procured to be made at ih^Cape.^ by Mr, Alexander Brovpn a Scotch Gentleman, who went to refide in on our Cornpanks sccoimL He carried with { 994 ) with him a very good Brafs ^adrant of above tvib Foot Radius, and at the Dutch Settlement at Table Bay, Pendulum-Clock by correfpondent Al- titudes, on the 4th of Augufl 59' the diftance of the bright Limb of the Moon from the right Shoulder of Orion was obferv’d tobez5° 3'. And the next Morning Aug< 5. at 5I1. rT. 1 1", the fame Limb was diQant from Prccyon 25’. 57', and at 48'' from the Lucida Atiais 29'. It were much to be wilht that the Moon had, either of \ thefe Mornings, been accurately obferv’d at Greenvrich ‘ or Paris, or at fome Place in Europe, W'hofe Longitude ^ from them is well known. But that failing us, 1 had re- ■ courfe to the Period of the Lunar Motions, which is perform’d in 18 Years and ten or eleven Days, after which the Eirors of our Lunar Computations return very nearly the fame ; and I found among my own old Obfervations, one that tallyed well with that of the 4th of Augu(l. Viz^ Anno 1676. 23°. 13’'. ii'. 35". at Oxford, I obferv’d the Moon to apply to the Star in medio Collo Tauri, by Bajer markt A. The Star at that time was diflant from the Southern and neared Cufp of the Moon by the Micrometer zo'. 32". and at I3^ 17'. 15''. when it Teem’d to immerge upon the bright Limb of the Moon, it was diftant from the Northern Cufp 2?'. 20"; but this lefs certain by reafbn of the hazey Air. The Star at that time was in ^ 28°. y6^ with ^1°. if .xd\ North Lar. whereby I found that our Lunar Tables, founded on Sir cor retd Theory of 1 her Motion, gave her place at that time only two Mi- 1 nutes too flow; which Error being allowed on the 4th I of Augujl 1694. the refult was, that 5\ 59'. at Cape Bonne f Efperance was London 53'. whence the difference of Longitude i6f degrees, fu&iently near what we had before determin’d. i ( 995 ) ; II. JACOBI KEILL, M,‘D, De Viribm Cordis EpiJIola. R I C H A R D O M E A D, M Z). S. in which it has fwom, as before. Then letting the Glafs upon the Air-Pump, thofe Bubbles burfi; af«| ter one another, as the Receiver was exhaufling, and the Air being again let into the Receiver, the lump of Cra([amer)tum funk to the bottom of the Glafs. Exp. Ill I have often placed a drop of Serum upon a clean Glafs before a Microfeope, in which I had diflblv’d a very fmall quantity of Blood, and obferv’d, that when the Glafs was held in a perpendicular Po- fture, the Blood-Globules fubfided to the bottom of the Drop ; and inverting the Glafs, the Globules again defeended thro’ the Serum to the Bottom. I had the ^fame fuccefs with a fmall quantity of Serum and Blood in a Capillary Tube, And the fame thing has been long fince obferv’d by the famous Mr. Leeumn- hoek. Thefe Experiments undeniably demonflrate, that the Cra([amentum, or globular part of the Blood, is fpecifi- cally heavier than the Serum; and confequently it is by no means probable, that the Blood Globules are Veficles fill’d with Air, or any other Fluid lighter than Serum. And that they are not fill’d with any fort of 9 0^ f 1004 ) Elaftick Fluid, will appear from the following Experi- ment. Exp.W. In a fmall quantity of Serum o{ Human Blood, I dillblv’d fo much Blood, as that the Globules might not lye too thick together, to hinder their being feen diftin(^Iy. Then having lodged a fmall drop of this Liquor on the infide of a thin Glafs Tube, I fitted the Tube on to the Air-Pump, and placed a MicroB cope by it, fo that I could fee the Blood>Globules through the Tube. This being done, I caus’d the Tube to be exhaufled, keeping my Eye upon the Glo- bules all the time, in order to obferve whether they dilated themfelves, as the Air was withdrawn ; but could not perceive the lead alteration, they appearing exadly of the fame bignefs in the Facuum^ as they had done before. Whereas if they had been fill’d with an Elaftick Fluid, they would either have burft, or have been dilated to at lead 70 or 80 times their former Magnitude. The Stop- cock being afterwards turn’d, and fuffer’d to re-enter the Tube, the Blood-Globulesdillretain’d the fame bignefs, as in Facuo, To this it will perhaps be objedled, that a learned Member of this Society, in a Book lately pubiifh’d, has aflerted the diredi contrary to what I here affirm, and has afiur’d us, that the Blood’Globules in an exhauded Receiver, indantly fwell, and dilate themfelves fo, as to become incredibly large. But as that Gentleman does not tell us, upon what Experiment this affertion is grounded, it may not be unreafonable to fuppofe, that he was milled by the common Hypothefis, which he there maintains, of the Blooa-Globules being fill’d with Air, and by what he has heard or feen of the bubbles of Air, which arife from Blood in the Air Pump in the fame manner as from other Liquors, and which not cafily breaking out from fq a Fluid; cccafion ( 7ooj ) the appearance he mentions. Howevir this may be* to prevent any difpute, and avoid the coming to Utri creditis, Omrites > I fhall offer a Teftimony, that every body will be fatisfy’d with, namely that of the learned and ingenious Mr. Machin, Profenor of Afiro^ mm'j in Grcjham CoUedge^ and one of our Secretaries, who having honour’d me with his Company at a re- petition of this Experiment, in order to be witnefs to the Event, was fully fatisfied upon repeated tryals, that there v/as no perceivable difference between the Magnitude of the Blood Globules in the Air, and in Vacuo. Upon this occafion the two firfl: Experiments were likewife repeated in his prefence, with the fame Succefs, as above related. Though what has been already faid is a fufficienc proof of the Opinion above- mention’d, yet however to prevent the Objedbions, which may arife for want of Experiments made in the fame manner with Mr. Boyle% as well as for the fatisfadion of the Curious, who may be defirous to know the true Specifick Gra- vities of Serum and Blood, I lhall proceed to demon- ff rate^ the fame thing by Hydroftatical Experiments. Exp. V. Novemh. 13. 17 13. Having fuffer’d a quan- tity of my own Blood to Hand about 24 Hours in the Porringer, and then drawing off the Serum carefully with a fmall Siphon into a convenient Glafs, 1 found by the Hydroftatical Balance it’s Specifick Gravity to be to that of Water, as 1029,8 to 1000^ Exp, Vf* Feh, a 1. 1716-7. I examin’d the Serum from the Blood of another Perfon in the fame manner and found it’s Specifick Gravity to be 1028,6. Exp.Vll. VIII. and IX. April 8th, 1717* I obtain’d three feveral quantities of Serum ftom the Blood of different Perfons. The firfl: of thefe wasj of a deep 9 0^2 colour. ( Too^ ) Colour, inclining fomething to red, and a little Turbid. It’s Specifick Gravity was 1019, 7. The fecond was likewife a little Turbid, and of a pale whitifli Colour. The Specifick Gravity of this was 1030, 2. The third quantity of Seram was perfedly clear, and of the colour of Canary. It’s Specifick Gravity was found to be 1050. Though thefe five feveral Experiments were all care- fully made, and with a Balance whofe accuracy I. was well afiur’d of, yet for farther Evidence, I thought it proper to make that which iollows, after another man- ner. Fxp. X. lyth. 1718-9. I drew off* all the Serum from five or fix feveral Porringers', containing the Blood of different Perfons. This I found to be a lit- tle tinged with Blood, which was occafion’d by my being oblig*d to draw it off pretty near to the bottom of the Porringers, in order to obtain a quantity (uffi- cient for my purpofe. For this reafon I fuffer’d it to Band about two Days, in which time the Globular part of the Blood was entirely precipitated to the Bot- tom, and the Seram was become perfeBrly fine and tranfparent. I then drew it off with a Siphon into a Glafs Vial with a narrow Neck, which 1 fill’d to a certain mark made in the Neck for that purpofe. This done, I plac’d my Vial in a nice pair of Scales,, in which I had a counterpoife for the \yeight of the Vial, and found that quantity of Serum to weigh Grains. ^ Then pouring out the Serum, I fill’d the Vial with common Water to the fame mark, and found the weight of the Water to be Grains. From which it follows, that the Specifick Gravity of this was 8029,4. % ( 1007,) Exp, XI. July 14. 1 71 9. I procur’d a quantity of Blood taken from the temporal Artery, from which I drew off the Serum the next Day, 'and weighing it in the fame manner found it’s Specifick Gravity to be I0i8, 8. Thefe Experiments agree fo nearly together, that the little difference between them may very well be attributed to that which is between the Serum of dif- ferent Perfons; or to the variations occafion’d by heat and cold in the feveral Seafons of the Year, in which they were made. So that from them we may fafely determine the Specifick Gravity of Serum of Human Blood at a Medium to be 1019, or in a round num^' ber lojo. From which the greatefi: Variation in any of thefe Experiments is little more than one in 10005 whereas the difference between Mr. Boyle's Experiments and mine amounts to 160 in 1000. Exp, XI k ^pril 6. 1717. In order to find the Specifick Gravity of Human Blood, which, by reafon of it s tenacity, and fudden alterations upon {landing, cannot be determin’d by the Hydroftatical Balance ; I took a narrow* neck’d Vial , and fill’d it to a Mark,, with Blood pour’d immediately out of the Porringer, as foon as the Perfon was blooded. This 1 weigh’d, as I had done the Serum before, and found it’s Speci- fick Gravity to be 105'r. Exp. XIII. Aug, 5th. 1717. Having fill’d the fame Vial with the Blood of another Perfon, running im- mediately out of the Vein through a Funnel, it’s Spe- cifick Gravity was determin’d at 1053. Suffering this to (land till it was cold, I found the Blood was funk a fmall matter below the Mark in the neck of the Vial. This being fill’d up with the Wa- ter, w’hich in fb fmall a quantity could make ao fenfi- ble. {. ioo8 ) tie difference from Blood, I found the Specifick Gra- vity of cold Blood to be Exp, XIV. /iug. 6th. 1718. The laft Experiment being repeated in the fame manner as the Year be- fore, the Specifick Gravity of cold Blood was again found to 1055'. £x/>. XV. 14th. 17*9. The Arterial Blood, from w'hich the Serum w^as afterwards drawn off for the iith Experiment, being w^eighd in the fame manner, it’s Specifick Gravity was 1051, As this Arterial Blood and it’s Serum, differ no more in Specifick Gravity from Venal Blood and Serum, than the feveral Portions ot thefe do from one ano- ther, it’s plain, that the difference in this refped be- tween Arterial and Venal Blood is wholly inconfide- ' rable. The Animal Oeconomy indeed teaches u% v that the Serous Liquor is perpetually drawing off . from the Arterial Blood by the ieveral Secretions, but as the quantity feparated in one Circulation is very ♦ fraall, the Blood muft arrive in the Veins nearly of the fame denfity, as when it runs through the Arte- ries. In the 15th Experiment we obferv’d, that the Blood altered it’s Specifick Gravity upon cooling from icyf3 ^ to 1055; ^t:otn which we may infer, that if the Blood ' made ufe of in the nth Experiment had beenfuffered to Band till ir was cold, it’s Specifick Gravity would have been 1053 5 wherefore, taking a Medium be- tween the four laft Experiments, w'e may allow the Specifick Gravity of cold Human Blood to be 1054. The difference of 14 Parts in a 1000, between this and the Specifick Gravity determined by Mr, Boyle, is eafily accounted for, if we confider, that that Gentle- man did not make ufe of a Veflel with a narrow Neck, as plainly appears from the circumflances men* . tioned it ( loop ) tioned in his Experiment; and confequenriy a fmall error in the height of the Liquor would make a confi- derable alteration in the Specifick Gravity. Since therefore the Specifick Gravity of Human Blood is lo^q, and that of its Seruw 1030, it is plain, that Blood is heavier than Serum by about one part in 43. From which it manifedly follows, that the Globular part of the Blood is fpscifically heavier than the Serum, fince the Globular part being feparated from the Blood leaves the remainder, or the Serum) fpecifically lighter than the intire Mafs. But in order to determine the exadt Specifick Gra- vity of the Blood Globules, it is firft necefiary to know the Proportion, which the whole quantity of the Craf. famentum contained in Blood bears to the Serum. To this end Mr. Bo^le has given us two feveral Obferva- tions of the weights of the Crajfamentum and Serum, af- ter they have feparated one from another in the Por- ringer. But befides the difficulty of making this Ex- periment with any tolerable exadfnefs, it is to be con- fider’d, that there is a great deal of Serum contain’d in the interftices of the Globules, that compofe the Crajfa- mentum. This difficulty however is in fome meafure anfwer’d by two other Experiments, which Mr. Boyle made for this purpofe, after the following manner. He put a quantity of the Craij'amerrtum, already feparated from the Seram, into an Alembick, and diftill’d off the re- maining Serum to drynefs, but without drawing off the Oil, or Volatile Salt ; after which he weigh’d the di- ftill’d Liquor, and the dry Mafs left behind. By comparing, thefe Experiments with the two for- mer, it will be found that the entire weight of Serum contain’d in Blood is nearly If of the whole, and con- fequently 1010 ; confequently the weight of the dry’d is only two fifteenths of the Blocd* But for farther fatisfadion, an Analyfis was made at ,my defire with a large quantity of Blood, amount- inn to four Pounds fcuitcen Ounces, by that ingeni- ous and skilfull C hymiit, Mr. John Brown. From tills was obtain’d, with a very gentle heat, two Pounds, fourteen Ounces , and fix Drachms of a Phlegmatick Liquor, that had fcarce any thing of the fetid Scent, which is ufual in the difiilJation of Ani- mal Subftances; and its Specifick Gravity was nearly the fame with that of common Water, being but I oo, 8. This being mixt with a (trong folution of Alum, fcarce a.Torc’cd zny Coagultim but exhibited a confiderable one upon mixture with a folution of Ro» man Vitriol. The difiillation being continued with the fame Hear, we had feven Ounces more of Phlegm confide- rably impregnated with Volatile Salt, as was manifefl: from the Smell. The Specifick Gravity of this was 1007, and having mix’d it. with Tindiura Martis opi- ma. Solution of Alum, and of Roman ViinoX,' a large Coagulum was precipitated. In diflilling thefe there was loft by Evaporation, two Ounces and two Drachms. The third portion of Liquor, being rais’d with a ftronger Fire, amounted to feven Ounces fix Drachms. This was reddifti, and turbid, and to ftrongly charg’d with Volatile Saits, that it might very well defer ve the name of Spifir. Its Specifick Gravity was »o8o, i. Befides thefe we had feven Drachms of Volatile Salt, an ounce of Oil, and eight Ounces four Drachms of Cafut Mortuum, which ftill retain’d fome fraall re- mainder of the Oil, as was manifefl: from its taking Fire at the flame of a Candle. In this latter part of the Operation was loft three Ounces, feven Drachms. ! Upon ( 'Oil ) Upon making due allowance for the diflerence be- tween the Specifick Gravities of the three firft Portions of Liquor and that of Seruw^ as likewife for what was loft in the two feveral parts of the Operation, which we may reafonably conclude to have been of a Specifick Gravity nearly the fame with that of the Li- quor drawn off, it will be found, that the quantity of Serum contain’d in this Mafs of Blood was about ^ of the whole VVcighc, and confequently that the quan- tity of Craffmentum was .7 of the fame Weight. If we calculate therefore upon this Suppofition, that the weight of the Globular part of the Blood is ~ of the whole, we fhall find the Specifick Gravity of a- Blood Globule to be to that of Water as 1177 to rooo. If we follow the proportion of ,7, which refults from Mr. Bo)le*s Experiments, the Specifick Gravity of a. Blood Globule will be 1241. But this computation is in all appearance a great’ deal too large ; for we cannot be affur’d, that our whole quantity of aqueous Liquor was rais’d from the Serum of the Blood. On the contrary it is more than probable, that a confiderable part of it was afforded by the Blood Globules themfelves, efpecially in the' latter part of the Operation, when their texture muft of neceffity have been broken and diffolv’d by the ftrong' Fire that was made ufe of. To prove this, we need only confider the condition of the dtyd^Craffamentum, after the Fhlegm is drawn off, chat being now a hard and brittle Subftance : whereas the Globules in their natural State are fofe and yielding. For which reafbns'- ic may perhaps be more facisfadory , if we at- tempt to find the quantity of the Globular part of the Blood after another manner. k appears therefore from Mr Boyle's Obfervations,' that the quantity of Serum, w’hich may be pour’d off ^ R from V ( 1012 ) 5from the Craffamtntum^ is about one half of the whole Mafs. The remaining Crajfamentum confifis of the Blood Globules, and a quantity of Serum filling up the Interftices between them ; which, if the Globules keep their Spherical Form, may eafily be found by the prin- ciples of common