TRANSACTIONS OF THE ROYAL SOCIETY OF EDINBURGH. EDINBURGH: PRINTED FOR T. CADELL JUN. AND W: DAVIES (SUCCESSORS TO MR CADELL) IN THE STRAND, LONDON, aes AND J. DICKSON, AND E, BALFOUR, EDINBURGH. MDCC XCVIIT. ee eure Bote ” soot, « RG Bote Seu : Saat at 2HOITOMEARAT. eal DR ee i 1 Af Dane ae Pale oe i oH co ak os os Se a. an : eee : iaoete see san 49 rs = i aS, MOAUVAWIAR TH CRAIG’ ANTOR™ : ; iol ‘ : a \ ; : oa at ORAL a a he ee ee eary 1 Gs GVA DT 4. (gan ve 10% GAT HIAT -« ; ModHor aeat ART 71 (ISSCA0 8M lor “yngeaagow2) 5 > “CsA < cues ais OA eee ee pavenias KuotsAu a GAR KO2ZAING A ok SS : on ; . THULORODE Be take fie ee a: é ea ‘ # ais . : Ry es ; : ¥ wl - id i) . f 7 J - * 4 ravine a pt Ree - hee 2. “ at) vey 3, CONTENTS OF THE POU RT Hh Vv.0O LU ME: PART TI HISTORY of the SOCIETY. Four Theorems for refolving all the Cafes of Plane and Spheri- cal Triangles, by the Reverend Mr Fisher, - Page. 4. Differtation on the ry ated of sid Heat, and Fire, by Dr Hutton, - - me Improvement of the Mereutiia Lik by Mr Keith, - 17. Experiments on the Effects of Opium on the Living Animal, by Dr Wilfon, - - -- - 18. On the Diurnal Variations of the Barometer, by Dr Balfour of Calcutta, - + - aot On the Sulphurating of Metals, by Dr Hutton, - 29. New Obfervatory at Aberdeen, -- ~ 29. APPENDIX. Office-Bearers of the Society, - - - 31. List of Memsers, continued from the third Volume, - 33 - MEMBERS DECEASED, - - - 36. Donations, n: = - - 38. I. Biographical Account of Lord Abercromby, - (1). If. Biographical Account - William PTET Efq; of Wood- heufelee, ~ “ - (17). Ill. Biogra-- i vi mee OND ee Nad 'p Ss Il. Biographical Account of Mr William Hamilton, Jate Profeffor of Anatomy and Botany in the Univerfity of Glafgow, - - Page (35). IV. Biographical Account of Tehin Roebuck,M.D. - (65). PoA RTS ke PAPERS READ BEFORE THE SOCIETY. 1 PAPERS OF THE PuysICAL CLASS. I. Account of a Mineral from Strontian, and of a peculiar Species of Earth which it contains. By Thomas Charles Hope, Profeffor * ae Medicine in the Uni- verfity of Glafgow, - Page 3 II. Obfervations on the Natural Hi ifory of Guiana. By William Lochead, Efq; - - 41. Ill. On the Principles of the Antecedental Calculus. By James Glenie, Efq; = = 65. IV. Od/ervations on the Trigonometrical Tables of the Brab- mins. By John Playfair, Profeffor of Mathematics in the Univerfity of Edinburgh, - - 83. V. Some Geometrical Porifms, with Examples of their Ap- plication to the Solution of Problems. By Mr Wil- liam Wallace, Affiftant-Teacher of the Mathematics in the Academy of Perth, - - 107. Vt. On the Latitude and Longitude of Aberdeen. By An- — drew Mackay, LL. D. & F. R. S. Edin. - 135- Vi. * Now Joint Profeffor of Chemiftry in the Univerfity of Edinburgh. + By miftake No. V. is repeated. CPO Neath eS Ni oD Ss VI. An Account of certain Motions which fmall lighted Wicks acquire, when fwimming on a Bafon of Oil. By Patrick Wilfon, F. R. S. Edin. and Profeffor of vil Praétical Aftronomy in the Univerfity of Glafgow, Page 163: VII. Account of a Singular Halo of the Moon. By William Hall, Efq; of Whitehall, F. R. S. Edin. < VILL. 4 New Series for the Rettification of the Eliipfis, with Obfervations on the Evolution of a certain Algebraic Formula. By James Ivory, A. M. . IX. Mineralogical Defcription of the Mountain of Gibral- — tar. By Major Imrie. - - X. Defcription of a Thermometer, which marks the great- eft Degree of Heat and Cold from one Time of Ob- fervation to another.. By Alexander Keith, Efq; F.R.S. & F. A. S. Edin. - = XI. Defcription of a Barometer which marks the Rife and Fall of the Mercury from two different Times of Ob- fervation. By Alexander Keith, Efq; F. R. Ss. & F. A. S, Edin. - - - XIl.- Meteorological Abftra& for the Years 1794, 1795s 1796, 2 ‘ ie II. PAPERS OF THE LITERARY CLASS. I. On the Origin and Principles of Gothic Architecture. By ‘Sir James Hall, Bart. F. R. & A. S. S, Edin. - II. M. Cuevaurer’s Tableau de la Plaine de Troye illu- ftrated and confirmed from the Obfervations of fub- fequent Travellers and others. By Andrew Dalzel, M. A. F. R.S. Edin. Profefor of Greek in the Univer/fity of Edinburgh, - - 174. 177: gt. 203: 209: 213: 29. -ADVER- ADVERTISEMENT. Edinburgh, February. 15. 1798. At a Meeting of the Council of the Royal Society it was,. this day, Re/olved, That a Publication of Papers, communicated to the Society, fhall hereafter be made annually, whether fuch Papers be fufficient to form an entire Volume, or only a Part. of a Volume. TRANS- FP TOGO LZ Ol Reon = OO Pan i O08 Sa On WS. - § (HE Third Volume of thefe Tran/actions brings down the . Hiftory of the Society no farther than the end of the year 1792, though it contains feveral Papers that are of a later date. Phyf. Cl. Dr Monro read a paper, entitled, Obfervations on the Mufcles, and particularly on the Effe@ts of the Oblique Fi- bres. This paper is inferted in the Third Volume of the Tranf- actions, Part II. No. XII p. 250. Lit. Cl. Mr Stewart read the firft part of his Biographical Account of the late ADAM Smitu, LL. D. [See Vol. HI. Hitt. P. 55+] YY a. 2: Lit, 1793: Jan. 7. Dr Monro on the muicles, and on the effects of the oblique fi- bres. Jan. 21. Biographical account of Dri Smith, 1793- Mar. 18. Biographical account of Dr Smith. April 3. Mr Playfair on porifms. Mr Fifer on strigonometry. 4 HISTORY of the SOCIETY. Lit. Cl. Mr Srewart read the remainder of the Biographi- cal Account of the late ApAm Smitu, LL. D. Phyf. Cl. Mr Puayrarr read fome Obfervations on Porifms, additional to thofe formerly communicated. Thefe were in- tended to prove, that the propofitions called Porifms do not, as fome mathematicians have alleged, involve in them any viola- tion of the /aw of continuity. This fubjec& belongs to the fecond part of the paper, No. VII. of the preceding volume; which fe- cond part has not yet been fully communicated to the Society. Ar this meeting was alfo read a paper on Trigonometry, entitled, An Eafy and General Method for, folving all the Cafes of Plane and Spherical Triangles, by the Reverend WALTER FisHER, minifter at Cranftoun. Ir has long been an object with mathematicians to reduce the rules of trigonometry to the fmalleft number poflible, and to give them the form moft eafily retained in the memory. Lord Napier, whofe difcoveries have fo much facilitated and abrid- ged the labour of numerical calculation, applied himfelf to fim- plify the rules of trigonometry with great fuccefs. He in- vented the rule of the Circular Parts, which gives an apparent unity to theorems, where a real unity is wanting, and is per- haps the moft fortunate attempt toward an artificial memory that has been made by any of the moderns. Various improvements of this rule have fince been pro- pofed. That of M. PincrE is one of the beft: He retains Lord Napier’s arrangement of the circular parts, and reduces the rules of fpherical trigonometry to four; the two firft of which are Napier’s, and the other two a generalization of the common theorems refpecting the fegments, into which the perpendicular, drawn to any fide of a fpherical triangle, di- vides that fide, and alfo the angle from which it is drawn. See Mem. HISTORY ‘of the SOCIETY. 5 Mem. Acad. Sciences, 1756, p. 301. There is a fifth rule, it muft be obferved, neceflary for the cafe, when the three fides, or three angles of the triangle, are given, as this cafe refufes to fubmit to NAPIER’s rule in any form of it. 7 Tue author of the paper, now communicated to the Society, has alfo been fuccefsful in his attempt to render the rules of tri- gonometry eafily retained in the memory. He employs the circular parts, and makes ufe of fewer rules than M. PincrE, as he has only four, including one for the cafe juft mentioned. TuE theorems Mr FisHer employs are/not new,. but they are judicioutly fele&ted, and are lefs embarrafling in the ap- plication than either thofe of Narier or PInGRE. They are as ‘little as poffible fubje&t to ambiguity ; they do not require the letting fall a perpendicular, and they apply both to plane and f{pherical triangles. 1. M denotes the middle part of the triangle, and muft al- ways be affumed betwixt two given parts. It is either a fide or the fupplement of an angle. 2. A and a are the two parts adjacent to the middle, and of a different denomination from it. 3- O and o denote the two parts oppofite to the adjacent parts, and of the fame denomination with the middle part. 4. lis the laft or moft diftant part, and of a different deno- mination from the middle part. THEOR. 6 HISTORY of the SOCIETY. LHEOR. F Sin A: fina: :finO: fino. THEOR. II. Rivera Sania ie oe anos ti SES. 2 ‘ 2 2 THE OR: Wy. Tan —— ee he Ss eee Sin A X fina: 1:: fin ” Mr FisHer recommends, for the purpofe of remembering thefe rules, to commit to memory the words Sao, Satom, Tao, Sarfalm, formed from the abreviation of the terms of the above proportions. It is obvious that thefe four theorems apply to plane triangles, providing that, inftead of the fine or tangent of a fide, you take the fide itfelf. N93 Phyf. Cl. Dr Hops read a paper, giving an account of a Mi- peli ; heral from Strontian in Argylefhire, and of a Peculiar Species of mincral from Sinha Earth contained in it. A fhort abftra@ of this paper was in- ferted HISTORY of the SOCIETY. 7 ferted in the laft volume of the Tranfactions. The paper it- felf is the firft of the Phyfical Clafs in this volume. [See Part IL. P. I] Phy/- Gl. Dr Monro read a paper, being Experiments on the Nervous Syftem with Opium and Metalline Subftances, with a view of determining the Nature and Effects of Animal Electricity. This paper is publifhed feparately. Ar this meeting a paper was alfo communicated from ANn- prew Mackay, LL. D. containing an Account of a Series of Obfervations, made by him in the Obfervatory at Aberdeen, for determining the Latitude of that place. Dr Mackay alfo promifed to fend his Obfervations for de- termining the Longitude of the Obfervatory. Thefe were not received till September 1796. Both papers are inferted in this volume, Part II. a o. VI. p. 135. Dr James ANDERSON read a paper, entitled, Obfervations on Peat Mofs. ‘This paper has been publifhed feparately: Phyf. Cl. A paper was read from Mr Locueap, F. R. S, Edin. on the Natural Hiftory of Guiana. It is inferted in this volume, Part II. No. II. p. 41. Phy/. Cl. Dr Huron read the firft part of a paper, being a Differtation on the Philofophy of Light, Heat, and Fire. This paper, which confifted of feveral parts, was read at the different Meetings of the Society in May, June, July, Auguft, and De- cember, of this year. It has been fince publifhed feparately in one volume 8vo. The following abftraé contains an account of 1793+ Dec. 2. Dr Monro on the nervous fy- ftem. Dr Mackay on the latitude of Aberdeen. = 1794. _Jan. 6. Dr Anderfon on peat mofs, March 3. Mr Lochead on the natural hit tory of Guiana. April 7. Dr Hutton on the philofophy of light, heat, and fire, 8 HISTORY of the SOCIETY. of the object of the Differtation, and of fome of the reafonings employed in it. Dr Hutton was led into the fpeculations contained in the Differtation, by an account of two experiments made by M M. DE Saussure and Picrer of Geneva. In the firft of thefe experi- ments, two concave fpecula were placed oppofite and parallel to one another, about twelve feet diftant; and in the focus of one of them was a ball of iron, which had been heated to incandefcence, but allowed to cool till it was no longer luminous, even in the dark, In the focus of the other {peculum a thermometer was placed, which prefently rofe 8° (of REaumurR’s fcale) above another that {tood near it, but without the focus. Voyages dans les Alpes, tom. II. § 926. To account for this phenomenon, M. pr Saussure fuppofes, that there exifts what M. Lambert and fome other philofophers have called radiant heat, and that this heat may be obfcure, and not accompanied with light.. This radiant heat he conceives to be refleéted in the fame manner that lights, and by that means to have produced the effet on the thermometer that has juft been deicribed. ; To this folution Dr Hutton objects, alleging, that it afcribes properties or capacities to heat which are inconfiftent altogether with our notions of it. We know heat only as a quality of bodies, and as acting either in expanding them, when it is call- ed fenfible heat, or in giving them fluidity, when it is termed la- tent heat. We never perceive it as exifting in any other fhape, and therefore, to fuppofe it capable of moving through {fpace, independently of body, and of being reflected from a polifhed furface, is to afcribe to heat properties not predicable of it, and quite inconfiftent with its nature, fo far as we have information concerning it. Dr Hurron therefore propofes another explanation. From experiments which he had made, long fince, he had found that the HISTORY of the SOCIETY. 9 the different fpecies of light, when of equal intenfity, as eftima- ted by the eye, are of unequal intenfity when their effect is meafured by the thermometer. In thefe experiments he ren- dered light of different colours equally intenfe to the eye, by inereafing or diminifhing the diftance from: the luminous body, till he could juft read by the light of it. In this way he compared the red light from a fire of coals, with the white light of flame, and found, that while they were equally powerful in affording vifion, the red was incomparably the moft powerful in producing heat. WueEw a body, therefore, is heated to incandefcence, like the jron ball in M. DE Saussure’s experiment, it emits at firft the white or compound light, but as it cools, the light which it emits becomes of the red fpecies, and this is the laft that difap- pears. As the body cools, therefore, the power of its light, to produce heat, increafes in proportion to its power to afford vi- fion, and, therefore, when this laft vanifhes, or ceafes entirely, the other may ftill remain in a certain degree. Thus, in the experiment juft defcribed, the iron ball, after it had loft all light to the eye, continued to emit rays of light, which, though they made no impreflion on the organ of vifion, had power to pro- duce heat, and expand the mercury in the thermometer. To the principle, therefore, of the irradiation of obf{cure heat, by which M. DE Saussure explains the above phenomenon, Dr Hutron fubftitutes that of ch/cure, or invifible light, which, though it be in appearance more paradoxical, is in reality free from the very ftrong objeGtions which prefs againft the other hypothefis. ; We muft not omit to obferve, that M. Picret varied the ex- periment, by placing a matrafs full of boiling water, inftead of the iron ball, in the focus of one of the fpecula. The thermome- ter im the other was ftill affe¢ted, and raifed a little more than a degree. The irradiation of invifible light explains this alfo; for it is natural to fuppofe, that fuch an irradiation takes place from Vor. IV. b all 10 AISTORY of the SOCIETY. all bodies, when above a certain temperature, whether they be in the act of cooling down from incandefcence or not. Tue fame ingenious and accurate obferver, made another change in the circumftances of the experiment, by fmoking the bulb of the thermometer; in confequence of which it was heat- ed fooner, and rofe higher than before. This appearance is per- fe&tly conformable to Dr Hurron’s theory, and feems quite inconfiftent with the other. The black coating of the bulb, by its well known property of abforbing light, tended to accelerate and increafe the effect of the light in heating the thermometer ; but the fame coating being of fmoke, and a very bad con- ductor of heat, muft have oppofed the tranfmiffion of heat through the glafs, and have both retarded and diminifhed its effect. Notuinc, indeed, can be more unlike than the laws which ufually regulate the propagation of light and heat. To move with extreme velocity through the tranfparent fubftance of fome bodies, without heating them in any fenfible degree; to be reflected from the furfaces of others, without entering them at all; and, laftly, to be abforbed by certain bodies, neither pafling through them, nor being refle€ted from them, thefe are the properties of light. . Heat, on the other hand, is lowly pro- pagated through all bodies, combines with them intimately in its paflage, and often remains at reft without any motion what- ever. Tue converfion of thefe experiments, which was very inge- nioufly imagined by M. Picrert, led to. a fact fill more fingu- lar and unexpected. Inftead of. the heated body, he placed a matrafs, with ice in the focus of one of the fpecula ; the confe- quence was, that the thermometer in the focus of the other was fenfibly deprefled.. When the cold was increafed, by pouring nitrous acid on the ice, the depreflion of the thermometer was alfo increafed. VTo HISTORY of the SOCIETY. re To account for this phenomenon, M. Picter tonfiders the thermometer as the body irradiating heat, and the matrafs with the ice as the body which receives it, fo that the experiment: ‘is the fame with the former, only ah, the ob{cure heat moves in the contrary direction. Tuts explanation, however, is not only liable to the objec- tions that have been made, in general, to the fuppofition of ra- diant and obfcure heat, but it involves in it new difficulties, It implies, for inftance, that the irradiation from the heated body is affected by the ftate of the body which receives that irradia- tion, a principle furely contrary to all analogy. In the irradia- tion of light from a luminous body, nothing fimilar to this is obferved : Whether the light of a candle fall on a white wall, by which it is reflected, or on a black wall, by which it is ab- forbed, no difference is produced in the quantity of light emit- ed, but it remains in both cafes the fame. In no cafe, it fhould feem, can the quantity of the radiating matter depend on the condition of the recipient bodies; yet, according to the prece- ding explanation, a body muft be fuppofed to irradiate heat more copioufly when the body on which the irradiation falls is cold than when it is hot ; a fuppofition which, being, as has been faid, contrary to analogy, cannot be admitted. Tue Doctor next proceeds to offer his own explanation, but with the diffidence that ought to accompany every attempt to account for a phenomenon fo fingular as this, and having fo little analogy with any other fact that relates to the communication of heat. He fuppofes that all bodies irradiate invifible light, when they are of an ordinary temperature, and that this irradiation di- minifhes as their heat diminifhes. The temperature of the thermometer, therefore, in the above experiment, is to be confiz dered, like that of all other bodies, as being maintained by the . action of two caufes, viz. the irradiation of invifible light from the furrrounding bodies, and the communication of heat from b 2 them : HISTORY of the SOCIETY. them by contact. The thermometer, therefore, that is placed in the focus of one of the mirrors, in the above experiment, will be affected by any body whatfoever that is placed in the focus of the other. If that body be cooled below the tempera- ture of the furrounding bodies, lefs light will be irradiated from it, and refleéted on the thermometer ; the thermometer, there- fore, will be depreffed, till the influx of heat from the air, or other bodies with which it is in contaét, fupply the deficiency. This, however, is thrown out rather as a queftion to be refol- ved by future obferyations, than as a theory already eftablith- ed. The experiments by which it muft ftand or fall are not indeed difficult to be imagined. They are however of extreme delicacy in the performance; and Dr Hurton, who, in differ- ing from the philofophers of Geneva, does juftice to the accu- racy and judgment with which they have conducted their in- quiries, expreffes a with, that the fkill and ingenuity of M. Pic- TLT were again directed toward this object. By the preceding inquiry, Dr Hutton was led to confider the connection between light and fire, as well as between light and heat; a fubject which he had formerly treated of in feve- ral papers read before the Royal Society, and afterwards pu- blifhed in his chemical differtations. In thefe he objected to the theory of fire as laid down by M. Lavoisier, and the French chemifts; acknowledging, at the fame time, that the oxygenating of bodies, by vital air, is to be ranked among the greateft difcoveries in phyfics. It is a difco- very, however, in his opinion, that will by no means explain all the phenomena of burning, by. which the exiftence of fome other caufe is clearly pointed out, betide the decompofition of the vital air, and the extrication of the calorigue or latent beat, which maintained: the air in a ftate of fluidity. The arguments in fupport of this aflertion, which Dr Hurron employs here, axe founded, on the appearances exhibited by bodies. burning without HISTORY of the SOCIETY. re without flame, and burning with flame; that is, on the pheno- mena of combuftion and inflammation. In the combuftion of a piece of charcoal, two diftinét effects may be traced, viz. 1. The oxygenating of the carbonic fub- ftance, by which fixed air is produced, or carbonic acid in an elaftic ftate; 2. The production of a great quantity of light and heat, while the charcoal is undergoing this change. It is with refpect to this laft part of the procefs only that different opinions are entertained. The phlogiftic theory maintains, that in the oxygenation of the carbonic fubftance by the vital air, the phlogiftic matter of that fubftance is fet free from combi- nation with it, and in making its efcape exhibits the phenomena of light and heat. Tue antiphlogiftic theory, on the other hand, fuppofes, that, by the decompofition or the condenfation which the vital air undergoes, while it oxygenates the carbonic fubftance, the la~ tent heat is transferred to that fubftance, and produces light and fire. : Now, if it can be fhewn that a burning coal, though placed wa circumftances the moft favourable for its oxygenation, may meverthelefs lofe its heat, and ceafe to burn entirely, it is cer- tain, that itis net alone by the calorigue of the vital air that the fire is fapported. Let then a confolidated piece of charcoal, fuch as the mineral kingdom, in many places, affords in great perfec- _ tion, be heated to the higheft degree of incandefcence, and expofed, infulated, to the atmofpheric air. Here every condi- tion is united favourable to the oxygenation of the coal, a fuf- ficient quantity of heat, and free accefs of air. If the heat, fup- pled, from the decompofition of the vital air, were able to main- tain the heat of the coal, it would continue to burn; but the fa&t is, that, in fuch a fituation as is here defcribed, the coal -dofes, its heat, and at is at Jatt extinguifhed. It is. plain, there- : OE, fore, 14 HISTORY of th SOCIETY. fore, that more heat is loft by communication with the atmof- phere than is acquired from the decompofition of the vital air. Now, let the experiment be fo far varied, that the incandef- cent coal, inftead of being fufpended fingly in the atmofphere, is furrounded with other burning coals, that are likewife fufpend- ed, and at fuch a diftance from it as to leave room for the free paflage of a current of air: We know, with certainty, that the central coal will now continue to burn as long as thofe that fur- round it are incandefcent, or emit a certain degree of light. But the circumftances of the coal, in this experiment, are in nothing more favourable to the receiving of heat from the decompofi- tion of the vital air than they were in the former ; for if it be faid, that the air afcends through the greater mafs of burning matter, with more rapidity than before, and fo depofits more of the calorique, it muft be remembered, that it alfo abftracéts more heat from the coals, juft in the fame proportion, or in propor- tion to its rapidity. If then the antiphlogiftic theory be true, the heat acquired by the coal, in the one of thefe experiments, fhould be to the heat abftracted from it, in the fame ratio that the heat, acquired in the other experiment, is to the heat abftra¢t- ed. But this does not hold; for the heat acquired, in the firft experiment, is lefs than the heat abftracted, and in the fecond it is not lefs, but is either equal, or greater. Therefore the anti- phlogiftic theory is not true; that is to fay, the theory which derives the fupply of heat, in nee ve bodies, entirely —_ the calorique of the vital air. We mutt therefore admit another caufe, before we can fully explain combuftion ; and this can be no other than the extrica- tion of the phlogiftic matter of the body which is oxygenated, the converfion of that matter into light, and then the produc- tion of heat. Iv the phenomena of inflammation, Dr Hutton thinks that the proofs of his theory of fire are no lefs conclufive than in thofe HISTORY of. th SOCIETY. 2 thofe of combuftion, . "The inconceivable rapidity with which fire is’ propagated through an,inflammable and tranfparent va- pour, is among the moft remarkable.of thofe phenomena, and is certainly, inconfiftent with ,the new theory of burning, and indeed with every other that makes fire to be produced by heat alone. Let.an inflammable fluid. be heated till it boil, and to the top of the column of vapour emitted from it let the {malleft {park of flame be applied. . The vapour is kindled, and, how- ever high the column, the flame defcends in an inftant to the furface of the inflammable fubftance, and fets fire to it. Now, it is impoffible that mere, heat could; defcend in this manner, againtt the ftream of vapour that:is continually rifing from the boiling fluid. This is quite contrary to the laws by which it is ufually propagated ; and it fhould feem, that the fa@ can on- ly be accounted for by the celerity with which light moves throngh. tranfparent, bodies, and by fuppofing that the extrica- tion of light is the immediate caufe of burning. _. Tue above.inftance i is conformable to the experience of every day : Another example, which Dr Hutron gives of the, celerity with, which. fire_is: ‘propagated: through | an inflammable and tranfparent ‘vapour, | is.more_ fingular, and. may, perhaps be thought. hypothetical, but it is at leaft a very happy application ts his theory... This example is the meteor, which was feen in 78 3, over all Great Britain, and as far fouth as Paris. There can = no doubt, fays he, that this was a ftream_ of, inflammable va- pour which had iffued. from the ‘mineral y regions: of Iceland; at that time laid wafte by. fubterraneous, eruptions... 'This. train of inflammable vapour, about 60: miles high in the. atmofphere,. had. been kindled at. the north end, probably by an eleétrical Apark,; and, the. ‘inflammation ran: the Apace of, feveral hundred. Shi 3 fftetiet 16 HISTORY of th SOGIETY. fiftent with the propagation of heat. Inftances, ftill more ‘re- markable, of the rapid progrefs of fire, are found in the inflam- mation of fuch vapours, when mixed with that proportion of vital air which is neceflary for decompofing the phlogiftic fub- ftance. On the whole, Dr Hutron concludes, that in no cafe is the light which appears in burning, an effect of the heat obtained from the decompofition of vital air, but that it is the extrication of phlogifton, of fixed light, or a certain modification of the fo- lar fubftance, which had exifted in the inflammable bodies, and had been chemically combined with their elements. It appears alfo, that it is light which is immediately produced in burning, and that it is only mediately that heat is excited: This is true both of combuftible bodies which burn in an affociated ftate, and of thofe inflammable fubftances where the emerging light heats both the inflammable body, and the contiguous atmofphe- ric fluid. Tue Doétor proceeds to explain, more at large, his notions of the folar fubftance, of which he conceives light, heat, phlo- gifton, and eleétricity, to be fo many different modifications. His notions on this fubjeét are very peculiar, as he conceives the folar matter to be without gravitation, without inertia, and, it may be added, without extenfion. The nature of this ab- ftract does not admit of entering further on the argument: It is fufficient to remark, that the theory of beat feems to be arrived at a point where it muft almoft unavoidably ftand ftill, till fome experiments fhall determine how far the gravitation of bodies is affected by the heat, whether fenfible or latent, that is contained in.them. The experiments already made, though ingenioufly contrived, and ably executed, are not fufficient to decide a queftion of fuch extreme delicacy; nor’ does it feem probable, that, without having recourfe to the pendulum, a {a- tisfactory folution of the difficulty will ever be obtained. Phy/. HISTORY of the SOCIETY. 17 Phyf. Cl. Dr Monro read a paper, concerning the Commu- nication of the Ventricles of the Brain with one another, in Man and Quadrupeds. This paper is publifhed in Dr Monro’s book, entitled, Three Treatifes, &c. Mr Keita alfo communicated an Improvement of the Mer- curial Level, defcribed in the Second Volume of the Tranfactions of the Society. TuIs improvement confifts in a contrivance for avoiding the trouble of pouring the mercury out and into the level, every time it is ufed. Befide the canal of communication at the bot- tom, between the two upright columns of mercuty, on which the flots fwim, (fee Vol. II. Part II. No. III.), there is, in the new conftruction of the inftrument, another canal, parallel to the former, cut in the upper part of the wood, which allows the air to circulate freely, according as the mercury below rifés or falls. The whole is made perfectly clofe, fo that no air can get admittance. ’ THE inftrument‘may be carried about in this manner, with the mercury remaining in it; and though by agitation that fluid calcines, and is converted into‘a grey powder, this only happens when it has free accefs to vital air ; and as all fuch ac- cefs is here prevented, the mercury will not lofe its metallic luftre. \ THE level, in this form of it, as it requires no previous ad- juftment, is very commodious, and, when much accuracy is not required, may be ufed with advantage. Phyf. Cl. Dr ANDERSON read a paper, entitled, Obfervations on Wool-bearing Animals, Phyf. Cl. Mr PLayFaAiR communicated an Abftra@ of a Journal of the Weather, kept at his Houfe in Windmill Street, | Vou. IV. Cc for 1794. Aug. 18. Dr Monro on the communica- tion of the ven- triclés of the brain. Mr Keith on an improvement of the mercurial, ~ level. 17952 Jan. 5. Dr Anderfon on wool-bear- ing animals. Feb. 2. Mr Playfair on: the weather. of 1794+ 1795- Feb. 2. Dr Anderfon on the making of indigo. Extract of a letter from W. Hall, Efq; March 2 Dr Willon on the effects of opium on the living animal. 18 HISTORY of the SOCIETY. for the year 1794. This abftraét, with thofe for 1795 and 1796, make the laft of the Phyfical papers in this volume. Ar this meeting Dr ANDERSON alfo read a paper on the Ma- king of Indigo at Tranquebar, by Dr ANDERSON of Madras. An extraét of a letter from W. Hat, Efq; of Whitehall, Berwickfhire, was read, giving an Account of a Great Degree of Cold which he had obferved on the Evening of the 22d of January, when the Thermometer ftood between 5 and 6 degrees below o of FAHRENHEIT’S feale. Phy. Cl. Dr ALEXANDER Witson read the firft part of a pa- per, concerning the Effeéts of Opium on the Living Animal. This paper has been publifhed feparately: An abftract of it follows. Tne difference in the refults of the experiments that have been made to afcertain the effeéts of opium, and the inconfiftency of the conclufions deduced from them, led Dr WiLsown to enter on the experimental inveftigation contained in this paper. The firft point which he endeavours to afcertain is, whether opi- um, applied to the internal furface of the heart, is capable of fo affecting its nerves, as to act on thofe of every part of the body, producing the general convulfions obferved on injecting a folution of this drug into the heart or blood-veflels. It *ap- pears from his experiments, that the only effects of the applica- tion of opium to the internal furface of the heart, are thofe of interrupting its motion, and deftroying its irritability ; and that when convulfions fucceed, they are owing to the opium being conveyed along the aorta, and immediately applied to the brain. It has alfo been aflerted, that opium, applied to diftant parts of the body, is capable of affe€@ting the motion of the heart, through the medium of the nervous fyftem. Injeéted into the cavity of the HISTORY of the SOCIETY. 