Geometry, to be nearly one half of the bulk of the Craffamentum: but if the Globules by their prefTure againfl one another change their Figure, the quantity of Serum will be fomething lefs. If this quantity of Serum lying between the Blood Globules be added to that pour’d off. it appears, that the Serum contain’d in Blood is about *- of the whole bulk, and confequently that the Blood Globules make about ~ of the whole. From which we ftiall find the Specifick Gravity of the Blood Globules to be to that of Water as iix6 to looo. If we fuppofe the Blood Globules to make f, or I of the whole bulk, their Specifick Gravity will be refpe<3ively 1174, 1150, noz, or 1078. So that upon any of thefe Suppofitions, the Specifick Gravity of the Blood Globules will be confiderably greater than that of the Serum, and confequently they cannot be fuppos'd to be Veficles fill’d with an Aereal Subftance. It will therefore perhaps be>askt, What do they re- ally confifl of ? In order to come to a Solution of this Quedion, it may be proper to take notice. That Blood is compos’d of Phlegm, Oil, Volatile and fixt Salts, and Earth. For as to the Spirit, we look upon it with Mr. Boyle, to confift of the Phlegm and Volatile Salt united together. That the Serum, upon a Chymical Analyfis, exhibits a great deal of the firft of thefe, and the others in a Tery fmall quantity. That ( lot^ ) That on the contrary the Crajfame^taf?t yields muchi iefs Phlegm, bat the other Principles muchi more co- pioufly than the Serum. From which Data^ I think, we may fafdy conclude,, that the Craffamentum, or Globular part of the Blood, confifts of fome Phlegm united with the Oil and Salts, and a fmall quantity of Earth But what is the exaifi proportion of thefe feveral Principles to one another ; what alterations are produ-- ced in the Body by a change of this proportion ; how, and in what part thefe Globules are form’d ; by what means they preferve their Figure, without difiblving in the Serum, or uniting with oiie another ; what varia- tions are made in their Specifick Gravities by Heat and Cold ; and what are the efFeds of thofe Variations, are Queftions not very eafy to be folv’d, and yet of lb much importance to the Animal Oeconomy, that it were greatly to be wiflit, we had a number of Dafa fulEcient to determine them. F. S. Since this F^per was lent to the Prefs, I made the following Experiments, which ferving to confirm^ the Method lad made ufe of, for finding the Specifick.. Gravity of the Blood Globules, it may not be impro^ per to relate them. Augufl 6 1719. I took a lump of the Craffamen^ ium, and walk’d it gently in fair Water, to free it from the loofe Globules, which precipitating out of the Scrum, after the Coagulum is form’d, do not unite ■ into one Body with it. This done, I laid it on fpungy brown Paper, in order to drain off the fuper- fluous Moifture. After which, weighing it firft: ins Air, and then in Water, I found its Specifick Gravity to be 9^ R z Anothetr ( 1014 ) Another lump of the lame Craffamentutn being weigh’d in the fame manner, its Specifick Gravity was Ic8^.9. Sept, 1 8. 1719. I found the Spec fick Gravity of another piece of Cra(famentum to be loSx.i. A fecond piece from the Blood of a different Per- fon gave me 1086,1. A third from the fame Perfon gave 1086,6. From this it follows that the Specifick Gravity of the Blood Globules is at lead 1084, whicli is the Medium between thefe five Experiments. But if we allow one half of the bulk of the Crajfa- mentum to confifl: of Serum^ filling up the Spaces be- tween the Blood Globules, we fhall find their Spe- cifick Gravity to be 1138. From this we mud make a fmall abatement, becaufe fome part of the Serum mud have been (quees’d out from between the Globules, by their yielding to one anothers Preffure, when the lump of (Cra(famertum lay upon the Paper : and this will reduce their Specifick Gravity fufficiently near to ^I^6, as we had before determin’d it. IV. Jn Accomt of the Sunk Ifland in Humber, fome Tears fince recover’d from the Sea, (Being an ExtraH of a Letter Communicated to the Royal Society hy John Chamberlayne, R. S. S. THis Idand goes by the name of the Sunk fo called 1 luppofe from the finking Marlh Ground about it. As for its Original, one may make pretty dire Conjecdures of that I believe, becaufc ’tis yet with- in ( *015 ) in the memory of Man, fince it began to raife its Head above the Ocean, there being ieveral old People here alive, who can remember when there appeared nothing of it but a waft and barren Sand; and that only at Low-Water too, when for the fpace of a few Hours it (hewed its Head, and then was buried again till the next Tides Retreat : thus fucceflively it liv’d and died until the Year 1666, when it began to maintain its ground againft the infult of the Waves ; about which time it began to be refcued wholly from future dan- ger, by the Care and Induftry of Colonel who having, as 1 am imform’d, a Leafe or Gift of it from the Crown, did raiie Banks about the rifing Grounds of it, and fo defending it from the Encroachments of the Water, it became Firm and Solid 5 and in a Ihort time afforded good Pafturage for Sheep and other Cartel. The Expences at firft to improve it to what it is, muft needs have been very confiderable ; it being en- compar’d with high Banks, and deep Canals for re- ceiving and difcharging the Liquid Element, which every now and then nocwithftanding threatens to re*pof* fefs it felf of its ancient Hereditament, but hitherto in vain; for I now acquaint you of its prefent Safety. This Ifland is now about 9 Miles in Circumference, within the Banks, which Teem to render it impregna- ble againft all future attacks of the Sea, and is of a very fat and fertile Soil, affords good Graft, Corn and Hay, and is repleniihed with numerous flocks of Sheep, which are of a larger Size and finer Wool than thofe in Holdernefsi from which it is divided by about two Miles in Water ; and from Lincolnjhire by about four, k is ftor’d with vaft numbers of Rabits, that feem innu- merable, they appearing through all Parts in prodigious Swarms; their Skins are counted the fincrt in England, of a dark Moufe Colour, Shagg’d, and foft as iilk. 1 here ( 1016 ) There are alfb Cows and Horfes feeding con- dandy in the Place, with great plenty of Wild Foul. The Inhabitants are not fo numerous, there being only three Families that live conftantly upon the Place; however they are never too folitary,there being abundance of Workmen and Labourers that continually refort thi. ther, fometimes I am told to the number of a Hun- dred and upwards, for the repairing of the Banks, The Yearly Income of the Proprietor Mr. G/%, a- mounts to about 800/. and pays the King’s Taxes to thofe who Colletd for the EaH»Riding^ and is ufually uplifted by thofe of the Liberty and Townlhip of Ottringhum, from the Marlhes of which there is a Paflage over the Sands to the Sunk at Low-water. But this Cuftom of paying the King’s Cefs to them, proceeds only from the conveniency, not NecelTity 5 for it never belong’d to that or any other Parifh, fo that I cannot refolve you in what Diocefe this (Band lyes, unlefs it had been united to feme neighbouring Parifh, or converted to one of it felfj which if effeded, the Tyth of Lambs, Wool and Habits, &c. would make up a handfbme BeneHce. It lyes nearer indeed to the Diocefe of Torkt by at lead two Miles, than to that of Lincoln, being two Miles South of Holdernefs, in the River Humbtr, and four Miles North of Lincoln(hire, Wehick, April 14. 1717* V. A I ( 1017 ) V. A IVay for Myopes to ufe Telefcopes mth» out Eye^GlaJfes, an ObjeEi-GlaJs alone becoming as ujeful to them, and fometimes more than a Combination of Glides. Com?nunicated to the Royal-Society, by J, T. Defagu- liers, LL. D. and F. R. S. Lemma i: WHat is requir’d of a Telefcope is to give large," and diftind Vifion ; that is, to make the Ob* ; ]eGc (as in GaliUds Telefcope) or its Image (as in the Telelcopes made up of Convex Lentes) appear under a great Angle, and to have all the Rays of thofe Pen- cils that enter the Eye, meet in a point upon the /ir- tina of the Eye, on their refpedive Axes. The firft Figure reprefents the Combination of two Convex Lentes for the Aftronomical or inverting Te* lefcope; where the above-mentioned Requifites are ob- tain’d. A B is the Objedl fuppos’d at a vaft diftance from the Oje ) A<\»ms Humour, converge, and .meet cither in the Vitreous, or Cryftallihe Humour, according to the Convexity of rhe CornzA thro’ which they pafs^d, and diverge again before they come to the Rttim ; the Rays of each Pencil converging upon their refpedive Axes, to the place where the faid Axes crofs one ano- ther, Fig, Dmonjlration, The Axes aQa, aCa, falling obliquely upon the (Cornea at C,C, and entring from Air into the Aqueous Humour, will be refraded towards the Perpendicular to K : v/here ftriking more diredfly upon the Cry- flalline , they will go on to a, a, upon the Retim R R R R, decuflating at V within the Vitreous Humour, The other Rays r, r ; js, after their Refradion in the Aqueous Humour, fall more obliquely on the Cr^jlalline^ and therefore are refraded again fo as to meet at V, where the Axes alfo meet, and thence go on to the Re- iina R R R R, Fig. 4. Lemma 4, But if the Axes of the above-mention’d Pencils are Parallel, the Rays that accompany them diverging from a Point fo near the Eye, that the divergence may be proportionable to the too great Convexity of the Eye ; then only the Axes will meet in the Eye before they come to the Retina (by Lemma j.) but the other Rays will not unite upon their refpedive Axes^ till they come to the Retina ^ (by Lemma 1.) Fropo/ftion, I fuppofe the Eye of the Myops fo Convex that he can fee no farther than a common Eye, with the Eye- Glafs of a Tekfeope before it ; then the Eye of the p S Myops ( 10 zo ) Mpfs being in the place of the Eye*Glafs, will receive the Rays diverging from the feyeral points of the Image f projected by the Obje<^-Glais in yx^ Fof^s,) in fucb manner, that they will after their fevcral refra(9ions meet in refpedive Points on the Retina^ and the Axes of the Pencils which come from the extremities of the. ObjetS, will, in the Eye, make the Angle B V A =: to h ca, under which the Image ah feen, by Lemma 4. The Cornea and (pilous Humour here fupply the place of the Eye-Glals, and the Cryflallwe and Fitreous Humours that of a common Eye, See the 5th Fig, wherein R is the Retina^ V th? Fitreoua Humour, and KK the Crjfialline Humour; and the Image ha isfup-- pos’d to be brought down from the Jfrfi Fig. which re- prefents the Ajlronamick Tele/egpe: the too great Con- vexity of the Eye here being in the place of an Eye— Glafs. An Objeeflion may be made to^ this, viz. that P P ‘ the Pupil of the Eye being fmall, will take in but a ve- ry little Image, or a fmall part of the Objed : - But then if the Eye be mov’d fuccelTively, to all the parts of the Space where the Eye-Glafs was, it can take any part of theObjed; and if the Ob jed- Glafs be large, which may more eafily be made than a large Ey€*GlaIs, and the Tube a Foot wide or wider, as much may fucceflively be taken in, as if an Eye-Glafs might be had of a Foot Diameter. A little ptadice may make any /kljops fo ready, to k^ep an Objed: when once found, though: the placo - where- he fland^ be (haken. . It would not be amils. to hold a in one’s Hand (for an Eye-Glafs) to find the Objed at . firft, tillcuftomhas madeitcafy without it : \^hen once the Object is foundi it ma^'he. eafily kf^c^ , • ; An- Eye mote thort-figbied than );;}ha\e.ifuppos’d, ■ will perform 'thei Office., oE a Ey^> Glafs, being C loii ) being brought nearer to the diftin^t Bafe of the Ob- ject Glafs ; and an Eye lefs Convex, the office of a lefs Convex Eye-Glafs : but with this difference, that the more Convex the Eye is, the eafier may any part of the Objed be found, and the larger and more lucid it will appear. I have feen Sattirns Ring very plain with an Ob- jcd*GIals of little more thart fix Foot Radius^ without an Eye-Glafs. I have alfo found out a way for the Prefb'jtx to make ufe of an Objed-Glafs, by placing their Eye nearer the Lem than its Focus^ by fb much as their Eye is flatter than a common Eye, fo as to make ( as it were) the Telefcope of GaliUo ; the fiat Eye ferving as a common Eye arm’d with a Concave Lem. I have fo fixed the Telefcope, as to make a Prefbjta read at a great diftance a fmall Print. The truth of this may be eafily demonfirated, if it be requir’d. If this Experiment be made at bea with a very large Tube, big enough to put in the Head and move it about, and the ObjedGia.fs be alfo large, it may not perhaps be difficult to obferve the Eclipfes of the Satellites of Jufiter^ which I would recommend to the Confideration of thofe that would try for the Longi* rude by fuch like Obfervations. VI. “Hew and accurate Tables for the ready Compu^ ting of the Eclipfes of the firft Satellite of Ju- piter , by Addition only. 33 33 33 34 361 36f 369 10 21 10 10 23 2f? 12 15 38 46 24 261 28 16 2 21 34 3’T 373 14 10 7 22 16 4 f8 24 265- 30 lo 30 SI 378 2f 270 Jmn- 17 23 4 3; 2) 274 19 17 3? 2T 279 0 10 30 SI 1 4 T9 32 3f 34 378 382 21 12 I 4J 26 283 23 6 30 21 26 287 2 25 28 8 36 386 2f 0 j8 ^7-^ ■27 292 4 17 44 36 391 26 19 27 33 27 296 6 12 2f 20 39T 28 13 9 27 300 8 6 t3 37 399 30 8 24 4j 28 ^4 10 1 22 32 37 403 Mau. n 19 5-1 8 38 408 28 13 14 19 44 38 412 0 8 24 4J 304 IT 8 48 26 38 416 2 2 ^3 21 28 309 17 3 16 j6 39. 420 3 2t 29 3‘3 18 21 4 T 32 39 42 T f .if fo 33. 7 io 19 9. 9 4*47 4) 29 29 if 1 ;-'7 ! ■?22 i 326 ■zo 16 14 8 2-2 lO 42 44 24 s i i 26 2T 23 39 t6 ,40 40 40 4^ 429 43'3 438 4+2 ro 23 16 2i 330 12 17 44 SI 3' 3 b* 27 18 8 32 41 446 1 14 12-13 33 ' 31 339 29 12 37 8 42 4T0 ( ioii{ y ^Volutiones Trimi SateUitts JoVts in menfibm. fulii N. Nu. D. h. A. B. . 1 7 44 42 4^5 ? I 2 j 42 459 4 20 2 y6 43 463 6 14 3^ 43 468 8 9 0 8 44 472 lO ? 2^ 44 47<5 11 21 S7 20 45 480 i6 2y TT 4? 48f If 10 f4 3' 45 489 17 r 2? 7 46 493 i8 2; n 43 46 498 20 18 20 19 47 yo2 22 12 48 n 47 5”o6 7 *7 3* 47 no 2^ I 46 7 48 ^7 20 H 43 48 fi9 29 4? *9 49 523 9 11 49 5_f_8 Augufiu o 9 II 49 T28 2 ; 40 3* 49 J32 ?2 9 7 ^o f36 16 37 4? 5® ^4» 7 I r 6 19 9 y 34 n J49 11 0 3 3» 12 18 32 7 J2 H »; 0 43 J2l $6z August. D. h. , „ N. A. Nu. B. 16 7 29 19 '53 567 18 1 5-7 n 53 571 19 20.26 ;i 54 21 14 n 7 54 y8o 23 9 2; 4; 54 584 2? 3 «8 55 y88 26 22 20 54 55 593 28 16 49 ;o 56 597 ;o II 18 6 56 602 Seftembris. I y 46 42 56 606 5 0 ly 18 57 610 4 iS 43 54 57 6jy 6 i; 12 ;o 58 619 8 7 41 6 58 624 10. 2 9 42 58 6i8 1 1 20 ;8 18 59 632 i; ly 6 y4 59 637 IS 9 35 3® 60 641 17 4 4 6 60 646 18 22 32 42 60 6yo 20 17 I 18 61 6yj 22 II 29 y4 61 6y9 24 y y8 ;o 62 66; 26 0 27 6 62 668 27 18 yy 42 62 672 29 i; 24 18 63 677 I OSiobris* \ % ( i027 ) (^Volutiones frimi Satelihis JoVis in menjlhus. OBobris. N. Nu. D. h. , „ A. B. I 7 63 681 5 2 2i ;o 64 686 4 20 JO 6 64 690 6 ij 18 41 65 695 8 9 47 17 ll 699 10 4 ij J3 65 704 II 22 44 29 66 708 17 i; j 713 IJ II 41 41 67 717 17 6 10 17 67 721 19 0 ?8 j} fz 726 20 19 7 29 68 750 N> N C\ 68 75 5 24 8 441 69 759 26 2 33 17 69 744 27 21 I j3 69 749 29 IJ ;o 29 70 755 9 59 y 70 758 Novewbrts. 0 9 59 5 70 758 2 4 2t7 4* 71 762 3 22 j6 17 71 767 j 17 24 5? 7-1 772 7 II j3 29 72 776 9 6 22 J ZL 781 11 0 JO 4» 75 785 12 19 19 *7 75 790 14 47 55 74 794 9T Novembris. N. Nu. D. h. , „ A. B> 16 8 i6 29 74 799 i8 2 45 5 74 804 19 21 13 40 21 808 21 IJ 42 16 75 813 23 10 10 52 76 817 25 4 59 28 76 822 .26 23 8 4 76 827 28 17 ;6 40 77 831 30 12 J 16 77 836 Decembris. 0 12 J 16 77 836 2 6 33 J2 78 840 4 I 2 28 78 845 5 J9 5» 4 78 849 713 J9 40 79 ^54 9 8 28 16 79 8j9 II 2 56 J2 80 863 13 21 2J 28 80 868 14 IJ J4 4 80 873 r6 10 22 40 81 877 18 4 ji 16 81 88i 19 23 19 J2 82 886 21 17 48 28 82 891 23 12 17 4 82 897 2J 6 4J 40 85 900 27 I 14 16 85 905 28 19 42 J2 84 909 30 14 I I 28 84 914 ( 1028 ) prhfite ^quationes ConjmiBionmn Prmi Satellite cum Jove,. Xquat. !®9 A-quat. XEq /Equal. iEq /Equal, /Eq Num. Conjun. Nu. Num. Conjun. Nu. Num« Ccnjun. Nu. Nuir. Conjun. Nu. A. Adde. , A. Addc, B A . dde. B. Adde. 8. i L # it 9 9 99 0 8 <5 128 1 2 7 26 2y6 0 Jl 31 384 II y2 26 12 16 ^32 It 27 26 260 6 0 31 ;8i< 12 37 26 847 16 i6 i;6 10 47 26 264 0 ) 31 392, 13 23 2y 12 21 16 140 10 9 27 268 0 3 3« 396 14 11 26 n 144 9 3* 27 272 0 7 ,3 4-0 14 y9'2y 20 ;4 n 148 8 4y 27 276 0 12 404 ly 48 24 24 ?? 3T ^7 iy2 8 *9 27 280 0 i9hi .408^ 16 38 24 28 40 18 if6 7 44 28 284 0 28 30 4' 2, 17 30 24 ? ‘ 4f^ i8 160 7 .'O 28 288 0 38 3® 1416*18 22|23 ;6 ;o fP *9 164 6' / 00 28 192 0 yo 30 42o;-i9 iy23 40 29 j-6 ‘9 168 6 7 28 296 I 3 30 424 20 9^3 44 29 ? 19 172 y 37 28 30c I 17 30 428 21 4, 22 48 2.8 10 20 176 4 8 29 3^4 1 33 30 lii 22 y9 2? J2 27 16 20 i8o 4 4» 29 308 I yo 30 436 22 yy,22 26 2; 20 184 4 15 29 312 2 8 30 44c 23 y3 21 60 21 x88 3 49 29 316 2 28 30 444 24 y‘ ti 64 24 ;8 2 1 ' 192 3 24 29 320 2 yi 30 448 2) 49 21 68 — 2? 47 2 1 196 3 j 29 324 3 ly 4y2 2 4 820 72 22 22 200 2 40. 30 328 3 40 29 4j6 27 48 20 76 22 y 22 204 2 20 30 332 4 6 29 460 28 48 19 80 21 *y 22 208 z 1 30 336 4 34'29 464 29 A9 19 8420 26 25 212 I 41 30 340 y 3 29 468 30 yo 19 88 19 ?7 2? 216 I 2f 30 344 y 34 29 472 u Si 18 92 18 48 23 220 I 10 3<^ 348 6 y 28 476 32 y; 18 96 18 b 24 224 0 y8 30 3f2 6 38 28 48c 33 y> n 100 17 H •24 228. 0 47 30 3^6 7 13 28 4«4 34 y7 17 104 i6 28 -24 232 D 36 30 360 7 yo 28 488 ,3)" yp 17 108 42 24 & 236 0 26 30 364 8 27 27 492 37 1 16 II2 f4 y? 2y 1240 0 l30 368 9 6 27 496 38 5 16 1 16 '4 2J 244 0 12 31 372 9 46 27 5" CO 39 8 128 12 / i6 2'5’6 0 I 3^ 3r4!>i y2 26 yi2 42 17 14 — — Frim^e ( 1029 > Prima Equation fs ConjunEHonum Primi Satellith^ cum yove. *quai. /Eq /Equal. /Eq /Equal. /tq /tqjat. diu Coofunsl. Nu. Sum. Conjun. Nu. >!«m. Conjun. Nu. Nutn. Conjun. Nj. A. /'dde. B. A. Adde. B. A. Adde. B. A. Adde. B. « / i tf t if 42 17 640 70 26 5 I CO 1 77 40 0 896 6 1 48 6 fi6 4? J9 14 644 7^ 5 5 772 77 29 0 900 61 2 7 J20 44 21 648 7x 58 5 776 77 18 0 904 60 15 7 4? 2? M 6J2 72 II 2 780 77 6 0 908 J9 28 7 46 2f 6f 6 72 42 2 I784 76 n 1 912 J8 55 8 47 26 12 660.75 2 78^ 76 54 I 916 J7 JO n6 48 27 12 664 75 42 2 792 76 1)- 1 920 )0 1 8 49 28 I J 668 74 *0 2 796 7J J6 J 924 J6 1 1 9 f44 fo 28 X I 672 74 56 I 800 7J 56 1 928 J? 20 0 / Ji 28 i 1 676 7J I 1 804 7J ij I 952 )4 29 9 f2 27 10 680 7y 2^ i 808 74 J2 X 956 J5 58,10 2J 10 684 7f 48 1 812 74 27 1 940 J2 46 10 j6o f4 2? 9 688 76 8 r 816 74 i 2 944 >■ I J5 10 ^64 TT 21 9 692 76 26 I 8io 75 2 948 JI 0 1 1 \ j68 17 9 696 76 45 0 824 75 8 2 9J2 )0 6 11 f7 8 700 76 ?9 0 828 72- 591 2 90 49 15 II f76k8 7 8 704 77 15 0 8:; 2 72 9 2 96oj48 20 12 jSo'fc,. I 8 708 77 26 0 856 71 58 5 9 64] 47 26 I i J84!f9 T4 7 712 77 58 0 840 71 6 5 968I46 51 1 2 f88 60: 46 7 7x6 77 48 0 844 70 52 5 972 4J 361; ^92 61 :;8 6 720 77 f7 0 848 69 ^7 5 976 44 41 15 ^96 62 28 ~6 724!?8 4 0 8^2 69 21 5 980 45 46 15 6oq 6; 17. 6 728 78 9 0 80 58 4j 4 984 42 JO 14 604 64 ^ > 7?2 78 15 1 0| 860 68 7 4 988 4* JJ '4 608 ^4 r? 756 78 If o' 864 67 29 4 , 992 41 0 H 612 6y J 740 78 16 0 868 66 49 4 996 40 4 U 6i6 66 24 J 744 78 15 0 1^72 66 9 J lOOO 59 8 I) 620 67 7 4 748 78 12j 0 876 6y 28 J X 004 58 12 16 624 67 49 4 7f2 78 9’ 0 880 64 46 J4 xoo8 57 16 16 628 68- 50 4 7)6 78 4* 0 884 64 5 Ji lOl? 56 21 I } 652 69 10 4 760 77 )*8 0 888 05 19 lo x6 5J 26 17 <^56 69 49 764 77 JO 0 892 62 54 1020 54 50 I 7 640 70 26 5I 768 77-40 c 896'6i 48 6! 1024 .55 5J 17 Secund4° f 4 ‘5 790 I 8 22 lOO ; T2 900 f 4 300 r 8 >)0 I 4 7 800 t 8 26 120 5 4 880 60 I 4 7 316 X 8 I) ^60 I 4 3' 8 ro 8 28 140 2 860 70 1 4 4 320 { 8 22 y?o 1 4 I 82c I 8 30 160 2 46 840 80 I 4 2 330 t 8 27 )8o r 4 c 830 I 8 28 180 2 H 820 90 r 4 0 340 1 8 28 590 I 4 3 840 I 8 26 200 2 22 800 100 r 4 2 jyo I 8 29 600 i 4 7 . 850 1 8 22 220 2 10 78 b liO r 4 3 j6o r 8 '2'7 3lO 1 4' 860 r 8 i6 240 r SI 760 120 I 4 370 r 8 24 026 I 4 870 1 8 8 260 r 44 740 130 I 4 *12 380 £ 8 8 17 430 4^ 3 5 ; 880 I 8 0 280 1 30 720 140 1 4 21 390 1 9 640 I 4 49 890 I 7 yo ;oo' I ^7 700 rjo I 4 3» 400 I 7 y8 6^0 I y 4, 900 I 7 37 ;20 I r 680 i6o 1 4 42 410 i 7 4^6 660 I y ^9 910 I 7 22 ■140 0 n 66b 170 f 4 yy 420 X 7 3.1 670 i y 36 jl 920 j 7 8 f6o 0 41 640 180 [ ? 9 430 t 7 14 680 1 y y4- ‘ 930 I 6 yy ;8o 0 31 620 190 X y 23 440 I 6 ys 490 I 6 10 940 I 6 40 400 p 22 600 200* T y 39 4yo 1 6 40 700 r 6 28 9yo I 6 23 420 0 -14 j8o 2 1'O^ I y yy ■ 460 I 6 20 7IQ I 6 46 960 i 6 8 440 0 '^1 j‘6b 220 r 6 II 470| I 6 2 720 1 7 2 970 r y 54 460 0 4* f4o 230 £ 6 26 480 jL y 45 730 I 7 J? 98. I y 37 480 0 5”20 240 I 6 43 490 I y 26 740 I 7 33- 990 I y 22 fOO 0 0 fOO 2^0 I 7 0 fCO 1 y 9 ?yo r 7 46 liooo I y 9 Ths ( J03* ) The life of the foregoing TABLES. ' H E Eclipfes of the firft Satellite of Jupiter j as Jl^ has been already faid, afford the beft means of determining the Longitude of places on the Land, where Telefcopes of a convenient length may be ufed ; thirteen of thefe Eclipfes happening every x3 Days; but it is requifite that the Obferver know near the matter when thefe opportunities offer themfelves, leaft on the one hand he let them flip, or elfe grow weary by a too long attendance on them. Thofe therefore who are curious to obferve them, may readily compute the times of the Immerfions or Emetfions of this Satellite, and that with great exadnefs, by the following very fliort Precepts, which admit of no Exception or Caution, viz. Out of the firft Table take the Epoche for the Year, with its correfponding tJumb. A and Numh B ; and to them add, out of the Tables of Months, the Day, Hour, Minute and Second, neared lefs than the time of the Eclipfe you Peek for, together with its Nam, A and B: the Sum of the times is the mean time of the middle of the Eclipfe. a. With Nam, A thus coL lefled take out the fird ^Equation of the Conjun- tdions ; as alfb the iEquaxion of Num. B. always to be added to Num. B. before found, j. With Num. B. fb equated, take out the fecond /Equation of the Con- lundions ; and in the lad Table, the third /Equation, as alfb the Semi-duration of the Eclipfe anfwering to Num. A. 4. To the mean time of the middle of the Eclipfe, add all thofe three /Equations ; the Sum fhall be the true equated time of the middle of the Eclipfe fought. 5. If Num. B. equated be lefs than 500^ fubdradl ^ ^ i 1035 ) the Semiduration, and you will have the time of the fm- merfion, or if it be more than 500, adding the fame, it will give the time of the Emerfion. But Note, the times thus found are equal time, ftill to be reduced to the Apparent : and that in the B/(fex- tile Year, after February ^ one Day is to be dedu 10.26 ^quat.IIT. 3*^^ 182 B. .^quat. 8.19.10.27 1 . 6.33 Semidur^ Subfi, Novemb, 8*i8* 3*^4 So that by this Catcuks^ on the ninth of Novemb*. at 4 Minutes after 6 in the Morning, equal Time, may be feen the Immerfion of thb Satellite into Jupk ters fliadow. Another Example (hall be of the Emerfion on tha fifth of April 17x0* viz^ t { t034 ) 1710. D. h. ' '' Nu.A. o. 20. X2. . 40 95^ 4 . 13. /}4 . 22 Bifs. 22 Conj. Me^. 5 . 10 • 07 . Oi 97^ ^quac. f. 44 • ^ J j'T.quat II.. O' 45" j^quat. Hf. 3 • '9‘ 1 . 5 . 40 SemUar. Add* April 5. 12. 01. 09 Na.B. yiQ 244 1 ? JEq B. 567 B. Aiquar. Hence it appears that at one Minute after Mid- night following the fifth of ril, equal l ime, will happen the Emerfion rcquiied Nor do we doubt but that the Event will very nearly anfwer. LaBly, it may not be amif^ here to inform the R^aS- der, that we have learnt, by the experience of many Years Obfervation, that the iecorid inequality of this Satellite proceeds from the progrelTive Propagation of Light, and is common to all the fed of the Satellites: Light being foUnd to proceed in about feven Minutes of time as far as from the Sun to thu Earth, whether with an equable motion or ocher Wife iS ftlH a'^efli'on* For this reafon we have added a Third j/^qitation, whereby to account for the greater diflance of Jnpiter from the Earth in /iphetio dhan in faAhxtro^ as the Second ^Equation anfwerS to the greater diftance of the Planet when near the Conjundlion of the Sail, than when near his Oppofition- F / N I JLondoni Printed by W. and J. Innys, Printers to the Ro)al Society, at the Princes-Arms at the Wed Corner of St. Qiurch-Yard. 1719. •i i f / N / JLondom Printed by W. and J. I n n y s. Printers to the Royal-Society, at the Princes^Arms at the Weft Corner of 5’t. Paul[^ Church- Vard. 171^. ( 1035 ) Num^ 3<^2.’ PHILOSOPHICAL TRANSACTIONS, For the Months of September and OBober 17 sp. The CONTENTS h A Letter of the curious Mr. Henry Barham, R. S. Soc. to Sir Hans Sloan, Bart. Vice-Prefident of the Royal Society, giving fever al Experiments and Ohfervations on the production of Silk- Worms and their Silk in England, as made hy himfclf lafl Summer, II. Epifiola Jacobi Jurin, M. D. e^R. S. Socii, qua. dodrinam fuam De Potentia Cordis, contra nuperas Ob~ jediones Viri Clarifs* D. Jacobi Kcillii, M. D. in Num. 361. Philof. Tranfad:. editas^ defendit, III. Meihodus Differentialis Newtoniana illuflrata, At> thore Jacobo Stirling, 'e Coll. BallioU Oxon. I * IV. An Account of feme Experiments made on the ^yth Drfytf/ April, and onthexyth of July 1719* find how much the Refi (lance of the Air retards falling Bodies ^ by J. T. Dcfaguliers, L. L. D. and F. R. S. 9X I. A { «oj<5 ) I. A Letter cf the curious Mr, Henry Barham, R. S. Soc. to Sir Hans Sloan, Bart, Vice-Prefident of the Royal Society; ghing feveral Experiments and Ohfervations cn the production of Silk-Worms, and of their Silk in ^England, as made hy him lajt Summer, Worthy Sir^ AS you are the Patron of Induftry and encourager of Natural Experiments, I think you juftly claim the firft View of thefe fmall ones, I made upon Silk Wormsy the laft Summer. And altho’ they may have been done before by others in fome other parts of the World ; yet in all the Authors I have Read I do not find they make ufe of the fame Me- thod ; and I dare be bold to fay, that thefe following Ob- fervations and Experiments were never made in England with that Nicety, as 1 have done, and, fhall do if 1 live. It being the firft Attempt of this kind, it may come fhort of that compleat Methodical Manner it may be brought to hereafter ; the which I hope you’ll excufe. . After you ha»'e pecufed it ^'our felf, if you fee any thing in it worthy the Communicating to the Rojal Society (\z being defigtfd for the Publickj you may do me the Honour. J3ut I wholly fubmit to your Judgment and Opinion in this, as I do in all other things whatloever. 1 am, .• Tour bumble Servant Henry Barham. Experiments made in Chel/ea Park, in the Months of May June and July 1719. l receiv’d a fmall parcel of Eggs from. Languedoc. May 6. Early in the Morning I found them. Hatcht of themfelves, the Wind fhifting in the Night from Nor- ^ therly to the Wefi .South erly\ changing the^ Air of.9:.fudd,enho Warm, two Days before the change of the Moon. Aftejc Feeding and Managing them according to Art, through the whole Courfe of their four Sickneffes, they were come to their State of Perfedion, being then as thick as a Man’s little Finger, and from 4 to f Inches long, of a yellowifix Colour,, and when held againft the Light, they - might ( ‘0J7 ) mtght be feen through as you may an Egg, being of the fame Colour andConfiftence ('fill’d with the matter th^at makes the Silk) This is a certain Sign that they will begin to Spin in- 24 Hours or lefs. They then forfake their Food ('being very Voracious beforej and hunt about for a convenient Place to fix their firft Hold-fafts, for fupporting the Balls or Cones that they arc to make, which they do in a molt wonderful Mathematical Manner, with a Mixture of a Gummy Sub- llance that tyes all together^ and vs^hen the loofe furzy Sub- ftance is taken off, and forae of the Silk is wound olF, the remainder is fo Smooth and Compadt, (hining like that they are made ufe of for Artificial Flowers,and efteemed the bed of any thing yet known for that purpofe, for which (only) they are generally kept in Boarding Schools. I weighed many hundreds ofthefe Silk-Balls or Cones, which I found to weigh from 5 j to 40 Grains, with their Aurelias or Chryfa- Us within them. June 27. They begun to Spin, having been Hatcht 7 Weeks and ; Days^ and in 4 or 5 Days finifhed their labo- rious and curious Work : but their Balls were not fit to be removed until 8 or 10 Days. July 7. Monf. Lacbivre began to wind off their Silk- Balls with a Machine that made great difpatch, winding much fine Silk in a Day: I found that an Ounce of Silk-Balls would make about a Dram of fine Silk ; but to be more cer- tain, I weighed out to the Winder 12 Pounds of Silk Balls at 4 times, and told the Balls ii^ every 3 Pound as follow- etb, 'viz,. The firft 5 Pound contained 8j2 Balls The fecond 5 Pound contained 842 The third 3 Pound contained 797 The fourth ■; Pound contained 868 So that the whole 12 Weight contained 3319 Balls. Which when wound off, was found to yield and make one Pound and one Ounce, or 17 Ounces of fine Silk, and about 7 Ounces of coarfe Refufe unwound, in all a Pound and hdXi oi Averdupois Weight, or 2 Pounds Trc/ ; which is as great or greater making or yielding as in any part of the World, and the Silk as fine, f (hewed it to a noted Silk Bro- ker, who faid it was Italian Silk, (not knowing it was made in England) and worth about 30 Shilling} per Pound, .if I had; never (o many Bales of it, &c. Now; ( ioj8 ) Kowupon this Experiment finding that ;;i9 Silk-Balls would make one Pound and one Ounce of fine Silk. I was <3efirous to know what quantity of Silk might be expe(fted from the Worms Hatched from one Ounce of Eggs. Of which to obtain the Knowledge^ I made ufe of the following Method; by often weighing and telling 1 found that one hundred Eggs weighed b^ut one Grain, fo that if one Grain contains loo, a Scruple mutt contain 2000, and a Dram 6ooo, and an Ounce at 8 Drams to the Ounce, mutt contain 48000 Eggs. Now if every Egg hatch a Worm, and every Worm makes a Silk-Ball, there mutt be from one Ounce 48000 Silk-Balls,- and if Balls will make one Pound and one Ounce of fine Silk, ( v;hich by Experience I found they did) then 48C00 Silk-Balls will make 15- Pounds and 6 Ounces of Avtrdupois Weight in fine Silk, or i8 Pounds and eight Ounces of Troy Weight, which is very confiderable. And in the fame Proportion one Pound of Silk Worms Eggs, will produce Worms fuflicient to make above 180 Pounds of Silk. But allowing for Cafualties, and fuppofing but 12 Pound of fineSilk made from theWorms and their Silk-Balls produced from an Ounce of Silk Worms Eggs ; it will be found much to exceed molt Countries, according to Augufiino Gallo's Computation ; For he fayeth, that in the Southern parts of France, viz. Languedsic and Trovettce, they make but 7 or 8 Pound of Silk from Silk Worms hatched from an Ounce of b'ggs ; and inBrefcia in Italy, but 8, 9, or 10 Pound of Silk from an Ounce; only in Calabria, where the Silk Worms and their Eggs are larger, they make 11 or 12 Pounds of Silk from an Ounce of Eggs ,- which ftill doth not exceed, nay hardly comes up to, what we make in Eng., land. As to the Charge and Expences of making the aforefaid quantity of Silk in England, different from that of other Places, I fliall be able to give you a more particular Ac- count in my next Experimental Obfervations. 1 have only this to add, that Experience hath taught me how to hatch Silk Worms twice in a Year, fo as to have two good Crops of Silk in one Year. And that the Mulberry Trees will have Leaves in England twice in a Year, without prejudice to either Tree or Fruit, is'moft certainly true. But more in my next. II. V IRC Viro Celeberrimo, Richardo Mead, Collegii Medicorum Londinmfium & Socio tatis Regime Socio. S, T. D, facobm fmn, M. D- Reg. Soc* S; Pologiam Prseftantiffimi Viri, Jacohi KeilH, qui acetbi nuper & immaturi morce praereptus mag- num fui defiderium Eruditis reliquit, ftudiofe pervolvi- mus. Quam inter legendum fingularem fimul candi- diiTimi Ingenii humanitatem, qu^ nofmet, utut a placi- tis fuis dilTentientes, excipere dignatus eft, fimul Ani- mi magnicudinem, & ftudium in Rempublicam Litera- riam canto Viro dignum, magn^ admiratione profe- quebamur. Huic enim ills non fblum per omnem vi- tx curfum diligentem & ftrenuam operam navavit, (ed etiam pulcherrimo Exempio, confedlus jam atroci mor- bo & fe perire fentiens, eruditam illam Epiftolam tan- quam fupremi amoris pignus, eidem legavit. Cui ta- men neceflario nobis refpondendum eft, non (ane quod acerrimo tuo Judicio diffidamus, (ed ne aliis Le^ori* bus minus idoneis impedimento efte poflit, ad re(ftam fententiam ferendam, Viri illius Do(ftiflimi Au(3:oritas. Accipe igirur, Vir Clariftime, quse in ejus defenfione minus rede tradita cenfemus, & tuum fimul Arbi- crium efto, utrum concentionis abrepti ftudio iniquiores fimus { 1040 ) iimus ipflus Manibus, an ita difputemus, ut qui de Ve- ritate potius quam de Vic3otii fimus folliciti. Queritur primo Vir Clariflimus, quod fefe una cum Dodtiffimis Viris Borello, & Morlando, tanquam Cordis Motum cum pondere inert! conferentem, injufte per- ftrinxerfm^ Ego cerce, cum prius notaflem Motum quendam Sanguinis & Artcriarum ex Cordis Vi or iri, dixi tandem iciri non pofle Cordis Potentiam quanta fit, nhi Motus hujufce quantitatem cognitam tenea- mus: Motum vero quemlibet cum pondere quiefcente comparari non magis pofic, quam Lineam cum Re- dtanguloi. Quibus verbis id fignificare volui, DodiiTi- raos Viros non quidem diferte Motum Cordis cum pondere quiefcente comparare, fed ipfos, cum Cordis Potentiam per pondus cxponerent, nullam oftendifle rationem, qud Motus quantitas ex Cordis Potentia ori- undi pofjet seftimari. Ex hSc Objedione, fi rede afle- quor mentem Viri Clariffimi, ita fefe expedite conatur. Cordis Potentia in preffione confiftit, eamque ajquabi- litcr in Sanguinem impendit, eodem prorfus mode, quo Gravitatis vis deorf'um pondus impellir, & adione perpetua in motum accelerat. Proinde, cum Cordis Potentia ponderi per Corollarium Newtoniamm definiro arqualis eft, ea Motum eundem durante SyftoJe in Sanguinem imprimet, quern pondus iftud eodem tem- pore cadendo per Gravitatis Vim comparabir. Ita vero cum menrern fuam exponic Vir Cl. fubla- tum iri penitus Objedionem iftam Uoftram confi- remur ; ft nimirum Cordis Potentia prardido ponderi ^qualis ftt, eademque conftftat in trquabili preftione per totam Syftolen continual. Atqui'ex duabus iftis Propofttionibus p6fteriorem neiftiquam pr.obare cona- tur Vir Dodiillmus , fed Hyp’Othefeo>s ';Joco ponit ; quamvis nos rationibus quiburdam addudis contrariam Smtenn^m conati fumus veriftmiliorem redd ere ; nem- pe, quod Cordis Potentia nequaquam ^equabilicer agat ifi; ( 1041 ) in Sanguinem per totam Syftolcn, fed cum totas vires exigua temporis particula collegerir, inde uno impetu in Sanguinem irruat, eumque ex Vencriculis expcllac, eo modo quern in Diflercatione noftra Epiftolari fufius expofuimus. Priorem vero Propofitionem, cciam cbn- cefla Viro Cl. Hypothefi, falfam efle mox demon- ftrabimus. Corollarii Newtomani fenfum quod attinec, nolumus Ledori moleftiam niraiam facelTere, cum neque puce* mus ejus interefle ucer Newtoni mentem redius acce- peric ; neque ita perfpicue fenterttiam fuam expofueric DodilTimus AdverfariuSj quin periculum fit, nealiquem ei fenfum affingamus, quern ipfe forfican, fi poilet ad- huc fe defendere, forec repud iaturus. Id vero adno- taffe operce pretium eric, quod cum loquatur KcHUus de Vi qui ex Orificio aliquo aqua exprimitur, Mewto- ms nullum omnino verbum in illo Corollario pofueri-^ quo Aqua per Vim aliquam exprimi fignificetur ; fed pond us folum determinaverit cequale ifli Vi, qua to- rus Aquse effluentis Mocus generari poteft, five quod Gravitatis Vi cadendo Motum comparare poteft Mo- tui aquse eodem tempore effluentis rsqualem. Quod aucem Corollarium illud, fi non male intel- lexerit Vir Cl. certe non fatis apte ufurp^rit, facile perfpiciet Ledor Erudifus, qui animum adverteric, quid incerfic difcriminis inter elHuxum aquce ex fora- mine in fundo vafis femper pleni, quomodo a Newtono confideratur in eo Corollario, &: elfiuxum Sanguinis ex Cordein Aortam. in cafu enim priori aqua jam to- tam velocitatem comparavic, & per datum temporis fpatium aequabiliter effluit ex foramine. At Cordis Vis per Hypothefin Kdllimam, applicatur Sanguini in Ven- triculo quielcenti, & eum primo temporis momento velocitate infinite par\4 verfus Aortam propellit ; con- tifiuat.