19 the abdomen, for inftance, it almoft immediately impairs the action of the heart. It is only, however, when applied to an extenfive furface that it has this effet; and if Dr Witson’s obfervations be juft, this effect is not produced through the me- dium of the nervous fyftem,; but is the confequence of the opium deftroying the mufcular power, and, confequently, the circulation in thofe veflels to which it is applied; thus fud- denly diminifhing the fupply of blood to the heart, and at the fame time oppofing an additional obftacle to its perfect evacua- tion. The experiments, next related; demonftrate that opium, immediately applied to the brain itfelf, although it excites vio- lent and univerfal convulfions in all the mufcles of voluntary motion, is incapable of affecting at all the contractions of the heart. It even appears, from thefe experiments, that although opium be applied at the fame time to the brain and fpinal mar- _ row of a frog, in confequence of which, (if the folution employ- ed be ftrong), the animal inftantly expires, as if thunderftruck, the motion of the heart is not in the leaft affected by it. It continues to beat with the fame frequency and force after, as it did before, the application of the opium. We arrive, then, at this conclufion, that opium, applied to a diftant part of the body, does not affect the motion of the heart, through the medium of the nervous fyftem; nor, on the other hand, does opium, ap- plied to the heart, affect any other part of the body, through the fame medium. But the heart is not the only mufcle, which opium, applied to a diftant part, feems incapable of affecting through this medium. Many confiderations render it highly probable, that the fame is true of all the mufcles of involuntary motion, without exception... That it is fo of the mufcular coat _ of the alimentary canal, which, next to the heart, may be con- fidered the chief of this clafs of mufcles, appears from the ex- periments next related. On comparing the experiments above alluded to, with thofe in which opium thrown into the ftomach i c2 and. 20 HISTORY of the SOCIETY. and inteftines, the cavity of the abdomen, &c. is found to-produce convulfions, it appears probable, that in the latter cafes, as in the former, the convulfions do not proceed from any action of the opium on the nerves of the part to which we apply it, but from its being received into the fanguiferous fyftem, and im- mediately applied to the brain, The experiments which follow, in the treatife, confirm this conjecture. On comparing toge- ther all the experiments there related, and thofe alluded to in the introduction, it appears, that the various effects of opium on living animals may be divided into three claffes. The firft comprehending its action on the nerves of the part to which it is applied, not differing effentially from that of any other local irritation. The fecond comprehending its effects on the heart and blood-veflels ; that of increafing their ation, when applied in a fmall quantity; and that of impairing, or altogether deftroy- ‘ing their power of action, when applied to them more freely. The third comprehending its effects, when immediately applied to the brain; which, when the dofe is moderate, are impaired fenfibility, languor, fleep; when applied more fully, convul- fions and death. In all its effects on the living animal body, opium has much, in common with other fubftances, but at the fame time fomething in each peculiar to itfelf. It may appear an omiflion, Dr WiLson obferves, that he has not ranked among the effects of opium, received into the fyftem, thofe which it feems to produce on the mufcles of voluntary motion. In fome of the foregoing experiments, the irritability of thefe mufcles was found much impaired after death, although the opium was not applied directly to the mufcles themfelves. But it appears, both from an experiment related in the Treatife, and others alluded to, that the impaired irritability of thefe muf- cles is owing, not to any direct action of the opium on them, but to the violent convulfions excited in them, in confequence of the opium being applied to the brain. THE HISTORY of the SOCIETY. ry Tur dodtrine of the fympathy of the nerves has been fo much employed in accounting for the effects of opium, that Dr Wixson judged it proper to make fome obfervations upon it 5 in which he endeavours to prove, that no fuch law of the ani- mal ceconomy exifts; and that all the phenomena, which have been referred to. this fuppofed law, depend on certain changes taking place in the /en/forium commune, In an appendix, he relates fome experiments, made with a view to determine the manner in which tobacco aéts on living animals. From thefe experiments it appears, that the fymptoms which tobacco produces, when thrown into the heart, are the fame with thofe excited by its immediate application to the brain. That thefe fymptoms, when the tobacco is exhibited in the for- mer way, proceed from no action of the tobacco on the nerves of the heart, but from its being conveyed along the aorta, and _ immediately applied to the brain; fince they do not follow its injeGtion into the heart, when the aorta is previoufly fecured by ligature ; although it was found, that interrupting the circula- tion does not unfit the nervous fyftem from undergoing the change neceffary for the produdtion of fuch fymptoms. It, alfo appears from thefe experiments, that tobacco produces the fame effects, though more flowly, when thrown into the ftomach and inteftines as when thrown into the heart: That in the former cafe, as in the latter, they are ftill to be afcribed to the tobacco being received into the fanguiferous fyftem, and immediately applied to the brain; and that the effe€ts of this drug, when it aéts merely on the nerves of the part to which it is applied, do not effentially differ from thofe of any ftrong topical irritation, It may alfo be collected from thefe experiments, that the pre- fence of tobacco in the fyftem, like that of opium, only affects the irritability of the mufcles of voluntary motion, when it pro- duces convulfions in them ; z. ¢, when it is applied in confider- j able 1795+ April 6, Mr Playfair on the trigonome- try of the Brah- mins. May 5 Mr Wilfon on motions of wicks in a ba- fon of oil, June 1. Dr Wilfon on the effects of opium on the living animal. Dr Anderfon on making chinam. June 15. Mr Marthall on the Argonautic expedition, Aug. 3. Mr Keith on different ther- mometers. Nov. 2 Dr Monro on the internal hy- drocephalus. 22 HISTORY of the SOCIETY. able quantity: to the brain. It appears, therefore, that the modus operandi of tobacco, on the living animal body, is in every in- ftance analogous to that of opium. Phyf. Cl. Mr Prayprair read a paper on the Trigonometry of the Brahmins. The paper is inferted in this volume, Part II. No. IV. p. 83. Phyf. Cl. Mr Prayrarirk communicated a letter from Mr Profeflor Witson of Glafgow, giving an Account of certain Motions obferved in {mall lighted Wicks, when made to fwim on a Bafon of Oil, or any other Fluid which can maintain Flame. [See this volume, Part II. No. VI. p. 163.] Phyf. Cl. Dr AtExaNDER Witson read the remaining part of his paper on the Effects of Opium on the Living Animal. Dr James ANDERSON alfo read an Account of the Method of making Chinam at Madras, communicated by Dr ANDERSON of Madras. Lit. Cl. Mr Dauzet read an Effay on the Argonautic Ex- pedition, by the Reverend Mr Esenezer MarsHatt, Minifter at Cockpen. Phyf. Cl. Mr Keiru read a Defcription of different Ther- mometers, accompanied with figures, by which the Degree of Heat may be recorded for every hour and minute throughout the year. Phyf. Cl, Dr Monro read a paper on the Internal Hydrocepha- lus. This, with fome other papers, already mentioned, by the fame Author, have been publithed feparately ; and as an account of the HISTORY of the SOCIETY. 23 the difcoveries, which Dr Monro has made in the Structure of the Brain, the Ear, &c. could not be fufficiently underftood without the numerous plates by which they are illuftrated, it is unneceflary to attempt any detail of their contents. Ply/. Cl. A paper, by Dr BAtrour of Calcutta, was com- municated, on the Diurnal Variations of the Barometer. Dr Batrour’s Obfervations, on the Diurnal Variations of the Barometer, were made at Calcutta, and communicated to the Afiatic Society in 1794. A copy of them, which he fent to a friend in Edinburgh, was the paper now read in the Royal Society. Tue fituation in which thefe obfervations were made, entitles them to peculiar attention ; for it is well known, that, between and near the tropics, the barometer is very fteady, and free from thofe great and fudden changes that take place in higher lati- ‘tudes. It is in fuch fituations, therefore, that the {maller periodi- cal variations of the barometer, if they exift at all, are likely to be difcovered, as being feparate from thofe accidental irregulari- ties with which they muft be complicated in our northern cli- mates. Dr Batrour’s diligence, in obferving the barometer, has al- fo been fingularly great. He impofed on himfelf the tafk of obferving the ftate of that inftrument every half hour, for an entire lunation, from the new moon on the 31ft of March, to that of the 29th of April 1794. THE refult was, the difcovery of a periodical variation in the _ barometer, confifting of two ofcillations, which it performs re- gularly every twenty-four hours. 1. ON every day, that Dr Batrour obferved, with fcarce any exception, the barometer conftantly fell between ten at night- 1796. jan. 4. Dr Balfour on the diurnal va- riations of the barometer. a4 HISTORY of the SOCIETY. night and fix in the morning; and this it did_progreflively, without any intermediate rifing but in one inftance. _ 2. BETWEEN fix and ten in the morning the barometer con- ftantly rofe; it alfo did fo progreffjvely, and rarely with any intermediate falling. 3. BETWEEN ten in the morning and fix at night the bare. meter fell progreflively, without a fingle exception. 4. Lastiy, between fix and ten at night the barometer rofe progreflively, without any intermediate falling, except in one in- ftance. TueEse are Dr BaALrour’s general conclufions ; and, accord- ingly, on cafting an eye over the table into which he has redu- ced his obfervations, one is immediately ftruck with the ap- pearance of two maxima, viz. at ten at night and ten in the morning ; and, again, two minima, alfo diametrically oppofite to one another, at fix in the morning and fix at night. Tue quantity of thefe diurnal variations is not very confider- able, but fufficient, at the fame time, to leave no doubt of their reality. The difference between the contiguous maximum and ’ minimum is fometimes ;'s of an inch, though in general it is lefs than half that quantity. Ir does not appear that the above variations have any rela~ tion to the heat and cold of the atmofphere, or to the changes of the temperature of the mercury in the barometer, though, with refpect to this laft, we are not furnifhed with fufficient information. Tix thefe obfervations are further multiplied and extended, it will be in vain to attempt any explanation of the facts to which they relate. It feems not improbable, however, that they are conneéted with the reciprocations of the fea arid land winds, during the day and night, or with the heating and cooling of the fuperincumbent atmofphere. It would be of great ufe to have HISTORY of the SOCIETY. 25 have the obfervations repeated at different feafons of the year. An obferyer equally affiduous with Dr Baurour will not be eafily found; but it will perhaps be fufficient to obferve the barometer every three hours, and particularly at the ftationary points... Ir is proper to remark here, that fome obfervations of a fimi~ lar fort have been made in Europe; where, though the fituation is far lefs favourable, than in India, for difcovering the true law of fuch minute variations, refults have been obtained tole- vably confiftent with one another, yet differing confiderably- from.thofe that, are {tated above. -A-sEr1es of fuch obfervations was inftituted. by M. PLANER ef Erfort in Germany, and is defcribed in the Ephemerides of the Meteorological Society at Manheim for 1783. Before thefe obfervations, it had been remarked, that when the barometer is. rifing, it ftands lower at noon than at any other time of the day, and. higher,.at the fame hour when it is defcending.. M. PLANER’s obfervations feem to extend and modify this conclu- fion ; for they make it appear, that between ten and two, both of the day and night, that is, for two hours before, and two hours after| the fun is on the nreridian, the elevations and depreflions of the mercury are lefs than at any other time of the day ; and that between fix and ten in the morning, and, again, between fix and ten, at night, thefe elevations and depreffions. are the gteateft., The fame rule feems to be confirmed by the obferva- tions of M.CorTe.in,France, of which he has given an account in the Journal de Phyfique for 1792 and 1794. -TuEse Jaft conclufions feem to indicate fome., periodical re-- tardation of the movement of the mercury in the barometer, whether afcending or defcending ; but it is difficult to form. any notion of the force by which fueh /an effect can be produced.. Perhaps the only general inference that is yet deducible, frong comparing all the circumftances, is, that certain diurnal va- Vou. IV. d riations: 1796. Feb. 1. Mr Playfair on the weather of 1795- Feb. 15 Bi parmticat account of Lord Abercromby. March 7. Mr Wallace on geometrical po- rifms. March 21. Biographical account of Dr Robertfon. April 4. Biographical account of Dr Roebuck. May 2. Extract of 9 letter from W., Hall, Efq; 26 HISTORY of th SOCIETY. riations of the barometer do actually exift; that more infor- mation on the fubjeét is neceflary before any explanation of them can be attempted ; and that it is in the countries lying near to the equator that we are to look for thefe periodical variations leaft interrupted and obfcured. by accidental irregula- rities. Phyf. Gl. Mr Puayratr read an Account of the Weather for 1795, extracted from his Journal kept for the Society. Lit. Gl. Mr Mackenzie read his Biographical Account of Lord AzercromsBy. [See Hiftory of the Society, Appendix, p- (1)}: Phyf. Cl. A paper was communicated, containing Certain Geometrical Porifms, with their Application ‘to the Solution of Problems, by Mr Witt1am Wattace, Affiftant-teacher of the Mathematics in the Academy of Perth. [See this volume, Part II. No. V. p. 107.] Lit. Cl. Mr Stewart read the firft part of his So Account of the late Dr ROBERTSON. Phyf. Gl. A Biographical Account of the late Dr RoEBucK was read, communicated by Mr Profeffor JanpINE of the Uni- verfity of Glafgow. [See Hift. Appen. No. IV. p. (65)]- _ Phyf. Cl. An Extraé& of a Letter from Mr Hatz to Sir James Hatt, Bart. was read, giving an Account of an Extraordinary Halo of the Moon, obferved on the 18th of February laft. [See this Volume, Part II. No. VIL. p. 173.] os Phyf. HISTORY of the SOCIETY. 27 Phyf. Cl. Mr Stewart read a paper by Dr HutTon, viz. An Examination of a New Phenomenon which occurs in the fulphu- rating.of Metals, with an Attempt to explain that Phenomenon. AN account that was given, fome time ago, in the Literary Journals, of certain experiments made in Holland on the ful- phurating of metals, gave rife to this communication. Accord- ing to that account, when metallic filings are mixed with ful- phur, and expofed in a clofe veffel to a certain degree of heat, the mafs kindles, and burns not only without vital air, but in any air whatfoever, or even in a vacuum. In the experiment, as thus reprefented, Dr Hutton readily faw a ftrong argument againft the theory which explains the phenomena of fire by the extrication of the calorique of vital air; and in this light he con- fidered it in the end of the Differtation on the Philofophy of Light, &c. of which an abftract has been already given. Dr Horr ha- ving however fuggefted to him, that, in making the experiment, he had feen reafon to doubt the reality of the inflammation, they agreed to repeat the experiments together. Dr Hutron was then convinced that this fact had been mifreprefented, or rather mif- underftood ; and therefore thought it neceffary, in this paper, to correct the error into which he had been led by that mifre- prefentation, defcribing the real appearances, and endeavouring to explain them on known principles. ‘ In doing this,” fays he, “ T fhall deftroy the argument which the experiment feemed to afford againft the doftrine of calerique, but | fhall have no rea~- fon to change the conclufion that I formed again{ft that doc~ trine, founded on faéts that are univerfally acknowledged.” Tue fact, as thefe gentleman obferved it, is this: The metal and fulphur being mixed in due proportions,.and expofed to heat in a clofe glafs veffel, the fulphur firft melts, then undergoes a kind of ebullition, emitting vapours which condenfe in the up- per part of the veffel, and are a fublimation of the fulphur. ’ In d2 this. 1796. May 9. Dr Hutton on the fulphura- ting of roetals, 28 HISTORY of th SOCIETY. this ftate, and while the heat communicated was {till under that of incandefcence, there appeared in the bottom, or hotteft part of the mais, an incandefcent f{pot, which increafed in fize. The glafs veflel was now removed from the fire, and carried into a dark room, that the light emitted from it might be the miore accurately obferved. ‘There the incandefcence was plainly per- ceived, {preading from the place where it firft began, and gain- ing ground continually, till the whole became very luminous. The heat, when thus diffufed through the mafs, begins inftantly to diminifh, and the body quickly cools, as a fimilar mafs of any other fub{tance would do. Thefe are the appearances obferved in the experiment ; and are what Dr Hutton proceeds to ex- plain. Ir is evident that the incandefcence, which has juft been de- {cribed, is an operation proceeding from the mafs itfelf, and not from the intenfity of the heat communicated to it, for that heat is not fenfibly incandefcept ; whereas the heat which the mafs acquires, after the veffel is removed from the fire, is confider- ably luminous. We have here, therefore, a fpecies of kindling like that of burning bodies; but, at the fame time, diftin@lly different from it. In burning, a phlogiftic fubftance is decom- pofed, by means of the oxygenating principle; and the matter of light, which was contained in that fubftance, being fet at liberty, . is emitted in the form of light, and heats thofe bodies by which it happens to be extinguifhed or abforbed. But, in this experi- ment, though the mafs is a phlogiftic fubftance, there is no de- compofition of the phlogifton, no appearance of inflammation ; fo that its incandefcence proceeds from another caufe than that which operates in burning. On attending to the circumftances, however, we fhall perhaps difcover that the phenomena of this experiment are not anomalous, but follow a rule, exemplified in many in{tances, though not precifely with the fame appear- ances, Tuis HISTORY of the SOCIETY. 29 Tuts rule feems to be no other than that which regulates the extrication of latent heat, when bodies pafs from a fiuid to a folid ftate, though this cafe is fomewhat more complicated than ufual, and attended with citcumftances that are yet but imper- fetly underftood. It muft therefore be confidered, whether the fources of latent heat in the bodies, here combined, be fuch as we can reafenably fuppofe adequate to the effect produced. First, then, we have the latent heat of the fulphur, when it is fimply in its melted ftate ; it has then an aqueous or perfect fluidity, to which the quantity of its latent heat neceflarily cor- refponds. But this is not precifely the {tate in which the ful- phur combines with the metal; for before that happens, and while the fenfible heat increafes, the fulphur becomes vifcid, and lofes its perfect fluidity. We have nothing with which we can compare this phenomenon, or by which we can eftimate the latent heat now contained in the fulphur. There is how- _ever reafon to think, that this heat is of the fpecies which Dr Hutton, in his Differtations on fubjects in Natural Philofophy, diftinguifhes by the name of the latent heat of ductility. The reafon for this fuppofition is, that when the fulphur, in its vifcid ftate, is plunged into cold water, it does not concrete into its ufual, hard, friable, and cryftallized ftru€ture, but is changed into a tranfparent ductile mafs. This ftate it feems to owe to the la- tent heat contained in it; for after fome hours expofure to cold, it gradually lofes its ductility, and undergoes another change of ftru€ture, fo as to refume its ordinary appearance, as if it had been concreted and cryftallized from the ftate of fimple fluidity. Bor the fulphur alfo emits another fpecies of heat, on its com- bination with the metallic fubftance. This is what may bé called the conftitutional heat of a body, or that by which its volume is preferved in oppofition to any force endeavouring to y diminifh 30 HISTORY of the SOCIETYK diminifh it) The volume of the fulphur is obvioufly much diminifhed on its combination with the metal ; and therefore a quantity of its conftitutional heat muft be expelled, correfpond- ing to the condenfation or diminution of bulk which it has un- dergone. This quantity may be very great; but it is what at prefent our fcience has not the proper means of eftimating. Sucu are the fources of heat contained in the fulphur. The metal alfo, by lofing its duétility, may emit a certain quantity of latent heat, and may thus contribute to increafe the fenfible heat of the compound mafs. The quantity of this effect, like the former, it is difficult to eftimate. ) TuEsE, then, are the different {pecies of latent heat, which may be fuppofed to emerge, and become fenfible, on the com- bination of the fulphur and the metal in the preceding experi- ment, and on the inftantaneous concretion of the compound mafs. The confequence of this muft be, that the mafs already heated, from without, nearly to a red heat, having this addi- tional heat communicated, muft become incandefcent, and emit light. This muft happen, even if the latent heat emerging fhould be but in a very fmall quantity; and thus the leading fa@t of the incandefcence feems to be fufficiently accounted for. Iv may alfo be ufeful to remark, that there are other cafes in which incandefcence feems to be produced, on the principle here afligned, though not perhaps in a degree equally remark- able. © In the aflaying of filver on the teft, when the lead is fufb- ciently feparated, fo as to leave the filver ftill fluid, but in a degree of heat inferior to what is required to melt it, or to preferve its fluidity, the button of filver inftantly concretes, and appears at the fame time much more luminous. Here there is evidently no caufe that operates, but the latent heat of fluidity, emitted, as on all occafions, when concretion takes place ; HISTORY of the SOCIETY. 31 place; and had the filver been here, in the loweft degree of in- candefcence, or the higheft degree of obfcure heat, the pheno- menon would have been as remarkable as in the fulphurating of metals. Own the fame principle it feems to be, that, in a very common, but very inftructive experiment, a bar of cold iron is made in- candefcent, by hammering it with a certain degree of rapidity and force, fo that the condenfation may be fufliciently quick to expel the heat all at the fame time, or nearly fo. In this cafe, it is the latent heat of ductility that is made to appear, as in the congelation of water it is the latent heat of fluidity. Tron alfo furnifhes another example of the fame kind, where the incandefcence is very confpicuous, but where the procefs is not fo fimple as in the former inftances, becaufe a part of the light is probably produced from another caufe. This example is found in the converfion of pig iron into malleable iron by Mr Corre’s procefs, viz. by keeping the iron melted in a re- verbatory furnace, and expofed, by being agitated, to the influ- ence of the atmofphere. When the caft iron comes in this man- Ner to its malleable ftate, it quickly difplays the brighteft incan- defcence poffible, coagulating, at the fame time, from its melted ftate. Now, there can be no doubt that this extreme incandef- cence arifes from the commutation of latent into fenfible heat, and the commutation of that heat again into light, in which {tate it is emitted by the incandefcent body. In this cafe, how- ever, it is probable, that there is alfo light emitted immediately on the principle of burning, and that the iron is in part {cori- fied, by being oxygenated and lofing its phlogifton. But this alfo is in a great meafure owing to the extreme heat produced by the congelation of the iron; for the heat of melted iron is not alone fufficient for that effeé. THE theory above laid down will enable us to explain all the different fteps in the complicated procefs of the fulphurating of 32 HISTORY of the SOCIETY. of metals. When the mixture of the metal and fulphur is ex- pofed to heat, and the fulphur melted, it is not immédiately combined with the metal; for it requires a greater degree of heat, and one which is perhaps nearly that of incipient incandef- cence, to produce the compound fubftance of the fulphurated metal. The moment, however, that this combination is form+ ed, that part of the mafs, in which i it began, lofes its fluidity, and is made to concrete, and at the fame time becomes ftrong- ly incandefcent. In this ftate, if the glafs veflel be removed: from the fire, the procefs of the combination of the fulphur with the metal will be carried on, as has been defcribed above.. For the firft incandefcent part is that which had been moft im-- mediately expofed to the heat of the burning coals, and had, by that means, acquired the temperature neceflary for the combi-- nation of the two fubftances ; but at this time the part imme- diately contiguous to the concreted portion of the mafs is in the next degree of heat; confequently, upon the emerging of the latent heat of the firft portian, this fecond portion, having’ its heat increafed, is made to combine, and, by its inftant con- {olidation, produces incandefcence. ‘This incandefcence of the fecond portion produces a like effect upon the third; and thus the heat, combination, concretion, and incandefcence,. {pread. quickly through the whole mafs, without any further affiftance from external fire. In all this there is fo great a refemblance to the phenomena: of burning, that fome attention is neceflary to enable an obfer- ver to diftinguifh the one procefs from the other. WHEN a mafs of charcoal, properly prepared for combutftion, is kindled in one part by the heat of incandefcence, the oxyge- nation begins, attended with the decompofition of phlogifton, and the emiffion of the fixed light. The neighbouring parts being then heated, by the light emitted from the firft kindled part, are alfo kindled themfelves, and ferve to augment both the HISTORY of the SOCIETY. 25 the intenfity of the heat and the extent of the burning. In this manner the parts of the mafs are kindled in fucceffion, until the whole is incandefcent ; it is at the fame time gradually confu- med, the vital air uniting with the carbonic principle, and this laft being deferted by the fixed light of the phlogifton. In the fulphurated mafs, though there be the fame appear- ance of ignition propagated fucceflively from a central point to the adjacent parts, yet it is not real ignition, but fimple in- candefcence, produced from the extrication of latent heat, in the manner already explained. It is diftinguifhed from ignition by this circumftance : that, as foon as the incandefcence has ipread over the whole mafs, there is an end of the generation of heat, and the fulphurated metal cools from its incandefcent ftate, like any other incombuftible body heated to the fame degree. In the'whole procefs there is no oxygenation; no production of fixed or carbonic air ; no apparent wafte ; nor any thing emit- ted from the mafs, except the light of incandefcence. Tuus, Dr Hutton concludes, that, in the procefs of the ful- phurating of metals, we perceive the action of the fame laws as in the converfion of water into ice, and muft explain both on the great principle, by the difcovery of which ‘his friend Dr Biack rendered fo important a fervice, not to chemiftry alone, but to many other branches of natural philofophy. HE is aware, however, that an explanation of it will alfo be attempted by fome chemifts, on the principle of the change of the capacity for heat ; an explanation which he confiders as ex- tremely fallacious and unphilofophical. When he applies thefe epithets to the doctrine of the capacities for heat, he does not mean to object to the phrafe, capacity for heat, or to the ap- plication of that phrafe to exprefs a mere matter of fact, viz. the difference of the fpecific heat of bodies, or the unequal quantities of theat contained in different fubftances, when their Vou, IV. € mafles 26 HISTORY of th SOCIETY. maffes and temperatures are equal. But what Dr Hutton calls fallacious and unphilofophical is, the affigning the change in ‘the capacity of a body for heat, as the caufe of the abforp- tion or emiffion of heat, at the moment when that change takes place. This fuppofition is grounded, as he contends, on a falfe view of the faéts concerning the tranfition of water from a hard to a fluid ftate, or the contrary. The chemifts, for example, who maintain this doétrine, hold, that when water is cooled down to a certain temperature, it neceflarily freezes and becomes ice, a fubftance that has a much lefs capacity for heat than water has; on which account a certain quantity of the heat contained in the water is expelled, and enters into the fur- rounding bodies... Now in all this it is fuppofed, that water, at a certain temperature, is neceflarily changed into ice, which is by no means true; becaufe it is well-known, that water May be cooled feveral degrees below what is called the point of con- gelation without lofing its fluidity. Dr Hurron tells us, that he has found means to cool it no lefs than 30° below that tempe- rature, without its being changed into ice. Though it be true, therefore, that water muft be cooled to a certain temperature before it can freeze, it is not true, converfely, that it does freeze whenever it is cooled to that temperature. It follows, as a ne- ceflary confequence, that fomething elfe befide a change of tem- perature is eflential to congelation, and is the caufe of that won- derful change which water undergoes in pafling from a fluid to a folid ftate. The feparation of the latent heat feems a caufe more adequate to the effeét, and ferves to explain the cooling of. the water below the point of congelation, without the lofs of its fluidity, becaufe this only happens when the efcape of the la- tent heat is prevented. Tuat the heat, abforbed by the water, is the true caufe of its fluidity, appears from the facility with which this. hypothedis explains HISTORY of the SOCIETY. ay explains all the other phenomena of congelation, There is, as has juft, been faid, a certain fixed temperature, at which water and ice are,convertible into one another. At this temperature, however, a mixed body of ice and water may remain for ever without any of the water being congealed, or any of the ice melted ; but let there be added to this'compound mafs a quan- tity of heat, by communication from a warm body, and there is a certain quantity of the ice melted, while the mafs remains in its former temperature. Now, if we meafure the quantity of the heat, communicated to this:;compound mafs, without chan- ging its temperature, and alfo the quantity of ice melted, that is, the quantity of fluidity produced, it will be found that they are in all cafes proportional to one another, and have therefore the relation of caufe and effect. This certainly amounts to no lefs than a full demonftration, that the heat abforbed, or ren- dered infenfible to the thermometer, is the caufe of fluidity. To fay, that the change of the capacity for heat is the caufe of the abforption of the heat, is, in fact, to affirm, that the fluidity of the water is the caufe of that abforption, and, of confequence, leaves the fluidity as a phenomenon without a caufe: for it has been fhown that mere change of temperature is not the caufe of it. Dr Horton has been remarkably happy in his explanation of the manner in which heat produces fluidity. Heat, fays he, has two diftinét effe@s on body: The one of thefe confifts in its power of diftending the fubftance of the body, or increafing its volume, and this is the effeét that is meafured dire@lly by the thermometer : The other effet of heat is to move the par- ticles of hard bodies on their axes, and by this rotatory mo- tion to feparate their poles of attraction, which were united in their ftate of hardnefs and folidity. The particles of the body, in confequence of this rotatory motion, are in a ftate e2 ; of 1796. June 20. Biographical account of W. Tytler, Efq; July 4. Dr Walker’s ftatiftical ac- count of Col lington. Nov. 7. Mr Ivory on the rectification of the ellipfis, Dr Mackay’s determination of the longitude of the Oblervatory. at Aberdeen, 28 HISTORY of the SOCIETY. of equilibrium ; they have no difpofition to cohere together, and are ready to obey the impreffion of the fmalleft force. Sucu are the ideas which Dr Hutron had formed on the fulphuration of metals, and the theory by which it muft be ex- plained; and they are rendered more interefting, by being the laft communication made by that ingenious and profound phi-— lofopher. Lit. Cl. Mr Mackenzie read a Biographical Account of the late Wittiam TyTLeER, Efq; of Woodhoufelee. [Hiftory, No. II. p. (17)]. Phyf. Cl. Some Paflages from Dr WALKER’s Statiftical Ac~ count of the parifh of Collington were read. Phyf. Cl. Mr Prayer air communicated an Extract of a Let- ter from James Ivory, A. M. containing a New Series for the: Reétification of the Ellipfis. [See Part Il. of this volume,, No. VII. p. 177.) Ar this Meeting Dr Mack ay’s Determination of the Longi- tude of the Obfervatory at Aberdeen was alfo communicated. [Part II. of this volume, No. V. p. 140.] Tue eftablifhment of a New Obfervatory, where there are fo few as in Scotland, is an event of too much importance, in the literary hiftory of the country, to be pafled over without notice. The eftablifhment of that at Aberdeen ought the more to be re- corded, that it does great honour to the public fpirit and {cien- tific zeal of the Principal and Profeffors of the Marifhall Col- lege, and of the other gentlemen by whofe voluntary fub- fcription it was brought about. From the fuads which their fabfcription afforded, an Obfervatory was built in 1781, on a part of the Caftle Hill, which was given in a prefent to the . College HISTORY of the SOCIETY. 29 College by the Magiftrates and Town-Council of Aberdeen. The building confifted of three rooms, two of which, forming the wings, were circular, about 12 feet in diameter, with co- nical roofs. The eaftermoft of thefe was for the quadrant, and had its roof moveable, and furnifhed with flits ; the weftern- was the tranfit room; its roof had flits, but was not moveable ; the room in the middle ferved for the accommodation of the aftronomer. THE inftruments, with which the Obfervatory was furnifh- nithed, were a tranfit inftrument by RamsDEN ; a moveable aftronomical quadrant, of 2 foot radius, by MacurLocu ; an equatorial inftrument by Sisson and RAMSDEN ; an achroma- tic telefcope and a divided object glafs micrometer by, Do1- LOND; an aftronomical clock, with a gridiron pendulum, by Marrotre. To thefe were added an afliftant clock by GapBy, Aberdeen ; an alarm clock ; a barometer and thermometer, the two laft by Miter, Edinburgh. THe tranfit inftrument, and the equatorial, were prefents from the late Earl of Bure, at that time Chancellor of the Univerfity. “They are both .inftruments of great value; the tranfit, in particular, is faid to be of fingular excellence, and . altogether worthy of the great artift by whom it was conftru@- ed: THE Obfervatory, however, fuch as’ it is here defcribed, has been but of fhort continuance. About three years ago bar- racks were built ‘on the Caftle Hill, immediately to the north of the Obfervatory ; and.as it appeared to be of confequence, that the ground occupied by the latter fhould belong to the bar- racks, it was purchafed by Government, and the Obfervatory demolifhed. It is to be rebuilt, however, on an improved plan, and in a fituation where it will be lefs incommoded by the vi- cinity of the town than formerly, and where, it is hoped, the feries * 1797: Feb. 6. Mr Playfair on the weather of 7796. 30 HISTORY of the SOCIETY. feries of obfervations may be continued, which Dr Mackay has begun with fo much diligence and accuracy. AccorpinG to Dr Mackay, the latitude, from a mean of 64 obfervations of the fun’s meridian altitude, is 57°. 9..1",,or becaufe the fun’s femidiameter, taken from the, Nautical Alma; nac, is about 14” too. great, it is more exactly 57°. 8. 5937, and this agrees to + of a fecond with the mean of 8 obfervations of the meridian altitudes of fixed ftars. __ Tue longitude, determined alfo by a mean of feveral obfer- vations, is ob. 8’. 32” of time, or 2°. 8’ weft of Greenwich, HENCE it appears, that the beft maps and charts require fome correction in the pofition they aflign to Aberdeen, and proba- bly to a great part of the eaft coaft of Scotland. AinsLEy’s map places Aberdeen in latitude 57°. 5’. 9’, which is 3’. 50” too far fouth: It is however very exact in the longitude, which it makes 1°. 6’ eaft of Edinburgh ; fo that, reckoning the longi- tude of Edinburgh 3°. 14/. 45” weft of Greenwich, as it is near~ ly, there remains 2° 8’. 45” W. for the longitude of Aberdeen. M. pe 1a RocHETTE, in a chart of the north fea, conftruét- ed with great fkill and accuracy, lays down Aberdeen in lati- tude 57°. 5, and in longitude 2°. 21’. 31” weft from Green- wich ; fo that there is an error of nearly 4’ in the latitude, and 13/ in the longitude. It is likely that the latter affects the pofi- tion of the coaft for a confiderable extent.. Phy/. Cl. A Report concerning the Weather in 1796 was communicated by Mr Prayrarr, [See this volume, the laft Article of Part II. APPEN.. A.P.. PEND. Dod. OrFicE-BEARERS of, the SocIETy. Office-bearersof OrFice-BEARERS elected for the enfuing Year,at the General the society. Meeting held for that Purpofe, 25th November 1793. Prefident. His Grace the Duke of BuccLEUGH. Vice-Prefidents. Lord Dunjinnan. | Right Hon. Henry Dundas. Secretary. Treafurer. Profeflor Jobe Robifon. | Mr Alexander Keith, Phyf. Cl. Counfellors. Eit.. Cl: Mr Benjamin Bell. Lord Craig. Mr Greenfield: General Fletcher Campbell. Mr George Ferguffon. Mr Mackenzie. Dr Gregory. _ Lord. Dreghorn. Dr Rutherford: Commiffioner Edgar. Profeffor Stewart. _ Mr David Hume. OFEICE- 32 HISTORY of the SOCIETY. Office-bearersof — OrFIicE-BEARERS of the SocIETY. the Society. PuysicaL CLAss. Prefidents. Dr Black. | Dr Home. Dr Hutton. | Dr Monro. Secretaries. Profeffor Playfair. | Dr Walker. LITERARY CLASS. Prefidents. Mr Baron Gordon. | Dr Hugh Blair. Sir William Miller. | Dr Adam Ferguffon. Secretaries. Mr Frafer Tytler. | Profeffor Dalzel. Ar the General Meetings in 1794, 1795,.and 1796, the fame office-bearers were elected. LIST LIST of Memspers or FELtows of the Roya Society of EpinsurGH, continued from the third Volume. [Hiftory of the Society, Appendix. | THE following Members were elected at the General Meeting, Jan. 27. 1794. NON-RESIDENT, The Reverend Fobn Breasbor of Brookhill, county of Cavan, “Treland. L. The Reverend Dacre Carlyle, A.M. L. Fames Glenie, Efq; F. R. S. Lond. P. TuHE following were eleéted at the General Meeting, Jan. 26. 1795+ RESIDENT, The Reverend George Baird, D. D. Principal of the Univerfity of Edinburgh. Robert Hamilton, Efq; Advocate. The Reverend Thomas Hardy, D.D. Profeffor of Church Hiftory in the Univerfity of Edinburgh. Francis Humberfion Mackenzie, E{q; of Seaforth. Alexander Phillip Wilfon, M. D. Phyfician in Edinburgh. Vou. IV. : f NON= Members che- fen, Jan. 27, 1794- Members cho- fen, Jan. 26. 1295+ Members cho- fen, June 27. 1796. 4 . HISTOR of the SOCTETY. NON-RESIDENT. Yohn Cooper, M. D. Phyfician at Fochabers. William Garfbore, E{q; of London. Joba Gillies, LL. D. F. R. S. London, and Hiftoriographer to his Majefty for Scotland. FOREIGN. Fobn Godfrey Smeiffer, A. M. & F, R. §. London. Ga/per Voght, Efq; of Hamburgh. Tue following were elected at the General Meeting, June 27. 1796. RESIDENT. Lieutenant-Colonel Alexander Dirom, F. R. 8. London. P. The Right Honourable Lord Fincafle. P. The Reverend Sir Henry Moncrief-Wellwood, Bart. D. D. Le Patrick Murray, Efq; of Ochtertyre, Advocate. P. NON-RESIDENT. Andrew Berry, M.D. Madras. P. Sir Heary Englefield, Bart. F. R. S. London. P. Dr Freer, Profeflor of Medicine.in the Univerfity of Glafgow. P.. Dr Fames Gafcoigne, Phyfician at Plymouth. P. Richard Kirwan, E{g; F. R. S. London. P. FOREIGN. Mark Auguftus Piet, Profeffor of Philofophy in the Academy of Geneva. FP. - M. P. Prevoft, Honorary Profeffor in the Academy of Geneva. P. THE APPENDIX. 35 THE following were elected at the General Meeting, June 26, Members che. fen, June 26, T797~- Ria? RESIDENT. Robert Beatfon, Eq; of Kilrie. P. Dr Andrew Duncan junior. P. NON-RESIDENT. The Reverend Walter Fi/ber, Minifter at Cranftoun. - P. The Rev. George Gleig, LL. D. Epifcopal Minifter at Stirling. Z. Charles Hatchett, Efq; F. R. S. London. — P. Major Zames Rennel, F. R. S. Lond. P. FOREIGN. Foln Feffcot, M. D. F. R. Coll. of Phyficians at Stockholm, and Profeffor of the Practice of Medicine at Upfal. P. f2 LIST Members decea- fed. LIST of Memsers who have died fince the Publication of the laft Volume. Colonel Edmonftone of Newton. June 24. 1793. Honourable Yames Veitch of Elliock, (Lord Elliock), one of the Senators of the College of Juftice. July 1. 1793. Honourable Francis Garden, (Lord Garden/ftone), one of the Se-- nators of the College of Juftice. July 22. 1793.. Abraham Guyot of Neuchatel. May 22. 1794. ‘fobn Roebuck, M.D. July 16. 1794. Reverend Dr Be//, Minifter at Coldftream. Auguft 9. 1794. Right Honourable Lord Daer, Nov. 5. 1794. Charles Scott, M. D. Phyfician in London. Sir William Fones, one of the Judges of the Supreme Court at Bengal, and Prefident of the Afiatic Society. Alexander Gerard, D. D. Profeflor of Divinity, King’s College, Aberdeen. Jan. 22. 1795. Sir Francis Kinloch of Gilmerton. April 16. 1795: Rev. ohn Main, D. D. Minifter at Newton. May 13. 1795: William Smellie, Printer in Edinburgh. June 24. 1795. Adair Crawford, M.D. Phyfician to St Thomas’s Hofpital, Lon- don, and Profeffor of Chemiftry in the Academy at Wool- wich. Auguft 5. 1795. Honourable Alexander Abercromby, (Lord Abercromby), one of the Senators of the College of Juftice. Nov. 17. 1795. Fames Robertfon, D. D. Profeffor of Oriental Languages in the Univerfity of Edinburgh, Nov. 25. 1795. Fohn , APPENDIX, 37 Fobn Anderfon, LL. D. Profeffor of Natural Philofophy in the Univerfity of Glafgow. Jan. 13. 1796. George Campbell, D. D. Principal of the Marifhall College, Aber- deen. April 6. 1796. Thomas Reid, D. D. Emeritus Profeffor of Moral Philofophy in the Univerfity of Glafgow. Nov. 7.1796. Honourable fohn Maclaurin, (Lord Dreghorn), one of the Sena- tors of the College of Juftice. Dec. 24. 1796. Thomas Gordon, Profeflor of Philofophy, King’s College, Aber- deen. March 11. 1797. James Hutton, M.D. March 206. 1797. Archibald Arthur, A. M. Profefflor of Moral Philofophy in the Univerfity of Glafgow. June 1797. DONA- peter crc er EL YE SSE RIE TE Lit of Dona. DONATIONS prefented to the RovAL SOCIETY OF EDINBURGH, ove continued from the preceding Volume. From the Author. Charts of the China Navigation, fol. by George Ribertfon, Efq; F. R. S. Edin. and now Commander of the Berrington, Eaft Indiaman. From the Author, Hiftorical and Biographical Sketches of the Progrefs of Botany in England, 2 vol. 8vo, 1790, by Richard Pulteney, M. D. and F. R. S. . General View of the Writings of Linnzus,8vo, 1781, by the fame. From the Reverend Andrew Brown. A Model of an Indian Canoe, with the Belt and Pouch of an In- dian Hunter. 1794. From the Author. Syftem of Mineralogy, 2 vol. 8vo, 1795, by 7. G. Smeiffer, F. R. S. Lond. & Edin. From the Author. Report of a Survey of the Thames, 8vo. 1794, by Mr Yobn Rennie, Engineer, F. R. S. Edin. From the Literary and Philofophical Society at Manchefter. Manchefter Memoirs, vol. iv. Part 2. 1794. From APPEND I X. pe From the American Academy of Arts and Sciences. Memoirs of the Academy, vol. i. part 1. Bofton, 1793. From the Author. Ueber die Bleyglafur unferer Topferwaare, vom Hofrath, G. A. Ebell, Wannover, 1794. From the Editor, Francis Ma/feres, Ef{q; Curfitor Baron of Ex- chequer. Scriptores Logarithmici, or a Collection of Curious Traéts on the Nature and Conftruction of Logarithms, 3 vol. 4to. 1791, 1796. From Fohn Thomas Stanley, Efq; Three Views of Geyfer, a hot Spring in Iceland, from Drawings taken on the Spot. From the Royal Society of London. _ Tranfactions of the Royal Society of London from 1790 te 1794. From the Author. Remarks on the Antiquities of Rome and its Environs, 4to, 1797, by Andrew Lumifden, Efq; F. R. S. Edin. From M, Chevalier, F. R. S. Edin. On the pretended Tomb of Homer, 4to. 1797. iy Le Te bi gi ing ori nasi a eal NO ABRT avoir to- Ac iiss Pie e ie ; ; y an lee pe, Ty y 7 ‘ ef RA a rly » Ove 2f PIA SRO. rere : af eer ys rt : eA . ; , 4 Fs co ore ’ . =, - a ~ a “ — : Ath piri 2 mh ids x iy LO Wa * a - ‘ ‘ s rity 5 ‘ oa J tf Go it To Se 1 - . 5 7 z A pl i 4 me mad! ‘ + é Bid F s al? i < P a 12 ' 2 ~ ad o pnt i 03K eikonivett isk has accisr , : | ain - , pando ty PE ROR UGH Th ouigpitag . AAG eek a aie pe haa i ee Pig . * 7 a 2 ee are : a PANS i ‘ q ra i &* 3, ¢ Se xt ae es bi ps edt) fs - So geecaae te a ‘ i a Sb ye ‘ Lae 13 aah ae Jae vet an dat ot r4 J 4 : i ; > ’ he ~ ‘ Ps \ a 2 6. APPENDIX. (1) I. Account of the Lire of Lord ABERCROMBY, By HENRY MACKENZIE, Efg; F.R.S. Evin. [Read by the Author, Feb. 15. 1796.] HE life of which I am about to give fome account to this Society cannot be called a literary one; of literary lives only it is perhaps the proper bufinefs of the Royal Society to record the particulars; but it has been in the practice of al- lowing a wider range to this cuftomary notice of its deceafed Members. Of the lives of fuch as were eminent in {tation or in ufefulnefs, in abilities or in virtue, it has been accuftomed to hear a narrative, which, though not important to learning, is interefting to humanity. Under this title, it will indulge me with a fhort account of the life of Lorp ABERCROMBY. HE was the youngeft fon of Grorcr ABERCROMBY of Tullibody, a gentleman of a refpectable family and confider- able fortune in Stirlingfhire, and of ANNE Dunpas, daughter of Mr Dunpas of Manor. He was born on the 15th day of Odtober 1745. His father ftill lives at the very advanced age of g1, and has had the fingular good fortune to fee two of his elder fons, who were both bred foldiers, appointed Commanders in Chief of the Britifh forces, one in the Weft and the other in the Eaft Indies, the moft important ftations with which their country could entruft them. His age indeed has, within Vou. IV. (a) thefe Account of Lord Abercromby. (2) HISTORY of the SOCIETY. thefe few months, been clouded by the death of him who is the fubjeét of this paper; but it is fomething for a father, it is fomething for his friends, to mix their forrows with the ge- neral regret of his country. His youngeft fon ALEXANDER was early deftined for the profeflion of the law, to which his father had himfelf been bred, at a time when the Faculty of Advocates comprehended one half of the gentlemen of Scotland. At that period, com- merce and manufactures had not attained, in this part of the kingdom, that extenfion and improvement which renders them objeé&ts of purfuit to men of birth or fortune. The fword and the gown were here the only profeffions fuited for fuch men ; for our church did not, like thofe of England and France, offer endowments confiderable enough to attract the interefted or to excite the ambitious. In Scotland, however, the profef- fion of the law was adopted by the eldeft fons of the gentry, rather as conferring a fort of fafhionable diftinGtion, than as one from which they looked for bufinefs or emolument. It led to a learned, or at leaft a polite education, and gave a fort of dignity beyond the mere idlenefs of a man of pleafure. Hence perhaps there was in thofe times an elegance of manners, join- ed with a degree of knowledge and information, among the Faculty of Advocates in Scotland, not to be met with among any fimilar body of men in-any other country. I mention this hiftorically, becaufe it does not perhaps exactly fubfift at pre- fent, from caufes which may be held not to improve the man- ners fo much as, in a political and commercial view, they may be fuppofed to meliorate the fituation of a country. Mr ABERCROMBY, with a view to the law, which his pro- fpects made it neceflary for him to follow as a profeflion, re- ceived the cuftomary education at the Univerfity of Edinburgh. There the writer of this memoir firft knew him. He had abi- lities which qualified him for being more a fcholar, than the 3 vivacity APPENDIX. (3) vivacity of his difpofition then allowed him to become. With uncommon beauty of countenance and pleafantnefs of manner, the favourite of every relation and acquaintance, he did not then (as is common with young men fo circumftanced) apply to his ftudies with the conftant and unremitting afliduity which is calculated to attain deep learning. But he had a readinefs and acutenefs that could eafily perform his exercifes when he wifhed to perform them. After going through the ordinary courfe of claffes at the Univerfity, confifting of the Latin and Greek languages, of Logic, Philofophy, the Civil and Scots . Law, he was admitted Advocate in the year 1766. For fome time after his coming to the bar, he retained fomewhat of that gaiety of deportment and of conduda, which are not exactly fuited to the dry and uninviting paths that con- duct men to legal eminence. His manners and difpofition were better fitted for the lefs ferious and more engaging fociety of men of fafhion and pleafure. During feveral years he lived a good deal in fuch fociety, and gave but little promife of that attention and application to bufinefs for which he was after- - wards diftinguifhed. Though not unremittingly attentive, how- ever, to his profeflion, he was never neglectful of its duties; and when any particular cafe was put into his hands, he gave very convincing proofs, both of his general talents, and of his power of application to bufinefs in detail. Bur it was not long before he felt the propriety of fecluding himfelf more than he had hitherto done from the {cenes of conviviality and amufement, which had interfered with a more ferious and determined application to his profeflion. He had lent to lighter fociety a certain gaiety and fportfulnefs of mind, which, in a character of lefs native vigour and ability, might have been fatal to the future profpects of his life. But he pof- feffed an intrinfic charater, which it was not: difficult for him to refume; and from that pride and dignity of foul which he (a 2) always | Account of Lord Abercromby. Account of Lord Abercromby. (4) HISTORY of the SOCIETY. always maintained in an uncommon degree, he felt it unworthy of him not to make every effort for rifing into eminence in the profeflion which he had chofen, from which, being a younger fon, and not likely to be poffefled of a large patrimony, he was to derive fupport and independence. AN opportunity foon occurred of drawing the attention ‘of the Court in which he praétifed, and indeed of the country at large, to the talents which he pofleffed, and to that exertion of them which he could command. He was counfel in a caufe, which, from its peculiar circumftances, had attracted much pu- blic curiofity, and divided for fome time the public opinion. This was the cafe of Wil//fon and Maclean, in which a particular _ fa& (the period of the death of a fhipmafter, from whom a receipt was produced in bar of the plaintiff’s claim, but which receipt was alleged to be a forgery) was involved in fo much uncertainty, and that uncertainty ftrengthened by the oppofite depofitions of fuch a number of witnefles, that it became a que- ftion of uncommon notoriety and expectation, not only from the extraordinary circumftances of that individual caufe, but as involving a general legal confequence of the incertitude of oral teftimony in fixing the date of not very diftant events. In this caufe Mr ABERCROMBY was employed for the purfuer or plaintiff, and made a fpeech, in oppofition to one of equal ability from Mr Biair, now Solicitor-General, fo confpicuous for the clofenefs of its dedu@tion, the force and clearnefs of its argument, the eloquence and impreflive fenfibility of its declamation, as to ex- cite a very ftrong fenfation at the bar and in the public, and to mark him as an Advocate from whom the moft f{trenuous and fuccefsful exertions were to be expe¢ted. It is feldom that at the bar of Svetland, any ‘appearance, however brilliant, has much effect in bringing a counfel into profeffional celebrity or employment. From the conftitution of the Supreme civil Court in this country, where trial by jury does not take place, and t ¥ APPENDIX. (s) and from the nature of its proceedings, which are chiefly car- ried on by written arguments, a {peech, however remarkable, is rarely followed by thofe important confequences to a barri- fter’s future bufinefs, of which there are daily inftances in We/fmin- fter Hall, But in this cafe Mr ABERcRoMBY’s appearance made fuch an impreflion in his favour as very foon to place him among the moft rifing young men of the profeflion. He took advantage of this circumftance by a f{tep, of which the expe- diency was doubted by many of his friends at the time, but was afterwards allowed by them all. Soon after his being call- ed to the bar, he had been appointed Sheriff-depute of Stirling- Jbire, which he now (in 1780) refigned for the lefs lucrative and more precarious fituation of Depute-Advocate, on the idea of the-latter office being more beneficial in its confequences, as not precluding him from bufinefs arifing within the county of Stirling, where he had many conneCtions both from relation- fhip and acquaintance, but rather tending to advance his em- ployment, from the opportunities it afforded him of appearing in. public and ‘criminal cafes. This appoimtment of Depute- Advocate he held under Mr Henry Dunopas, then Lord Advo- cate for Scotland, in conjunction with Mr Brarr, fince his Ma- jefty’s Solicitor, and Mr Crarc, now a Judge in the Courts of Seflion and Jufticiary. Thole two gentlemen and Mr ABER- CROMBY were as much connected in private friendfhip as in pu- blic bufinefs ; a friendfhip to which one who has known ‘them Jong and intimately, may be pardoned for afcribing a confi- derable advantage towards the attainment of that profeffional ‘eminence, as well as of that general eftimation and refpedtability which they have all enjoyed. Mr ABERCROMBY ‘now rofe with great rapidity in his profef- fion, and was among the beft employed barrifters of his ftanding in Scotland. To this fuccefs he was not more entitled by his ta- tents than by his affiduity ; and it was a peculiar merit in him, who Account of Lor} Abercromby. Account of Lord Abercromby. (6) HISTORY of the SOCIETY. who had once indulged fo much in gaiety and amufement, and who was fo much fitted by nature to fhine among the gay and the amufing, to devote himfelf now to bufinefs with a rigid at- tention and pun¢tuality not always met with even among men of the moft grave and ferious difpofitions. His fpeeches and his papers were held in equal eftimation. His general method in both was, to ftate the fac? which gave origin to the caufe fimply and perfpicuoufly, and then to apply thofe principles and arguments in /aw which bore upon the cafe, from which he drew the conclufion in favour of his client. When the cafe admitted of it, he was fond of illuftrating his argument by fome appofite claflical allufion, or fome anecdote of ancient or modern times, with which his memory was abundantly ftored, His expreflion was always elegant, and when the fubject called for it, rofe to a degree of animation and eloquence much be- yond what bufinefs-men might think neceflary in a mere legal pleading. He excelled particularly in that indignant tone in which a good man rebukes injuftice or oppreflion, and that pa- thetic in which he pleads the caufe of the unfortunate ; a ftyle which his own mind, nice as it was in honour, and open to compaflion, naturally prompted. Tue laborious employments of his profeffion did not fo en- tirely engrofs him as to preclude his indulging in the elegant amufements of polite literature. He was one of that fociety of gentlemen, who, in 1779, fet on foot the periodical paper, publifhed at Edinburgh, during that and the fucceeding year, under the title of the Mrrror, and who afterwards gave to the world another work of a fimilar kind, the LouncER, publith- ed at Edinburgh in 1785 and 1786. To thefe publications he was a very valuable contributor, being the author of ten pa- pers in the Mirror and nine in the Lounger. His papers are diftinguifhed by an eafe and gentlemanlike turn of expreflion, by a delicate and polifhed irony, by a ftrain of manly, ho- nourable APPENDIX, (7) nourable and virtuous fentiment. In fome of them we find that unaffected tendernefs, of which I took notice above as fre- quently diftinguifhing his profeflional labours. One of thofe papers I have often read fince his death, with feelings which I believe to be fo much in -unifon with thofe of my prefent au- dience, that I hope I fhall not be thought to trefpafs on their time or patience, if I quote the conclufion now. In N° go. of the Mirror, he mentions as one of the calamities of extremely lengthened life, the lofs of friends, and gives a very natural and affecting account of his own feelings on an occafion of that fort. The picture contained in that paper is no fancy-drawing ; it is a portrait of one of the earlieft and moft excellent friends of Mr ABERCROMBY, and of the writer of this memoir, Mr Gorpon of Newhall, whofe accomplifhments and whofe virtues will not be foon forgotten by fome members of this Society. Alas ! I did not imagine, when I heard Mr ABERcRomBy read that paper of the Mirror, that, in a few years, it fhould be applicable to the lofs of its Author! If any of thofe who now ‘participate in this reflection, fhould one day have occafion to recal in this place the remembrance of him who reads the pre— fent account, may his memory be as dear to his friends, and as valuable to fociety, as thofe to whom his feeble words now en- deavour to do juftice ! _ “ ‘THERE is one circumftance (fays Mr ABERcRomBy, in the paper I allude to) which with me is alone fufficient to decide the queftion (whether long life be an object much to be defired). If there be any thing that can compenfate the un- avoidable evils with which this life is attended, and the num- berlefs calamities to which mankind are fubject, it is the plea- fure arifing from the fociety of thofe we love and efteem. Friendfhip is the cordial of life. Without it, who would with to exift an hour? But every one who arrives at extreme old age, muft Account of Low Abercromby. Account of Lord Abercromby. (8) HISTORY of the SOCIETY. muft make his account with furviving the greater part, per= _haps the whole, of his friends. He muft fee them fall from ‘him by degrees, while he is left alone, fingle and unfupported, like a leaflefs trunk, expofed to every ftorm, and fhrinking © from every blaft. “ I nave been led to thefe reflections by a lofs I lately fu- Ytained in the fudden and unlooked-for death of a friend, to whom, from my earlieft youth, I had been attached by every tie of the moft tender affection. Such was the confidence that fubfifted between us, that, in his bofom, I was wont to repofe every thought of my mind, and every weaknefs of my heart. In framing him, nature feemed to have thrown together a va- riety of oppofite qualities, which, happily tempering each other, formed one of the moft engaging characters I have ever known. An elevation of mind, a manly firmnefs, ‘a Cafilian fenfe of honour, accompanied with a bewitching fweetnefs, proceeding from the moft delicate attention to the fituation and the feel- ings of others. In his manners fimple and unafluming ; in the company of ftrangers modeft to a degree of bafhfulnefs ; yet poflefling a fund of knowledge, and an extent of ability, which might have adorned the moft exalted ftation. But it was in the focial circle of his friends that he appeared to the higheft advantage ; there the native benignity of his foul diffu- fed, as it were, a kindly influence on all around him, while his converfation never failed at once to amufe and to in- ftruc. “ Nor many months ago I paid him a vifit at his feat in a remote part of the kingdom. I found him engaged in embel- lifhing a place, of which I had often heard him talk with rap- ture, and the beauties of which I found his partiality had not exaggerated. He fhewed me all the improvements he had made, and pointed out thofe he meant to make. He told me x : all APPENDIX. (0) al) his fchemes, and all his projects. And while T live, I mutt ever retain 4 watt remembrance of the pleafure I then enjoyed in his fociety. “ Tye day I meant to fet out on my return, he was feized with. a flight indifpofition, which he feemed to think fomewhat ferious ; and, indeed, if he had a weaknefs, it confifted in ra- ther too great anxiety with regard to his health. I remained with him till he thought himfelf almoft perfectly recovered 5 and, in order to avoid the unpleafant ceremony of taking leave, I refolved to fteal away early in the morning, before any of the family fhould be aftir. About daybreak I got up, and Jet myfelf out. At the door I found an old and favourite dog of my friend’s, who immediately came and fawned upon me. He walked with me through the park. At the gate*he ftopped, and looked up wifhfully in my face; and, though I do not well know how to account for it, I felt, at that moment when ‘T parted with the faithful animal, a degree of tendernefs, joined with a melancholy fo pleafing, that I had no inclination to check it. In that frame of mind I walked on (for I had or- dered my horfes to wait me at the firft ftage) till I reached the faummit of a hill, which I knew commanded the laft view I fhould have of the habitation of my friend. I turned to look back on the delighful feene. As I looked, the idea of the owner came full into my mind ; and, while I contemplated his many -virtues and numberlefs amiable qualities, a fuggeftion arofe, if he fhould be cut off, what an irreparable lofs it would be to his farnily, to his friends, and to fociety. In vain I endeavoured to combat this melancholy foreboding, by refleéting on the un- common vigour of his conftitution, and the fair profpect it af- forded of his enjoying many days. The impreffion ftill recur- red, and it was fome confiderable time before I had ftrength of mind fufficient to conquer it. - Dee . Vou, IV. (b) ot Account of Lord Abercromby. Account of Lord Abercromby. (10) HISTORY of the SOCIETY. “ T wAp not been long at home when I received accounts of his being attacked by a violent diftemper, and in a few days after I learned that it had put an end to his life. “ Tus blow, for a time, unmanned me quite. Even now, the chief confolation I find is in the fociety of a few chofen. friends. Should they alfo be torn from me, the world would to me be as a defert ; and, though I fhould ftill endeavour to difcharge my duty in that ftation which Providence has afligned me in life, I fhould never ceafe to look forward, not without impatience, to thofe peaceful manfions where the weary are at reft, and where only we can hope to meet again with thofe from whom we have been parted by the inexorable hand of death.” ; In 1792, when in this high and advancing fituation at the bar, an offer was made to him of the appointment of Judge of the Court of Sefion, in the room of Lord RockviLLe, de- ceafed. ‘This appointment he hefitated for a confiderable time | to accept, from an idea he had formed of the difficulty of exe- cuting the office in that manner in which he conceived it ought to be executed, and of the laborious and fatiguing