^ vero a:quabili preffione taiideni ei finitam ve= 9 Y z locitatem ( 1042 ) locitatem imprimit, camque perpetiiti auger, donee omnem Sanguinem ex Ventriculo expulerit. Rurfum in cafu Newtoniano confideratur Motus noa quidem toCius aqu2 Cataradd contentae, quae omnis in mom conftituta eft, & diverfa velocitate verfus exitum tendit, fed aquae folum in ipfo foramine pofitas & jam exilientis. Vis autem Cordis tori Sanguinis moli Ven- txicuio contencae Momm imprimit, tocamque Aorcam verfus propellit. Denique negamus pondus quinque undarum, 5 Viro Cl. decerminacum, pofte earn Motus quanticacem duran- te Cordis Syftole per Gravitatis Vim comparare, quam Cordis Potentia producic, concefta etiam ei Hypothefi iftd, quod Cordis Potentia in srquabili preflione con- Cftat. Per hanc enim Hypothefm' erit Motus a Ven- triculi finiftri Potentia produdus, ex Calculo noftro- [TrafsJ. Numb. 359. p. 932., 934.] aequalis Motui Pon- deris Ododecim librarum cirdter, quod fingulis mimi- tis fecundis longitudinem undalem percurrat. Motus autem, quern pondus quinque undarum durante Cor- dis Syftole, ft tollatur omnis Arteriarum & Sangui- nis praecedentis refiftentia, ftve dedmi parte minuti fe- cundi. per Gravitatis Vim comparabit, aequabitur fere Motui Ponderis duodedm librarum, quod fuprapoftr ta velocitate moveatur. Quod ii cui libuerit adfump- ta hac Hypotheft verum pondus definite, quod Cordis ^otentiae aequale eft, is pofito Calculo eliciet pondus unciarum circiter (eptem cum ^mifte. Hoc enim du- rante Syftole Cordis eundem fere Motum cadendo . comparabit, quern producic ipla Cordis Potentia. Sed inquiet forfitan aliquis diferimen modo expofttum inter Motum pondere acquifitum, & Motum ex Potentia Cordis oriundum inde proficifti potuifle, quod forte minus accuratae fuerint pofttiones illx, quibus Cfiaratoes Algebraicos in Calculo noftro ad numeros leva- . ( *045 > revocavimus. Cuidubio ut occurramus, & oftendamus fimul nos longe majus difcrimcn invencuros fuifle, ni(i contigidec ut pofitiones iUss Keillio faverent; operse pretium erit cafum aliquem fimpliciorem adfumere, quo data moles aqux, per datum oridcium> dato tem- pore, per vim aliquam five predionem asquabilem ex- primatur, qus funt conditiones ab Adverfario pofitae ad Potentiam Cordis dedniendam. In eo autem cafu demonftrabimus neque Motum aquae efHuentis, neque Motum toti tandem moli aquse per Vim illam impredum, Motui aquiE in Corollario Nnvtomano ; neque Vim earn five predionem, ponderi- per iftud Corollarium definito, sequari. Quod d prae- ftare licuerit, corruat funditus necede eft tota demon** ftratio KdJUana, Adfumemus igitur Cylindrum aquae datum, tubo ^ Gylindrico infinite longitudiniscontentum ; eritque pro oridcio ifta fetftio tubi ad quam pertingic utralibec aquae fuperdcies, alteri autem iuperdciei Vis applicabi- tur ope Emboli eadem Diametro cunt ipCo tubo. Per- fluat jam dato tempore data quaevis aquae quantitas per didam (eiftionem tubi ; cum alia quantitas aequalis per foramen pari Diametro faftum in fundo vafis, quod more Newtomam ufque plenum confervatur : & primo • loco difpiciamus, urrum pares futuri fint in utroque calu Motus aquae edluencis. * Exponatur tempus edluxus aquae per re 104^ «tatis mediae, velocitatem Sanguinis aequabilem ponat, penes aequum Ledorem fit Judicium. Idem quoque facile arftimabit, utrum Vis aliqua five preflio fluido in vafe quiefcenti applicata, quae eft Hypothefis Viri Dodifiimi, id fluidum prime temporis momenco, e^dem velocicate qu<1 in fine, propulfura fit. Pofiquam ita fatisfadum putac Vir Cl. iis Objedio nibus, quas contra priorem fuam Methodum attule- ram, jam ad alteram illam faciliorem vindicandam ac- cedit. In hac Ego animadverteram Virum Cl. adfu- mere iftam Propofitionem, quod Vires Cordis in diver- fis An'malibus fint in ratione ponderum, item ponere velocitatem Sanguinis ex (edd lliaca Arteria profluen- tis aequalem ei, qua Sanguis ex Corde in Aorcam emit- ^itur ; quas ambas pofitiones falfas efife nobis demon- ftratum eft. Vitium pofterius non defendic Vir Cl, prius vero tuetur BorelU & aliorum Dodorum Viro- fum audoritate, qui afilimptioncm iftam fkpius ufur- parunt. Ita quidem, & nos ejurmodi afiumptionem in Bordlo reprehend imus, neque valet cujufquam au- doritas contra legitimam demonftrationem. Supereft ergo ViroCl. ad examen revocanda noftra demonftra- tio. Hanc autem fallaci quodam Principio inniti pu- tat, quo cum omnia Theoremata noftra fuperftruda fine, communi ruin4 omnia involvit. Air enim me ponere, quod Ventriculi Cordis, tanquaro folidum cor- pus dat^ velocicate motum, in Sanguinem impingunt, ^oque idu Motus fui partem eidem communicant* <^am Hypothefin. Motui neque Sanguinis , neque Cordis, neque xAeris ex Pulmone expreffi, competere cenfet Vir Clarillimus. Quod Pulmonem attinet, quoniam hoc obiter attin- gere voluit Vir D.agnofco me confiderafte Pulmonem inter concrahendum tanquam data velocicate impingentem in Aerem contentum, idque confulto fecife proficeor. Quum ( 1047 ) ^Qyum'enrm turn BelUnus, turn alii multi Viri Dod^i-, flimi, quos inter cminet Cl. Adverfarius, multa protu- lerint de Vi illd, ^ua Aer inter exfpirandum in Sangui- tiem Pulmones praeterfluentem agit, ejufque moleculas dillblvit; quam folucionem ipfo exrpirationis initio cenlent accidere ; mihi propoiitum erat hanc ipforum fententiam ad trutinam revocare, Videbam autem, quod, fi aerem per Vim arquabilem five preflionem ex- pelli ftatuerem, Motus aeri a Pulmone impreflus initio exfpirandi, five readio aeris in Pulmonem, adeoque in Sanguinem praeterfluentem, pro quantitate infinite par- vi habenda erat, adeoque nihil omnino eorum efied- uum, quse ipfi adfcribebantur, pr^sfiare poterat. Ita vero fi fcciflem, jure quefturos putabam Bellini (equa- ces, quod inique fecum ageretur ; quippe cum rejicere- tur ipforum fenrentia propter demonftrationem ex Hy- pothefi arbicraria & eadem omnium adverfifiTima de- dudam. Malui igitur ex ilI4 Hypothefi demonftratio- nem deducere, qua: omnium maxime ipfis faveret, maximamque Motus quantitatem exfpirandi initio aeri tribueret. Ha:c autem erat, qua ponebatur Pulmo ini- tio exfpirationis data velocitate in Aerem impingere. C^terum in Potenti4 Cordis definiendi ifiam quidem Hypochefin, qu4 ipfius Ventriculi, omni impetu mo- menco temporis concepto, tanquam (blidum corpus da- ti velocitate prsdirum, in Sanguinem irruunt, primo loco propono, tanquam omnium fimplicilfimam, ex ea- que folutionem deduco. Atqui deinde confidero turn earn Hypothefin, qu4 Ventriculi Cordis Motum omnem fuum particul4 temporis admodum parva concipiunt^ quseque mihi veri fimillima videtur, turn ipfam Hypo- thefin Keillianam, atque alias infinitas, iifque omnibus iblutionem meam accommodo. Adeo ut, five ifiud Principium uiceicum & fallaxi five verum & fiabile 9 Z repe-. ( to48 ) raperiatar, nihil exitide folucionis noftrse certitudini de- traliatur. Non tamen videmus aliquid argument! allacum, quo minus iftam pofitionem nobis adhibere, pari jure at- que Viro Cl. contrariam illam de Vi five preffionc ufd'rparo licuerit. Nihil fane fpatii inter parietes Ven- friculorum & Sanguinem intercedere non difficemur, Sc tamen quare res i(^u peragi nequeat nondum liquet. Certe, fi Cubo Globum contingenti idius imprimatur, Cubus partem Motus fibi impreffi Globo communica- bit pari facilitate, ac fi fpatium inter eos interceflerit. At haee funt corpora folida, & ubi de fluidorum Motu agitur, longe alia res eft. Difcrimen fane inter i(ftus corporum folidorum, & adtionem five folidi in fluidum, five fluidi in foiidum, fufius exponit Vir Cl. quod difcrimen cum me minus advertifle cenfeac, ex eo fonte fluere pronunciac quicquid Erroris in meis Propofitionibus cominetur. Ego vero differentiam iftam uc redte traditam a Viro Cl. lubens admitto, & aio me communCm illam dodrinam neutiquam igno- rafle, cum nihil frequendus in Mechanicis fcriptoribus occurrat, fed cafus quofdam novos expofuifle, quibus ea dodrina cum adhiberi nequiret, alia erat ineunda ratio atque hadenus fuerat ufurpata. Ea tribus verbis abfolvi poteft. Nam, ut exemplo facillimo utamur, quiefcere pqnatur Cylindrus aquae datse longitudinis in datp tubo, *& moyeatur per iftum tubum Gylindrus alius rolidus p^i diamctro, ac dat^ velocitate in Cylin- drum aqueum impmgat. (^id inde futurum eft? Nem- pe totus Cylindrus aquae eo iiftu in motum ciebitur, pa^; ratione, ac ft fuiftet & ipfe ‘ folid'us Cylm^^ al- ^er Motus fui ^arj:^ mpmento temporis deperdet, amfeo Cyhhdri^cbftjtnUnt vclocitat^ pe^ tubum deferehtur. ^Simili modo res eveniet, fi Cy- lindrus aqueus per tubuna’fluens Cylindro folido quief- centi ( '049 ) centi impegerit. Quod fi Cylindru^ aqueus data velo- citate per tubum feratur, eique occurrac Cylindrus fo- lidus alia velocitate, ica ut quantitates Motuum Cy- lindri aquei & folidi utrinque pares fint, jam mometi- to temporis deftruetur utriufque Cylindri Motus,. pari- ter ac fi duo folida corpora :squali Motu prsedita fibi mutuo occurrant. Cafus magis compofitos quofcunque ex diflertatione noftra de Motu Aquarum fluentium facile eruet Le<5lor Eruditus, idemque fimtil videbit, quomodo id fieri polfit, quod Adverlarium Cl. prxci- pue torfifle videtur, nempe, quod Sanguiqem toto impe- tu ex Ventriculo ruentem fifti pofie docuerim, occur- rente in contrarium corpore folido dad Motus quan- titate prsedito. Quod autem nos amice admodum hortatur Vir Candidifiimus, ut (epofid noftra de Vaforum idu Hy- pothefi, & Vi preflurse, qua Naturam uti cenfet, pro Principio adhibita, Theoremata alia conftruamus; id profedo, nifi gravi morbo impeditus perfundorie prorfus evolviflet noftram Diftcrtationem, dudum a nobis prxftitum animadvertere potuifter. Quum enim poni- mus Motum Cordis in ratione temporis augeri, eadem utique Hypothefi utimur, ac ft Vim preflionis adhibea- mus. Hoc autem pofito, Motum ex Cordis Potentid oriundum determinavimus, duplo fcilicet majorem quam ubi Ventriculorum idu res peragitur. Galculum vero ipfum, ut fatis facilem & priori noftro ftmilem, Ledori reliquimus inftituendum. Quas autem fequun- tur Theoremata & in iis Theorema quintum, quod reji- ciendum ftatuit Vir Cl. tanquam ex Hypothefi de Ven- triculoriim idu dedudum, neutiquam pendent ex ifti Hypothefi, fed ex ipfa Hypothefi DodilTimi Adverfar rii pari facilitate demonftrantur. Nequaquam dubitamus, quin ipfe Vir Cl. quid ifta vcri habeant, ft in vivis adhuc ageret, pro (ua (agaci- 9 Z X rate (■ lo^o ) rate facile petfpe^mus foreci; jam veroj quoniam ei gregium illud Rei Medic^e Lumen amifimus, eadem aliis Eiudicis perpcndenda fimul proponimus jk dijudi- canda. Tibi praefertimj Vir Dod:iffime, cujas audori^ cacem & ille plurimi fecit, & nos praecipuam habemus, Judici fimub incegerrimo & maxime idoneo, cotam iRam diTpucationem lubentiilime fubjicimus.* IIL Methodus Differ entialis Newtoniana llluflrata, Juthore Jacobo Stirling, e Coll, DallioL Oxon, f A Rithmeticse pars prascipua confiftic in invenienda ,Xx in numeris quantitate quacunque determinate ; cum veto quantitatum & numerorum natura non pa- tiatur ut omnes quantitates exhibeantur in numeris ao curate, necefle habemus ad Approximationes confugere. Hoc efl, ubi quantitatum valores maihematice accura- ti neqeunt obtineri, qusrendi funt ii qui ab accuratis diftant minus date quevis diflerentie. Quicquid hec de re a Veteribus ad nos pervenit, vel eft particulare, ut Methodus eorum reducendi JE- quaciones Quadraticas ; vel faltem ufibus generalibus male deftinatum, ut Methodus Exhauftionum. Het4 quidem primus erac qpi aliquid generals in hac arte aftequutus eft.* quippe invenit methodum reducendi iEquationes Rationales, quaz fol^e tunc in ufu erant. In hec acquievere omnes Geomecrse ex ejus tempori? bus ufque ad ea Newtoni. Hie ex Intetpolationibus primo pervenit ad Series : quas poftea ad redudionem iEquationum omnium< omnino generum univerGiliter applicuic. Hsc autera methodus procedit per quan« citatum naftrentium & evanefeentium rationes primas It ultimas^ feu ft ita loqui liceat, per quantitatum coin> cidencium ( «05« ) dxkntium dif!eretitias infinite parvas* Sed- & ulcerius^ promovic Nervtonus hanc mechodum; docuitque qua ratione approximandum fit ad quantitates quss deter- minantur per regularem feriem terminorum, non pet j^quationem ut vulgo fif. Atque fic pofuit fundamcn- ta calculi hujus Differentials, qui procedit per quanti- tatum differencias cujufcun^ue magnitudinis .* ideoque eft methodo Serierum univerfalior. Per hafee artes Mevetcniaius univerfa docftrina Approximationum redu- citur ad folutionem Probiematis, Invemre Lmam Geo- metricam qua per data quotcunqm pun6la tranftbtt. Ex hujus inquam folutione inveniuntur radices ySqua- tionum quarumcunque, & etiam quantitates quarum relationes ad alias datas per nullas iEquationes hadc- nus notas poffdnt exprimi. Exiffimo \^\\.\xx. i^evetonum perduxiffe methodum Approximandi ad fumnium per- I'ecftionis faftigium ; dum ex unico fimpliciffimo prin- cipio totam hanc dodrinam' longe lateque patentem * deducit. Quapropter credendum eft animum J^evptoni non fatis perfpedum fuifle iis, qui ejus methodos ap- pellant particulates, & alias tanquam fuas & folas ge- nuinas atque generales venditant? quse aliis non eranc quam Corollaria facillima a Newtontanis. Author nofter, in Epiftola ad OUenhurgum^ 05toh. iq; 1^76. data, mentionem fecit de methodo expedite du- cendi Lineam Parabolicam per data quotcunque pun- <3a ; qua dixit fe ufum fuifle ubi Series fimplices non 1 func I'atis tradabiles. Et hanc methodum primo pub- licavit in Lemmate quinto Libti tertu Principiorum, Atque in Leflionibus publicis, circa idem tempus quo • dida Epiftola fcripta eft, Cantahrigia habitis, expofuic modum generalem determinandi Curvas cujufcunque “ generis qu£ tranfibunc pec totidem data punda quot earum natura patitur. Hse Lediones fub tiiulo Arith^ meticA Unmr{a\h anno 1707. publicatas funt, ubi ha» betas r ( To5» ^ 'betur methodus exemplis illuftrata in fe<3ionibus Coni- cis. Anno vero 171*. tandem prodiit, inter alios ejuf- ^ dem Authoris tradatus, ipfa Methodus DifFerentialis plenius quam ante expofica, cum fundamento ejus de- imonftrato* Archimedes in methodo Exhauftionum, Cavallerius in methodo Indivifibilium, & Wallifim nofter in A- rithmecica Inhnicorum, pofuerunc fundamenca dodrinse de determinanda quantitate quccfiti per locum quern obtinet inter terminos in data Serie : at qua ratione approximandum eflet ad valores quantitatum fic deter- minatarum. horum nemo docuit ; Hoc primus & (blus perfecit Idemonus: atque exinde baud parum ampliata eft univerfa Analyfis. Nam ficut ante hoc inventum, ea Problemata Arithmetica Cola pro fplutis habebantur, 'Ubi relatio quantitatis qusefitse ad alias datas definie- ■batur iEquatione, jam pro folutis habenda funt non minus ea, in quibus quantitas qusefita locum datum forticur inter terminos datas Seriei ; fiquidem numeri defiderati non minus accurate obtinentur perMetho- dum DifFerentialem, quam per extradionem Radicum: hifce vero habitis, parum intereft quomodo ad cos de- ventum eft. Et experientia multiplex docuit, quod plurima Problemata ad ^quationes asgre deducuntur, dum ad methodum DifFerentialem facillime. Qpalis eft ex mulcis aliis tories decantata Circuli Quadratura ; quam tarn perfedam, mea opinione, Wallifius in Arith* imetica Infinitorum exhibuit quam Archimedes illam Parabok. PropoJjtio ( iofj ^rofoptiol lAvtnln LhsAm TaraholicAm qu£ trAnfihif . fer txtn*- mA OrdinAtornm quoteunqus aquidifianthm, . C Cz C3 C4 Cq C6 C7 D Di DS D$ D6. E Ez E^ ^4 Eq^,^ F Fz F^ F^ , G Gz Gi H Hz 1. I Cajus Trimusl Dengneiit A, Az, Aq, A 6, A j] A S,' A , Ordinatas sequidiftantes infiftentes Abfciffe iti^ dato angulo. Collige earum differentias B, Bz, B , B^,Bq,B6, By^ C^c, harumqus differentias C, , CZi C C4, C 5, C6, C7, &c, harumque differentias ^ £), Dz, D3, r>4i Dq, D6, &c* harumque differentias E, Ez, £3, E^, Eq, &c. harumque Fy Fz, F3, F4, ^ Et fic porrq. Differentiae autem cqlligi debent au-. " “ ' ----- - ferendo^ ( I0J4 ) -ferendo priores fempcr de pofterioribuS. Hoc eft po- nendo B=.Az — A, Bir=:A^—mAz, Bi~Aj=C4 — C3, CS'f. £t ftmilicer (unc omnes difterentiac fequentes colligeud.'e. ;Vel fint a,/3, squales A, Az, A^, A^, A6, Ay,^c» Eritque A = oc,, B = B — «, C — y ' 2, /3 “1“ a, £) rrz — Jy-|— 3/2 — 0-, e — 4^”4~^^ — 4^ + 06., — je + ioj^ — icy 5/3 — a, G— « — 6^ + 156— 20<^ -f- 1 5y — 6/3 -j- a, In hilce yaloribus numerales Coefficiences ipforum a, /3, y, JVfs&c. gcnerantuf ut in dignitatibus integtis Binomii 1 — a[®, I— *1*, 1 — I— &c, Scribendo numeros *» 2,, 3, 4, la Sene i X y x — X — x — X X &c. iucceflive pro n. Sit jam P ^quaelibet Or- dinata reliquis intermedia, 6>c A P ejus diftaniia ab Or- -dinata prima A appelletur a, turn crit B X -4- ■ * Cx4xS=^4- * X * Vt.. ‘ dideoque ( 1055 ) Ackoque fignum ipfius mutandum eft, quatido ? ^ cadic ad alteras partes Ordinatse primse, nt Cafus Secundus, Sit jam A q Ordinata in medio omnium ; pone H -}- drc. 6>c a C4, £3, ^ d= /, &c. id eft, fifmt A6z=a, Aq=::/3, J8 = y, Ap==/^, = 3t> ^3 = A, Az ■=.fA, A — V, cjrc. Pone ^=ra— .jc, /3 — 2a-|-2}t — A, 4/3-f -f 1 4/3 — 1 4a *f 1 4»t — 1 4A -1- 6//^ ^ y, + ^ = /3 — 4a-}- 6/45 — /3— 56 «-}-70/45— 56>c4-i8A^8At-fy, ^c. Ec dicatur A qP, z, turn eric PX=A; + ^l^ + + 5;5_r f 3*4* 3£i+5? _ I . 