application and exertions of mind which its various duties required. He was at length prevailed on to accept of it, principally from the very handfome manner in which it was offered to his accept- ance, and in compliance with the wifhes of his friend Mr Se- cretary Dunpas, who knew, from early and continued ac- quaintance, the value of that acquifition which he wifhed the Bench to make, in the appointment of Mr ABERCROMBY to a Judge’s feat. That appointment accordingly took place on the oth of May 1792; and on the 14th of December following, he was called to a feat in the Court of Fu/ficiary, on the vacan- cy occafioned by the death of Lord HaiLes, 3 THE APPENDIX. (11) ‘THE manner in which he executed thofe very important offi- ces, is frefh in the memory of everyone. To the moft affidu- ous and unremitting attention to his duty, and the moft accu- rate confideration of the legal principles which were to deter- mine his decifion, he joined a talent for announcing that deci- fion, and the grounds on which it refted, in fuch a manner as to give fingular weight and dignity to his opinion, and to make the ftrongeft impreflion on his audience. He did not {peak often, but when he did, he never failed to throw light on the cafe before the Court. He never forgot, (what is liable to be forgotten in a Court which, from the number of its Judges, partakes fomewhat of the nature of a popular affembly), that — he was delivering the opinion of a Judge, not arguing the caufe of a barrifter. He never replied to any of his brethren, re- membering that a Judge does not {peak for victory ; that it is his bufinefs to pronounce his own opinion, not to combat the opinions of others. He fpoke fhortly, feldom on the circum-. ftances of the cafe in detail, but on fome leading and promi- nent point on which the opinion he was to deliver was found- ed. His expreflion was clear and perfpicuous, correct, at the fame time, and elegant. His fpeaking was flow and delibe- rate, and in that cool and folemn manner which becomes a ju- dicial opinion ; yet, like his appearances at the bar, it did not fail in animation when it was directed to the cenfure of unfair- nefs, to the detection of difhonefty, or to the rebuke of oppref- fion. He was of particular ufe in the civil Court, by an at- tention to the proceedings, and to the checking of any impro- priety in the conduét of the bufinefs. On this ground, his own ftrié& obfervance of propriety gave him great advantage. When he did cenfure, even when there was occafion for feverity, it was with fo much gravity and dignity of manner, and fo much temperance of expreflion, as to enfure the approbation (b2) - of Account of Lord Abercromby- Accountof Lord Adbercromp: y. (12) HISTORY of the SOCIETY. of the impartial, as to imprefs conviction, as well as to impofe filence, on the cenfured. Lord ABercromsy poileffed thofe virtues and accomplifhments which inveft the ftation of a Judge with an authority the moft venerable and the moft perfuafive. Purity of mind and of character, a nice fenfe of honour and decorum, a delicacy of private and a dignity of public deport- ment ; thefe are at all times moft important qualities in a Judge ; at no time perhaps fo much as at the prefent, when they are fo eflential to conciliate the efteem and to command the reverence of the people for the magiftracy and conftitution of their country. To the criminal Court thofe qualities are peculiarly appropri- ate. In that Court, the Judge is the organ of the offended ma~ jefty of the law; his deportment ought to be fuited to that fundtion, grave, deliberate, decided. Above the atmofphere of the paflions, he may fpeak with feverity, but never with re- fentment ; and his duty is too folemn and too majeftic, to ad- mit of the light or the frivolous, either in manner or expreffion. Yet, amidft the unbending declaration of the law, and the fteady decifion of its. minifter, he may, and in fome cafes ought to feel that dignified compaflion for human frailty, that tempers the rigour, but does not detraét from the awfulnefs of juttice. Such was the deportment of Lord ABERCROMBY. The firmnefs of his mind, and the dignity of his demeanour, were particularly called forth at that momentous juncture, when the decifions of the criminal Court of Scotland vindicated the laws, and upheld the conftitution, againft the daring attacks of turbulence and fedition. Tue laft piece of duty which Lord ABERcROMBY performed. as a Judge of the Court of Jufticiary, (immediately after the admiflion of his friend ‘Lord Craig as a colleague), was the northern circuit in the {pring of the year 1795. On that jour- ney (APPENDIX, (13) ney he felt himfelf a good deal indifpofed, but returned to Edinburgh, reftored, as he faid, to his ufual health, though his altered looks and appearance {trongly excited the apprehen- fions of his friends. ‘Thofe apprehenfions were but too foon verified, He was attacked in fummer 1795 with a breaft-com- plaint, attended with dangerous fymptoms, for which, after fome palliative means, to which his diforder never at all yield- ed, he was adviféd to try the milder climate of Exmouth m De- yonfhire, a voyage to the Continent being, in the prefent fitua- tion of public affairs, difficult to accomplith, and particularly difagreeable to his inclinations: He was accompanied in this journey by his nephew, the eldeft fon of his brother Sir Ratew ABERCROMBY, who watched the laft days of his uncle with that tender afliduity which, though the world can neither fee its merit nor feel its fufferings, is one of the moft important and moft difinterefted of all the domeftic duties, On the road to - Exmouth, he was feized with ftill more violent fymptoms than any his diforder had hitherto exhibited; and though he expe- rienced, during the {pace of about two months, fome tempo- rary relief, he never gained any material: advantage, and the difeafe made progreflive advances, till at laft it carried him off on the 17th day of November 1795. He bore its fufferings with the greateft patience and fortitude ; and though for fome time he entertained hopes which his phyficians and friends faw to be but too ill founded, he met its conclufion with perfect compofure and refignation. _ Tue diforder which terminated fo fatally was perhaps only the effect of a gradually debilitated conftitution, not of any determinate and immediate caufe, Yet fome of his friends, with an anxiety natural in fuch a circumftance, have traced it to yarious fources, An accidental fall into the uninclofed foun- dation of a houfe in the New Town of Edinburgh, was by ; fome, Account of Lord Abercromby. (14) HISTORY of the SOCIETY, AccountofLord fome, I believe not on any medical authority, fuppofed to have oe produced the complaint to his breaft. The anxiety and appli- cation he beftowed on the duties of a very laborious profeflion, might contribute, to exhauft the ftrength of his conftitution ; and, if mental affections are to be allowed fuch force, the un- eafinefs which for fome years he experienced on the fubje& of public affairs and the political ftate of his country, might im- pair and weaken his health and fpirits. Deeply impreffed him- {elf with the excellence of the Britifh conftitution, and of the happinefs derived from it, he faw with horror and indignation (at a period confiderably earlier than that which excited the ap- prehenfions of moft other people) the efforts of defperate and defigning men to overturn it ; he lamented the delufion of thofe who were mifled to join them ; and he trembled for the effects of that delufion in eftimable and benevolent but vifionary minds, who might indulge the: pride of political theory and fpeculation, to the danger, as he conceived, of all good order and regular government, of all focial happinefs and focial virtue. Or the public virtues of Lord ABERcRomBY, I have given a pretty full detail, becaufe thofe fpeak loudeft in example, and are moft generally ufeful to mankind. Of his private virtues and accomplifhments I might {peak in this Society on the tefti- mony of many of its Members, who will long remember the excellence of his difpofition, the worth and honour of his heart, the amiable and engaging manners which he exhibited. From birth, from education, from native fentiment, and im- proved fociety, he cultivated, and was never a moment unim- prefled with the feelings of a gentleman, with that delicacy of mind, “ above the fixed and fettled rules,” which polifhes the manners, which refines morality, which dignifies virtue; of which fuch an example is the more valuable in thefe days, when ‘APPENDIX. (15) I am afraid a ftyle of life and manners has become in fome de- gree fafhionable, which deftroys this honourable diftinétion ; which degrades the higher ranks by vices and follies that ufed to be a reproach to the leaft worthy among the lower ; in which name and ftation fanctify groffnefs in pleafure and coarf{nefs,in demeanour, and wealth fhoots out into caprice and abfurdity, inftead of expanding into generofity and ufefulnefs. THE Society will pardon this digreflion, which I confefs to be unneceflary, and to fome may appear ungracious ; they will forgive it to him who, looking from the tomb of his friend on the world he has left, with that gentler mifanthropy (if it fhall be thought to merit that term) which is made up rather of re- grets than of refentments, naturally enough indulges in an ag- gravation of what he has loft, and, it may be, in an unfavour- able eftimate of what remains for him to enjoy. IN DEPENDENTLY, however, of the eftimation of friendfhip, it may certainly be affirmed, that in the death of Lord ABER- cromBy fociety has fuftained a lofs of no light nor common kind ; a lofs which his friends and acquaintance will long and deeply lament ; and which, without difparagement to the vir- tues or the abilities of his furvivers, will not be eafily repaired to the public. Il. Account of Lord Abercromby. ; bate ¥ Ut cat ui ‘ A, See ; Pay) BE Rese Rotindem Ape Sei tied ae Sica Wh 9 Viv-tug i peteD ip! II. A /oort Account of the Lire and Wruitincs of WILLIAM TrTLER, Efq; of Woodboufelee, F.R.S. Evin, By HENRY MACKENZIE, Efq; ¥.R.S. Evin. [Read by the Author, Fune 20. 1796.]} HE cuftom which this Society has eftablifhed, of giving fome account of the lives of its deceafed members, is in every cafe gratifying to friendfhip, in many interefting to cu- riofity, but in thofe which ferve to record the purfuits and oc- cupations of men of letters, it is more ftri€tly and properly an object coming within the views of a literary inftitution. The hiftory of the authors is always in a great degree the hiftory of the literature of a country ; and even exclufive of an immedi- ate relation to their works, the narrative of their private and domeftic habits is often, in a moral point of view, ufeful and interefting to the fcholar and the author. In both thefe re- {pects, I may claim the attention of the Society to the following fhort account of the life and writings of our late worthy col- league, Mr WiLt1aM TyTLER. Mr TyTLer was the fon of Mr ALEXANDER TYTLER, wri- ter in Edinburgh, by Janz, daughter of Mr WiLu1AM LEstiz, merchant in Aberdeen, and grand-daughter of Sir Parrick Lesuik of Iden, Provoft of Aberdeen. He was born at Edin- burgh, October 12. 1711. He received his education at the High School and Univerfity of his native city, and diftin- Vou. IV. (C) bs guifhed Account of W. Tytler, Efq; * (18) HISTORY of the SOGIETY. guifhed himfelf by an early proficiency in thofe claffical ftu- dies, which, to the lateft period of his. life, were the occupation of his leifure hours, and a principal fource of his mental en- joyments. In the year 1731, he attended the academical lectures of Mr: ALEXANDER Bayne, Profeflor of Municipal Law in the Uni- verfity of Edinburgh, a gentleman diftinguifhed alike for his profeffional knowledge, his literary accomplifhments, and the elegance of his tafte. The Profeffor found in his pupil a con- genial fpirit, and their connection, notwith{tanding the difpa- rity of their years, was foon ripened into all the intimacy of the ftricteft friendfhip. So ftrong indeed became at length that tie of afféGtion, that the worthy Profeflor, in his latter years, not only made him the companion of his {tudies, but when at length the victim of a lingering difeafe, chofe him as the com- forter of thofe many painful and melancholy hours which pre~ ceded his death. Ar the age of-thirty-one, Mr TyTLER was admitted into the Society of Writers to his Maje/ty’s Signet, and continued the prac- tice of that profeffion with very good fuccefs, and with equal ref{pect from his clients and the public, till his death, which happened on the 12th of September 1792. He married, ir September 1745, ANNE Craic, daughter of Mr James Crate of Dalnair, writer to the Signet, by whom he has left two fons, ALEXANDER Fraser TyTLER, his Majefty’s Judge-Advocate for Scotland, and Profeffor of Civil Hiftery in the Univerfity of Edinburgh, and Major Parrick TyTier, Fort-Major of the €aftle of Stirling ; and one daughter, Mifs Curistina TYTLER. His wife died about nine years before him, and previoufly to that period, he had ‘loft a-fon' and a daughter, both grown to maturity. Ir is perhaps only in fmaller communities, like that of Edin- burgh, that the union of bufinefs and literary ftudies can eafily- take place. In larger focieties, fuch as that of London, here the A) PP BE NOD UAX (19) the profeflional objects are greater and more extenfive, and the different clafles of men are more decidedly feparated from one another, there is a fort of divifion of mind as well as of labour, that makes the lawyer or the merchant a perfect lawyer or mer- chant, whofe mind and time are wholly engrofled by the ob- jects of his profeflion; and whom it might confiderably difcre- dit among his brethren of that profeffion, were he to devote any portion of either to claflical ftudy or literary compofition. In Edinburgh it is otherwife ; the profeffional duties are not in general fo extenfive as to engrofs the whole man, and his con- nections in fociety extending through many different clafles of his fellow-citizens, he has opportunities of converfing, of read- ing, and of thinking on other objects than merely thofe imme- diately relating to the bufinefs which he follows. This is per- haps the moft agreeable ftate of fociety of any, which, if it may fometimes prevent the higheft degree of profeffional emi- nence and {fkill, (though even.on that ground many arguments might be offered in its favour), certainly tends to enlarge the mind, and to polifh the manners ; to give a charm and a digni- ty to ordinary life, that may be thought ill exchanged for the inordinate accumulation of wealth, or the felfifh enjoyment of profeflional importance. Amonc that Society of which Mr TyTieER, at the period I have mentioned, was admitted a member, the Writers to the Sig- net, there were always many individuals pofleffed of much ge- neral learning and knowledge; and the claffical education which was generally beftowed on young men deftined for that Society, frequently led them to indulge in hiftorical and literary difqui- fitions, little conneéted with the ordinary courfe of their pro- feflional employments.. Mr Tytrer was one of thofe who, from his earlieft years, had applied himfelf to letters and clafli- cal ftudy ; and amidft an accurate knowledge and unremitting attention to his bufinefs, he never ceafed to cultivate and to en- joy them. (C 2) THE Account of W. Tytler, Ety; Account of _ W. Tytler, E'q; (20) HISTORY of the SOCIETY. Tue moft remarkable feature of Mr TytTrer’s character was an ardour and activity of mind, prompted always by a ftrong fenfe of reétitude and honour. He felt with equal warmth the love of virtue and the hatred of vice; he was not apt to dif- guife either feeling, nor to compromife, as {ome men more com- plying with the world might have done, with the fafhion of the time, or the difpofition of thofe around him. He feldom wa- ved an argument on any topic of hiftory, of politics or litera- ture; he never retreated from one on any fubject that touched thofe more important points on which he had formed a decided opinion. Decided opinions it was his turn to form ; and he ex- preffed them with a warmth equal to that with which he felt them. He took ftrong common-fenfe views of obje¢ts, not from want of acutenefs to perceive lefs palpable relations, but from that warm and ardent caft of mind to which fuch views are more congenial than the fubtleties of abftra& or metaphyfical difquifition. Nor was it in opinion or argument only that this warmth and ardour of mind were con{picuous. They prompted him equally in action and conduct. His affection to his family, his attachment to his friends and companions, his compaflion for the unfortunate, were alike warm and active. He was in fen- timent alfo what Jounson (who felt it ftrongly in himfelf, and mentions it as the encomium of one of his friends) calls a good hater ; but his hatred or refentment went no further than opi- nion or words, his better affections only rofe into adtion. In his opinions, or in his expreflion of them, there was fometimes a vehemence, an appearance of acrimony, which his friends might regret, which ftrangers might cenfure; but he had no afperity in his mind to influence his actual condu@t in life. He indulged oppofition, not enmity ; and the world was juft to him in return ; he had opponents, but I fincerely believe not a fin- gle enemy. His contefts were on opinions, not on things ; his difputes were hiftorical and literary. In converfation, he carried. APPENDIX. (21) carried on thefe with uncommon intereft and vivacity ; and the fame kind of impulfe which prompted his converfation (as is juftly obferved by an author, who publifhed fome notices of his life and character in the periodical work entitled The Bee) induced him to become an author. He wrote not from vanity or vain-glory, which RoussEAu holds to be the only in- ducement to writing ; he wrote to open his mind upon paper ; to {peak to the public thofe opinions which he had often {poken in private ; opimions on the truth of which he had firmly made up his own conviction, and was fometimes furprifed when he could not convince others ; it was fair to try, if, by a fuller ex- pofition of his arguments, he could convince the world. Wir this view, he publithed, in 1759, his “ Enquiry, hifto- “ yical and critical, into the Evidence againft Mary Queen of “ Scots, and an Examination of the Hiftories of Dr RoBEerT- * son and Mr Hume with refpect to that Evidence ;” in which he warmly efpoufed the caufe of that unfortunate Princefs, af- tacked with feverity the conduct of her enemies, and expofed the fallacy, in many parts the fabrication, of thofe proofs on which the charges againft her had been founded. This work was the firft on that fide of this celebrated queftion which in- terefted the public in general, and appealed in behalf of the Queen to the judgment and feelings of the people. The learn- ed and induftrious Mr WaLter Goopatu had feveral years before publifhed his examination of the Letters of Mary, on which ler accufers had fo much refted as evidence of her guilt ; but that examination, however elaborate and acute, was: not well calculated, either in form or ftyle, for general perufal. Mr Tyrier’s work gave to the arguments of GooDALt the: concifenefs and compreffion neceffary to command the attention. of the reader, fupported them. by a variety of new proofs and illuftrations, and drew from the general hiftory of the period. in queftion, and from the characters of the leading actors of . the fcene, arguments more impreflive and interefting than any which. Account of W. Tytler, Efq; Account of W. Tydler,-Efq; (22) HISTORY of the SOCIETY. which mere verbal criticifm of the letters, or an examination of cotemporary documents, could fupply. The firft editions of the Enquiry were in one volume 8vo ; but the author afterwards confiderably enlarged it, particularly in the hiftorical part, and publithed, in 1790, an edition (being the fourth) in two volumes of the fame fize. THE problem of Mary’s guilt or innocence, (to ufe the lan- guage of a near relation of Mr TyrLer’s, expreflive indeed of Mr TyTLeEr’s own fentiments on the fubject), if confidered merely as a detached hiftorical fact, would appear an object which, at this diftance of time, feems hardly to merit that Ja- borious and earneft inveftigation to which it has given rife ; though, even in this point of view, the mind is naturally fti- mulated to fearch out the truth of a dark myfterious event, difgraceful to human nature ; and our feelings of juftice and moral rectitude are interefted to fix the guilt upon its true au- thors. But when we confider that this queftion involves a dif- cuffion of the politics of both England and Scotland during one of the moft interefting periods of their hiftory, and touches the characters, not only of the two fovereigns, but of their mini- fters and ftate{men, it muft then be regarded in the light of a moft important ‘hiftorical enquiry, without which our know- ledge of the hiftory of our own country, and of that political connection with England which from that time influenced all State-affairs in Scotland, muft be obfcure, confufed, and unfa- tisfactory. In addition to thefe motives of enquiry,this que- ftion has exercifed fome of the ableft heads both of the former and of latter times ; and itis no mean pleafure to engage in a conteft of genius and of talents, and to try our ftrength in the decifion of a controverfy, which has been maintained on both fides with confummate ability. Ir to perfons, however, of cooler and lefs fanguine tempers, it fhould ftill appear fingular, that any ancient hiftorical difgui- fition fhould fo keenly engage the minds and the paflions of li- terary APPENDIX. (23) terary men, it may perhaps be obferved, that it is on objects of this fort that thefe are frequently more occupied and excited than on others which might at firft fight appear better calcula- ted to occupy and excite them. On objects of prefent and im- mediate concern, the mind and the affections have certain li- mits to which the actual and known intereft neceflarily con- fines them. ‘The others have a fort of ideal range which no fuch fixed and certain boundary reftrains. The intereft is crea~ ted, not found, and the fancy fofters and nourifhes the fubject of its own creation, till, it engroffes the attention and excites the paflions to a degree that muft appear very extraordinary to thofe who confider it in its natural and unexaggerated colours Difputes of literary as well as political enthufiafm, have there- fore been generally the moft obftinate and warm of any ; and this, which is quaintly termed the-Marian controverfy, of all fuch difputes the keeneft. Even Mr Hume, placid as he was from nature, and accuftomed, from-his earlieft literary life, to contradiction and attack, loft fomewhat of his ufual temper on the occafion, and fubjoined an angry note to the latter editions of his Hiftory, which I fhall not quote, becaufe, from my re- fpe& for his memory, I am rather inclined to wifh that it had’ . mot been written. - i WITHOUT venturing any opinion on the queftion itfelf, it may be fufficient in this place to fay, that Mr TyTLeEr acquired high reputation by his difcuffion of it. The Enquiry was unt verfally read in Britain, and very well tranflated into French, under the title of “ Recherches Hiftoriques et Critiques fur les “ principales Preuves de V’Accufation intentée contre MARIE “ Reine d’Ecoffe.” The intereft it excited among literary men, may be-judged of from the character of thofe by whom it was reviewed on its publication, in the periodical.works of the time. Dr Doveras, now Bifhop of Salifbury, Dr SamuEL JoHNson, Dr Joun Campse 1, and Dr Smotzet, all wrote reviews of ‘Mr TyTiER’s book, containing very particular accounts of its merits, , Account of W. Tytler, Efg; Account of W. Tytler, Efq; (24) HISTORY of the SOCIETY. merits, and elaborate analyfes of the chain of its arguments, As an argument on evidence, no fuffrage could perhaps be more decifive of its merit than that of one of the greateft lawyers, and indeed one of the ableft men that ever fat on the woolfack of England, the late Lord Chancellor Harpwicke, who decla- red Mr Tyrner’s Enquiry to be the beft concatenation of cir- cumftantiate proofs brought to bear upon one point, that he had ever perufed. What effect that body of evidence, or the argu- ments deduced from it, ought to have upon the minds of thofe to whom the fubjeé&t becomes matter of inveftigation, I do not prefume to determine. The opinion of the late Dr Henry, author of The Hiftory of Great Britain on a new Plan, may per- haps be thought neither partial nor confident ; who fays, in a letter to Mr Tyrer, publithed in the volume of Zran/aétions of the Antiquarian Society of Scotland, That he would be a bold man who fhould now publifh an hiftory of Queen Mary, in the fame ftrain with the two hiftorians, (Mr Hume and Dr Ro-— BERTSON), whofe opinions on the fubjecé the Enquiry had exa- mined and controverted. I cannot help obferving, in juftice to Mr Hume’s impar- tiality, that no poflible motive could be afligned for the preju- dice which the favourers of Queen Mary have fuppofed him to entertain againft her. As a party queftion, in which view Mr Tyrer has placed it in his Introduction to the latter edi- tions of his work *, Mr Hume had furely no bias to miflead him * “ Tue character, accomplifhments and misfortunes of this Princefs, (fays the Introduétion), have been the fubjéct of much-writing and controverfy among the Britith hiftorians. Republican writers, equally averfe to monarchy and to the Houfe of Stuart, have drawn her pidture in the blackeft colours, by traducing her as an accomplice with the Earl of Botuwe xz in the murder of the Lord Darn Ley her hufband. On the other hand, the writers attached to the ancient conflitution of their country, and to the Family of Stuart, have regarded that unfortunate Princefs as one of the moft virtuous and accomplifhed charaéters of that age, and as a victim to the fecret con{piracies carried on by fome of the heads of the reformed party in her Kingdom for her deftruétion.” APPENDIX. (25) him in the confideration of it; and it is a circumftance rather Gingular, that while he has generally been charged with Toryi/m by one party, he {hould, on the other hand, be accufed by, 1n- plication of Republicani/m im this queftion on the hiftory of the unfortunate Queen of Scots.. Tue other illuftrious hiftorian, whofe opinions Mr TyTLEer controverted in his Enquiry, though of oppofite fentiments from Mr TyTLer as an author, lived with him in habits of private friendfhip and familiar intercourfe. The laft time Mr TyTLer dined at Dr Ropertson’s, he faw with peculiar fa- tisfation Hamitton’s hiftorical picture of Queen Mary, with the portrait of the Doctor on one fide, and his own upon the other. Dr Rozertson, talking accidentally with the writer of this account on the fubject of the Marian controverfy, faid, “ 1 have told Mr Tyrrer, that nothing but a regard for what I conceive to be hiftorical truth, could have given my hiftory that complexion which is fo different from what he thinks it fhould have worn. Mary was the natural heroine of my hi- ftory, if truth had allowed me to make her fo.” Sucu would have been the natural vanity of an author; nor was the national vanity of a Scotfman lefs interefted in the fate ‘of this beautiful and unfortunate Queen, whom her evil de- {tiny tranfplanted from the funfhine of a gay and gallant court to a barbarous and unfriendly clime ; to a clime, fhaken by the ftorms of faétion, and defolated by the furious contentions of a tyrannical and favage ariftocracy. It has been matter of regret with fome who feel for the Princefs in this view of her hiftory, that her advocates have not left her caufe to thofe feelings, but have pufhed very far her pretenfions to unimpeachable conduct and princely virtues, inftead of pleading an apology for error or weaknefs, from the circumftances of the times and the intrica- cies of her fituation. Even in the pages of ROBERTSON, after all that he has allowed of prefumptive evidence for her impru- VoL.IV. - (D) dence Account of W. Tytler, Efqs Account of W. Tytler, Efq; (26) HISTORY of the SOCIETY. dence or her crimes, the fentiment of the reader,. let his hifto» rical opinion be ever fo adverfe to the Queen, prevails over his juitice, and the dramatic effect of the ftory is uniformly, com- pailion for the Princefs, and refentment againft her enemies. To him who looks on that portion of hiftory rather with the eye of a moralift than of an antiquarian, her marriage with BoruweELt is the moft unfavourable paflage of her life, both as affecting the propriety of her conduct in that particular, and as tending to corroborate the evidence produced by her ene- mies on the great charge of privacy in the murder of her huf- band. Of that marriage, Dr Henry thus exprefles himfelf, in the letter I mentioned above, written to Mr TyTLer on the 2oth of July*1790, a few months before his (Dr Henry’s) death. “ Her laft marriage (fays the Doétor)’ was the moft unhappy, and there feems ftill to be fome difficulty i in vindica-- ting her condué in contracting that marriage. Was-fhe feized by BoruweELL in her paflage from Linlithgow, in confequence of a pre-concert, and with her own confent ; or was it by mere violence, and without her having any intimation, that fuch an attempt was made? If I could anfwer that queftion, I fhould: know what to think of feveral other things.” In confequence of this letter from Dr. Henry, Mr TyTier: wrote a Differtation on the Marriage of- Queen Mary with the Earl of BoruweEtx ; which, with the letter that occafioned it,. was publifhed, in 1792, in the Tranfactions of the Antiquarian Society of Scotland, of which Mr TyTLeR was one of the Vice- prefidents. In this diflertation, he maintains, in conjunction with WHITAKER and Srevart, that the Queen’s marriage with BorHwELL was an object which the treacherous MuRRAY and his alflociates had all along wifhed to accomplith, and: that it was at laft brought about by the daring ambition (encou- raged by them) of Boruwetu himfelf, who, having feized the Queen.on her return from vifiting her fon at Linlithgow, car- ried her prifoner to Dunbar, where, by the moft flagitious and violent APPENDIX. (27) violent means, he firft obtained the privilege, and then the legal character of a hufband. I HAVE placed this Difértation next in order to the Enquiry, becaufe both relate to the fame hiftorical fa&, though in point of time it was the laft of Mr TyTier’s compofitions. Before that Differtation, he had produced feveral other works on hifte- rical and literary fubje@ts, namely, — I. The Poetical Remains of James the Firft, King of Scotland, In one volume 8vo, publifhed at Edinburgh in 1783. The vo- lume, of which the above is the general title, contains a Difler- tation on the Life and Writings of King James the Firft, one of thofe Princes, in whofe lives, difaftrous rather than unfortu- nate, adverfity was the parent of wifdom and of virtue, and was cheared by religion, philofophy, and the mufes. This Dif- fertation introduces two well known ancient poems, which Mr TYTLER, on very {trong grounds, afcribes to the King, viz. The King’s Quair, and Chrif’s Kirk on the Green. The poem of The King’s Quair, or in modern Englifh the King’s book, is a very ftriking proof, not only of the poetical genius and imagi- nation of its author, but of a tafte cultivated and refined by an acquaintance with the claffical poetry of the ancients, and the works of thofe eminent bards who were his cotemporaries, Cuaucer, GowrErR and Lypcatse. The fubject of the poem is the paflion of James for his lovely miftrefs Jane, daughter of the Earl of Somerfet, who afterwards became his Queen ; and the chief ciscumftances of the poet’s life, the misfortunes of his youth, his long captivity, the incident which gave rife to his love, its purity, conftancy, and fuccefs, are well defcribed under the quaint, but at that time fafhionable figure of poetry, allegorical vifion. This work, which is mentioned by Joun Major as the compofition of James, and which in later times had been feen by Bifhop TanNeER in an ancient MS, among (D 2) the Account of . W. Tytler, Eig; Account of W. Tytler, Efq; a Y (28) HISTORY of the SOCIETY. the Seldenian archieves in the Bodleian library at Oxford, was, in confequence of a diligent fearch made at Mr TyT1eEr’s infti- gation, happily recovered, and by him now for the firft time given to the public, with explanatory, critical and hiftorical notes. The poem of Chri/’s Kirk on the Green was well known to the public, and had long been admired’ for its wit and humour ; but it had been afcribed, even by antiquarian writers, to JAMES the Fifth of Scotland, the author of The Gaberlunzie Man, and other ludicrous compofitions. It occured to Mr TyT er, that the public was in a twofold error refpecting this favourite poem ; firft, in confidering it merely as a jeu d’e/prit, or fanciful dif- play of the author’s imagination and powers in the ludicrous ; and fecondly, in attributing the compofition to James the Fifth. In the Differtation on the Life of James the Firft, he has ar- gued, with much ingenuity, that the {cope and view of the work was political and patriotic; its end, the beft purpofe of a Sovereign’s writings, the improvement of his people. The En- glifh at that time excelled all other nations in the ufe of the bow. James, on his return to his kingdom, was mortified by the ftriking inferiority of his own fubjedts in that particular to their warlike neighbours. The practice of archery, and of weapon-fchawing, a military exercife, had gone into fhameful neglect during the weak adminiftration of the Regents of the kingdom. To remedy this defeét, a more regular difcipline was enforced by the young Monarch, by ftatutory regulations ; who tried at the fame time the efficacy of ridicule in compo- fing this ironical fatire (for fuch, according to the ingenious fuppofition of Mr TyTier, is Chri/’s Kirk on the Green) on the awkward management of the bow, and the neglect of archery among the Scots. In the age of James the Fifth, the vulgarly reputed author of the poem, the ufe of fire-arms had completely fuperfeded the bow as an engine of war. The laws of James the Fifth required, that every man fhould arm himfelf with a hackbut or mufquet. In that era, therefore, the fatire on the want APPENDIX. (29) want of {kill in archery would have been loft or mifapplied, its irony no longer felt, its falutary end no more perceived. Be- fides this argument from the general tenor of the poem, Mr Tyrer has adduced the intrinfic evidence arifing from the /an- guage of the piece, as clearly afcertaining its date to belong to that period to which he has afligned it. At the end of the poem of Chrif’s Kirk on the Green, is a note by Mr TyTtLer, in which he pays a juft tribute to the worth as well as genius of our celebrated paftoral poet ALLAN Ramsay, and contradiéts, from his own perfonal knowledge, the abfurd ftory of Ramsay’s not being the author of the well known paftoral drama, The Gentle Shepherd. . SuBJOINED to the Differtation and Poems, is an Effay by Mr TyTLer (firft annexed to Annot’s Hiftory of Edinburgh, pu- blifhed in 1788) on the Scotti/b mufic. This laft was very pro- perly included in the volume above mentioned, from its con- nection with the hiftory of the Prince, whofe poems it was the chief purpofe of that volume to record: and. illuftrate ; the fy- ftem maintained by Mr Tyrrer in this eflay on the Scottifh murfic, being, that the ftyle of the ancient melodies of this coun- try was firft introduced by King JAmes the Firft. This was chiefly founded on a paffage in the penfieri diverfi of Tassont, better known as the author of the celebrated mock-heroic la fecchia rapita, who, mentioning the mufical talents of this Mo- narch, afcribes to him the “ invention of a new kind of mutfic, plaintive and melancholy,” which Mr Tyrver,. in this effay,. fuppofes was the original of thofe beautiful and pathetic airs: which are known and. diftinguifhed as the national mufic of: - Scotland. A HL. Ob/er= Account of W. Tytler, Efq; (30) HISTORY of the SOCIETY: Oi Tytles Ela; II. Obfervations on the VISION, a Poem firft publifbed in Ramsay’s Evergreen. ‘Thefe obfervations, which vindicate ALLAN RAMSAy’s title to the poems in queftion, were publifhed in the before-mentioned volume of the Antiquarian Tranfactions in 1792. Ill. An Account of the fafbionable Amufements and Entertain- ments of Edinburgh in the laft Century, with the Plan of a grand Concert of Mufic | performed there] on St Cecilia’s Day 1695. Mr TyTLer was likewife the author of a paper in the Loun- ger, No. 16. “‘ Defects of modern Female Education in teaching the Duties of a Wife.” On all Mr TyTLeER’s compofitions the charaéter of the Man is ftrongly impreffed, which never, as in fome other inftances, is in the {malleft degree contradicted by or at variance with the character of the Author, He wrote what he felt, on fubjects which he felt, on fubjects relating to his native country, to the arts which he loved, to the times which he revered. A zealous Scotfman, a keen mufician, an old man with his youthful re- membrances warm in his mind, he wrote on the hiftory of Scotland, on mufic, and on the amufements of former times in Edinburgh ; and I confefs, that from a knowledge of this cir- cumftance, I read his works with an intereft which I fhould not feel, if I confidered them as flowing from a pen which was the inftrument of the author’s ingenuity rather than of his heart. His heart indeed was in every thing he wrote, or faid, or did. He had, as his family and friends could warmly atteft, all the kindnefs of benevolence: he had its anger too; for be- nevolence is often the parent of anger. There was nothing neutral APPENDIX. (31) neutral or indifferent about Mr TytLeR. In philofophy and in hiftory, he could not bear the coldnefs, or what fome might call the temperance of fcepticifm ; and what he firmly believed, it was his difpofition keenly to urge. His mind was ftrongly impreffed by fentiments of religion. His piety was fervent and habitual. He believed in the doc- trine of a particular providence, fuperintending all the actions of individuals, as well as the great operations of nature ; and he had a conftant impreflion of the power, the wifdom, and the: benevolence of the Supreme Being. Hits reading was various and extenfive. There was fcarcely a fubjeét of literature or tafte, and few even of {cience, that had not at times engaged his attention. In hiftory he was deeply verfed ; and what he had read his ftrong retentive me-- mory enabled him eafily to recal. Ancient as well as modern ftory was familiar to him, and in particular the Britith hiftory, | which he had read with the moft minute and critical attention. Of this, befides what he has given to the public, a great num-.- ber of notes which he left in MS. touching many controverted points in Englith and Sceottifh sari afford the moft ample proof. In mufic as a fcience ke was di sahiestculs filled. It was his favourite amufement; and with that natural partiality which all entertain: for their favourite objects, he was apt to af- - fign to it a degree of moral importance which fome might deem a little whimfical. He has often been heard to fay, that he ne-- ver knew a good tafte in mufic affociated with a malevolent: heart; and being afked, what prefcription he would recommend: for attaming an old age as healthful and happy as his own?. “ My prefcription, faid he, is fimple ; fhort but cheerful meals, . mufic, and a good confcience.” In his younger days, he had_ been a good performer on the harpfichord ; but his chief inftru- ‘ment was the German-flute, which he thought peculiarly adapt-- ed to. the expreflion of thofe natural and fimple melodies in: ( which: Account of We Tytler, Efq; Account of W. Tyuer, Efq; (32) HISTORY of the SOCIETY. which he moft delighted, the Scottifh airs. He was one of the original members of the Mujical Society of Edinburgh, in which he continued, during a period of near fixty years, till his death ; during the greateft part of which time, he was a Diredtor of that Society, and felt for its permanence and_profperity that warm and lively intereft, which animated him alike in bufinets, in ftudy, and in amufement. In perfon, Mr TyTrer was rather thin, and fomewhat below the middle fize. His walk, even at the lateft period of his life, was of that quick and fpringy fort which accorded with the activity of his mind. In his youth, he was fond of manly ex- ercifes, and often talked with regret of thofe which the gentle- “men of Scotland had loft in the refinement or effeminacy of modern times. Enpowep with fo many qualities adapted for friendfhip, Mr TyTLer had many friends, and among thefe were fome of the moft diftinguifhed literary characters of the age. In that num- ber were the late Dr Joun Grecory, Principal CAMPBELL and Dr Gerarp of Aberdeen, Dr Re1p, Dr Beatriz, Lord KamgEs, and Lord Monzoppo. A man who lives fo long mutt necefla- rily lofe much of his cotemporary fociety ; but the lofs was compenfated to him more than it generally is to perfons of his age, by that intereft which he took in the converfation and in the amufements of the younger people who were the acquain- tance or companions of his children. He was indeed of a temper remarkably focial, and found, from the congenial ardour of his own mind, particular delight in the company of young people; to whom, from the ftore of anecdotes he poflefled regarding the incidents, the manners, and the habits of former times, his converfation was equally in- ftruétive and entertaining. He was, however, one of thofe fortunate praifers of times paft who are perfectly alive to the enjoyment of the prefent; whofe partial recolleCtion of former times and former joys refults from the fame warm and a¢tive temperament, APPENDIX. (33) temperament that ftill preferves cordiality for prefent friends and fpirit for.prefent amufements. He retained this ardour and aétivity to the clofe of life ; and at fourfcore, was as ready as ever to join in the converfation, to participate the mirth, even to enter into the innocent convivial frolic of his young friends and relations. At his country-feat of Woodboufelee, di- {tant about fix miles from Edinburgh, where he faw them with peculiar fatisfaction, he had ereéted in a private and fombre walk, an urn, with this infcription : Hune lucum Caris mortuis amicié Sacrum dicat W. T. Yet from this walk, from the indulgence of the remembraiicée and regrets which it infpired, he would return to the focial circle within, with unbroken fpirits and unabated cheerfulnefs. In domeftic life, Mr TyTier’s character was particularly amiable and praife-worthy. He was one of the kindeft hufbands and moft affectionate fathers. At the beginning of this account, I mentioned his having loft, at an advanced period of life, an excellent wife, and a fon and daughter both grown to maturity, who merited and pofleffed his warmeft affections. The temper of mind with which he bore thofe loffes, he has himfelf ex-+ preffed in a MS. note, written not long before his death ; with which, as it conveys a fentiment equally important in the con- fideration of this life, and in the contemplation of that which is to come, I fhall conclude the prefent Memoir: “ The lenient hand of time, (fays Mr TyTLeEr, after mentioning the death of his wife and children), the lenient hand of time, the affec- tionate care of my remaining children, and the duty which calls on my exertions for them, have by degrees reftored me to Vou. IV. (E) mytfelf. Account of W. Tytler, Big: (34) ston oF myfelf. The memory of thofe dear objects gone before me, came and the foothing hope that we fhall foon meet again, is now the In my retired walks in the HISTORY. of the. SOCIETY. fource of extreme pleafure to me. country I am never alone ; thofe dear fhades are my conftant companions ! Thus, what I looked upon as a bitter calamity, is now become to me the chief pleafure in life.” Iii. Ill. 4 Biocraruicat Account of Mr Wittt4m Hamicqtoy, late Profeffor of Anatomy and Botany in the Univerfity of Glafgow.. By ROBERT CLEGHORN, M. D. F. R. S, Evin. Lecturer in Chemifiry in the Univerfity of Glafzow. [Read 6th Nov. 1792.] N writing the life of a perfon who himfelf publifhed nothing, it is extremely difficult to fatisfy the expectation of his par- ticular friends, without incurring the charge of adulation’ from the reft of the public. How far I have fucceeded in doing ju- ftice to Mr Hamitton’s merit, without infenfibility or exagge- ration, muft be determined by thofe who knew him, and by thofe who can appreciate the worth of fuch profeffional remarks as I fhall lay before them in the fequel, Mr Writ1am Ha- MILTON was born in Glafgow July 31. 1758*. Having fi- nifhed the ufual courfe at the Grammar School, he went to Glafgow College in 1770, and continued there ftudying with great diligence till 1775, when he became Matter of Arts-at the age of feventeen. Brey, a (E 2) Havine * His father was Mr Tuomas Hamitton, an eminent furgeon, and profeffor of anatomy and’ botany in Glafgow ; his mother Mrs IsapeL ANDERSON, daughter of Mr Anerson, formerly profeffor of church-hiftory in the Univerlity of Glafgow. (36) HISTORY of the SOCIETY. RereR es Havinc fhewn an early and ftrong predilection for the ftudy of phyfic, he went to Edinburgh, which was then, as it is ftill, the moft celebrated fchool of medicine in Europe. During the fummer of 1775, he ftudied botany under the late worthy Dr Hore; and during the two enfuing winters. he ftudied with great ardour under all the medical profeflors, and enjoyed the friendfhip of Dr Cutten and Dr Brack, who having been for- merly members of the College of Glafgow, were the companions and friends of his father. Mr Hamitron intended to have remained a third feafon in Edinburgh, but the ftate of his father’s health rendered it necef- fary for him to give up this plan. Accordingly, in fummer 1777, he accompanied his father to Batu, and from thence to London, where he was recommended to the particular notice of the late Dr W1itt14mM Hunter, and of his brother Mr Joun Hunter. Each of thefe gentleman was connected with Mr T. Hamitton by early friendthip, and a conftant intercourfe of good offices. Under their direction Mr Hamirron quickly diftinguifhed himfelf by that ardent purfuit of anatomical and profeflional knowledge,which marked every part of his fubfequent life. Though left at an early age to his own condudt, in a city. abounding above ali others with objects of pleafure and amufe- ment, he refifted the blandifhments of both, devotmg his time to the acquifition of knowledge, applying not only to thofe parts of ftudy which were entertaining, but to thofe alfo which the young are apt to neglect as uninterefting, or to defpife as ufe- lefs, and manifefting, on every occafion, a diligence difcouraged by no difficulty, and interrupted by few avocations. SucH conduct did not efcape the eye of Dr Hunter. Indefa- tigable himfelf, he was delighted with appearances of profeflional zeal among his ftudents ; and he was fo particularly pleafed with them in the fon of his old ftiend, that, after the firft feafon, he in- vited Mr HamiLTon to live in his houfe, and committed the dif- feting- \ “APPENDIX. (37) fecting-room to his-care. In this fituation, the beft that a ftudent of anatomy could wifh for, Mr HamiLron continued two years hearing the leGtures, and enjoying the converfation, of the firft anatomift in London. How far, in Dr HunTer’s opinion, he improved this opportunity, appears from the following letter addreffed to Mr T. Hamittron, December 31. 1778: “ Your fon makes me very happy on your account, and for his own fake. I fee and hear much of him; and every body regards him as fenfible, diligent, fober, and of amiable difpofitions. He is now in the direct road for acquiring knowledge, as director in the diffeGiing-room. It obliges him to apply, becaufe he is to anfwer any queftion, and folve any difficulty that may occur; and which is beft of all, he is to demonftrate all parts of the bo- dy again and again to ftudents. This is a moft inftructive pro- vince, and a fine introduction to giving letures, as it gives fa- cility in public fpeaking, and a habit of demonftrating diftinG- ly and clearly, both of which are eafily acquired while we are young; and yet, for want of that very opportunity, are pofleffed by few. In this way he will acquire not only knowledge, but a charatter for knowledge with the public, which 2 young man cannot procure but by being in fome public ftation.” ‘ Iw another letter to the fame gentleman, dated May 18. 1780, Dr Hunrer fays: “ Your fon has been doing every thing you could with, and from his own behaviour, has profited more for the time than any young man l ever knew. From being a favourite with every body, he has commanded every opportu-. nity for improvement which this great town afforded during his ftay here ; for every body has been eager to oblige and en- courage him. I can depend fo much on him, in every way, that if any opportunity fhould offer for ferving him, whatever may be in my power I fhall confider as doing a real pleafure to myfelf.” THE Account of W. Hamiltoi. Account of W, Hamilton. (38) HISTORY of the SOCIETY. THE opportunity hinted at foon occurred. Mr HAMILTON came to Glafgow in 1780, and taught for his father during the enfuing winter. Having given mot fatisfying proofs of know- ledge in anatomy, and of talents as a leCturer, he was appointed in 1781 fucceflor to his father, who had refigned fome time be- ‘fore. When confulted about this appointment, Dr HuNTER faid to the Marquis of Granam, now Duke of Monrrose, “ That from an intimate knowledge of Mr HAMILTON, asa man, and as an anatomift, he thought him every thing that could be wifhed for in a fucceflor to his father, and that it was ‘the intereft of Glafgow to give him, rather than his to folicit the appointment.” His father lived till January 1782; but the whole burden of le@turing, and the greateft part of the bufinefs, devolved on the, fon. The bufinefs was very extenfive, as.old Mr HamitTon was connected with many of the moft refpeCtable families in Glafgow and its neighbourhood. His profeffional character, too, was high as a fuccefsful practitioner, and a fkilful opera- tor ; and being withal a man of great hilarity, and genuine hu- mour, his company was courted by all who relifhed wit and good fellowfhip. From the co-operation of fo many favourable circumftances, Mr HamiLton’s progrefs was extremely rapid, his outfet being encumbered with few of thofe difficulties, which have often obftructed the courfe of other young practitioners. His father lived long enough to introduce him fully. His youth did not diminifh the confidence of his patients ; becaufe, befides knowing that he had ftudied with uncommon care, in fituations the moft favourable for acquiring knowledge, they believed that he had ready accefs at all times to the experience of his father. By gentlenefs of manners, by unaffected benevo- lence, by the moft prudent circum{fpection in all his conduct, and by unremitting attention to his patients, he not only re- tained moft of thofe who had employed his father, but added many AP PEN DIX. (39) many to the number. While he practifed extenfively as a fur- geon, his {kill in anatomy made him be confulted by many fur- ' geons, older’ than himfelf, before they performed operations ; and, in a few years, thofe who had been his pupils, practifing in diftant parts of the country, confulted him on fimilar occa- fions. Befides anatomy, he taught botany and midwifery ; which laft he practifed with fuch fuccefs, that he was called to almoft every difficult cafe near Glafgow. In Odtober 1783, he married, Mifs Ex1zapeTu. STIRLING, an accomplifhed lady, connééted with feyeral opulent families in Glafgow and. its neighbourhood. ,, From. thefe connettions, his practice, already extenfive, was very confiderably increafed. Anxyous to excel, not only as a fkilful phyfician, and an ex- pert furgeon, but as a public teacher, he was led to confider every cafe that he treated more accurately than is ufually done by thofé who confine their attention to pra@ice merely. Though -maturally convivial, and endowed with a confiderable degree of this father’s humour, he avoided company as much as he could with prudence, and devoted every vacant hour to: ftudy, and efpecially to writing. He kept a regular account of all uncom- ‘mon cafes, accompanying the. conclufion of each: with remarks fuggefted at the moment, and forming, at the end of each year, a general table of the difeafes which had prevailed during the different feafons. . This. plan facilitated his practice, and was highly gratifying to his patients, by convincing them, that their former complaints were diftinétly remembered: But he had a higher object in view than the affifting of his own, memory, or the. gratifying of particular patients. His object was to have publithed'a Syftem of Surgery, illuftrated with cafes, of which feveral aré fully and accurately drawn up. . As a fpecimen of what might have been expected from this work, had he lived to finifh it, I fhall mention a few particulars, which, on account of their Account of W. Hamilton. Account of W. Hamilton. (40) _ HISTORY of the SOCIETY. their novelty or importance, feem moft worthy of being record- ed. Upon performing lithotomy for the firft time, he was ftruck with the difficulty of introducing the gorget, and, on examina- tion, he found it blunt at the point, where fharpnefs was moft needed, fo that inftead of cutting, it tore the urethra. The cut tler finding it difficult to fharpen the gorget, as commonly made, up to the button which goes into the ftaff| Mr Hamrrron di rected him to make it in two feparate pieces, which, locking to- gether, had all the firmnefs of the old inftrument, with the ad- vantage of being eafily fharpened when taken afunder. This inftrument he always employed afterwards in operating, which he did often, and with great fuccefs. ; In midwifery he met with feveral uncommon cafes, of which the moft remarkable are inftances of two women who furvived a complete inverfion of the womb*. He detailed thofe cafes to his pupils, along with ‘others that ended fatally ; and took occa~ fion from them all to enforce the neceflity of avoiding force, or even hafte, in delivering women. The following extra¢t, nearly in his own words, proves with what caution he treated his pa- tients, and with what care he confidered their cafes afterwards’: “ T have feen four cafes of inverted uterus, of which two pa- tients died, and two recovered. This recovery is fo fingular, that I know only one cafe by Tomas BarTuoutnus fimilar to it. “ THE great object in all cafes of fuch danger, is to under- ftand fully how the accident happens, that fo we may be able to prevent is occurrence. It is evident, that the uterus can ne- ver be inverted when it is contracted, or even beginning to con- tract itfelf; it therefore muft happen when the fibres of it are relaxed, * Boru thefe patients are ftill alive; and the hiftory of one is given in the Medi- cal Communications of London, vol. 2. APPENDIX. . (41) / gelaxed, allowing themfelves to be bent in any direction, and eer when the uterus is ftill large. This is the condition of the ute- ‘e rus; when the child has been forced away, either by the action merely of the abdominal mufcles and diaphragm, or by the af- fiftance, as it is called, of the midwife, fhould the placenta ad- here to the very fundus or near it, a fmal] degree of force, ap- plied to the cord, may invert the uterus while large, flaccid, and empty. “ Tue fureft method of preventing fuch an accident, then, is to produce a complete and regular contraction of the uterus, which may be accomplifhed more eafily than fome haye imagin- ed. For we know, that as long as any ftimulus is applied to the cavity, and efpecially to the mouth, which is the moft irri- table part of the womb, a contra¢tion will take place, in order to expel the ftimulating caufe. Therefore, by allowing the child to be born folely by the pains of labour, by giving no afliftance in the extra¢tion, (except where the fize of the child, or the mal- conformation of the pelvis, render affiftance abfolutely necef- fary), and by preventing the delivery of the body from being accomplifhed by the abdominal mufcles folely, we force the ute- rus to contract itfelf, and to expel its contents. After the deli- wery of the body, by allowing the legs to lie for a fhort time in the vagina, and.to prefs on the mouth of the womb, we enfure its contraction. “ By fuch management, the uterus having been made to.con- tract itfelf properly, we have the placenta feparated, and ready for extraction... Thus, together with the danger of inverfion, we are freed from two more common accidents, viz. a retained pla- ~centa anda flooding. . Befides, the child is lefs hurt, when the flow delivery allows time for the dilatation,of the paflage ; and it runs no rifk of thofe {prains and bruifes which often happen in -attempting to pull away the child without the afliftance of a la- sbour-pain. (F) . - a | Account of W., Hamilton. (42) HISTORY of the SOCIETY. “* | wave paid particular attention to this fubject, and I have always found, that where the womb was inverted, where the placenta was retained, or where much flooding followed the birth, the child had been born, head and body at once, by a fingle pain. An attention to this point, procured Dr HunTER part of the fame which he fo juftly pofleffed, on account of his fkill and caution in midwifery. He has often told me, that many women had been under his care, who, with other: practi- tioners, had loft much blood, and been expofed to much danger, from the fpeedy extraction of the after birth. By allowing it to feparate flowly from the uterus, and after feparation to lie for half an hour in’ the vagina, he completely avoided the flooding, and the danger that attends it.” Mr Hamitron was called to many cafes of luxation;, both: of the fhoulder and thigh jomt; in reducing which, he fucceed- ed by very fimple means, after other furgeons, who-employed the force of machinery, had failed. On this fubje& le wrote an accurate’ paper ; in which, after defcribing the joints, with the ligaments and mufcles that furround them in a natural ftate, he confiders fully the change brought on every part by luxation, deducing partly from the ftructure of the parts, chiefly from his own extenfive experience, the following directions concern- ing the beft mode of reducing the joint to its natural pofition. “Tue fituation of the mufcles round the joint differs much according to the kind of diflocation, “ Iw all cafes the deltoid is ftretched, but particularly when the bone is thrown dire&tly downwards. The long head of the biceps muft be fometimes torn, but, where it is not, it will be extended, and the ligament through which it pafles, and which binds it to the humerus, will be always lacerated in a greater or lefs degree. The mufcles that are moft deranged, are the fu- prafpinatus, fubfcapularis, and infrafpinatus. Thefe two laft we {hall call the lateral mufcles of the joint. “ In ‘AP PEND DX. 43) ** Iw the diflocation downwards the fuprafpinatus will be on the ftretch, the fubfcapularis and infrafpinatus will have their fibres lengthened, and their direction altered, in confequence of the head of the humerus being thrown below the glenoid cavity. “ WueEn the bone is diflocated outwards, and refts on the dorfum fcapulz, the fituation of the mufcles will be nearly the following: The fubfcapularis and fuprafpinatus will be both very much ftretched, while the infrafpinatus, having the hume- rus thrown under it, will be relaxed, and a number of its fibres will be torn from the fcapula, to make room for the head of the bone. _ “ In the third fituation, when the bone is luxated inwards, the fuprafpinatus and infrafpinatus will be on the ftretch, while the fub{capularis will be relaxed, and in the fame fituation as its oppofite mufcle has been defcribed in the preceding fpecies of - diflocation. ‘« THis account is drawn from the natural fituation of the parts, and the few cafes of diflocation where there has been an opportunity of diffe€ting the arm. It may be obferved, that in all the three f{pecies of luxation, the fuprafpinatus and dekoid are put much upon the ftretch, the laft in a lefs degree. From this we may. infer the propriety of relaxing thefe mufcles com- pletely during the time of reduction; and this is another reafon for raifing the arm when we attempt to replace the bone. “ Mr Tuomson * {peaks of the head of the humerus being caught between the tendons of the infrafpinatus and teres mi- nor,-as in a noofe; this can happen only in the luxation out- wards, and is one reafon for relaxing them completely in at- tempting reduction, by throwing the arm towards the fide of ‘the fcapula, oppofite to that where the head of the bone is lying. Having mentioned the fituation of the mufcles, I fhall now (F 2) point * London Medical Obfervations, vol. 2. p. 354. Account of W. Hamilton Account of _ W: Hamilton. (44) _ HISTORY of the SOCIETY. point out the changes that take place on the joint, when teft un- reduced, as being our proper guide in judging what line of prac- tice is to be followed in fuch cafes. An unreduced luxation may be defcribed in three fituations: The firft, when the parts. are little changed from the {tate they are in, immediately after diflocation happens. The fecond, where motion is beginning to- take place, and when the foft parts become adapted to the diflo- cated ftate of the bones. And the laft, when a new joint is formed. After the head of the bone is lodged on fome part of the fcapula, it is found to confolidate the cellular membrane and mufcular fibres under it, fo as to form a kind of foft focket for itfelf, which, by the preffure of the cartilage on the end of the humerus, and by the motion the arm admits of, gets a fmooth farface. The burfa]l ligament torn on that fide next the humerus, is pulled acrofs the glenoid cavity, and the muf{cles will be found in the ftate I have already defcribed. “ ArTeR the inflammation and fwelling, confequent upon the injury, have gone off, the patient will be plagued with pains in . the ftretched mufcles, and will be incapable of moving the joint with eafe. The inflammation will however make the lacerated parts grow together, fo as to obliterate the paflage through which the head of the bone efcaped from the joint. This may be reckoned a luxation in a recent ftate. After fome time the mui{cles begin to adapt themfelves to the {tate of the bones, thofe that were overf{tretched are lengthened, and the relaxed ones contra¢t, fo that the perfon is capable of moving his arm, and by degrees the motion becomes more confiderable. The burfal ligament now gets adhefions to the edges of the glenoid cavity, over which it lies, and the opening in it, through which the bone pafled, is filled up, fo that it embraces the humerus clofe- ly. The torn paffage in the foft parts has become as firm as if no’ laceration had ever take place. The focket, formed in the cellular fubftance, between the head of the humerus and the f{capula, APPENDIX. (45) fcapula, begins now to be removed, from the conftant preffure made upon it; and before this, which we would call the fecond . ftate of the diflocation, is completed, that bone is refting on the furface of the fcapula itfelf. It is much to be withed, that it were afcertained, by accurate obfervations, when thefe changes take place, and particularly when the third ftate, which we are next to defcribe, begins. This laft {tate of a diflocation is, when nature is beginning to form a new joint to fupply the place of the old one. : “ Tue foft focket having been completely removed, the hu- merus is refting on the furface of the fcapula. By preffure, and frequent motion, a cavity is formed for the head of the bone; the furface of this new cavity becomes fmooth, and is covered with a cartilaginous cruft; the attachment of the humerus to the parts around anfwers the purpofe, and at laft affumes the ap- pearance of a ligament, fo that a new joint may be {aid to be formed completely in all its parts. That this can happen, has been proved by diffection; and particularly in a- man, after whofe death my father had an opportunity of examining his arm, which had been diflocated for upwards of thirty years. This perfon was a fencing-mafter, and, as it was his right arm, he was obliged to perform with it a great variety of motions. He had acquired fo completely the ufe of it, that he could per- form all the different motions neceflary in the {mall fword, ex- cept pufhing a high carte *. ** Monfieur Moreau f gives two