2 X + 3.4 y -6 + I 4 9 I *2 X I .2 X 3 .4 X X 7i8 + 5,6 7 , 8 ^ , 10 Cafus Tertius.- Sint jam Aq, Ordinatse duas in medio omnium: A4 -f- -45 _ Pone A g = gj±l^, C=:^2+/\ D z z 10 A G+6z ( ioj<5 ) &c. a = B4, i = Vj, c = Fz', d = H, &c. Vel fine As=za,, A6 — {^t Aj~y, A^z=S^, &c. A4 = x. As = h, Az=.fA, Az=, p, &c. Deinde erunc zA =: (X, -\- X., zB z=: ^ a, — X zC y — g/3 4- xa -V" — 3^ + zD=S^ — Sy-^9^—5‘^ — 9^ — Sf^ Et • 3 4 • 5 ' 7Q 4^^— I ^KK—9 ^ AKK—^S t 4’ 6.7"^ 9E+3^ ^ 4H=9 X ,< ^S=*2 + &C. 4+ 2.3 4-5 6.7 8.9 ' In hifee duobus etiam cafibus z eft negativa, quando Ordinata P ^ cadit ad alceras partes inicii Abfcifc Ec in omnibus tribus cafibus diftantia communis Or- dinatarum ponituc unitas, Omnes tres cafus demonftrantur facillime per calcu- lum. In cafu primo pro F^feribo fucceflive a, /3, q<-, g, &c. & pro z interea p, i, x, 3, 4, &c. quse funt longitudines Abftiffie ordine fequentes ; & provenient sequationes € zz:. A -]f 4^ H“ 4^ "1“ /3 — a ( 1 ojr ) ^ — ^ — 5/ n: B iC -|- e — eT = B + 3G4-3D-p£', &c. y T!Z 2/3 -j- cc zzz C, ■ =: O a — 3/3+ — ^=0 a, — 4/3 + 63/ — 4J^ + €r=:0 a. •— 5/3+ lOy -.-IO? — 3 69+9J&— A=o. &C. HfEC I ( ioj8 ) H*c Tabula in ufum teiervanda «(V, ut contiilatut quoties opus fit. Quod autem ha: i^quationes vel ob- tinent accurate, vel ad verum approximant, ubi diffe- ssentisc terminorum funt parvar, patet ex d^onftratio- ne cafus primi Propofitionis. Affumatur quaslibet Series- &c. Et quaeratur terminus qui flat proximus ante : patet quod ille eft ; vidcamus ergo qualem hsc methodus exhibebit eundem. Repraefentet ct terminum quasfitum, eritque ,-7, = /S— 0099,0099,0099,0, 0098,0392,1 568,7, ~r:r;'^oo97, 0873,7864, 1, a— 0096,1 538,461 5.4, i^=C=°°9S*i38o,9523.8, -^n^M.;=oo94, 3 396,2264,2. 1*" ima' T ro®99, 0099,0099,0,' 1 2da ■ 0099,9805,8629,3; 1 Jtia * dat It < 0099,9994,3455,0, 4ta 0099,9999,7824,8, 5taJ 0099,9999,9895,8, 6ta L J _Qo99,9999,9993,i. Patet ergo quod h^c methodus continue approxi- mac. Si terminorum differentiae fuiftent minores, va- lores acceffiftent citius ad verum, & contra tardius quando differentiae funt majores* Hinc fi in Tabuiis numericis defit terminus, poteft is per. hanc methodum inferi. Hocmodo etiam prodeunt ipfiflima: Series Speciofte, quae per alias method os prod ire foie nt. Proponatur OrdinataCurvae quadrandae; Ea eft prima in ferie regU' lari. &C. Ordinatarum, quae omncs praeter primam dant fuas areas z-\-~z\ z-\-jz^ -f \z\ z &c.. conftituentes novam feriem cujus primus terminus erit Area quaefita : quae ideo invenietut ponendo pro & pro reliquis in fuo Oirdine /3, 3/, g, &c.* Pri- mal .Aiquatio dat ulcernas in quibus numerus terminorum eft impac* Nam earum differentiae relinquent cerminos in hac Se* rie ; quae itague ad libitum produci poteft. Sit Ordinata Hyperbolae, & quaeratur Area ^us qux jacet fupra Abrciffam z, quando ea evadic unicas. Haec Ordiaata eft media in Serie Ordinata- rum^ rum, &c. 14-4"^} ^4~^l % i-\-z\\ i+z-f, &c. sequidiftantium, hinc inde excurrente in infinitum- Adeoquc Arex ab hifce Ofdinatis genitas conftituent feriem confimilem, cujus medius terminus eric Area quaefica; quse proinde obtinebitur per Seriem modo expofitam. Quando z eft unitas, ut in cafu prsefente, arex curvarum evadunt &c. a. K f, & I, r, h r. Hinc eft i + * i n — 5 1? — 15 rmL_L2.r=” D — ’J I »5 — i?s r==r» ^r“r“r« — ^ *> ^ 4~r«4 «4» &c. Hifce in Serie fubftitutis, prod it P, id eft, area Hyperboix, | + ^ 97.5'58<^,9I30»8 3 90.4086,1 i88,774S'.5 2,7085,0 393j4 5.7 Negathi. o6i5^539»3930,7494‘I — 0631,7821,3370,8041,1 Summam negacivam fubducens ab aftirmativ^, babeo pro Arei, id eft, pro Logarichmo Hyperbolico Binarii, numerum 6931,4718,0559,9453, Pro _ ( lo^l ) Pro conftrudiione Tabularum quarumvis numerica- rum percommoda eft Series quce fequitur. Defignent &c. f, c, h, a, a, y, cT, g, &c. terminos alternos in Serie utrinque ferpente in infinitum ; Pone Az=a -J- a, Q C rrr: ‘y -\- D n:; ^ dt E — S &C» Ec terminus inter a & <* eric ^ * rx— + 1^3 2 A — jB-f-C , X + 1 . z 1.3.5 X 5/4— 9B-f-5C— D I . z . 3 1 . 3 . S • 7 14. A — zSB-l-ZoC — 7D-f--E 1 • z . 3 • 4 ^ I . 3 . 5 , 7 . 9 41/4— 90B4-75C— ^‘>0+9^ — F , 1" Z .3.4.5 ^ z'“ ‘ il3i?.7.9‘ir l^^A—l97B-h^7 5^ — 154D4-54^ — TlF-p*^ t i.Z.3.4.5.6 ^ 2'^ ‘‘ 8ic. Hsec Series fequitur ex cafu tertio Propofitionis, ponendo z=^o. Coefificientes numerales literarum fie producuntur ; exempli gratia, in quarto termino coe- fficiens literal penukimae C eft 5 ; pone 5 -f- i = », & numeri qui proveniunt ex multiplicatione terminorum I ^ Y “1“ ^ ^ ^ ~5~ ^ erunt i, 6, 1 5:, 20, &c. Horum differentiae 5’, 9, funt numeri quaefiti, Atque adeo Series ad libitum produci poteft. Datis Logarithmis numerorum q6, 48, 50, $%, jq, 56, 58 & 60 ; invenire Logarithmiim numeri 53, qui confiftic in medio omnium. Pone /, 5”2 -j-;/, ^4 = ^4 = 344S3>97*o>34> $o+h ^6 = B ;=a, 4471, 5803,1 Y ( lo6l ) /, 48+/, 58 — Crrr 3,4446,6913.08, /, 46 + /, 60 = D =: 3,4409,0908,19. Hifce valoribus in Serie fcrip- tis, primi quacuor termini dabunc I,7^42,^586,96 pro Logarithmo numeri Ec eadem ratione invenire licet quemvis alium intermedium. In Conftrudione ergo Tabularum fufficit primo quae- rere aliquos terminos in debitis didantiis, nam reli- qui poiliint hoc modo interCeri. Etenim continuo lunt intercalandi termini primo inventi, ufque dum perventum fuerit ad ultimos qui defiderantur. Hoc modo habebitur tota Tabula ex datis paucis terminis Tub iniiio pro fundamento operationis. Sed non con- venit ut termini quos primo quxrimus, fint omnes per totam Tabulam aequidillantes ; nam fi omittimus al- ternos ubi eorum differentia efl maxima, poflumus ali- bi per faltum omitterc duos, tres, viginti aut forte plures terminos. Numerus autem terminorum inter duos datos confiflentium, qui omittuntur, debec Tem- per efie aliquis fequentium i> 3, 7, if, 31, 63, &c.' dummodo volumus inferere eos per hanc b'eriem ; hoc veto neutiquam incommodabit opus. PofTunc autem pro Praxi lernrini in unam fummam colligi. ut fadum vides in hac Tabella. Prima expreffio eft primus terminus ; fecunda eft fumma primi & fecun- di $ teitia eft fumma primi, Tecundi Sc tercii : Sc Tic porro. 4 I 8 10 z ^A—B ia2 5/j-.243B-f~49C-.-5D 2048 3969o-»^— 882GB+2268C>-3o;D-f-3sg 6J536 Sic { I0(5j ) Sic daCiS' aiiquibus terminiSrf altern^i^ intefTn^tfii confeftim dabuntur pec hafce expreflTiones, nulll ra- tione habit^ naturae Tabulae particularis. Nam hae fe- gulae funt eaedem in omnibus. Areas curvarum funt proxime squales areis Parabolicae iigurae quae, tranfic per extrema Ordinatarum fuarum. ’Sed quoniam labd- riofum nimis eflet Temper recurrere ad Parabolam. computavi Tabulam fequentem, qua Areje dire^e exhi- bentur ex dacis Ordinatis* ' ‘ I 3 5 7 9 II -R I R 90 41 A-\-2, {6B“f-27C-f-27lD 840 R ’li D 989/^+58882 — 9z8C-f-ro496D — 454oE^ 28350 i6o67y#4-f 06300B — 4852504.2714000; — 26o5-5oE4-4^73^8F 598752 -/?. St , Hie numerus Ordinatarum eft impar, A eft fumma primae & ultimse, B fecundae & penultimae, C tectias & antepenulcimae ; & Tic porro> ufque dum deventum fit ad earn ,in medio omnium, quse per ultimam literam in quiq'ue expreffione reprsefehtatur.^ eft bafis feu pars Abfciilae inter primam & ultimam Ordinatam in- terceptse- Expreffiones funt Areas contentae inter Cur- vam, bafin & Ordinatas hinc inde extremas. Tabulam pro pare numero Ordinatarum non appofui, quoniam Area cseteris paribus ex impare earum numero accura- tius definitur. •“ ' ' (^^ratur area quae generatur ab Ordinad i 6? jacet fupra Ablciflam z qdando ea evadic unitas. In ^ ^ 10 B i zz> < i'o<54 > X “J— 2 2I ^ pro Sj fcnbc ,"3» i'o» , io> is> » « & prodibunt undecim Ordinate i , S, H* ;-n,^ Hinceft A=I + i = f, B — If: + ez=:i4.:i=^,i?==:f:+Tr,r=iis, F = f . Hifce vaEoribus fubftitiitis in, w^ti/Pa ^xpreffipae, & unitate pro./?, invenies areamj eiTe ; 7^5398187; Juftus eft hie numerus in feptim^ figura; in odav^ ve- rum fuperans Binario. Si undecim Ordinatas non dent aream fatis exaeftam, crige plures; & concipe aream divifam efle in plures partes, quarum quamque feorfum qusrens habebis pro lubicu juftam. ^Valor ipfius i + exprimi poteft per quameunque trium ferierum fequentium. I+^1”= i-f ex 4 -If: " n n — I n — % , £, ,t; ‘ ■- ^ ■^T?f 1JT ^ ■ 3 ■ ’ n ^ «— 3 Ji f!I>. jj:' zC ^ '*'8 nr r;.. ' . .. m'J. ■ v. Veli+^'’'=i+ ■ . iJx ' i -!Jv -I.. . . I ir- ; n . ,n? ' X j Ui .'i. - it ' j. ■q Lii .L.:. o ^uur 'ij ■ nsq i.o )r ^ Jil T , A Z’ tjp t j -I H u: yy>i \ Htx j «■ I z pofito fcilick R 1 +^1'’= ^ i— f-W-f-I VS ^Vd' X X 4 -f- 8iCr X'^ 1 . 1 ■ I ^ 4+«+ax6>. , — , I — x^’x — »4-gj; ^ i. *+2^1* ^ i.i 3,4 « «« — . I , X 4- 3-4 ««• 5.6 H- 1 J+21 -S, » w«— I M»_4 nn~^Q . X ^ ^ 9_|^ I. a 3.4 5.6 '' 7 .8 io4-«+«;yQ. -I- &c. » ^ww — 4^^w»~9 ««— ig. 3 -4 - , X- — 5.0 7 . a 9,10 PrimsE dusE Series demonftrantur per Cafiim primum Propofitionis Nam i -{- ^|°, i -j-^|‘, r^jT^ja I I defignenc Ordinatas totidem cequidiftantes in ParaboKca figura, erit dem Ordinata, cujas diftaiitia Ec lie prod it Series pHma. At Ciiti alia Parabola *-1-.^°, &c. fmt if^uidiOantes Qrdiftar^^- dit '1 4*7^'* 'Ordinata iii-'eaL dem.cujus diftantii a i d&'—ji; ^fic proveiiiet Series lecund^^ ^tjam in rertia Parabola &c. i +^|r‘*i 7+^1°, r+^iC • + » + ^P, I + ^P, &c. Series Ordinatarum lo B X £Equi- ( io66.) ssquidi{lantium hinc inde progrediens in iniinitumf eritque in eadem i + ^1“ Ordinata, diftantii » a ter- mino medio i ^1° remota. Ec fic provenit Series tertia per Cafum Secunduni Propofitionis. Prima ab* rumpit quando eft » integer & affirmativus, fecunda quando eft » integer & negativus, & tertia in cafu utro- que abrumpit. Per harum quamque radices numera- les commode evolvuntur in Series. Tertia reliquis mul* to citius convergit: ejus terminus fecundus adhiberi poteft pro correSione, ubi fit extratftio per repetitio- nem calculi. Halleius in fua methodo conftruendi Logarithmos, ex prima harum ferierum demonftrat Seriem Mercato- rls pro Quadratura Hyperbola. Sit ejus Ordinata I -|- veil 2,l”~’,exiftente»numero infinite parvo; unde per methodos (^adrandi, area quse jacet fupra Abfciflam id eft, Logarithmus numeri i -j- jc, eric aaeoque 1 'i z '.I 2 3 in cafu prsefente, ubi eft n infinite parvus, eft i zY = I -U — zi z^-\- — z' — —z'^ (S-c. quo fubftitu- I 13 4 to in valore arese, ea prodic z — \ 4* \z^ — &c.~ quse eft Series Mercatoris, Similiter per Seriem fecundam prodic ha:c regula ; Sic datus numerus i + ^ eritque ejus Logarithmus /J + ^ 4‘ T "V 5 4" Per Seriem tertiam provenit fequens regula. Sic p j ia quilibet numerus /?, pone z eritque ejus Lo- garithmus ( >0(57 J garithmus — ^ Bz—’-Cz~ fDz — f.Es' — &c. Ubi A, B, C, DfEf &c, more Nerctemano defig- nant terminos Seriei ficuc ab initio. Hxc Series, uc ea ex qua deducitur, reliquis duabus multis vicibus cele- rius approximac: eftque eadem generalius exprefia quam, ex fundamento baud abfimili, pro invencione Logarithmi Binarii prius dedimus. Methodus inVeniendi yalores Seriertm Arithmetical rum utcunque tarde conyergentium. In aliquibus Seriebus fumma terminorum haberi ne- quit nil! ad pauciffima figurarum loca, dummodo prse- ter fimplicem eorum additionem alise artes non adhi- beantur.' Proponatur jam Series quaelibec cujus termi- ni omnes iifdem fignis afficiuntur, & quorum proximi continue tendunt efie inter (e tequ’ales; quales funt fe» quentes + '+? + ? + Collige fummam aliquot terminorum fub initio, ii proxime addendi fint a, |8, y, g, &c. In numeris proximis fit r ■= «i3 — 2M.y-f-/3y* 8c quantitatum + tJ' + + differentiae fint a, l>, c, Cy &c. Deinde in numeris proximis fit ac — bb o • /- a , . b~i-sc . . « -r — , « 4—4^ n /* ab^zac-\~bc c-^sd d’^se + f X ar\-h-{-c -\-dx , &c. differentiae fint AC — BB Ay By C, D, «{C. & fit / = cede ( t0^8 ) cede quoad libuerit. Turn erit « , a-\-sh , j ^ A-^tB f o 1 a-Tst? , + &C. + &c. at- que ultra duos pritnos tetminos hujus novse Seriei ra- re opus erit progredt. ‘ ’ Ut fi defideretur valor Seriei — + — h 1.2 ' 3.4 5.6 ' 7.8 &c. collige primos zi terminos, quorum fummam reperio fore68i3, 8410, 1885. Termini proximo ad- dendifiint a=, 0005, /3 =,0x304,8309,1 787, ^ =,0004,43 i6,x4i I, ^=,0004,0816,3265, &c. Hinc fit r = i proxime, & =»ou 7*6449, 6182, a = — ,0000,0017,5096, ^= — ,0000,0014,7410,' ^ = — ,0000,0012,4986, &c. Unde ^ = i prope, & .4X^-i^ = — ,0000,0141,8111, quern propter fignum negativum fubduco ab a x— &remanet, 0117,6307, A [5 8171: hie additus fummse primo invents 6813,8410, 1885, dat pro fumma totius Seriei numerum 6931, 4718,0056, qui juftus eft in nona decimali ; at ante duas hafee corrediones fumma erat jufta in prima fi- gura foli. Si animus fit propius fcOpum attingere, pergendum eric ad approximationes fequentes. Si^er- mini Seriei diverfa habeartt figna, conjuOgendi funt, ut omnes eadem tandem habeant, ut in Serie i — f + f “-l- i — &o conjun(ftis terminis ea evadit h &c. Sed hie notandum eft quod difterentis a, h, c, e, &c. ut & A, B,C,D, c8rc. colligi debent fubducendo quantitates antecedences dc fubfequentibus. Et in omnibus hujufmodi Seriebus fi pi 4, r, reprsfentOttt tres terminos' ofcdifie ft^emes; p pri- mum. ( lO^p ) mum, f fecundum, »■ tertium, & reflangulum ttT x « non fic majus />r, valor Seriei erit infinite magnus: at inagnifudinis femper finirse ubi accidie contrarium. Poteft hxc regula nonunquam failere, ubi termini p, q, r parum diftant ab initio Seriei, at fi confiftant inter eos ab initio aliquantum remotos, evadec regula cer- rilTima. Ad alia Serierum genera debent alije regulae adhibe- ri. Sit Series regulaiium Polygonorum Circulo Incrip- prum, exiilente Kadi^Vwnitate. ' — H~ z,oooo,cooojOOOo,coo 1 4 G ~ 1,8x84,17 IX, 4746, 1 90] 8 =3 3,0614,6745,8910,718! A == 3 J 1 1 j 4,4 5 1 58,051-1 \% jD = 3,1365, 4849,0545*93:^ I64 ^ ~ 1 1 5,6954,751] 1 18 5=: 3, t4ii,77i5, 093^,772.125^ ^ = 3,1415,1380,1144,2991512. Dicatur jam ultimuili Polygonum penultimum B, .:antepeiiukiniuin O, & reliqua . iu fuo ordine retrorfum ^ g 'p, £, F, 6:c. atque area Circuli quaefita eric A + 4. 5 ® 4~ , 64^ ‘ ’ 84 n ^ T~ 1^ 3 i 1 f »409i?^ — S4.40B-4' 1418C 3 .15 -63 — "4~ E- •5.i?v63 .a55 Ubi fi pro A, B, CyDf Ef &'c. feribantur proprii valores, primi q.uatuor termini dabunt 3,1415,9265,3589,790 pro area circuli. H^cc autem Series eft generalis, ex natura Circuli neu* Iriqiiam dependens: applicabilis eft quociefeunque nu- 'merorum approxirnaatium differentiae priores ftinc po- fteriorum quaff quadruplae. Fadores in Oenominato- . ribus Punt dignitaces' integrse numeri 4 unicatibus mi- f nUttKo ( to7o ) iiutse; quibuS datis, coefficientes literarum in diverfis terminis formantur ex multiplicatione continua nume- rorum i, — . &c. Ubi pro n Tub- fticuendus eft ultimus Fadorum in Denominatore. Ultima quantitacum x — 1, zljx — 2, ^ijx — 4, — 8, 16, &c. sequalis eft Logarichmo numeri x. Pro x fcribe 2. & per repetitam excradio- nem radicis quadratse exibunt numeri JM= 1, 0000, 0000,0000,0000. /.=; 8284,2712,4746,1901. /=r 7968,2864,0010,8843. 7240,6186,1322,0613. 6 = 7083,8091,8838,6214. = 7007,087^,693 1,73 3 7. £= 6969,1430,7308,8294. V = 6950,2734,2438,7611. C =: 6940,8641,2891,8363. B =: 69^6,1698,4799,4014. 6933,8182,9699,9493. Dicatur ultimus numerorum penultimus B, & Tic retro, atque Logarithmus quxfitus erit ^ -| 1- lA — ^B-+C t^A — .I4B-4-7C— D ,6^A — ■tzoB-4-7oC — rfO+H 1.3 1.3.7 * . 3 • 7 - 15 4-&C. Prirai quinque termini dant 6931,4718,0999, 9497 pro Logarithm© Hyperbolico Binarii. Et quo- modo hsEc Series procedit in infinitum facile colligiturex eo quod de priore diximus: eftque etiam univerfalis, ' proprietates Hyperbola minime relpiciens. Extenditur quoque Methodus h^cce Difierentialis ad Refolutionem .^£quationum & alia quamplurima quorum hie non fit mentio- Continetque fundamenta Serierum ge- neraiiftima; ut inRedueftione ^quationumlrrationalium & Fluxionalium brevi forfan mohftrabo. ly. C 10/i ) IV. Jn account of fome Experiments jnade on the 27th day of April, i7ip. to find how much the ^efifiance of the Air retards falling Eodies, By J. T. Defaguliers, LLt D. O' F. R. S. ITook iz Balls ('fix of which were folid Leaden Globes of about z Inches Diameter ; three hollow Glals Balls of about 5 Inches Diameter; and three light Paftboard hollow Globes of abou: the fame Dia- meter) and having carried them to the upper Gallery in the Lanthorn, on the Dome of St. Paul's Church, I caufed them to fall down by two at a time, in the following manner; Firfi, a Leaden Ball and a Glafs Ball. Secondly, a Leaden Ball and a Glafs Ball. Thirdly, a Leaden Ball and a Glafs Bali. Then I let fall in the fame manner the three other Leaden Balls, each with a Paflboard Ball. After that, having the Leaden and Paftboard Balls brought up again, i repeated the Experiment twice more with a Leaden and Paftboard Ball ; then I made the Experiment twice more with a Paftboard Bali alone, to fee how long it would be in falling. Upon the whole it appeared that the Leaden Balls were a very little longer than 4 ~ Seconds in falling ; the two largeft of the Glafs Balls 6 Seconds, and the Paftboard Balls 6 7 Seconds. The height of the Gallery, from whence the Bodies fell, was zjz Foot above the Pavement of the Church (then cover’d with Boards) upon which they fell. The times of the Falls were taken two ways above, viz* with a Wheel- Chronometer, which meafures a to C fmali ( 1072 ) fmall part of Time accurately, nearer than to a quarter of a Second ( made and contriv’d by Mr. George Graham, an ingenious Clock-maker) and with an r Second Pen- dulum: And the differences of Time between the fall of the Leaden Balls and the other Balls were taken below, by the Prefident, Martin Folkes E(q; F. R. S. and another Perfbn,whoall agreed in their Obfervations of the Time, which they made each with an half Second Pendulum*. The following Table gives the Marks, V, ^eights, and Diameters of the feveral Balls, in three Columns. Leaden Balls Troy iVtight, Diameters in In:hes L oz. d. and Decimals, 1 c 1 : I : f 1 , I 1C I : 11 : 4 * » 99 3^ I : 1 1 : 11 1 , 0 AC I : 1 1 : 1 1 1 , 0 sc I : 1 1 : 11 1 , 0 6c I : 10 : 0 I ,98 Pafthoard Balls. > A 0 .* 3:6 S , S B 0 .* 1 .* 14 5 , I C 0 .* 1*17 S * * Glafs Balls, D 0 .- 3- 13 1 3 > 9 E 0 .• 3-: 5 »42- F 0 .* 6: 0,- 5 ,SS N,B, The Polar and Equatorial Diameters of the Glafs Balls being different, I have fet down a Mean Diameter for each of them ; the true Diameters are thus, of D 4 ^ 3)8. of E 5-, 6 and ^,2.5. of F f,7 & 5,4 Inches. the ( «07J ) the particular Experiments are as folio ms. Experiment I. Fall of ic and D. c fell by the Pendulum in 4^". The Fall of D was fo near it, that the Difference was not taken either above or below. Experiments II. Fall of ic and E. %c fell by the Chronometer in 5", by the Pendulum in 47". Time of the fall of E not taken above. The Difference taken below xf'. Experiment III. Fall of ‘^c and F. 38: *4r D 97r 22i 5)02, 21 F 17 * A 19" i4r B i8| Hr * C i8| H D 24 i9r E 2-li The Diameters and Weights may be reLyed upon, being taken the Day that the Experiments were made, and the Day after ; but the Diameters and Weights taken i o Days before, not agreeing with thele, I have left them out. For the Bladders by drying had loft of their Weight, and altered their Diameters. As the Necks of the Bladders in drying (brink, fo as to open a little, they muft be blown before each Experiment. And for the manner of letting them fall exadly in the fame Inftant of time, it is defcribed by Figure If, in which A, A, A A, is the Hole through which the Bodies fell; I, 2, is a Board laid over the Hole. G, D, D is another Board fixt to the firft Board by the two Wood- Screws D, D, with a Pulley G at the other end of it, over the Hole. W is a two Pound Ball of Lead faftned ( 1078 ) fdftned to a {Irong Thread, which going over the Pulley is (Iretched horizontally from G to the Nails F; to which it is faftned, fo as to be about a quarter of an Inch above the Board. B is one of the Bladders, hanging with the Neck gr hea- vieft part downwards, by means of a Loop of fine Thread as E H, which goes over the Horizontal Thread G E F. Now when with a pair of Sciflars the Thread of the Lead ( which in all is but one Foot long) is cut juft at E, before the Loop of the Bladder, the Lead pulling away the String the Loop of the Bladder flips off the remaining Thread F E, and begins to fall exadly in the fame Inftant as the Lead : But if the Thread fhould be cut between E and F, as the Lead falls its Thread might give the Bladder an oblique Oiredion. He that obferves the time either with a Pendulum or Chronometer may take it very exa(ftly, by feeing the motion of the Sciflars as they cut the Thread. tJ. B. As the Diameters of thq Bladders were taken by wrapping a Thread twice round them, and fomething muft be allowed for the thicknefsof the Thread; i have here under fee down the Diameters of the Bladders, as eorreded by that Allowance. Fiz. A y.aS Inches; B 5,19 ; C 5,30 ; D 5” and E juft y Inches in Dia- meter. The Bladder E was rough, with feveral Wrinkles and in- equalities, which made it be longer in falling than it ought to have been, according to its Diameter and Weight. A Pail of Water thrown down met with fuch a Refi- ftance in falling ^7^ Foot thro’ the Air, that it was all turn’d into Drops like Rain. F I M r s. Errata. Phll. Itrarf. N°. 357. Page 848. 1, aa.lege ab ii' 32" N°. 359. p. 932. 1. 1 7- lege t rr o",i. p. 957. 1. 5, 6. lege reftitui^ tur. Et Syftole Arteriaram cum Cordis DiaRole duratione convenit. p. looj, I. i(S. read, pooj of the f^ipy of the Opvion. ■’T" ■ \ ,^•’1 J^Aclc/rjp/i. ^ran/ac^ • Numb. 3(^5; ( 1079 ) PHILOSOPHICAL TRANSACTIONS. * , ^ For the Months of NoVemk and Decemb. 1719- • The CONTENTS. I. A Letter of Air. Jofeph Williamfon Jf^atcJnnaker^ to the Pithlifer., wherein he ajferts his right to the curious and life fill Invention of snaking Clocks to keep Time with the Suns Apparent Alotion. II. An Account of fome new Experiments.^ relating to the ABion of Glafs Tubes upon Water and ^uickflver. By James Jurin, M. D. Reg. Soc.& Coll. Med. Lond. Soc., III. Part of a Letter from Dr. Rich. Richardfon, to Dr. Will. Sherard, R.S.S. giving a relation of a wonderful Fall of Water from a Spout, upon the Alores in Lancaihire. IV. An Account of the Phenomena of a very extraordina-^ ry Aurora Borealis, feen'at London on November to. 1719. both Adorning and Evening, By Dr. Edmond Hal- ley. R. S. Seer. V. A Relation of the fame Appearance, feen at Cruwys Morchard in Devonfhire. Being part of a Letter to Sam. Cruwys, Efq-, R. S. S. and by him Communicated to the Royal Society. VI. A further relation of the fame Appearance as feen at Dublin, communicated to the Publifer by an unknown Hand. VII. An Account of another very confiderable Aurora Bo- realis objerved at Streatham in Surry, by Air. Thomas Hearne ^ and Communicated by Coll. Francis Nicholfon, R. S. S. VIII. Nupera Obfervationes AfrroiiomicA cum Regia Socie~ tate communicate. 10 D T. A ( io8o ) I. A Letter o/A/r.Jofeph Williamfon Watchmaker, to the Tuhlijher, wherein he ajferts his ^ight to the ' curious and ufeful Indention of making Clocks to keep Time with the Suns Apparent Motion, HAving been inform’d of a French Book lateiy pub- lifhed, wherein the Author fpeaks of making Clocks to agree with the Sun’s apparent Motion 5 and fup- poleth that it was a thing never thought of by any before himfelf.- I was therefore willing by the advice of (bme of my Friends, to write this fliort Account of what I have performed in that matter my felf. r And in the firfl place I mull take notice of the Copy of a "Letter in this Book, wrote by one Krefa a JeJuit, to one Mr Williamfon, Clockmaker to his Imperial Ma' j^Jly; of a Clock found in the late King Charles the Second of Spains Cabinet, about the Year 1 699 or 1 700.- which llieweth both equal and apparent Time according to the Tables of Equation; and which went 400 Days without winding up. This I am well fatisfied is a Clock of my own making; for about fix Years before that time, I made one for Mr. Daniel ^uare, for whom I then wrought moftly, which agrees with the Delcrip- tion he gives of it, and went 400 Days as he faith. This Clock Mr. Daniel Square fold, foon after it was made, to go to the faid King Charles the Second of Spain: and it was made fo that if the Pendulum was ad- julled to the Suns mean Motion, the Hands would Ihew Equal Time on two fixed Circles, on one the Hour, and on the other the Minute. But there were other two moveable Circles of the fame kind, that moved ( loSi ) moved forwards and backwards, as 'the time of the year required; on which the fame Hands fhewed Ap- parent Time like wife, according to the Equation Tables. This Method the Author owns he knew of. and appiyed the fame Motion to Pocket Watches iz or 14 Years ago, which I confefs I never did ; being well fatisfied that Watches with Springs and Ballances are very unfit to Ihew the minute difference, as it iucreafeth and de- creafeth, between equal and apparent Time. Soon after this Clock was fent to Spain, I made o- thers for Mr. ^lare which Ibewed Apparent Time by lengthning and fhortning the Pendulum, in lifting it up and letting it down again, by a Rowler fomew^hat in the form of an Ellipfis, through a flit in a piece of Brafs, which the Spring at the Top of the Pendulum went through* By this means every vibration of the Pendulum would agree to a Second of Time of the Suns apparent Motion ^ that Rowler which lifted up the Pendulum, and let it down again, being continually moving about all the Year ; fo that it may feem very ftrange that this Author never heard of it, fo many Years after they were made ; For one of thofe, and not the firft, made with the rifing and fetting of the Sun, Mr. Quare fold to the late King William, and it was fet up at Hampton-Court in his Life time, where it hath been ever fince. This contrivance of lengthning and fhortning the Pendulum, I thought of feveral Years before I made any of them. Since then 1 have made others for Mr. ^are likewife, which (hewed the difference between equal and apparent l ime according to the Equation Ta- bles, by a Hand moving both ways from the top of a Circle; on one fide fhewing how much a Clock keeping equal Time ought to be fafler than the Sun, on the other fide how much flower. But ( loSi ) I But thefe Clocks that I then made to agree with the 1 Sun’sApparent Time,were done according tothe Equation ■ Tables, which I found nor to agree very exactly with the t Sun’s apparent Motion : neither can any other be made to keep equal Time that will gain and lofe all the Year a- greeable to the faid Tables: for though the Tables them- (elvesmay be true, yet fome difference in Motion does proceed, in both forts of Clocks, from Cold and Heat al- tering the length of their Pendulums* This difference by fome Obfervations I have made, I fuppofe to be about the 77, part of an Inch in the length of a Pendulum vibra- ting Seconds, which will alter the Motion of the Clock about 1 1 Seconds in xq Hours. Hut to make my Clocks made for keeping Apparent Time to go as exad as poffi- blc, I made a Table my felf by Obfervation ; For obferv- ing the Sun, as often as it was to be feen, when it came on the Meridian, for feveral Years together, always fetiing down the Difference between its coming to the Meridian and the Time by a Clock I had adjufted as well as I could to equal Time, and always taking notice how much my Equal-Time Clock gain’d or loft at the end of every Year, 1 compleated my Table in the Year lyti. Since then I have made a confiderable many of thefe Clocks, feveral of which I fold to Perfons of great Note and Ingenuity; and in particular one I made about five or fix Years fince for the Right Honourable the Lord Parker, at prefent Lord High Chancellor of Great Britain ; and all of them have given good content to thofe that bought them So that I think I may juftly claim the greateft right to this contrivance of making Clocks to go with Apparent Time ; and I have never yet heard of any fuch Clock fold in England^ but what was of my own making, though I have made of them fo long. Ik An ( 1085 ) ir. An Account of fome new Ex[)enments, relating to the AEiion of Glafs Tubes upon Water and Quick^/Uver, By James Jurin, M. D. Reg.’ Soc. Coll. Med. Lond. Soc. IN a Difcourfe formerly prefented to the Royal Socie- ty, T maintain’d, that the SufpenfTon of ^/ater in a Capillary Tube was owing to the Attradion of a (mail annular furface on the infide of the Tube, which touch’d the upper part of the Water. Among the feveral Experiments made ufe of to prove this AfTertion, was that of a Glafs Funnel of feveral Inches Diameter, hav- ing its fmall end drawn out into a very fine Tube, which Funnel being inverted and fill’d with Water, the whole quantity of Water therein contain’d was fli- fiain’d above the Level by the Attradion of that nar- row Annulus of Glafs, with which the upper furface of the Water was in contad. Soon after that Difcourle was printed, came out a Book publilh’d by a very Learned and Ingenious Mem- ber of this Society, in which that Experiment was ac- counted for in the following Manner. If there be a Funnel, as ABC, Fig, r. full of IVater^ and rrhoje rride end fiands in a F'effel of Water as B C ; and the Top of the Funnel A ends in a Capillary Tube open at A, the rohole Water will he [uflaind: the Pillar 'a a by the Attrallion of the Circle of Glafs within the Tule immediately above it ; and all the rejl of the Pillars of Water, as F f D d, Ee, G g, - here to them both, and will be vifibly drawn out from a globular to an oval Shape; the longer Axis palfing through the middle of thole Surfaces, in which the drop touches the Glafies. PROPOSITION V. s 1 ^ ' The Particles of Water are more ftronglj attrafied hy Glafs, than ly one another. This manifeftly appears from the rifing of Water in fmall Tubes above the Level For when the Water begins to rife into a Capillary Tube, all the Particles of Water, which touch the fmall Anrmlm at the bottom of the T«be, muft have quitted the contacft: of the other Water, and have rifcn contrary to their Gravity, to come into conta 8. A B is a perpendicular Sedion through two Glafs Planes join’d at A, and open’d to a fmall Angle at B. C reprefents a pretty large drop of Mercury, the larger the better, which being made to defcend as far as C, by holding the Planes in an e- red pofture, with the end A downwards, retires from the contad of the Planes to D, upon inclining the Planes towards an horizontal Situation ^ and the diflance C D becomes greater or lefs, as the Planes are more or lefs inclin’d towards the Horizon. A drop of any Oily or Watery Liquor moves the contrary way, as has been fliewa by the late Mtr Hawks- hee. Exp. V. Fig. 9. A B is a Tube open at both ends, and a Foot or two in length, whofe lower part is drawn out into a fine Capillary at Bi This Tube being fill’d with Mercury, the whole Column of Quickfilver will be fufiain’d in it, provided the Capillary Tube at B be fufficiently fmall. But if the Mercury in the end B be fuffer’d to touch any other Mercury, it runs all out of the Tube if, without letting it touch any other Mercury, a fmall part of the end B be broken off, I o F X the ( *094 ) the Mercury will run out, till it comes to fomc Icller height as B C, at which it will again flop, the height B C being nearly in a recipr -cal proportion to tire Dia- meter of the (mall end of the Tube. The Seventh Experiment in Phil. Tranf. N®. 