cafes fimilar to this, of old luxations of the thigh, where the head of the femur had formed a new acetabulum for itfelf in the os innominatum. Another cafe, though-not of a diflocated fhoulder, I fhall likewife de- {cribe, * Mz Tuomson diffe@ed a man with a new focket, formed in the infide of the fcapula, Med. Obf. vol. 2. + MemorrEs de l’Academie de Chirurgerie, tome v. p. 45. {mall edition, Account of W. Hamilton, Account of W. Hamilton. (46) HISTORY of the SOCIETY. {cribe, as illuftrating the efforts of nature, to fupply the motion between bones after diflocation, and where.a procefs for forming a new joint, that, fo far as | know, has never been defcribed, is taking place. The bones are from a woman, who was difflected in the theatre here, about four years ago; the thigh had been long diflocated, and the woman had been able to walk about. The neck of the os femoris lay on the edge of the acetabulum, while the head, which is changed in its fhape from the preflure of the furrounding parts, was on the dorfum ilii beyond this cavity. The edge of the acetabulum filled up the hollow at the neck of the femur, which is made deeper by its preffure. There are two procefles of bone growing into the acetabulum from the os femoris, and which at laft would have formed a kind of head to play in this the cavity of the old joint, and thus have made a new one confiderably different from that in the ‘cafes already mentioned. By one or other of thefe different ways, nature attempts to remedy the injury done to a limb after luxation. At the time the head of the humerus is forming a new focket for itfelf, the glenoid cavity is deftroyed, its fides approach each other, and the hollowed part is filled up by gra- nulations-of bone. The burfal ligament adheres to the furface -of this cavity, and is thus to all appearance loft. “ Tue patient continues in this ftate, with a joint either more or lefs perfe@t, and, when proper attention has been paid, the new joint may be made a very ufeful one; and to this point alone our treatment of old diflocations ought to be directed. The treatment of luxations muft differ according to the ftate of the difeafe. When they are recent, reduction in the eafieft and fafeft manner is the furgeon’s objet: And here we fhall make a few obfervations, drawn partly from what we have already fhown to be the ftate of the joint and mufcles, and partly from experience. “ Tue head of the humerus being in all cafes pulled beyond the glenoid cavity, and lodged on the fcapula, the firft ftep to- : wards APPENDIX. (47) wards replacing it, muft be to draw it out, fo as to bring it over that cavity out of which it was thrown. “« Tus is to be done by making the extenfion of the arm, with fuch a-degree of force as to feparate the bones from each other, and fo applied that it may act only upon the parts round the diflocated joint. When extenfion is omitted, as was the cafe among the old furgeons, the attempts made by the lever to force the humerus into its place, fo far from having falutary, were attended with very bad, confequences. Extenfion, how- ever, in the modern practice, is our firft view. The refiftance to the extention is owing to the contraction of the furrounding mufcles, which is partly voluntary, and partly the effe@ of their being much ftretched, from the new fituation of the bone. The firft it is feldom in our power to prevent, as the terror of reduc- tion, and the uneafinefs confequent upon moving: the: arm, makes the patient exert his mufcles to refift what gives him» pain ; and fo far as no. refolution in him can prevent this ac- tion; it may be faid to be involuntary. Were it poflible to de- ceive him, and make him fuppofe we were only examining the {tate of his arm, when we were really making the proper exten- -fion, this caufe of difficulty might be overcome in fome degree. The refiftance from the overftretched mufcles is of more impor- tancé, as it is in our power to prevent it, and, when not attend- ed to, muft increafe the furgeon’s difficulty, and by extending the mufcles, already too much on the: ftretch, may produce greater laceration than from the difeafe intended to be remedied. “Tye obfervations we have already made on the ftate of the mufele after diflocation, muft now appear neceflary, being on a -fabje@ little attended to, though of great importance, and par- ‘ticularly as they lead us to place our patient in fuch a manner as to remove this caufe of difficulty and danger. “ ANoTHER caufe preventing reduction, is the bone being pulled in fuch a direction by the furgeon, as not to pafs through the Account of W. Hamilton, (48) HISTORY of the SOCIETY. eater the cavity it formed for itfelf in diflocation, but is made to prefs aoe furrounding parts, fo that if the force is continued to be exerted in the fame direction, a new paflage muft be torn for it. This, like the laft, may be avoided, by attending to the moft probable pofition of the limb when the accident happened. We have attempted to prove, that, in general, diflocation is moft apt to happen when the arm is raifed ; and therefore that this pofi- tion is the preferable one for redu@tion. I fufpe in many cafes, where improper attempts to reduce the bone have been made, that the difficulty is increafed -by the bone tearing a paf- fage for itfelf in a new direction, and thus, by twifting the muf- cles, preventing reduction from being accomplithed. “ Tae laft obftacle is from the burfal ligament. As in no cafe of diflocation the head of the bone-can pafs out without la- -cerating it, fo, in reduction, at cannot be replaced, unlefs it is brought through the fame opening by which it went out; for if we attempt to bring the humerus over the glenoid cavity in a wrong direction, the ligament will get between it and the fca- pula, and thus, when apparently reduced, the bone will return to its old fituation, as foon as the arm is let loofe. This.can be avoided only by the pofture of the limb; and here alfo, in the raifed ftate of the arm, the bone will return moft readily through the opening in the ligament, as being put into the fame pofition im which it was luxated. “ Turse three great difficulties in reduction, then, are to be remedied by a proper pofitioa of the patient and of his arm; and this, I think, there can be no doubt, is by placing him fo, that the extenfion may be made when his arm is raifed. In order to © this, 1 make him fit on the ground, the fcapula, with the glenoid cavity upwards, being kept fixed by two afliftants who are pla- ced behind him, I put a towel round the humerus, immediate- ly above the elbow, both to give mea firmer hold of the part, and likewife, that, if neceflary, Iimay have.a place forjan afliftant or : A POP EVN DEX: (49) or two in the extenfion to lay hold by. The fore arm is bent up, fo as to relax the biceps completely ; and this I prefer to the ftate of half flexion, as the extenfor triceps is not one of the mufcles that gives any difficulty in reduction. When the bone is. luxated dire@ly downwards, I. make the extenfon ftanding oppofite to the patient’s fide; but, when it is either outwards or inwards, | place myfelf towards that fide, oppolite to where the head of the bone is lying, and I carry the arm in the fame di- rection. If, for example, the head of the humerus is under the pectoral mufele, I carry the arm outwards towards the patient’s back, and vice ver/a. “ | rHEN begin to make the extenfion with a flow and fteady force, but of fuch a kind as I find is capable of overcoming the refiftance of the mufcles, and of bringing the bone out of its place. After it is completely difengaged, it is pulled into the glenoid cavity by the action of the furrounding mufcles, fo as not to require any preflure in the axilla to raife it up. In this manner I have reduced feveral diflocations of the fhoulder ; and in none have I failed, or been obliged to ufe the force I have {een applied in other modes of reduction, and without effect. Among the cafes | have fucceeded in, there were feven where all the other methods had been tried in vain; and in three of thefe the arm had been out for three weeks. Mr WuitTe of Manchefter * has employed a mode of reduction fimilar to this, as to the pofition of the arm; but I think the other parts of -his plan are not equal to that here defcribed. The raifed ftate of the arm is likewife advifed by Mr T'uomson, from the fituation he found the mufcles in the difle@tion of two men with difloca- ted humeri, who had died before reduction had been effected. “ In this manner of reduction, all the extended mufcles are relaxed by the arm being: raifed ; the fuprafpinatus and deltoid (G) | in . * Medical Obfervations, vol. 2. P- 373- Account of eyrtes Account of W. Hamilton. (50) HISTORY of the SOCIETY. in the diflocation downwards; and in that to the fide, by turning the humerus towards the fide of the fcapula oppofite to that on which its head is lodged, the lateral mufcle is taken off the {tretch it was put into by the diflocation. When thefe over- ftretched mufcles are thus attended to, the redu@ion becomes more eafy to the furgeon, and much lefs hazardous to the pa- tient, as laceration is guarded againft. “ Arrer long and violent attempts to reduce the fhoulder, particularly with the mufcles on the ftretch, I have heard of the bone becoming fo loofe, that when it had been at laft got into its focket, it fell out again very readily. This I imagine muft have been owing to the mufcles round the joint, and the ligament, having been very completely torn, fo that the humerus had loft its natural fupport. In the two modes of reduction moft com- monly made ufe of, the ftate of the mufcles is not enough at- tended to. When the arm is at an acute angle with the fide, as when we attempt to force in the bone with the heel in the ax- illa, the fuperior mufcles are very much on the {ftretch; and when the patient is placed on a chair, and the arm forms a right angle with the body, they are {till not fufficiently relaxed to pre- vent additional difficulty and danger; and I muft agree with Mr Tuomson in thinking attempts in thefe directions often the caufe of fucceeding bad confequences. Another advantage of re- duction with the raifed arm is, that as foon as the humerus is difengaged from the fcapula, the mufcles, that from the nature of the diflocation were moft extended, contracting, pull it into its focket. In other modes of reduction, a confiderable force is required to prefs the bone into its place, after the arm is fully extended. When this force is great, the parts that lie over the bone mutt be bruifed, particularly if a hard body is ufed to ef- fe& this purpofe. On this account the 4mbe, both of FREAcK and PETIT, appears to me a bad inftrument. It pulls out the arm at right angles, and therefore it requires confiderable ac- tion APPENDIX. (51) tion of the end of the inftrument as a lever to force the humerus into its place, while the preflure on the patient’s fide is equal to the force of the extenfion. It can likewife be properly ufed on- ly in the diflocation downwards. “ In all diflocations of the humerus, the extenfion, I think, fhould be made with the hands, in place of pulleys, as by the firft, the direction of the bone can be better adapted to the re- fiftance and fituation of the furrounding parts. “ In what we called the fecond ftate of an unreduced diflo- cation, the obftacles are more numerous than in the recent. The mufcles have now adapted themfelves to the fituation of the bones, the hole in the ligament is in part grown up, and the la- cerated paflage in the foft parts is obliterated, the fides of it ha- ving, by inflammation, adhered to each other. Thefe being added to the difficulties in recent luxations, render the reduction here both more difficult, and more apt to be attended with lace- ration, than in the other. Thefe obftacles are to be got over, however, by the fame means. The patient ought to be put in- to the fame pofition, and the extenfion made in the fame man- ner, only it will require the force to be greater, and to be longer continued, before it accomplifhes the end in view. I do not think, however, it will be neceflary to employ any other me- thod, (as that of Mr Wurre), as every thing may be done by the hand, that can be expected from pulleys. “ In the laft ftate, and even in the latter part of the fecond, inftead of reduction, we fhould attempt to render the new ‘joint that is forming as perfect as poflible. This is to be done prin- cipally by making the patient ufe his arm as often, and for as long a time as he can, without pain or fatigue, and to perform with it a variety of motions. “In this way we will haften the formation of the new joint, and render him fooner capable of ufing his arm. That this~is eee is evident from the cafe of the fencing-matter already (G 2) mentioned, Account of W. Hamilton Account of W. Hamilton, (52) HISTORY: of tha SOCIETY. mentioned, who followed his profeffion for upwards of five and twenty years before his death, and who, by being obliged to ufe his arm, acquired the motion of the new joint fooner than if he had been under no fuch neceflity. “ Tr is a matter of importance to afcertain when the changes, we have defcribed, take place. I imagine the recent ftate may continue for a fortnight or three weeks: But ftill we want ob- fervations to point out when the mufcles become completely adapted to the new fituation of the bones; when the glenoid ca- vity begins to lofe its fhape, and the ligament to adhere to it ; and, particularly, when the furface of the fcapula begins to be- come hollowed and {mooth, fo as to receive the head of the hu- merus. Thefe, however, may be guefled at, by the quality and degree of motion enjoyed in the diflocated joint. Were thefe points fully afcertained, they would guide us in our practice, and prevent attempts being made to reduce old diflocations, where the furgeon, from want of knowledge of the procefs car- rying on by nature to form a new joint, and the obliteration of the old cavity, racks the patient’s limbs to no purpofe; and even fhould he be fuccefsful, he might be faid not to reduce, but really to diflocate, as he deflroys a new joint beginning to en- joy motion, and throws the end of the bone on a furface which has now loft every thing neceflary to make it a part of a joint.” Mr Hamirton had occafion once to open the cheft of a Lady, who had water in her breaft. The quantity at firft drawn off amounted to fixteen ounces; a great deal oozed out afterwards, and fome of the fymptions were for a little relieved, but the patient died ina few weeks. On the beft manner of performing this operation, he makes the following remarks: “ Iy Mr Bexv’s mode of operating, which I here followed, fimply drawing off the water, and avoiding every thing that may bring on inflammation on the cavity, is not fufficiently kept in view. An extraneous body, a canula, is introduced and kept in for APPENDIX. Nis cba for two or three days. The effet of this practice is evident ; inflammation may be brought on over the cavity; fuppuration will fucceed, and the café will be converted into one of em- pyema, with an opening in the cheft. The effects of keeping in a canula in the abdomen were found, by the old furgeons, to be fo bad, that the practice was given up, even before the faint- nefs, from drawing off the water at once, was fo well under- ftood as to be capable of being prevented. In our patient, fymptoms of inflammation. from the canula were beginning when it was withdrawn, and had it been kept in another day, the inflammation would probably have become fo confiderable, that it might have been expected to produce the worit confe- quences. “ Tue view with which a, canula is introduced and kept in, 1s, to allow the water to run off only when we choofe it, and to prevent air from getting into the cavity. The frit intention it does not anfwer; as in our patient, though it was introduced through the pleura when only a fmall perforation had been made in it, fo that it might be clofely embraced, the water ooz- ed out by its fides, and more was difcharged in this way than “by the canvla itfelf. “ Arr is likewife more apt to get into the cavity by the ca- nula, than if the water was difcharged without it. It is impof. fible to ftop it fo accurately and quickly with the finger or cork, as to prevent the accefs of air, when there is little water left, or when the lungs are not in a fituation to fill the cavity, ‘and efpecially when the patient is infpiring. This I found to be the cafe, when I drew off the laft water by it. But before I left the patient, I evacuated the air as completely as poilible, by deprefling that fide of the cheft during expiration. “ From the ftrudture of the thorax, air is apt to be drawn in by the external wound, and is again not eafily expelled. The moit ready method of evacuating it, is by compreiling that fide of Account of W. Hamiiton Account of W. Hamilton. APPENDIX. (55) of the cheft during expiration, at the fame time prefling up the vifcera of the abdomen, fo as to make the diaphragm afcend; and thus, by leflening the cavity, while the patient, by fhutting the glottis, prevents the air from efcaping, but forces it into the collapfed lung, we force out as much of it as poflible. Other ways of evacuating it hath been fuggefted by different writers. Sucking it out by a fyringe, or an elaftic bottle, are common propofals, but I am afraid can never be put in practice. The bottom of the wound between the ribs is fo irregular, that they can never be applied when the canula is out; and when it is in, more air would be admitted during the time the fyringe, or bottle, was fitting on, than could be extracted by them. But after all the water is evacuated, the wound muft be healed up, for if not, fuppuration will come on the wound, and when the canula is then withdrawn, the fkin, that was intended to act as a valve, will have become fixed by the inflammation, and will not come down over the hole in the pleura, fo that air muift be admitted, though it was excluded before. “ WHETHER common air does hurt to any cavity, I doubt much. Water, with a penetrating wound, would be as bad. The inflammation of the wound is what is moft to be dreaded, as it fpreads from that over the whole cavity. The canula, there- fore, as inducing inflammation, muft, in my opinion, be very hurtful. “ In place of the operation defcribed by Mr Bett, I would propofe doing it in the following manner: I would place my patient in the common pofture, and, after the fkin was well pulled up, make my incifion in the ufual place and manner, tll I came down to the pleura. I would, then make an opening through it, about half an inch in length, merely dividing the membrane. In cutting into the cavity, great care fhould be ta- ken not to do it rafhly, left an adhefion of the lungs to the pleura be over the incifion. At the fame time we muft expect to find the (54) HISTORY of the SOCIETY. the pleura much thicker than it naturally is, owing to the ef fects of inflammation, and the preffure of the water, fo that a timid operator, not aware of this circumftance, (which is not taken notice of), might defift, from an idea of having met with an adhefion, when he was really only haif way through the mem- brane. In a cafe of hydrothorax I opened, I found the pleura coftalis a fifth of an inch thick. I would then ailow as muca water to run off as I thought proper, two afiiftants making fuch a degree of preffure on the ribs of that fide as to prevent their being raifed in breathing, during the time the fluid was dif- charged. After I had drawn off fuch a quantity as flowed rea- dily, and the patient could bear without faintnefs, I would bring the loofe fkin over the hole in the pleura, and fix it there with flips of emplaft. adhefiv.; I would then lay the patient on the dif- eafed fide, fo as to allow the water to ooze off by the wound, while air would be prevented from getting in, by the {kin act- ing asa valve. If the patient grew faint, from the evacuation being too quick, it could eafily be leffened, or ftopped, by ma- king him turn more and more towards his back, or oppofite fide, fo as to make the hole in the pleura lefs a depending open- ing; or, by making preffure upon the {kin over the opening, the difcharge might be completely ftopped. If the lung was not difeafed, as the water flowed off, it wotld be more and more filled with air, and expanded. If it was fo much difeafed as to be incapable of expanfion, by no mode of operation can more water be drawn off than what diftended the cavity; a quantity muft be left equal to the want of enlargement of the lung ; if we draw off more than this, air muft fupply its place ; for we are not to imagine we can take away all the water, and leave a vacuum. The wound will admit of the water oozing long enough to evacuate all that fhould be taken away; and it will not be prevented from healing, fo as to endanger the pa- tient, from the rifk of internal inflammation. If we find a large Account of W. Hamilton (56) HISTORY of the SOCIETY. large quantity thus evacuated, it will prove the lung of that fide to be found; as, air being entirely excluded, the cavity mutt be filled up by that alone, after the water is difcharged. If little runs off, it is probably one of thefe cafes where the lung is fo much indurated as to be for ever incapable of performing its function. In the firft cafe, the patient may derive benefit from the operation; the difeafe may be prevented from recui- ring. In the other we have done him no hurt; he will breathe more eafily as long as the oozing continues, es taking away the redundant water, but, as this cannot be kept up long, he muft at laft be left to his fate. ; “ Lavina the patient on the difeafed fide after the operation mutt be of fervice, as it both allows the water to run off, and it prevents him from enlarging that fide of the cheft, and thus running a rifk of drawing in air by the wound. When a canula is kept in, this is impracticable; the patient cannot be laid much towards that fide without the canula prefling on the bed- clothes. In the manner I have propofed, the operation will, I think, be more fafely performed, and might therefore be oftener tried, ; ) “ Wuat I have faid applies only to hydrothorax. In em- pyema an opening muft be kept in the cheft, to difcharge the matter as it forms. The two difeafes certainly require different furgical treatment. In the firft, inflammation has not come on, and is to be guarded againft In the other, the collection of matter is the effect of it, and its being regularly difcharged will, if any thing can, abate it. I fhould therefore follow Mr BELL’s plan* in this, though I would differ from it in the other; and as the fteps of the operation in thefe two cafes would be the fame, except leaving in the canula in empyema, we may attempt it * Tue canula recommended by Mr Betx,has no lip or margin round the opening. By fuch an addition it has a hold of the parts round the Opening, and can be kept much feadier. APPENDIX. (57) it when proper, though we may not be certain of -the nature of the fluid contained. In moft cafes we may afcertain this before from the fymptoms; but, at all events, the puncture in the pleura will put it beyond a doubt.” _ Mr Hamizton had an opportunity of feeing feveral hernix ‘in women, upon fome of whom he operated fuccefsfully ; and, from confidering all the cafes he had feen, he was led to make the following remarks, fome of which he thought new. “© WueEn I began the practice of furgery, as I had never met with a cafe of hernia in women, I believed implicitly i in the doc- trines we find in every writer on the fubject, viz. that women have feldom bubonocele, but are more fubject to femoral hernia, Soon after I had begun to practife, I was called to a confultation about a woman with a hernia, which had been ftrangulated for two days. As it was placed in the groin, I at firft fight thought it a femoral hernia ; but, upon examining it attentively, I found it'was a bubonocele that had gone towards the thigh, in place of towards the labium. The operation which was performed put the matter beyond a doubt, and fhowed that it came through the ring of the mufcle. In a few months I was called to another patient in the fame fituation, and I found, to my furprife, the fame appearances which in the firft I'took to be a lufus nature 5 the hernia in the groin, at the top of the thigh, and yet evident- ly coming through the ring; having all the appearances at firft fight of femoral jhernia, but in reality a bubonocele. The operation here, likewife, which I performed, made me certain of the fa&. In a third, under ftrangulation, I found the fame appearances, and operated. “ Frnpinc the hernia bubonocele in thefe three cafes, yet with all the appearance of .that {pecies where the gut is pufhed out under Paupart’s ligament, I began to fufpect that the common account given by authors was erroneous, and that bu- Von. IV. (H) bonocele Account of W. Hangin, (58) HISTORY of the SOCIETY. Aaeonat of | bonocele had, from inaccurate obfervation, been often defcribed ’ for femoral hernia. From the time I began to have thefe fuf- picions, I have miffed no opportunity of determining my point ; and I have been lucky enough to have the diffection of two wo- men, with the apparent femoral hernia, which turned out bubo- nocele. I have likewife had five or fix living patients with her- nia, where I had an opportunity of a careful examination, and have again operated in a fimilar cafe. As the refult of thefe ten or twelve cafes is againft the common opinion, I fhall ftate my obfervations at full length. ““ Tue idea that a bubonocele in women was to take the fame road with a fimilar hernia in men, has, I fancy, mifled; for we find, that this is the account commonly given of the difeafe, that the gut pafles down into the labium. Now, if we compare the two cafes, we will find there is no fimilarity. In men, the gut and fack are furrounded by the cremafter, and are therefore conduéted towards the tefticle. The cellular membrane of the fcrotum is free of fat, and therefore yields more eafily to the preffure of the gut than that of the parts around ; and thus the hernia pafles more eafily in this direction than in any other. In women, when the hernia has paft the ring, it has no crema- fter to conduét it to the labium, it may therefore pufh in any other direction ; but as the cellular membrane of the labium, and from it to the ring, is very much loaded with fat in moft women, it will find more obftrudtion in this direction, and will | therefore be pufhed where the parts yield more readily. The parts on the groin are lefs loaded with fat, the gut therefore will be preffed here. This I found corroborated by all the three cafes, where I either operated or was affiftant; and in the two diffeCtions the hernia was pufhed outwards from the ring, and in one it had gone up along the belly above the ring. This on- ly takes place when the hernia is fmall. If the ring is much opened, and a great quantity of gut forced out, the motion of the APPENDIX. (59) the thigh preffes it inwards and downwards, and it then goes towards the labium. This I) have inftances of in fome women I have lately examined with hernia. “ THE appearances of the bubonocele, when, fmall, will de- eelve a practitioner if he is not on his guard, and make him ima- gine it a femoral rupture. ‘The marks by which the one may be diftinguifhed from the other, though fituated in the fame place, are few and fimple. “ As the fafcia of the thigh joins Pauparv’s ligament, the femoral hernia is always under.this fafcia ; it is therefore more compreffed ; it is not loofe, and we cannot fo well grafp it with the hand; and, inftead of being rounded on the top, it is more or lefs flattened. The bubonocele again is only under the {kin and cellular membrane, is therefore loofer, can be eralged, and is rounded on the top. “ In femoral hernia the fwelling begins at the edge of Pavu- PART’S ligament, and goes down, and we feel the ring and the parts above the ligament uncovered by the hernia. In the bu- bonocele of women it goes over PAuPpART’s ligament, and fome- times up upon the mufcles over the ring, and extends more to each fide along the bending of the thigh than the other. “ From thefe marks not having been attended to, I fufpect much that the place where the hernia lay was alone taken into view, and cafes fimilar to mine had been called femoral rup- tures. Indeed { have every reafon to fuppofe fo, as fome of the cafes where I was moft certain of their being bubonocele, had _ been looked on as of the other kind. *« T wouLp therefore recommend to praé¢titioner’s attention to. thefe marks, fo as to determine how*far the obfervations I have been led to make are juft. _ “ Tue bubonocele in this fituation in women, from its often lying in parts over the ring, makes the redu@tion much more uncertain, as we cannot grafp the part of the hernia juft coming (H 2) through Accaunt of W. Hamilton Account of W., Hamilton. (60) HISTORY of the SOCIETY: through the ring, fo as to force it back, which is effentially ne- ceffary to ready reduétion, and which we can always do in men, from the loofenefs of the fkin at the top of the ferotum. “ Upon examining the ftate of the parietes of the belly in women, and comparing them with thofe of men, I fee no reafon for their being more fubject to femoral hernia than bubonocele, though im general I think them lefs liable to the difeafe altoge- ther than men. The figure of the pelvis makes Paupart’s ligament a little longer in them, but the {pace under it is in pro- portion as well filled up by mufcles, veflels, and fat, tc. fo that no more room is allowed for the vifcera to be forced out in the one taan in the other. The rings of the mufcle in women, though lefs apt to yield, as being more contracted than in men, are in proportion the weaker part, and therefore the paflage through which a vifcus will be more readily pufhed. In opera- ting upon this fpecies of bubonocele, I varied a little from the common method. As the tumor extended along the bending of the thigh, my incifion being made in this direction, was pa-. rallel in fome meafure to the ring. This made the introduction of the biftory, to cut the tendon, a little more difficult, but it gave me advantages to counterbalance this inconvenience. I had after the reduction a piece of integuments above the inci- fion, which when preffed down covered the ring. This foon formed adhefion with the parts below, and effectually excluded the expofure of the cavity of the abdomen, which adds much to the danger of the operation. In the common operation, where the ring is laid in view, and is at the bottom of the wound, the integuments over it having been divided, I fufpect the inflammation on the edges and bottom of the wound, which is kept open, extends through the ring to the peritoneum, alto- gether independent of the expofure, and produces very fatal ef- feéts. Now, in my method, this was prevented ; the integu- ments being found immediately over the ring. In drefling the wound APPENDIX. (61) wound I ufed ftitches to keep the lips together, which was like- wife aflifted by bending up the thigh. This I look on as of confequence in every operation for hernia, as the healing the parts by the firft intention over the ring muft be of effential fer- vice in preventing inflammation in the abdomen; and the only objeétion that has been made to it, the rifk of the gut flipping out, may be eafily prevented by a comprefs over the opening in the tendon for a few days: And after this, as adhefions will have taken place, unlefs great force is ufed, no protrufion can happen.” To thefe {fpecimens others might be added, were not this me- moir already too long, and were not thefe fufficient to juitify what has been faid of the unremitting attention and found judg- ment of a gentleman, whofe premature death was regarded by all his friends as a lofs to {cience and to fociety.. His conftitution, fomewhat enfeebled by early and intenfe application to ftudy, Was worn out with the toil of bufinefs and thought, in which he was continually engaged ; and, after a tedious illnefs, he ex- pired, March 13. 