35J i^ the Reverfe of this. Exp. VI. Fig. lO. Is the fame in fubflance with the former, but made with a large Glafs Funnel A B, inftead of a Tube. The Reverfe of this in Water is the thirteenth Expe- riment in the fame Eranfadfion. In all thefe Experiments it is eafily feen, that the Ef- fect is owing to the difference between the two Artra- dions, by which Mercury tends to Glafs and to its own body ; they being always oppofed to one another, fo that a particular Explication is no way neceflary. But perha^ it may fave fome little trouble to the Rea- der, to remove the following Objediion, which wHl readily occur to him. In the Experiments brought to demonflrate the fourth Propofition, the Globule of Mercury adheres to the Glafs in a plane Surface, w’hich cannot be done without encreafing the Surface of the Globule, and con- iequently removing fome of its Particles from the con- cad of one another. If therefore they tend more flrong- ly to one another than to the Glafs, |yhy do they nor recede from the Glafs, and alTunie a figure perfedly Spherical, that they may all have the greateft poffible contadt with each other I To this we may anfwer, that the Power, by w hich Mercury is atttaded either by Glafs, or by other Mer- cury, is proportional to the attrading Surface; and therefore, though, cotter is parihus, the tendency of Mer- cury to Glafs is not fo ftrong as its tendency to other Mercury, yet in this cafe a much greater number of Met-. ( 1095 ) Mercurial Particles coming fnto contact with the Glafs, than what recede from the contadt of one another, it is no Wonder, that the Attraction of tlie Glafs prevails, and cautes the Globule to adhere to it For the num- ber of Mercurial Particles which lofe their contaCl with the other Mercury, is no more than what makes up the difference of Surface, which arifes from changing the figure of the Drop: whereas the Particles, W’hich by this means come to adhere to the Glafs, are all thofe that conftitute the plane Surface, in which the Globule touches it. Which Confideration ought likewife to be apply’d to the Sufpenfion of Quickfilver in Glafs Tubes, cither at extraordinary heights in the open Air, or at lefTer heights in a f^aerntm, as above mention'd. For the top of the Tube being Spherical, or nearly fo, it will be found, that the contaCf of the Mercury with the extre- mity of the Tube, is to the contad with other Mercu- ry, which would be gain’d by its leaving the Top of the Tube and defeending a very fmall fpace, in zRath infinitely great ; and confequently that the contaCl of the Mercury with the top- of the Tube is one caufc of its Sufpenfion. Coroll ifi. From this Propofition it appears, that in a Barometer made with a narrow Tube, the Quickfilver will never (land at fb great a height as in a wider. Which accounts for the I hxnomenon fo often mention’d in the Yearly Hiftory of the Royal Academy of Scien- ces at ?Arh^ by Monf. De Ia Hhc \ that in the Barome- ter, which he confiantly made ule of for his annual Ob- i'ervations, the Quickfilver did nor rife lo high, as in another he kept by him, by about three Lines and a half, which is near a third of an Inch our Mealure : For he tells us, that the Tube of his Barometer is very fmall*^ So that there is no need to have recourfe to any pc.CllS ( '®9<^ ) peculiar'fty either in the Quickfilver or the Glafs of which that Tube was made; or to an unperceived remnant of Air left in the Tube, from fome of which caufes that EfFedl and fome others of the fame kind were imagined to proceed. Cor. xd. In a Barometer made with a fmall Tube, the Mercury will rife and fall irregu'arly. For, as the height of the Mercury depends partly upon the Dia- meter of that part of the Tube that touches the up- per Surface of the Mercury, it is plain, that the unavoi- dable inequalities in the Diameter of the lube will be more conflderable, in refpedi to the whole Diameter ; and confequently will afTc<^ the height of the Mercury more in a fmall Tube than in a wider. And this I take to be the reafon, why it is fo very difficult, noc to fay impoffible, to make two barometers, which ffiall exaiSfly agree in the height of the Quickfilver in all conftirutions of the Air, efpecially if the Tubes be ve: ry narrow. This irregularity is flill more conflderable in the Pendent Barometer in which the Quickfilver moves through a large fpace, in order to make a fmall alteration in the length of the Column fufpendedJ The fame confideration is eafily extended to ihofe Levels, that depend upon the rifing of Mercury to the fame height in the oppofite Legs of a bent Tube ; an loftru- ment of which kind has been lately offer’d for the fervice of the Publick. And as the effedi is juft con- trary in Levels made with Water or Spirit of Wine, due regard ought to be had to this Property in the conftrudlion of thofe Inftruments, by making the Tubes fufficiently wide, in order to diminilh the Error as much as poffible. III. Fart ( '0J»7 ) III. Tart of a Letter from Dr, Rich. Richard- foiij to Will. Sherard, LL. D. R. S. S. giVtng a relation of a wonderful Fall of Water from a Spoutj upon the Mores in Lancafhire. JHad an opportunity when in Larjcafhire of vifidng a fecond time a vaft breach in the Ground, which was made by a Spout, which fell upon Emott-more. The account I took of it when I firft faw it, I put into Writing ; and upon a fecond Infpedion, finding it to be pretty exadit, I thought a Tranfcript of it, would not be ungraceful to you, which you may communicate to your Friends, and make what ufe of it you pleafc. You may depend on it as true. Tho’ our printed Voyages of feveral parts of the World furnifli us with frequent accounts of damage done at Sea by Spouts of Water, yet fuch rarely hap- pening at Land, induc’d me to take the following Rela^ tion of a remarkable one, which fell on EmotUmorCj nigh- Coin in Lancapire, on Tusjday the 3<^of 1718. about ten in the Morning: when feveral Perfbns who were im- ploy’d in digging Peat nigh the place where this Acci- dent happen’d, upon a fudden were fo terrify ’d with an^ unufual noife in the Air, that they left their Work and ran Home, which was about a Mile from the Place : But to cheirgreat fu^ prife they were intercepted by Water ; for afmall brook in the Way was rifen above Six Foot Per- pendicular in a few Minutes time, and had overflown, the Bridge. It is to be obferv’J, that there was no Rain at that time on Emott-mors, ojily a Mill, which is very frc-*.. quent ( lojiS ) quenc upon thofe high Mountains in Summer time- There was a great Darknefs in the Place where the Wa* ter fell, without either Thunder or Lightning, ('as I had my Information from an Eye Witnefs^ The Meadows at Wicolae were fo much floated that the like had not been feen in feveral Years before, tho' there it was a very bright Day. Upon this account, I went to view the Place where the Water fell; tho’ 1 believ’d this Inundation might proceed from an eruption of Water out of the fide of the Mountain ; fuch being not unfrequent, where Lead or Coal have been Dug, but neither have ever been fought fOr here. Upon approaching the Piacc,, I was ftruck with unfpeakable Horror, the Ground was torn up to the very Rock, where the Water fell, which was above Seven Foot deep, and a deep Gulf made for above half a Mile, and vaft heaps of Earth call up on each fide of it, fome pieces remaining yet above twenty Foot over, and fix or feven Foot thick. About ten Acres of Ground were deftroy’d by this Flood. The firft Breach where the Water fell is about fixty Foot over, and no appearance of any Eruption, the Ground being firm a- bout it, and no Cavity appearing. 1 muft not forget to mention, that the Ground on each fide the Gulf was fo fhaken, that HxgQChajmes appear’d at above 30 Foot diftance, which a few Days after I obferv’d the Shep- herds were filling up, leaft their Sheep ihould fall into them. IV, An { lop? ) IV. An Account of the Phaenomena of a very extraordinary Aurora Borealis, feen at London on November lo. 1719* hoth Morning and Evening, Dr. Edmond Halley. R.S.Secr, UPON Tuefdaj^ November 10. 1719. in the Morn- ing, Jnpiter applying to the Second in the Wing of N/rgo, I got up about $ of the Clock to obferve him, and having had the Satisfadion to fee my Calculus per- fedly well anl’wer the Heavens, I found certain white Streaks in the Sky, feeming nearly Perpendicular ; which whilft I confidered them feemed inftantly to vanifli, and foon after others came as inftantaneoufly in their room, f began to imagine that this was likely to be (bme part of the Phenomena of the Aurora Borealis. But there appearing nothing like that luminous Arch which we haveof late fo often feen in the Norths knew not what to think; till look- ing up towards the Zemth, 1 perceived an entire Canopy ot (uch kind of white Stride, feeming to defcend from a white Circle ol faint Clouds, about 7 or 8 degrees in Diameter, which Circle fometimes would vanilh on a fudden, and as fuddenly be renewed. I obferved that the Center of th s place of Concourie was not precifely in the Zenith, but rather 14 degrees to the Southwards thereof ; which I was well enabled to eftimate by a Star, which on each return thereof fliewed its felf about the Center of the Circle. This Star is the iph Star of the Great Bear in r-yf^o’s Catalogue, whole diftance from the Pole at this time is 5i Ydegrees, and which about half an hour paft Five that Morning pad the Meridian, fo that thofe Rays centred very nearly on the Meridian it felf It i o G was ( I lOO ) a very entertaining Sight, till fuch time as the Day-break began to oWcuri thcfe Lights, whrdi were but faint, though fufliciently diftinguilhable. They came none of them low'er than to about 30 or 40 degrees of Altitude, and (eem’d not to have afcended from the Horizon. The Sky was perfectly Serene and Calm, which fccms to be one of the concomitant Circumftances attending the Au- rora Borealis, of which this was certainly a Species. For the Night following a Neighbour gave me notice of a flrange ftreaming of Lights feen in the Air, wJiich there* .Upon I attended from the Hours of 97 to 11, when a Fog came fo thick as to put an end to my Pr fpeiL. but during thk whole ttme there afcended out of the E. and N. E. a continued fuccellion of whitifli Striae, ari- fing from below ; and after changing as it wc'^e into a fort of luminous Smoke, pad over head with an incre- dible fwifenefs, not inferiour to that of Lightning; and as it pad, in Tome part of its Padage, feemed as it w’ere guilded, or rather as if the fmokc had been drongly illu- minated by ablaze of Fire below. Some of the StH£ would begin high in the Air, and a wdiole let of them lubordinatc to one another, like Organ Pipes, would prefent themfelves with more rapidity than if a Curtain had been drawn from before them ; fome of which would die away where they fird appeared, and others change into a luminous Smoke, and pals on to the Wedvvards with an immenfe Swiftnefs And I am of opinion that had it not been for the Moon, then ten Days, old and ve- ry bright, this for the time would have been reckoned as confiderable an Appearance as that of the, 6th of March, 17^6. V. A ( 1 1 0 1 ) V. ^ Relation of the fame appearance, Jeen at Cruwys Morchard in Devonfhire. ^eing part of a Letter to Sam, Cruwys, Efq-, R. S S. and hy him Communicated to the Royal Society. yO U have doubtlefs been furprized again afrefli by the wonderful Lights which have been feen feve- ral times of late like thofe defcribed in the Philofofhicd' TranfaPHons ; feen on P/Iarch 6. 1716. Monda) the 26 of OPioher, between 7 and 8 in the Evening, 1 faw Come fmall appearance of it, •viz. 3 or 4 large Corulcations in form of Pyramids, of reddilh Co- lour inclining to Yellow, which rofe about 50 degrees above the Horizon, and continued but few Minutes. But the North part of the Hemifphere was very bright and red all the Evening both before and after, till Ten, if not longer. Tuefday, Movemh. 10. Thefe Lights were feen again a* bout 4 in the Morning, of which fome fay (to ule their own Exprelfions^ that the Element opened fometime at one place; then at other ; from whence came great lliining Lights that continued a while and then went a> way by degrees, and the Holes clofed up again. This continued till Day break. The Evening following coming from Tyvertm 2h''uz half an hour after Eight, I faw* the North part of the Horizon, very light and reddilh fnotwithftanding the Moon being about 10 Days old, was then in or pad the Meridian, and ihone very bright) in a fhort time the ftrearaing luminous Rays began to appear very plain, fome in one Ihape, Tome anothef; many of them 10 G 2 like ( 1101 ) like Cones or Pyramids, but mod of them badly ter- minated ; feme of which mounted very highf almoft to the Zenith, to which place, or near, they all or mod, feemed to point. Shortly after there appeared a long Streak of about 30 Degrees, parallel to the Horizon and about 1 5 or z6 didanc from it, and about i or ; broad, but badly terminated and of a fiery red Colour: which Cent out Tome of the fame dreaming Beams towards the Ze- nith. About 6 or 7 Minutes after there appeared (fome- W'hat fudden) a Circular Figure like an IriS; but twice as broad, of a pale Colour* The Fad part w’as termina- ted by the Horizon at full Had, if not fomething to the South, and the Wed End about North Wed; the up- per part of its Arch being 50 or 60 Degrees high, great numbers of luminous Rays darted from it up- ward and downwards, (or elfe pading crofs it from the Horizon) at oblique Angles pointing to the .Zenith, ef pecially from the North Ead parr. This continued, as near as I can guefs Cby the didance I rode) about 8 or Q Minutes, when it divided and difappeared. After an Interval of 3 or 4 Minutes, another Iris-like Figure appeared, (of a Colour (as it feemed) paler than any of the dreaming Lights had been) whofe Diameter w as lefs than that of the former, and (hewed more than its Se- micircle above the Horizon, tl>e upper part of its Arch approaching near the Zenith. I could not obferve any Rays to pafs from, (or a- crofs) this as from the others The Centre of this lad was much more to the Wed than* that of the fird- After the continuance of a Minute cr o, it began to break in the upper part of its Arch and fliining Particles being fent out from both its broken Ends towards the Zenith, (to which they w’ere near be- fore) or rather a little beyond it to the South or >5outh W^ed, they there formed a fort of Corona, curving and bending fomewhat like Flames reverberated, on tl3e Arch of { 1105 ) of an Oven : tho’ this exprefleth it but badly, yet I know not how to defcribe it better. It Teemed to me and others to be finely tinged with various Colours, Red-Yellow and Blueilb, and Tent out every way from it (except South and South- weft) long flame-co- loured Rays, After this had continued about two Mi- nutes, its ftiining Light abated, and it left behind it for Tome Minutes, fomething like a whitiQi Cloud (like in Colour to what the Light on the of M^nch laft; left behind it, after the fiery Particles were extinguiftied, but thinner). M. B. All this while the Moon (hone very bright, from which this Corona was not very far diftant, per- haps not twenty Degrees, to the North Eaft. After this there continued to be fent up many fiery Coloured cr Yellowifli dreaming Lights, fometimes more, fome- times lefs, now here, now there, all along the North part of the Hemifphere, but moftly from the North North Eaft All this while fomething like fmall whitifli Clouds f which to me Teemed to move towards the Ze- nith, or to point a little more Southward, but difap- peard as they approached the Moon) were carried ve- ry fwiftly, and at very Ihort Intervals, moftly coming from the Eaft and North Eaft, bur many alfo from North and North Weft. We took but little notice of this at firft, fuppofing it had been nothing but the re- fledion of the other Lights, or the fhadows of the Clouds ( whereof the North parts were pretty full) as the ftreams of Light paft behind them: But af laft we obfervcd that, when the Lights at any time abated, thefe kind of Clouds continued to fly as fwift and frequent as ever. This \ faw till Twelve or One next Morning : many others faw it next Morning till al- moft break of Day, when it appeared much more red and fiery than it was in the Evening ; the Moon perhaps. bcingj; ( ‘104 ) being then fet. Some People obferved tall Cones ro arife in the Eaft, and to be carryed to the Weft pretty fwiftly in an ered Pofition, but I faw them not. It has been reprefented here in all forts of Appearances, Ar- mies, Battles, dv and has put abundance of People in difmal Frights : But I had not an Imagination ftrong enough for it, 1 6. IVill, Maffndfr. \l. J further relation of the fatne- Jfpearance as feeji at Dublin, communicated to the Tuhlip?er by an unlqiown Hand. IT is with pleafure that I now give you the trouble of reading the enfuing Account of the furprizing Lights which on Tuefday the tenth of November we faw in the Northern Semicircle of our Horizon, The Afternoon was very Calm and Serene; about fix in the Evening the Sky was ting’d with a ftrange kind of Light, and fomc Streams began to projed from the North and North Eaft. One of them arofe about N by E- and was nearly a Subtenfe of an Arc between that and S. W. by Weft ; it was a little curvated toward the Sun, and what I faw of it (for the North part of the Horizon conceal’d by Houfes) very much re- fembied the tail of a Comet : About the fame time there was one or two which arofe in the Eaft, afeend- ing obliquely fo as to leave she Zenith feveral Degrees to the Northward, Thefe Strid continu’d to appear and difappear alternate- ly till toward Eight in the Evening ; they were Pyramidal, and their Vertices frequently projeded feveral Degrees to the South of our Zenith. Between I ( ) Between nine and ten I was agreeably furpriz’d with a kind of Corufeation, or Flalliing, that fliew’d it felf between twenty and fixty Degrees from the Ze/iith, iii the South or South by Weft 5 and which from four or five, fometimes from more places at once, darted with a Velocity not much inferior to that of Lightning ; and by interfering with each other produc’d a beautiful Tre- mour or Undulation in that ['ubiWo. which I can- not better illuflrate, than by comparing it to the Beams of the Sun, refletfted on a Ceiling from the Surfaces of two or three Bafons of Water ; Thefe Waves of Light were only vifble at the inftant of Corufeation, and were of a pale whicifli Colour, fomewhat refembling the flaflies produced by the violent agitation of Quickfiver in an Exhiufted Receiver; but fo ftrong that a Gentle- man who about that time w^as in a Room by himfelf, without a Candle, afTur d me he took it for common Lightning : Thus it continued inceftantly for more chan an Hour, during which time feveral lucid Areas^ like little Clouds, difeover’d themfdves in the pure Sky, and after they had continu’d about fve or fix fecond Minutes, as near as 1 could guefs, would in- ftantaneoufly difappear ,• moft of them pretty much.re- fembl’d a very thin white Smoke or Vapour illumina- ted by the Full Moon. About three quarters paft Ten, this Vapour was al- moft fpent, or by a brisk Gale at South by Weft difpers’d and driven to the Northward; at which time, be- tween the Weft and North, a vaft body of it, like a very bright Flame-colour’d Crcfufculum, feem’d to be fix’d : From this Bafts feveral Beams or StrU of {hmmg matter were at uncertain intervals, emitted ; and tho’ it was not fo feniibie to tbe Eaftward of the North, yes; feveral mighty Pillars wefe alio cjjtfted from thence; One, which if 1 rmftake not, arofs dired^Iy under ( 1 1 o6 ) the Pole, was, above all others that had preceded it, both as to its Magnitude and Denfity fo furprizing, that I’m perfuaded the fmalleft Print might have been read by the Light thereof, had not that of the Moon, which (hone very bright, pretty much effac’d it: ’twas ting’d with a kind of Yellow and Violet Colour. In about two or three Minutes it died away, and was fuc- ceeded by others of an inferior Order: It was now about a quarter part Eleven of the Clock, and nothing but repeated Fhafes of the fame Spesflacle offering them- felves to View; the Vibrating Motion had cealed j-thc Vapour fliewed it felf no longer in lucid Areas ; the dreams of Light were not fo frequent, and thofe more langtiid than before ; and the bright Aurora having fet- led nearer the Horizon^ I concluded iht Scene was at an End, and accordingly gave over the queft of new Ph£- nomena^ with only oblerving that about N. E there ap pear’d feme Clouds that refleded an unufual kind of reddifh fight. Others, who thro’ a Principle of Feat fat up longer than I did, reprefent the End with very luf prizing Circumflances ; but as it, efcap’d the Eyes of thofe who were bell qualified to oblige the World with an Hiftory of it^, fo I defpair of adding any thing that may be fatisfadory : and there were no doubt many Circumflances of Weight that I did notobferve; for the wonderful Variety x.