1790, in the thirty-fecond year of his age, leaving a widow and two fons. Havine lived according to the laws of religion and virtue, and being naturally of a placid, cheerful temper, he bore much fuffering without complaint, looking forward to death, which for fome time he knew to be unavoidable, with thofe fenfibili- ties indeed which every good man feels on the profpect of lea- ving his deareft friends, and entering into an untried exiftence, but without unmanly dejection or timidity. Befides the appro- bation of his own mind, he was foothed with the affectionate attentions of all his family, and with the regrets of his brethren and the public, who from day to day teftified the utmoft folici- -tude concerning his health ; uttering not the, unmeaning lan- guage of ceremony, or the interefted one of flattery, but that of fincere Account of W. Hamilton. (62) HISTORY of the SOCIETY. fincere efteem and gratitude. Even when his funeral paffed along, many among the crowd were obferved to fhed tears for one whofe kindnefs had foothed their minds, and whofe {kill had relieved them in the hour of diftrefs; nature prompting them to pay this grateful tribute to him who could no longer obferve or reward them. Tue foftnefs and tendernefs with which he fpoke to his pa~ tients ; the attention with which he liftened to all their com- plaints, however frivolous ; the readinefs with which he fym- pathized with their feelings ; to a byeftander in health might fometimes appear exceflive, but, to the fame perfon in difeafe, the whole appeared but a reafonable exertion of humanity. De- lighted with the kindnefs of his manner, his patients vied with each other in their commendations, of which he proved him- felf worthy, by the utmoft delicacy of converfation, and the ftriGeft purity of conduét, no lefs than by exertions of fuperior fkill, and by a punétual laborious attendance. His prudence, which was uncommon for his years, led him to avoid all often- tatious difplay of the extent to which he was employed; by which means, together with the moft modeft demeanour, he, in part, ftifled that envy which is apt to rife in the old, when they fee themfelves overtaken or out{tripped by the young. As a lecturer, his manner was remarkably free from pomp and affectation. His language was fimple and perfpicuous, but fo artlefs, that it appeared flat to thofe who place the beauty of language in the intricacy of arrangement, or the abundance of figures. His manner of {peaking correfponded with his ftyle, and was fuch as might appear uninterefting to thofe who think it impoflible to be eloquent without violent geftures, and fre- quent variations of tone. He ufed nearly the tone of ordinary converfation, as his preceptor Dr Hunter did before him, aim- ing at perfpicuity only, and trufting for attention to the impor- tance of the fubjects he treated. Thefe he feleted with great judgment. ae P BN T x, 63 judgment. Holding in contempt all hypothefes unfupported by fact, and inapplicable to the improvement of practice; omitting or pafling flightly over parts remarkable for curiofity more than utility ; he demonftrated with great diftinétnefs and precifion thofe parts which it is neceflary to know accurately ; accompa- nying his demonftrations with fpecimens of morbid parts, and with every remark, phyfiological or practical, which he was able to collect from extenfive reading, and careful reflection on his own praétice. To excite emulation among his ftudents, and to honour the memory of his friend, he gave a gold medal, bear- ing the figure of Dr WiLtttam Hun Ter, as a prize to the beft diflertation on a furgical fubject. By thefe means, he had the fatisfaction of contributing to increafe the number of medical ftudents in Glafgow ; and while his ftudents became from year to year more numerous, they began to difcover alfo that ardour, which it is impoflible either to excite or maintain where the ftu- dents are few. IV. Account of W. Hamilton, ' t sageneon 4% aRUsIyh HORA 6), c ee aa brdtom. & ‘our. oagt Dies p 2 Pare ee Pie Bates | Pe. ae oda. env “al Aik tye Sialfs 1 38Y he rig a .* gid Bo “oil pfea te tots: > pig T. ; OF hor atcabesitt e) d sno ae oa + A agit iad Sshantdbtc re Rs vizg oad pear, . eh sine ss a x %, eer *, 3 wis Bao oil 2oson sted XE po aan La siay ee a: . eS ; Loibus Ks tod crea oi Stesrasit ee te" oe ‘5a oot amino: of? aaah iii aul hie. ae is antewel 7 ey Mgt = | epbae gced-oile aarti « o1 Of “E4 CO ea are Pate c rai “ht orit. o75uhve faiusitiocn: 40 otto 2 0f, f ~~) e ie : mt a Ja : Tee rae, i r - ¥ _ , } } ys ay io \ r , a ‘ 2 A : 5 ’ ’ ¢ & Dri ae WI ay * ' " ‘. a ’ t d a y » iz . ; y a © : ~ ees 3 J ee : ; ee ‘ { art dU, “7 4 ) ay A ae 4 . rer ¢sez 7 iy 6 ‘ . * al a F Sa oa ‘ ay Bie ety rs r; nae * | te ta Bh Wd} be i - : ae 4 ’ rn ae » r + : + x ~ ‘ ‘ = n * IV. Account of Foun Rozsuck, M.D. F.R.S. Epin. Com- municated by Mr FARDINE, F. R.S. Evin. and Profeffor of Logick in the Univerfity of Gla/gow. [Read April 4. 1796.] D Ocror Joun Rozsuck was born at Sheffield in York- ‘fhire, in the year 1718. ‘His father was a confiderable manufadurer. and exporter of Sheffield goods, who, by his abi- lities and induftry, had acquired a competent fortune. JoHN, his eldeft fon, the fubject of. this memoir, was intended, by his father, for carrying on his own lucrative bufinefs at Sheffield; but was, from his early youth, irrefiftably attached to other paituits, _more calculated to gratify his ambition, and give fuller play to _his powers. Notwithftanding this difappointment in his fa- vourite ie his father ne liberality aries to encourage his k wma ing Arrer he had gone through the ufual courfe of diced Gram- mar-fchool at ‘Sheffield, both me father and mother being ftrict _diffenters, they placed t their fon, for fome years, under the tui- tion, of she late, Dr, Doppripce, who was, at that eee matter ti reputation, among the diffenters, both’ as a divine and’as an in- _ Structor of youth. Under. the Dotter’ g ‘care Mr Rorsuck made §tgat, proficiency, and laid the foundation of that ‘claffical tafte _and knowledge for which he was ‘alterwards ‘eminently diftin- Vou, IV. (I) guifhed. Accourit of Dr Roebuck. (66) HISTORY of the SOCIETY. guifhed. It would appear that Dr DoppripcE had been much pleafed with the ardour and enthufiafm, in the purfuit of know- ledge, difcovered by his ‘pupil 5 for, Mr Rorsucx;anean-after period of his life, ufed frequently to mention the fubjeéts of converfations and inquiries of various kinds, in which the Doc- tor had engaged him. It was during his refidence at this Aca- demy, that he contracted an intimate acquaintance with his fellow - ftudents, Mr Jeremiran Dyson, afterwards much known in the political world, and Mr Mark AKeEnsIDk, after- wards Dr Akenstpr, which terminated only with their lives. From the Academy at Northampton, he was fent to the Uni- verfity of Edinburgh, where he applied to the ftudy of medi- cine, and particularly to that of chemiftry, which, about that time, began to attract fome attention in Scotland. While he refided there he diftinguifhed himfelf much, among his fellow- ftudents, in their literary focieties and converfations, by great logical and metaphyfical acutenefs, and by great ingenuity and refource in argumentation. The late fagacious Dr PORTERFIELD, to whom he had been introduced, obferved and encouraged his rifing genius, and was greatly inftrumental in promoting his improvement. There, too, he formed an intimate acquaintance with Mr Hume, Mr Rosertson, afterwards Dr RoperTson, Mr PrinGLe, afterwards Lord ALEmoor, and feveral other perfons of literary eminence ; a circumftance which produced, _ in his mind, a partiality ever afterwards in favour of Scotland, and contributed not a little to his making choice of it for the chief field of his future exertions and induftry. Arter Mr Roesuck had gone through a regular courfe of medical education at Edinburgh, being now determined to fol- low the practice of phyfic, he next {pent fome time at the Uni- verfity of Leyden, then in high reputation as the firft {chool of medicine in Europe: There, after the ufual refidence and courfe of trials, he obtained a degree in medicine ; and his diploma, dated APPENDIX. (67) dated 21ft February 1743, has affixed to.it the refpe@able names of MuscHENBROEK, OsTERDYK, VAN Royen, ALBINUS, GAU- Brus, &c. He left Leyden, after having Sete fome part of the north of Germany, about the end of the year 1744. Soon after his return from the Continent, fome circumftances induced Dr Rorzguckx to fettle, as a phyfician, at Birmingham. Before that time, Birmingham had begun to make a rapid pro- grefs in arts, manufaCtures, and population, and, by the death of an aged phyfician, an opening was prefented to him, which afforded an immediate profpect of encouragement in that line. His education, talents, and interefting manners, were well cal- culated to promote his fuccefs as a phyfician. He accordingly met there, at a period more early than he expected, with great. encouragement, and was foon diftinguifhed, in that town, and the country adjacent, for his kill, integrity, and charitable com- paffion, in the difcharge of the duties of his profeffion.. Ir appeared, however, foon after his refidence was fixed at Birmingham, that his. ftudies and induftry were turned to other objects befides thofe of his profeffion. Strongly attached to. the rifing {cience of chemiftry, he conceived high views of ex- tending its ufefulnefs, and of rendering it fubfervient to the improvement of arts and manufa@tures.. With this view, he fit- ted up,a {mall laboratory in his own houfe, in which he fpent every, moment of his time, which. he could fpare from the du- ties of his profeffion, There, in the true fpirit of his creat ma- fter, Lord Bacon, of whofe philofophy he was.a great admirer, he carried on. various chemical proceffes of great importance, and laid the foundation of his future projects, on well tried and well digefted_ experiments *. (Lay. THE *. Verus experientize. ordo, primo lumen accendit, deinde per lumen iter de- monttrat, incipiendo ab experientia ordinata et digefta, atque ex ea, et educendo axis omata, et axiomatibus conititutis, rurfus experimenta nova.. Account of Dr Roebuck: Account of Dr Roebuck. (68) HISTORY of the SOCIETY. Tue firft efforts of his genius and induftry, thus direéted; led him to the difcovery of certain improved methods of refi- ning gold and filver, and particularly to an ingenious method of collecting the fmaller particles of thefe precious metals, which had been formerly loft in the practical operations of many of | the manufacturers. By other chemical proceffes, carried on about the fame time in his little laboratory, he difcovered alfo improved methods of making fublimate, hartfhorn, and fundry other articles of equal importance. After having received full {atisfaction from the experiments upon which fuch difcoveries and improvements were founded, he next digefted a plan for rendering them beneficial to himfelf, and ufeful to the public. A great part of his time being ftill employed in the duties of his profeflion, he found it neceffary to connect himfelf with fome perfon in whom he could repofe confidence, and who might be, in other refpects, qualified to give him fupport and affiftance in carrying on his intended eftablifhments. With this view, he chofe as his affociate Mr SAamuEL GarBET of Birmingham, a gentlemen well qualified by his abilities, acti- vity, and enterprifing fpirit, for bearing his part in their future undertakings. Their firft projet was the eftablifhment' of an extenfive laboratory at Birmingham, for the purpofes ‘above mentioned, which, conducted by Dr RoEBuck’s chemical’ know- ledge, and Mr Garset’s able and judicious management, was productive of many advantages to the manufacturers of that place, and of fuch emolument to themfelves, as contributed greatly to the boldnefs of their future projects. That laboratory has, ever fince that time, continued at Birmingham, and is ftill conducted by Mr Garser. Dr Roesuck, long before’ his death, had given up his intereft in it. AzsouT this time, in 1747, the Doctor married Mifs ANN Roe of Sheffield, a lady of a great and generous’ fpirit, whofe temper and difpofition equally fitted her for enjoying the pro- {perous APPENDIX. (69) fperous circumftances of their early life, and for bearing her equal fhare of thofe anxieties and difappointments in bufinefs which fhaded, but did not obfcure, the later period of their lives. Dr Roesuck’s unremitted perfeverance in his chemical ftu- dies, together with the fuccefs that attended them, led him, {tep by ftep, to other refearches of great public and private benefit. Tue extenfive ufe of the vitriolic acid in chemiftry, and the profpeét of its application to fome of the mechanic arts, had produced a great demand for that article, and turned the at- tention of chemifts to various methods of obtaining it. The late Dr Warp had obtained a patent for making it; and, though the fubftances from which it might be obtained, as well as certain methods of obtaining it, had been known to others, and particularly pointed out by Lemery the elder, and by GLauBER, yet Dr Warp was the firft, it is believed, who efta- ‘blifhed a profitable manufaéture upon the difcovery. Much, however, was wanting to render the acid of univerfal ufe in chemiftry, and of extenfive utility in the arts, where great. quan- tities of it~were required. The price of it was high, arifing from the great expence of the glafs veffels, which were made ufe of by Dr Warp in procuring it, and the frequent acci- cidents to which they were liable in the procefs. Dr Roesuck had been, for fome time, engaged in making experiments with a view to reduce the price, and at length dif- covered'a method of preparing it, by fubftituting, in place of the glafs veffels formerly ufed, lead ones of a great fize ; which fubftitution, together with fundry other improvements in diffe- rent parts of the procefs, completely. effected his end. AFTER the neceflary preparations had been made, Meflrs Roresuck and Garset eftablifhed a.manufacture of. the oil of "vitriol at Preftonpans, in Scotland, in the year 1749. \ This efta- blifhment not alittle alarmed Dr Warp, who attempted to de- feat Account of Dr Roebuck, Account of Dr Roebuck. (70) HISTORY of the SOCIETY. feat their plan, by taking out a patent for Scotland, in addition to the one he had formerly obtained. In this attempt he failed. Dr Roesuck’s difcovery was found not to come within the {pecification of Dr Warp’s patent. Tue Preftonpans Company, convinced that patents are of little avail in preferving the property of new inventions or dif: coveries, in conduéting their vitriol works refolved to have re- courfe to the more effeCtual methods of concealment and fecrecy. By that method they were enabled to preferve the advantages of their ingenuity and induftry for a long period of years, and not only ferved the public at a much cheaper rate than had ever been done formerly, but, it is believed, they realized, in that manufaéture, a greater annual profit from a fmaller capital than had been done in any fimilar undertakng. The vitriol work is ftill carried on at Preftonpans ; but, long before Dr RoEBuCK’s death, he was obliged to withdraw his capital from it. AsourT this time Dr Rozesuck was urged, by fome of his friends, to leave Birmingham, and to fettle as a phyfician in London, where his abilities might have had a more extenfive field of exertion. He had been early honoured with the ac- quaintance of the late Marquis of RockiINGHAm, who, as a lover of arts, had frequently engaged him in chemical experi- ments at Rockingham-houfe. It was there, alfo, he became ac- guainted with the late Sir GEorGE SaviILte, and with feveral other perfons of rank and influence. His old friend and fchool fellow, Mr Dyson, too, by this time, had acquired confider- able name and influence, and preffed him much to take that {tep. Under fuch patronage, and with the energy of fuch ta- lents as Dr RoEBucx poflefled, there could be little doubt of his foon arriving at an eminent rank, as a phyfician in London. But the chemical concerns, with which he was at that time deeply occupied, held out to him a profpect of a richer harvett, determined him to give up the practice of medicine altogether, and APPENDIX. (71) and’ to fix his refidence, for the greateft part of the year, in Scot- Jand. Tue fuccefs of the eftablifhment at Preftonpans, which had far exceeded their expectation, enabled the Doétor and his -partner Mr GARBET, to plan and execute other works of ftilt greater benefit and public utility. In the profecution of his chemical ftudies and experiments, Dr RoEBUCK had been led to beftow great attention on the procefles of fmelting ironftone, and had made fome difcoveries, by which that operation might . be greatly facilitated, particularly by ufing pitcoal in place of charcoal. Mr Witt1am Capbetu of Cockenzie, in the neigh- bourhood of Preftonpans, a gentleman earneftly intent upon promoting manufactures in Scotland, had, for feveral years, la- boured, without much fuccefs, in eftablifhing a manufacture of iron; a circumftance which may have probably contributed to turn Dr RorBuck’s attention more particularly to that fub- jet. As the capital which he and his partner Mr GARBET could appropriate for carrying on the iron manufacture was not equal to fuch an undertaking, and chiefly depended upon the profits of their other works, their firft intention was to at- tempt a fmall eftablifhment of that kind, in the vicinity of their vitriol works at Preftonpans. But the flattering profpects of fuccefs, arifing from a courfe of experiments which Dr RoE- puck had lately made, encouraged them to extend their plan, and to project a very extenfive manufactory of iron. A fuffi- cient capital was foon procured, through the confidence which many of their friends repofed in their abilities and integrity. In fact, the eftablifhment which they made, or rather the capi- _tal which gave it exiftence, was the united capital of a band of relations and friends, who trufted to Dr RozBuck and Mr GarseT the management, of a great part of their fortune. When all previous matters had been concerted, refpecting their intended eftablifhment, the chief exertions of chemical and me- chanical Account of Dr Roebuck. Account of Dr Rocbuck. (72) HISTORY of the SOGIETY. chanical fkill, neceffary in the execution, were expected from Dr Roesuck. It fell to his fhare alfo to fix upon the beft and moft favourite fituation for erecting their intended works, With that view, Dr Rorsuck examined many different places in ‘Scotland, particularly thofe on both fides of the Frith of Forth ; and, after a careful and minute comparifon of their advantages and difadvantages, he at length made choice of a fpot, on the banks of the river Carron, as the moft advantageous fituation for the eftablifhment of the iron manufafture. There, he found, they could eafily command abundance of water for the neceflary machinery ; and in the neighbourhood of it, as well as every where both along the north and fouth coafts of ‘the Frith, were to be found inexhauftible quarries of iron{tone, limeftone, and coal. From Carron, alfo, they could eafily tranfport ‘their ma- nufaGtures to different countries by fea. ‘The communication with Glafgow, at that time, by land-carriage, which opened up to them a ready way to the American market, was {hort and eafy. Many other things, which need not be‘here enumerated, fell to Dr Rogesucx’s fhare in preparing and providing for the in- troduction of this new manufacture into: Scotland, particularly with refpect’ to the planning and ‘ereétion of the furnaces and machinery. To infure fuccefs, in that department, nothing was omitted which ability, induftry, and experience could fug- eeft. With’ this view,’he called to his afliftance Mr Smeaton, then by far the firft engineer in England. It was from him he réceived plans’ and drawings of ‘the water-wheels and blowing apparatus, which, notwithftanding all the mechanical improve- ments which have been-made “fince,- remain unrivalled. in any of ‘the other ironworks erected in Britain. “This was “the “firft imtrodudtion ‘of! Mr’ Smeaton into Scotland, and “was the oceafion of various other difplays of the ‘fkill and ex- “perience of ‘that ‘celebrated -engineer~in ‘that part of the ifland. With APPENDIX. (73) With the fame view, and to the fame effect, in a future period of his operations, he employed Mr James Warr, then of Glaf- gow, and had the merit of rendering that inventive genius, in the mechanical arts, better known both in this country and in England. Tue neceflary preparations, for the eftablifhment of the iron- works at Carron, were finifhed in the end of the year 1759; and on the 1f{t January 1760 the firft furnace was blown: and an a fhort time afterwards a fecond was erected. No period of Dr Rozsucx’s life required from him more vi- gorous and laborious exertions than that of the eftablifhment of the Carron works, and the firft trials of the furnaces and ma- chinery. His family and friends remember well the ardour and intereft which he difcovered; the inceffant labour and watchfulnefs which he exerted on that occafion. Every thing was untried, the furnaces, the machinery, the materials, the workmen; the novelty of the undertaking in that country, its extent and dithculty, and the great ftake at iffue, were circum- {tances that muft have occafioned much ferious thought and an- xiety to the partner, upon the credit of whofe knowledge and experience the work had been undertaken. But the Doctor had great powers and great refources: and the firft trial gave fufl- cient indications of future fuccefs. For fome time after the eftablifhment of the Carron works, Dr Roesuck continued to give his attention and affiftance in the general management and fuperintendance of them, and with him all meafures of future operations were concerted. During this period, fome alterations of great importance were fuggefted by him, and carried into effet. By carefully obfer- ving the progrefs of {melting in the furnaces, at firft worked by bellows, befides their being fubject to various accidents, the Doctor difcovered the neceffity of rendering the blaft both ftronger and more equable; and propofing, as a problem to Mr Vor. IV. (K) SMEATON, Account of Dr Roebuck Account of Dr Roebuck. (74) HISTORY of the SOCIETY. SMEATON, the beft method of effecting that end, that celebra- ted engineer foon gave the plan of a blaft by three or four cy- linders, which was afterwards tried, and fucceeded even beyond expectation. Wuen the bufinefs at Carron funk by degrees into a matter of ordinary detail, and afforded lefs {cope for the Do¢tor’s pe- culiar talents, he was unfortunately tempted to engage in a new and different undertaking ; from the failure of which he fuffer- ed a reverfe of fortune, was deprived of the advantages refult- ing from his other works, and, during the remainder of his life, became fubjected to much anxiety and difappointment. Tue eftabhihment of the Carron works, and the intereft Dr Rorsuck had in their fuccefs, had naturally turned his atten- tion to the ftate of coal in the neighbourhood of that place, and to the means of procuring the extraordinary fupplies of it which the ironworks might in future require. With the view, there- fore, of increafing the quantity of coal worked in that neighbour- hood, by an adventure which he thought would alfo turn out to his own emolument, he was induced to become leffee of the Duke of Hamitton’s extenfive coal and falt works at Borrowftounnefs. The coal there was reprefented to exift in great abundance, and underftood to be of fuperior quality ; and as Dr Rorsuck had made himfelf acquainted with the moft improved methods of working coal in England, and then not practifed in Scotland, he had little doubt of this adventure turning out beneficial and highly lucrative. In this, however, he was cruelly difap- pointed. The opening of the principal /fratum of coal required much longer time, and much greater expence, than had been calculated ; and, after it was opened, the perpetual fucceflion of difficulties and obftacles which occurred in the working and rai- fing of the coal, was fuch as has been feldom experienced in any work of that kind. The refult was, that after many years of APPENDIX. (75) of labour and induftry, there were funk in the coal and falt works at Borrowftounnefs, not only his own, and the confiderable fortune brought him by his wife, but the regular profits of his more fuccefsful works ; and, along therewith, what diftrefled him above every thing, great fums of money borrowed from his relations and friends, which he was never able to repay: not to mention, that, from the fame caufe, he was, during the laft twenty years of his life, fubjeéted to a conftant fucceflion of hopes and difappointments, to a courfe of labour and drudgery ill fuited to his tafte and turn of mind, to the irkfome and teafing bufine(s of managing and ftudying the humours of working colliers. But all thefe difficulties his unconquerable and perfevering {pirit would have overcome, if the never ceafing demands of his coal- works, after having exhaufted the profits, had not alfo compell- ed him to withdraw his capital from all his different works in fucceflion ; from the refining work at Birmingham, the vitriol - work at Preftonpans, the ironworks at Carron, as well as to part with his intereft in the project of improving the fteam-engine, in which he had become a partner with Mr War, the original inventor, and from which he had reafon to hope for future emolument. It would be painful to mention the unhappy con- fequences of this ruinous adventure to his family and to him- felf. It cut off for ever the flattering profpect which they had of an independent fortune, fuited to their education and rank in life. It made many cruel encroachments upon the time and occupations of a man, whofe mind was equally fitted to en- joy the high attainments of fcience, and the elégant amufements of tafte. As the price of fo many facrifices, he was only ena- bled to draw from his colliery, and that by the indulgence of his creditors, a moderate annual maintenance for himfelf and family during his life. At his death, his widow was left with- out any provifion whatever for her immediate or future fupport, (K 2) and Account of Dr Roebuck (76) HISTORY of the SOCIETY. a and without the fmalleft advantage from the extraordinary ex- ertions and meritorious induftry of her hufband. % Dr Roesuck had, fome years before his death, been attack- ed by a complaint that required a dangerous chirurgical opera- tion, That operation he fupported with his ufual fpirit and re- folution. In a fhort time he was reftored to a confiderable fhare of his former health and aétivity. But the effects of it never entirely left him, and feveral flighter returns of the com- plaint gradually impaired his conftitution. He ftill, however, continued, till within a few weeks of his death, to vifit his works, and to give direction to his clerks and overfeers. He was confined to his bed only a few days, and died on the 17th July 1794, retaining to the laft all his faculties, his fpirit and good humour, as well as the great intereft which he took, as a man of fcience and reflexion, in the uncommon events which the prefent age has exhibited. From a man fo deeply and fo conftantly engaged in the de tail of active bufinefs, many literary compofitions were not to be expected. Dr Roezsuck left behind him many works, but few writings. The great objet which he kept invariably in view was to promote arts and manufa¢tures, rather than to efta- blifh theories or hypothefes. The few efflays which he’ left, enable us to judge of what might have been expected from his tale ts, knowledge, and boldnefs of invention, had not the ac- tive undertakings in which, from an early period of life, he was engaged, and the fatiguing details of bufinefs, occupied the time for ftudy and imvelligation. A comparifon of the heat of London and Edinburgh, read in the Royal Society of London June'2g. 1775, Experiments on ignited bodies, read there 16th: February 1776, Obfervations on the ripening and filling of corn, read in the Royal Society of Edinburgh 5th June 1784, are all the wri- tings of his, two political pamphlets excepted, which have: been publithed. The publication of the eflay on ignited bodies was occafioned APPENDIX. (77) occafioned by a report of fome experiments made by the Comte pE Burron, from which the Comte had inferred, that matter is heavier when hot than when cold. Dr Rogsuck’s experiments, made with great accuracy before a committee of the Royal So- ciety at London, feem to refute that notion. Ir is the works and eftablifhments projeéted and executed by Dr Rozzuck, with the immediate and more remote effects of them upon the induftry, arts, and manufactures of Scotland, which urge a juft claim to the refpeét and gratitude of his coun- try. This tribute is more due from the difcerning part of man- kind, as this {pecies of merit is apt to be overlooked by the bufy or the fuperficial, and to fail in obtaining its due reward. The circumftances of Dr RoEsuck have, in this refpect, been pecu- liarly hard: For though, moft certainly, the projector and au- thor of new eftablifhments highly ufeful to his country, and every day becoming more fo, he was, by a train of unfortunate events, obliged to break off his connexion with them, at an un- | feafonable time, when much was yet wanting to their complete faccefs: and thus he left others in the poffeflion, not onlv of the lucrative advantages now derived from them, but even, in fome meafure, of the general merit of the undertaking, to a con- fiderable part of which he had the moft undoubted claim. - Tue eftablifhment of the laboratory at Birmingham, in the year 1747, the firft public exhibition of his chemical talents, was, at that particular period, and in the ftate of the arts and manufac- tures at that time, highly beneficial, and fubfervient to their fu- ture progrefs: and the continuance and fuccefs of it, in that place, is a proof of the advantages which many of the manufacturers receive from it. Much had already been done, and many improvements made in arts and manufactures, chiefly by the fuggeftions of that ingenioufnefs and experience, which, in the detail of bufinefs, might be expected from the pra¢tical ar- tift. Dr RoEsucK was qualified to proceed a ftep farther ; to: direct: Account of Dr Roebuck. (78) HISTORY of the SOCIETY. Account of Ds Rone dire@ experience by principles, and to regulate the mechanical operation of the artift by the lights of fcience. The effects of that eftablifhment extended, in a particular manner, to all that variety of manufactures in which gold and filver were required, to the preparing of materials, the fimplifying of the firft fteps, to the faving of expence and labour, and to the turning to fome account what had been formerly loft to the manufa@turer. It is well known, that, while Dr Roesuck refided at Birmingham, fuch was the opinion formed of his chemical knowledge and experience by the principal manufacturers, that they ufually confulted him on any new trial or effort to improve their feve- ral manufactures ; and, when he left that place, they fincerely regreted the lofs of that eafy and unreferved communication they had with him, on the fubjects of their feveral departments. On account of fimilar circumftances, the benefit to the public, from the eftablifhment of the vitriol works at Preftonpans, in the extenfion and improvement of many of the arts, cannot now be exaétly afcertained. The vitriolic acid is one of the moft ac- tive agents in chemiftry, and every difcovery which renders it — cheap, and acceflible to the chemift, muft be greatly fubfervient to the progrefs of that fcience. By the eftablifhment at Prefton- pans, the price of that valuable acid was reduced from fixteen to four pence per pound. It is to Dr Roresuck, therefore, that chemifts are indebted for being in poffeflion of a cheap acid, to which they can have recourfe in fo many procefles. But Dr Roesucx’s objet, in the profecution of that {cheme, was not fo much to facilitate the chemift’s labour, as to render that acid, in a much higher degree than it had formerly been, fubfervient to many of the practical arts. By rendering the vitriolic acid cheap, great ufe came to be made of it in prepa- ring the muriatic acid, and Grauser’s falts from common falts. Its ufe has been farther extended to many metallic pro- ceffes; and it has lately been employed in feparating filver from the MPO PE NSD TX. _ (79) the clippings of plated copper, the ufe of which is very exten- five. Tue application of the vitriolic acid in bleaching linen, or a fabftitution of it for four milk, was