\\\s Fi'Anomenon and the frequency and fuddennefs of its Alterations, made it impoihble for the Eye of any Tingle Perfon to trace It. On Tuefd&y the iqr/; of Novemher we had the fame Thdtnomena repeated, tho’ not with the lame Variety: About a quarter pafl ten at Night, a vafl Body of fiiining matter was colleded between N. W. by Wefl, and N. by E. in the form of the Segment of a Circle, whofe Center was about 25 or 30 Degress below the Horizon ; ( 1107 ) Horizon ; from its Periphery a few fhort Pyramidal Streams, of the fa^ne luminous Vapour, afcended by a flow and nearly uniform Motion, and were exceeding rare fo as not to efface the fmallefl of the fix’d Stars ; and in a Mi- nute or two vanifh'd : It was very remarkable that the Light which that Colletiiion of Vapour emitted was fo great, that in the otherwife very dark Night, I cou’d thereby ('at three quarters pafl: Ten) read the Title of the laft Philo f. Tranfa^. which then happen’d to lye on my Desk ; and at four or five Yards diflancefee the fmal- left Books in my Study. VII. Jn Account of another Very confiderable Au- rora Borealis obferVed at Streatham in Surrey, by Mr, Thomas Hearne j and Communicated by Coll. Francis Nicholfon, R, S. S, Aving feen Dr. Halleys Account of the Coruf- cations in the Morning and Evening of Movemh. lOth. (and the Letter annexed to it from Devonfhire) I had the Pleafure to find the Obfervations made upon that Appearance very agreeable to what 1 had my felf obferved the Evening of that Day ; and to what i did not at that time obferve, but had an opportunity of obferving in the Night of Dec, ii. I believe much more plainly than Dr. Halley had in the Night of No- vember lO. Dec. nth. About one a Clock at Night (or rather in the Morning of Dec. itth) I was called to obferve Corufeations which appeared of a much different Co- lour, and in a very different manner from any I had before feen. 10 H The ( 1 1 0 .8 ) The dreams of Light that darted upwards from the Horizon Teemed to be at confiderably a greater diftance, but not at all in Icfs quantity than thole of Mov.ioth, But their meeting in a Point near the Zenith, and there forming a kind of Can<>j>j, was what was particularly remarkable in the Manner of the Corufeations now di^ ferent from thole of t^ov. i o. The dreams of Light role from the Horizon only towards the North, and on each hand towards N. Ead and N. Wed : But near the Zenith a Canopy was formed of dreams of Light meeting in a Point, not only from thofe Quarters, but allb from the South, &C. Only to thofe Points they extended downwards from the Zenith but a little Way, and were neither in To great quantity nor quite To bright as thofe Northwards. At fird I thought the Point in which the Streams met was cxadly the Zenith, but upon obferving it fomething longer, I found it was not To, but a few Degrees to the South of the Zenith. The dreams of Light near the Zenith, which formed this Canopy, were of a pret- ty bright Colour, and in great Quantity, and darted very Iwifily. On each fide of the N. towards E. and W. but not exactly in the N. it felf fat lead when I faw it) from about 10 or 15° to 40 or 50° above the Horizon, the Streams were of a glowing red Colour, whereas all that I had ever feen before vv^ere very pale. The rednefs was like that of a burnt Brick, and neared of any thing I have feen to the Colour, which remained for a few Minutes, like that iradt through which the Meteor paded in the Spring. The Streams appeared of this fierce Colour when I fird faw the Corufeations, and continued fo for fome time, till the rednefs by degrees wearing off, in about ^ of an Hour they appeared of the ufual Palenefs, when ( no? ) when I left them ftill forming a Canopy neat the Zenit hf as is above defer ibed. The Air was very Calm and Serene, not a breath of Wind ftirring ; as I remember it was alto Nov. lotk The Moon was now a Day or two older than it was on Nov. loth. and a good deal further to the W. than when I faw the Corufcacions that Night being then near full South. She had now round her what is commonly called a Burr larger than ordinary, and fe' veral very lucid Clouds at a little diftance. VIII. Nuperce Obferyationes Jjlrommicd cum ^egta Societate communicate. CU M in Num. harum Tran[a6iionum 357“°. Obfer- fervationes nonnullas Planetarum ac Luncs con- fervari digniflfimas in unum congellimus, ac probante Societate noftra edidimus; liceat paucuia folia hujufmo* di colledionibus in fequentibus quotannis confignari. Nuper^e autem quas habemus Obfervationes has funt. 1718. OSioher 10°. mane, applicabatur Jupiter 2id Fi* xas Telefcopicas, quarum loca, occafione primee appa- ritionis Cometse anni 1680, fde qua vide Phil. Tran]., N'^. 341^ ledulo inquifivit Rev. D. Pounds ac nuper ve- rificata nobifeum communicavit, una cum accurata ob- fervatione tranfitus Jovis juxta eas hac vice, ac deinde alters Fehr. 1 1°. Batim ab oppofirione Solis & Jovis. Ineunte autem Januario 1719. loca fteilaruro ficfe habuere. Long. ^ A 2.9°- 59' -43" ^ jt? o . 6.13 C It? o . 3.13 Lat. Bor. Long. I- 7-50 4n? o°.xy'. 41" I . 10. 18 xmo , y .43 0 • 0 10 ti Lat. Bor. i°.x8'54" o . yi .56 Ubi t mo ) Ubi notindum ftellas d & e eandem precise hoc ft* culo fortiri declinationem, ,v vero exiguam cfTe (Idlulam in priore defcriptione ob parvitatcm oniiflam. Jam O^ob. 9°. 17^ 50' T. sq. Jovis limbus orientalis. atcigic lineam ftellas e h c jungentem, fimul centrum ejus diftabat ab^ zi' . zq" & a c U> . ftatimque a- berat k d 19' . 35". Parvula a; Jovi proxima latuic, luce ejus obumbrata. Decemb. 1 1°. i8K 30. T. a:q. Saturni centrum diftabat a /X Libra Bayero, zS' . 3.1", & Fixa Borealius erat 4' • 3 1". Hinc conclufic D. Pound Obfervator Saturni locum jt? 10°. 41' . 10 ", cum Lau Boreal. . 16'. 43". 1719 Feb. 11°. 6^ 561 T. s:q. Jovis retrogradi cen* trum diftabat a ftella d fuperius defcripta Io'.4^" 6. 58^ Idem centrum diftabat ab ^ 6. 7 9. 377 Iterum diftantia capta a d — - ■ • lo. 9 9 . 437 Icerum ab ^ 6. n 9 . 497 Jovis centrum diftabat ab a — 15 . a i- 9.587 Idem centrum a parvula x — ^ -q-jS Circa Horam feptimam Jovis limbus orientalis attigit lineam per at & ^ produdam; Jupiter itaque tunc ha- buit np o°.(5 cum Latitudine Boreal. 1°. 16'. 30"'. Deinde, Feb. 13°. 8’’. o'. T.xq. Declinatio centri Jovis, Ml- crometro menfurata, Borealior erat ea ftellje urriufque d II ' . 37", & 8^. 20' eadem differentia inventa eft 1 1'. 36". Hord vero 8^ 48' centrum Jovis diftabat ab e 1-7'. 40'''. Apr. 22°. ^o^ 45'. T. aq. Saturni centrum fequeba- rur fA, Libra 4"iTemp. five i'. 8" Afc. Red^. Micro- metro autem Borealior inventus eft Fixa 3 5'. zs". Stella autem in Catahgo Britannko tunc habuit, m 8'V Iu.3t. Bor.. 2°. 3.'. 54^. Math ( 1 1 1 1 ) 1 6°. 8\ oo' T.seq. .r fcqucbatur Cor Leo^is i°. 34'^ Afcenfionis redce ; Borealior auremerat (lelia ilia o'. 41 "j-. Temporis, licc eft, 10'. 7" Arcus cceleftis. Fadem node, 15*', 18' T. app. Obfervavit D. Ste->^ fhanus Gre-j Murtem, ratione Afcenfionis redt^, fequi ftellam in Cauda Cafricorni Ofiencalem 16'. 15"; ftmul non nifi o'. 1 1''. auftralior erat quam Fixa. '^mii 7°. io\ 15'. T. app. Jufitcr diredus keriini !£■* verfus eft ad ftellas Telefcopicas pr^^didas, & turn (e- quebatur ftellam d. o'. 35" Afcenfionis reda?, &^o^ 30' diftabac ftxa a limbo Jovis proximo 4'. 1 8". Poftridie Junii 8*^. lo^. lo', Jupiter fequebatur ftel^ lam alteram e \'. 30'’ Afcenfionis red^e, ac ftatim di- ftantia limbi Jovis proximi a ftella capca eft Microme- tro 7'. 30". JulH 5. 8^ 26’. T. app, Conjungebantur arde J^^pt- ter & Fenu^, quce turn Borealior prxcedebat Jovem fe- cund um Afcenfionem redam 1'. 20": Centrorum autem diftantia ex decies repetitis media, capta eft 13'. 36". H£Ec tria Londini obfervata communicavit harum Scien- tiarum eximius Cukor D. Martinus Folkes, R. S. Soc. 3. I2^ 20' T, xq. Mars pene Acronychus fe- quebatur ftellam t Aquarii Bajero I o'. 58" 'Temporis, five 2°. 44'. 57" Afcenfionis Redae*^ Erat autem fixS Mars Borealior o'. 36" tanium ; unde concefTo loco ftel- \x Eritannico fit locus Martis obfervatus x 1°' 10'. 10" cum latitudine Auftrali 6°. 38'. 10". Aug. 10°. 50. T. xq Mars fequebatur fixam minorem qux prxcedit t Aquarii 1°. 39'. 30" rations' Afcenfionis redx ; Auftralior veroquam fixa lo'. 42". Augi 16°. 7^ 18'. T*xq. SpicA firginis prxcedebat Veneris centrum 5 "" fecundis temporis, five i'. 20" Afcert- flbnis redx, auftralior Planeta i8”~ temp, five 4’, 35'^- Aug. 17^ Mar’s pridie Acronychus ac Terris proxi- mus obfervatus eft ad duas fteliulas contiguas, Parallaxis^ ( »'•» ) cjus invefligandi gratis, juxta method um ^ D. Cajfinot in libro de Cometa anni 1680, exhibitam, Unde tis Parallaxin etuere in Tranfail. proximi conabimur, Harum vero ftellularum borea turn temporis locum habuit X 5^- ' cuni Lacitudine aullrali 6®. 6'^ * altera vero Auftralior habuit x 3° 5 • 30”* cuni Lar, Auft. 6°. lo'jproxime. Hor^ vero 10'’. 40'. T. seq. Au- Hralem (equebatur Mars 41' min. 40" Afcenfionis redlse, €aque adhuc Auftralior erat 7'. 50*'. Sept. 18. 9^ zQ*. T. aeq. Mars vifus eft praecedere ftellam in Catakgo Britannko Aquarii 53*®"’. 5*. 45*' Temporis, five 56'. 24". xAfcen. Recftx ; fimulque Stella Borealior erat limbo Martis boreo, non nifi una Pla* netae diametro. Locus ftellae tzi 19'. 57 7 Lac. Auft. 4-487. ^ , O^cb, 30. Vefperi 5\ 45. T. app. Mars proximus ftellis duabus contiguis ad ^ Bayero^ quae funt 73*® & 74'^ CataL Brit. Practerierat reeftam per eafdem du- <3am, eratque angulus ad Martis centrum ad fenfum redus .* Borea vero ftellarum eandem habuit declinatio- nem cum limbo Planetac auftrino. 53' diftantia ftel- lae a centro Martis 30". 5^ 56' centrum difta* bat a tertii & Auftraliore ad b, five 75'® Aquarii, 17'. 04". 6\ s8' diftantia centri a Bore^ five 73'* erat 3'. 5". Hinc concludere licet Martem, hora 3^ 30' proximo, ftellae Boreae conjundum fuifte, eamque uno tantum mi- nuco ad Boream reliquifte. Fixac autem locus eCatalo* go'Britarmico tunc erat x 00" cum Lat. Auft. 1°. 40'*. 74*^ vero habuit x 10° 29'. $o cum Lat. Auft. 1°. 44 7. Novemh. 16°. l9^ 18', T. xq. Venus praecedebat Lan- •eern Lihr^ Aufirinam 3’. 13" Temp, five 48'. 23" Af- cen. Red. fimulque fixa borealius erat centrum Veneris 7'. 45". Venus quafi Stationaria apud Nodum ejus Af- cendentem. Decemk I ( in? ) Decemh. 5®. T 9^ T. seq. Saturnus prsececlebat certiam ad I ^Lihr* ii09» Aurora Bore ales in Kent. n. 35'i-’ p. 58^. OnQ in London. n.‘^$^.‘p. 585. Another n.%6‘^,p. 1099, 1101, 1104* At StreathaWf ihid. p. iioy. . . - B. ■ ' Barometer, The Caufe of its Variation, align’d in the Hi/l. Acad. Rojale, confides 35 i , 570. Blood, Of its Motion, n. 355, p. 7^6. Of its Specifick Gravity, 361, />. 100 Books, Accounts of them. I. Polenus de Motu Aqu^n rnixto. ^•3 J4 P-T^}‘ l\. Apollonius Fergaus de CorAcisJkQ.Ah.pj Britain, Whether once aPeninfuIa, p $p, .Spme Account of its Affairs under the Roman Government, ».356.^783. * ■ “ ‘ Burning Loncave, Experiments made with it, n. 360, p. 97^. - • » • -‘-C. ■ .ii ■ ‘ , , Cape of Good Hope, Its Longitudev ^*..3^1. /». ypr. CatuviiUuniJ A People formerly in the South of England, n. 356, /^. 8i4. 10 I Chsik, INDEX. Cheekt Ad extraordinary Wen cut out of it, Colick, An extraordinary EfTedt of it, n, 351, p» 58c. Comets, A Telefcopical one, 3J4> 7^^• One Ber- lin, n» 357, f, 820. Conick Seilions, Some fimple Properties of them, Cows, Of the contagious Difeafe among them, ^.358, 872. Curves, Of the Condrudlion and Meafure of them, 3 56, 803. An univerfal Method of delcribing them only by the help of Angles and Right Lines, n, 359. p, 939. Of the Curve defcrib’d by a Body defcending in the lead Time,with a given Law of Attra<3ion, »«3 58.^.860. Clocks, made to agree with apparent Time, f.ioyy. D. Viffe6Hon, of an emaciated Child, 631I E. Earth, An unufiial Falling in of it, 355. p» 768. Eclipfe, Of the Sun, ». 357, ^.822. Of the Moon, n, 361, />. 991. Another, «. is?*?- ^55* Elephant, Its Organ of Hearing defcrib’d, n. 358, ^.885* Experiments, To prove an interfpers*d Vacuum, ». 354, p*Til* Of the Refidance of the Air to falling Bodies, n* 361, p, loyii Of theCaufeof theAfcent andSuC- penfion of Water in Capillary Tubes, 355, />.' 739.’ On the Adion of Glafs Tubes upon Water and Quick- filver, n, 363, p> ?o83. G. Gafcoigne, fMr.) his excellent Inventions, and great A- bilities, ». 351, 606. Gibraltar, The Situation of feme Roman Towns about it, 359, f.903. H. Heart, INDEX. H. f/eart^ Of ics Force, 95^. p» S6^, 35^9, /«• pip. p»99S» 361, f. 1039. J» Jamaica f Some Remarks on it, ». 357. P» 838. Infcriptions, A Roman one in the North oi England, /?. 3 5"^. p, 701. n* 3 J7, p* 8x5. Another n» 3 jt. /. 813. Ano- others. 359, 94 Jupiter, The Occultation of a Fixt Star by him, n, 3jr, ^46. Tranfit of xhe 4^^ Satellite over its Disk. 359- p. 900. Tables of the Eclipfes of the firft Satellite, n»}6i» p» loii. Lanchefier, Of the Roman Caftrum there, K»\$^,p* M. Mars, His Tranfit near a Fixt Star, n* 3^1, p, 54 8. Maxmazwdi Minima in the Celeftial Motions; ^.960 /'.948 Meteors, One in Jamaica, n. 3^7, f. 837, One feen all over England, n» 360. p» 978. Method of Fluxions, Two Letters concerning it, n. 35*9, An Illuftration of it, n, 362, p, 1050. Moon, Of its Appulfes to the Blades, n, 354, p. 6^1, O. Oaks, Of Three which funk into the Ground, ft»}SSfP*7^^ P. Plants, A new Genus call’d Araliafrum, n: 3 J4, p. yoy Problem, Propos’d by Mr. Leibnitz, folv’d, ». 3^4, p 69 y Pyrmont Waters, Their nature and quality, 3 y i. 7, 564 S. Saturn, An Obfervation of him, 3 y i , p. yqS. His Sa- tellites Motions redified, 35y, p» 768. ». 3y6,f. jy6 Sceleton, The Imprcflion of one in a very hard Scone, ». 360, 963 Sea, Several Irruptions of it, n, 352. p, yp7 Silk. Worms, Experiments of them and of their Silk iii England, n»l6%,p* 1036. SpouU, I N D E- x: Scouts, The ftrange Effedsof one in Lancajhirey fJ» V Y* 1097 • * ^ ‘ . Stars, On the Change of Ldcitudo of fome of them, ^ 73^ Strata in a Coal' Mine defcnb’d, r* 360, f» 968 . 6‘a;?/^ Ifland in Hamher^ 1014 ' • • T\ • Taylor, (Dr.) his Defence againft Mr. BernoHlU, tf»^6o, P-955 Telefoopes, A way for Myopes to ufe them without Eye Glafles, rj» 36r, p* »Gi7 • , . Tdefcopick Sights, Who firfl: invented the Application them to Mathematical Inftruments, ^. 3 52, p* 603 Tubes Capillary, Of the Afcent and bufpenlion of Water in them, /?. 35'^, p»7l9 Turneps, Their great and fpeedy Vegetation, W. 9^^ ‘ f.974« ' ^ • V. b^enereal Difeafe, Of its Antiquity, Ari Eruption of it, 35/j, />, 708 > . W. . . . ' . Water, An Enquiry ir.to the Caufe of its Afcent and Sufpenfion in Capillary Tubes, 35'5', f. 739. Of the Morion of tiinnihg W’aters> 74^ ^ Williamlon (Mr.) alTerts his'lnvcntion of making Clocks to agree with apparent Time,^/?. 9^3* f* *079 ' Wine-y £hQ Danger of drinking cold Liquors after a •large Quantity of it, m 351, f» 58k v ■ ' 'r- . ’ ERR A T.UM;' P.ii*ic. /. ii, pro m /. uv. . . I ■ *4 I^mV t .V -Ov