firft publifhed by Dr Francis Home: But it is well known to feveral of Dr RoE- BUCK’s chemical friends, that he had tried it, found it effeCtual, and had frequently recommended it to bleachers before the - date of that publication. The quantity of it now confumed in that art is very great. Of late it has been ufed in decompo- fing common falt, with the addition of manganefe, in order to obtain the oxygenated muriatic acid, by which the procefs of bleaching fine linen is amazingly fhortened. Much of it too is ufed in preparing the beft kind of aquafortis, or nitrous acid, from faltpetre, which was decompofed formerly, and ftill is, in many cafes, by vitriol, inftead of the vitriolic acid ; but the vi- triol gives an aquafortis of inferior ftrength and purity. The dyers alfo employ great quantities of it in different procefles, particularly in diffolving indigo, in one of their methods of dy- ing with that drug. Ar firft, the manufatories of the vitriolic acid in Britain fupplied foreign nations as well as our own, though forcigners, having fince difcovered or learned the art, now make it them- felves, But it would be tedious to mention all the applications of it which have been already made, and it is impoflible to fay how far the ufe of this powerful agent in chemiftry, and the arts, may be carried. Enough has been faid to fhow, that Dr Roesuck’s difcoveries, in that department, have been of the greateft advantage to fcience and the practical arts, in facilita- ting the procefs for procuring this acid, and in rendering it of general ufe ; and it is but fair that the name of that perfon fhould ftand on record, to whom chemifts and artifts are fo much indebted for their fubfequent fuccefsful labours. THE Account of Dr Roebuck, Account of -Dr Roebuck, (80) HISTGRY of theo SOCIETY. THE project and eftablifhment, however, of the ironworks at Carron, the moft extenfive eftablifhment of that kind hither- to in Britain, muft be confidered as Dr RoEBuck’s principal work. The great and increafing demand for iron in the pro- greflive ftate of arts, manufactures and commerce in Britain, and the great fums of money fent every year to the north of Europe for that article, turned the attention of chemifts and artifts to the means of promoting the manufacture of iron, with the view of reducing the importation of it. No perfon has a better founded claim to merit, in this particular, than Dr Rog- Buck. The fmelting of iron by pitcoal, it is indeed believed, had been attempted in Britain in the beginning of the laft cen- tury. In the reign of James I. feveral patents feem to have been granted for making hammered iron by pitcoal, particular- ly to the Honourable Dup DuDLey and Simon STARLEVANT. It does not appear, however, that any progrefs had been made in the manufacture in confequence of thefe patents. In later times trials have been made by fo many different perfons, and in fo many different places in England, nearly about the fame time, that it may be difficult to fay where and by whom the firft attempt was made, particularly as the difcoverers of fuch procefles wifhed to conceal the knowledge they had gained as long as they could. But Dr RozBuck was certainly among the firft, who, by means of pitcoal, attempted to refine crude or pig iron, and to make bar iron of it, inftead of doing it by charcoal, according to the former pradlice : And he was, with- out all queftion, the perfon who introduced that method into Scotland, and firft eftablifhed an extenfive manufacture of it. It is not meant to afcribe to him the fole merit of the eftablifh- ment at Carron. No man was ever more ready than he was, to do juftice to the abilities and fpirit of his friends and partners, Meffrs Garset, CADDELL, &c. who firft embarked with him in that great undertaking. But ftill it may be faid with truth, that - the APPENDIX. (81) the original project of the ironworks at Carron, the chemical knowledge and experience on which they were founded, the com- plicated calculations which were previoufly required, the choice of the fituation, the general conduct and direction of the build- ings and machinery, the fuggeftion of many occafional im- provements, together with the removal of many unforefeen ob- ftacles and difficulties, which occurred in the infant {tate of that eftablifhment, were, in a great meafure, the work and labour of Dr Rorsuck. Nor can it, with the leaft fhadow of juttice, detract from his merit, that a larger capital, and greater expence than was at firft calculated, have been found neceflary to bring the works at Carron to their prefent {tate of perfection ; or, that great alterations and improvements have taken place, du- ring the courfe of forty years, ina great and progreflive efta- blifhment. In all works of that kind, the expence exceeds the calculation. The undertakers even of the lateft ironworks which have been erected, notwithftanding all the advantages obtained from recent experience, will be ready to acknowledge, that, in thefe refpeéts, there is little room to blame the original projector of the firft eftablifhment of that kind in Scotland. But the beft, and moft infallible proof of Dr Rozpucx’s merit, and of the found principles on which thefe works were efta- blifhed, is the prefent profperous ftate of.that eftablifhment, the great perfection of many branches of their manufactures, and, particularly, the many extenfive and flourifhing ironworks, -which have been fince erected upon the model of Carron, in different parts of Scotland, at Cleugh, Clyde, Muirkirk, and ‘Devon. - It cannot be denied that all thefe works have fprung from the eftablifhment at Carron, and are ultimately founded upon the knowledge and experience which have been obtained from them; for fome of the partners, or overfeers of thefe new works, and many of the workmen, have been, at one time, or ‘another, connected with that of Carron. Hence, then, it if ow- Wow.tV. - .. (L) ing Account of Dr Rocbucks Account of Dr Roebuck. (82) HISTORY of ers ocrieETyY. ing to the projector and promoter of the eftablifhment at Car- ron, that Scotland is, at this moment, benefited to the amount of many hundred thoufand pounds, in working up the raw ma- terials of that manufacture found in the country itfelf, and which, previous to that eftablifhment, was of no value what- ever. Such are the prefent, but fcarcely any idea can be formed of the future advantages to this country, which may be derived from the extenfion of the iron manufacture. About 60,000 tons of iron have been annually imported into Great Britain for more than twenty years paft, and though there has been, for fome time, about 20,000 tons of bar iron made in Britain by pitcoal, yet the foreign imported iron has fuffered little or no diminution in quantity. This great confumption of iron, no doubt, is owing to the various improvements of late years, and the general extenfion throughout all Europe of commerce and the arts. The manufacture of iron muft therefore conti- nue to increafe, and Scotland, abounding every where in iron- ftone, pitcoal, and in command of water for machinery, has the profpeét of obtaining the largeft fhare of it. To the eftablifhment of the Carron works, and to the confe- quences of that eftablifhment, may be afcribed alfo the exift- ence of other public works in Scotland of great importance and utility. The opening of a communication by water be- twixt the Forth and the Clyde had long been projected, and frequently the fubje&t of converfation in Scotland, but nothing in fact had been attempted. The eftablifhment of the iron- works at Carron foon called forth fufficient intereft and enter- prife to bring about the execution of this grand defign. Some of the partners of the Carron Company, forefeeing the advan- tages they would derive from fuch a communication, propofed, at their own expence, to execute a fmall canal; and, after taking the preparatory fteps, actually applied to Parliament to obtain authority for that purpofe. But the project of the {mall canal not APPENDIX. (33) not meeting with the approbation of fome noblemen and gen- tlemen in that part of Scotland, they oppofed the bill, and obli- ged themfelves to execute a greater canal, which has now been many years finifhed, and is found to be of the greateft advan- tage to the trade and commerce of Scotland. - The merit of this undertaking is not meant to be afcribed to Dr Rorguck, ex- cepting in fo far as it neceffarily arofe from the eftablifhment of the Carron Company, of which he was the original projector; and it may reafonably be doubted, whether, without that efta- blifhment, it would have yet taken place. Several other canals have, fince that time, been executed in different parts of Scot- land, and other very important ones are at prefent projected. The different eftablifhments which Dr RozeBuck made at. Borrowftounnefs in carrying on the coal and falt works there, though ultimately of no advantage to himfelf, were attended, during the courfe of thirty years, with the moft beneficial ef- feéts upon the trade, population, and induftry of that part of Scotland. They were the means alfo of adding very confide- rably to the public revenue. Previous to the time thefe works fell under Dr RoEBuck’s management, they produced no ad- vantage either to the proprietor, or the adventurers, or to the public. But by his mode of conducting them upon a more ex- tenfive plan, by opening up new feams of coal, and of better quality, he was enabled to export a very confiderable quantity, _ to increafe the quantity of falt, and, of courfe, the revenue ari- fing from thefe articles. In thefe works, and in the manage- ment of a large farm, Dr RoeBuck gave employment to near a thoufand perfons at Borrowftounneds, and in the neighbour- hood, Nor was it folely by the different eftablifhments which he. projected and executed, but by many other things neceffarily. connected with them, that Dr Rorzuck’s labours were beneficial to Scotland. Along with them he may be faid to have introdu- (L 2) ced : Account of Dr Roebuck. (84) HISTORY of the SOCIETY. Acco ar rt Cee eae apr ier ae enterprife and induftry, before that time little — known in Scotland,-which foon pervaded many other depart- ments of labour, and gave birth to many other ufeful projects. He brought from England, then much farther advanced in arts and induftry, many ingenious and induftrious workmen, at great expence, who, by their inftructions and example, commu- nicated and diffufed fkill and knowledge to others. At all times Dr Roesuck held out liberal encouragement to rifing genius, and induftrious merit ; and fpared no expence in making trials of improvements and difcoveries, which were connected with the different projects and works which he was carrying on. Sucu was the active and ufeful life of Dr RokBucK, a man of no common caft, who united, in a very high degree, a great number of folid and brilliant talents, which, even feparately, fall to the lot of but few individuals. Diftinguifhed by an ar- dent and inventive mind, delighting in purfuit and inveftigation, always afpiring at fomething beyond the prefent ftate of fcience and art, and eagerly prefling forward to fomething better or more perfect, he thus united energies the moft powerful, with the moft unwearied and perfevering induftry. To that pecu- liarity of imagination, fo fitted for f{cientific purfuit, which rea- dily combines and unites, which fteadily preferves its combina- tions before the eye of the mind, and quickly difcovers relations, refults and confequences, was added, in his character, great promptitude and firmnefs in decifion. Strongly and early im- preffled with the great importance of applying chemical and phyfical knowledge to the ufeful arts, to the melioration of civil life, he never loft fight of that favourite view, and dif covered great boldnefs and refource in the means and expe- dients which he adopted to promote it. He was certainly ma- fter of the beft philofophy of chemiftry known in the earlier parts of his life, and though, in every ftage of that fcience, he marked and underftood the progrefs of the difcoveries, yet his numerous APPENDIX. (85) numerous avocations did not permit him to follow them out by experimental procefles of his own. Upon that, and indeed almoft upon every fubject, his mind readily grafped the moft ufeful and fubftantial points, and enabled him to throw out fuch hints, and hypothefes, as marked him the man of genius. Durine the courfe of a regular education, both at Edin- burgh and at Leyden, Dr Rorsucx ftudied the claflic authors with great attention, particularly the hiftorical and political parts of their works. Upon thefe fubjects he had read much, felected with judgment, and was well acquainted with the facts and philofophy of ancient governments. This tafte he carried with him, and improved in every period of his life, and in every fituation. It abundantly rewarded him for the earneftnefs and diligence with which it had been acquired. It became his fa- vourite refource, and indeed one of the chief enjoyments of his life. Poffefling the happy talent of turning his mind from fe- rious and fatiguing, to elegant and recreating purfuits, it was no uncommon thing with him to return from the laboratory or the coalpit, and draw relaxation or relief from fome one or other of the various ftores of claffical learning. No man was better acquainted with the hiftory of his coun- try than Dr Rorsuck, or more admired and revered the con- ftitution of its Government. By temper and education he was a Whig, and at all times entered, with great warmth, into the political difputes and controverfies which agitated parties, in the different periods of his life. If the natural warmth of his tem- per, and his enthufiafm on thefe fubjeéts, led him, on fome occafions, beyond the bounds of candid argumentation, his quick fenfe of decorum, and his perfect habits of good man- ners, produced an immediate atonement, and reftored the rights of elegant and polifhed converfation. THE general acquaintance which Dr Rorsuck had acquired with natural and experimental philofophy, together with his claffical Account of Dr Roebuck. Account of Dr Roebuck. (86) HISTORY of the SOCIETY. claffical and political knowledge, rendered him an agreeable companion to the learned, almoft of every department, and pro- cured him the attachment and friendfhip of many of the firft literary charaéters in Britain. With his friend Dr Buack he lived, till his death, in clofe habits of intimacy ; and he often acknowledged, with much franknefs, the advantages which he derived, in his various purfuits, from a free and unreferved communication with that eminent chemift. Tue amiable difpofitions of fenfibility, humanity, and gene-- rofity, which ftrongly marked his character, in the general in- tercourfe of fociety, were peculiarly preferved and exercifed in the bofom of his family, and in the circle of his friends. In the various relations of hufband, father, friend, or mafter, and in the difcharge of the refpective duties arifing from them, it would not be eafy to do juftice to his character, or to determine in which of them he moft excelled; nor muft it be forgot, for it refle@ted much honour on his benovelent heart, that his work- men not only found him at all times a kind and indulgent ma- fter, but many of them, when their circumftances required it, a fkilful and compaflionate phyfician, who cheerfully vifited the humbleft receffes of poverty, and who attached them to his fer- vice by multiplied aés of generofity and kindnefs. WE cannot conclude this narrative, without exprefling our regret, that talents fo great, and fervices fo ufeful to his coun- try, as were thofe of Dr Rozsuck, fhould have turned out of fo little account to himfelf and his family. But this is, in fact, no uncommon cafe. The great benefactors of fociety have never been men actuated by gain or intereft, but thofe whofe ambition was fixed on promoting the convenience and happinefs of men. The Doétor had in faét too little regard for money, and was ge- nerous in the extreme. It muft be confefled, too, that his con- fidence and ardour prevented him from forefeeing fome of the difficulties and obftacles he met with, and frequently tempted him, APPENDIX. (87) him to lay out large fums, in the profecution of fome of his projects, without fufficient ceconomy, and, of courfe, without proper returns. His open, unfufpicious temper, alfo, led him frequently to put too much truft and confidence in fome of thofe who had the charge of his works, which proved to him the caufe of many cruel difappointments. But even from his errors and failure the public have derived advantage ; and it is furely indifputable, that a man, who paffed fixty years in ac- quiring knowledge, and enlightening his countrymen, is well entitled to the gratitude of his country. During his life, his public fervices were not altogether overlooked. He often met with flattering marks of approbation from many liberal and public fpirited noblemen and gentlemen in this country ; and the City of Edinburgh, then under the aufpices of Provoft Drummonp, when they honoured him with the freedom of their City, was pleafed to add in his diploma, “ That it was given for eminent fervices done to his country.” But enough has not yet been done. Some farther tribute is due to his me- mory: For there is a juft debt of gratitude conftituted againtt the public, which cannot be confidered -as difcharged, as long as the Widow of Dr Rozsuck, whofe fortune was funk in thefe great undertakings, is left without any provifion for her imme- diate or future fupport. END OF THE HISTORY Account of Dr Roebuck, The Biographical Account of Dr Rozertson, read before the Society March 21. and May 9. 1796, will appear in the next Volume of the Tranfattions. 2 i. PAPERS OF THE PHYSICAL CLASS. I. Account of a4 MINERAL from STRONTIAN, and of a pe- culiar Species of Eartu which it contains. By THomas CHarLis Hope, M.D. F.R.S. Epin. Profeffor of Medicine in the Univer/ity of Glafgow, and Phy/ician to the Glafgow Royal Infirmary. [Read Nov. 4. 1793-] : HE mineral, of which I have the honour to lay an ac- I count before the Society, was brought to Edinburgh in confiderable quantity about fix years ago by a dealer in foffils, though indeed it had found its way, long before this period, into one or two collections. By fome it was miftaken for fluor. Its great fpecific gravity, its fibrous appearance, and its quality of forming an infoluble fubftance with fulphuric acid, made it generally be received as . the native carbonate of barytes. -From a few experiments, I was led at that time to entertain fome doubt of its being any form of barytes ; and for feveral years, when I filled the che- mical chair in the Univer fity of Glafgow, I ufed, when I exhi- bited the’ mineral itfelf, to mention in my le€tures fuch of its - properties as, ‘I had difcovered, and which indicated that it did ~ not belong to the barytic genus. Towards the end of the year ye 1791, 4 ACCOUNT of a MINERAL 1791, I commenced and executed a feries of experiments, the detail of which [ laid before the College Literary Society of this place in March 1792. ‘Thefe not only fatisfied me that I had been right in my conjecture, which was, that this mineral dif- fers from acrated barytes, but alfo gave reafon to imagine, that it contains a peculiar and hitherto unknown kind of earth. Other experiments, more lately performed, ftrongly confirm, and perhaps | may add, eftablith this notion. . Dr Crawrorp, having remarked the confpicuous difference inthe form of the cryftals of the muriate of this foflil and of the muriate of barytes, and in their folubilities in water, has thrown out a conjecture to the fame purpofe, at the end of his paper on the Muriated’ Barytes, in the fecond volume of the London Medical Communications. 2. THE mineral of which | have been fpeaking, I am in- formed, is found in the lead-mine of Strontian in Argylethire. It lies imbedded in the metalliferous vein, fcattered among the ore and the different fpecies of fpar that are moft commonly met with in fuch fituations. I have fpecimens in which por- tions of lead-ore are attached to.this mineral, and others in which it, calcareous and ponderous fpars, are intermingled in large and confiderable maffes. More obvious Qualities. 3. THE appearance of this foffil varies in different famples, Tt univerfally poffeffes the fparry ftructure, and fometimes bears a ftrong refemblance to fome forts of calcareous or fluor. fpars. Its texture is commonly fibrous. The fibres fometimes are flender, and in clofe contact with each other, fo as to give the mafs a confiderable degree of compactnefs. At other times the fibres are much more grofs, and aflume a kind of columnar appearance. The fibres or columns have, in the greater num- ber of f{pecimens, a degree of divergency, iffuing as radii from a tr ee 4 From STRONTIAN. 5 acentre. The uniformity of this radiation is frequently in- terrupted by the fibres proceeding from different points of con- vergence, croffing and interfefting each other. Occafionally on the furface, but more frequently in vacuities within the mafs, the mineral is difcovered fhooting into flender prifmatic or co- lumnar cryftals of various lengths. Some of thefe end obtufe- ly, others of them in a fharp point; they are generally ftriated, and have fix fides. I have feen thefe cryftals traverfing the cavi- ties in the form of the fineft and moft delicate fpicule, and when difpofed in a radiated form, equalling in ‘delicacy, and refembling in appearance, the moft exquifite zeolites. In other portions, the ftriated fibrous contexture is fcarcely difcernible. Sometimes the Strontian {paris tranfparent and colourlefs, more commonly it has a tinge of yellow or green, and fome diver- fity is obfervable in the depth of the tint. 4. It is not fo hard as to fcintillate ; it may be fcratched by a knife; it readily yields to the ftroke of the hammer; it has — no particular fracture, though it commonly breaks alorig the di- rection of the fibres. 5. Iv is a heavy fpecies of fpar, having a fpecific gravity, go- ing between 3.650 and 3.726. Chemical Qualities. 6. Tuts mineral to the tafte is infipid, and is only in a fmall degree foluble in water. 1 boiled ten grains of it, reduced to a very fine powder, in four ounces of diftilled water for fome _time ; about two grains and a half were diffolved. 7. Ir is powerfully attacked by feveral of the acids, and a fo- lution takes place in fome of them. This is accompanied by a lively and brifk effervefcence, which in this as in every other inftance, proceeds from the difengagement of an aerial fluid. 8. Tue gas that arifes during a folution of this mineral in muriatic acid, extinguifhes the flame of a candle, and is ab- forbed 6 ACCOUNT of a MINERAL forbed by water. The water thereby acquires the tafte of wa- ter impregnated with fixed air or carbonic acid, and the pro-._ perty of precipitating lime-water and of rediflolving the preci- pitate when added to excefs ; from which circumftances I infer, that the elaftic fluid that is difengaged is carbonic acid gas. 9- To difcover how much of this acid it contains, I diflolved in diluted muriatic acid 960 grains, ufing every precaution to prevent any thing but elaftic fluid from efcaping during the ef- fervefcence. The diminution of weight that took place a- mounted to 290 grains. This correfponds with the refult of fe- veral other experiments made with the fame intention. This {par confequently contains 30.2 per cent. of carbonic acid. 10. Havine premifed thus much with regard to the ation of acids in general on the foffil, and concerning its compofition, I fhall delay mentioning its habitudes with each till I have de- tailed the effects of heat upon it. 11. WHEN heat is applied to the Strontian fpar, it crackles a little, and as the temperature increafes it lofes its tranfparency, _ becomes white, opaque, and in fome meafure friable. It re- quires, however, a very {trong fire to produce any further change. 12. I puT two pieces, weighing together 320 grains, into a {mall crucible, and inverting another over it, I placed it in an open fire. In this fituation it remained for three hours, the fire being good, and at different times animated by means of bel- lows. Thefe pieces retained their form; they were white, opaque and brittle, and had loft only two grains of their. weight. Their chemical properties were unaltered. 13. A veRY vehement heat occafions remarkable changes. A {mall mafs was inclofed in a crucible, made of pure Stour- bridge clay, already prepared for forming glafs-houfe pots, ha- ving a lid fitted to it of the fame materials. The crucible, gra- dually heated, was kept for forty-five minutes in the intenfe heat excited by the well managed fire of a fmith’s forge. At k the = Ber Oe Ce From STRONTIAN. 5 _the expiration of this time, the crucible itfelf became foft. and from being turned in the fire was diftorted in its fhape. On examination after cooling, part of the fpar was found to have undergone fufion, and was converted into a glafs of a bottle- green colour. The vitrified portion occupied the furface; the internal part was to appearance fimilar to the refult of the laft experiment, but it felt much lighter. It now had an acrimo- nious tafte; it attracted water with great avidity, and imbibed it with a hiffing noife; it was reridered foluble in this fluid. The lofs of weight which the fpar fuftains when the a¢tion of the fire has produced its fulleft effe&t, amounts to 38.79 per cent. When a little water is poured on the calcined mineral, it {wells, burfts with a hiffing noife, and becomes hot with more rapidity and in a greater degree than lime ; like it, it falls into a dry powder, but the particles are not fo fine. THE powder unites with acids into the fame fort of com- pounds as before, but no effervefcence attends the combination. When the glafs is dropped into muriati¢ acid, it is flowly acted upon; at length a jelly is formed, which becomes perfectly fluid on the addition of water, a minute portion of powdery matter, which probably comes from the crucible, remaining undiffolved. If the calcined fpar be left expofed to the atmo- f{pheric air, in the courfe of twenty-four hours, it {wells, cracks and crumbles into powder, at the fame time attracting carbonic acid, and becoming effervefcent. 14. Unper the blowpipe the {par becomes white and opaque, and lofes a part of its carbonic acid. I have not been able to vitrify it per fe. With borax, mineral alkali and microfmic falt, it melts readily into a white vitreous matter. An _effervef- cence attends the fufion, particularly when borax is employed. 15. Iv appears from the experiments already recited, that the Strontian mineral lofes a greater weight when fubjected to heat | than during folution in acids. This muft be afcribed to the ex- pulfion of moifture in the one cafe, and the retention of it in the -§ ACCOUNT of a MINERAL the other. The difference marks the quantity of water which enters into the compofition of the {par. By heat 38.79 per cent. is expelled, while there is a lofs by folution of 30.20. HENCE 100 parts contain of earthy bafis, 61.21 carbonic acid, = hgoro water, - 8.59 100 16. As I hope to be able to render it probable, that this earthy bafis differs from any of the hitherto known fpecies of earth, I fhall, to fave circumlocution hereafter, take the liberty of calling it by the name of Strontites ; by which | with to be underftood to mean the earthy matter in a ftate of purity, in the fame way as lime and barytes denote the pure earthy bafes of calcareous fpar and of aérated barytes. 17. Or the qualities of the Strontites it will be proper to add fome more particulars. SrRONTITES has a pungent acrid tafte. When brayed in a mortar, the fubtle powder that arifes is penetrating and offen- five to the noftrils and lungs. It is foluble in water in the pro- portion nearly of 2.7 grains to the ounce, at temperature 60. The folution is clear and tranfparent, poflefling a ftrong tafte, not unlike that of lime water; it changes to a green, papers ftained with the juice of violets or radifhes. On expofure to the air, ftrontitic water quickly acquires a cruft on the furface, in confequence of the earth attracting carbonic acid and beco- ming infoluble. 18. Hor water diffolves a much larger quantity than cold, and depofits the Strontites as it cools in the form of colourlefs and tranfparent cryftals. The moft ready way of obtaining thefe is to pour a quantity of boiling water into a Florence flafk, » and then to throw in the recently calcined fpar in {mall pieces. After the ebullition that enfues has ceafed, fhake the flafk well, I and, M4 i a rll From STRONTIAN. 9 and place it fo that it fhall cool flowly and without difturbance. The cryftals will be found attached to the infide of the veffel, fhooting beautifully through the water to the length of an inch or more. The form of the cryftal is abundantly diftiné ; it is a thin quadrangular plate, which is fometimes {quare, though more frequently a parallelogram ; the largeft of them feldom exceed a quarter of an inch in length, and that is ufually fome- what more than their breadth. Sometimes the edges of the plates are plain, oftener they prefent two facets meeting like the © roof of ahoufe. They, for the moft part, adhere to each other in fuch a manner as to form a thin plate an inch or more in length, and half an inch in breadth, the margin {being irregu- lar from projecting rectangles, the whole terminated by a regu- lar cryftal. Sometimes the-plates are thicker, and form folid parallelopepids, and occafionally are feen perfect cubes. 19. In the courfe of expofure to the air for a few hours, thefe cryftals ceafe to be tranfparent; they become white, powdery and effervefcent. The gain of carbonic acid does not compenfate the lofs of humidity ; for they fuffer a diminu- tion of weight which amounts to nearly to per cent. To pre- ferve them, we muft have recourfe to phials very clofely corked. When fubjected to heat, they lofe the fuperficial moifture with a hiffing noife ; as the heat approaches to near a dull red, they undergo fufion, which feems to be of the watery kind; for as _ foon as all the humidity is diffipated, there remains a white powder that refifts an extreme degree of heat. Water enters . largely into their compofition ; 100 grains of them loft by the expulfion of the moifture, 68 grains. Water diffolves them but flowly, particularly when they have not been bruifed, in the pro- portion of 8.5 grains to the ounce at temperature 60. An ounce of water, in a heat fufficient to keep the folution boiling, diffolved no lefs than 218 grains. This is an aftonifhing degree of folubility in an earthy matter, and affords a diftinguifhing feature of Strontites. Thefe folutions are pofleffed of all the Vou. IV. CNRS i tae properties 10 ACCOUNT of a MINERAL properties of Strontitic water above recounted. In acids the cry- {tals are diflolved without effervefcence, and there refult the fame products as when the native mineral is employed. 20, WHEN I firft obferved the Strontites in a ftate of cryftal- lization, I imagined it was the only earth that could, in confe- quence of its greater folubility in warm than in cold water, be obtained in this form, and I noted this property as character- iftic of it. I have however been fo fortunate as likewife to pro- cure cryftals of barytes. HaBITUDES OF STRONTIAN MINERAL WITH ACIDS: With Sulphuric Acid. 21. WHEN a folid piece of fpar is dropped into fulphuric acid, a few air bubbles arife, but thefe foon ceafe, and the mafs remains undiflolved. If, however, the {par be firft reduced in- to fine powder, and then added to the acid in fmall portions, an effervefcence takes place, a combination is formed, and the compound falls to the bottom. The acid, in very minute quan- tity, renders Strontitic water turbid, which arifes from the forma- tion of the fulphate. 22. Tue fulphate of Strontites is in the form of a white powder. It has no tafte, and very little folubility in water. I boiled one grain for fome minutes in four ounces of diftilled water, half a grain was diffolved. The folution became tur- bid on the addition of the carbonate of potafs, of barytic wa- ter, and of muriate of barytes. Sulphuric acid, when aided by heat, readily diffolves it. An effufion of water caufes the acid to part with the earthy falt. With ee — From STRONTIAN. T1 With Nitrous Acid. 23. WHEN the nitrous acid in its ftrongeft ftate is poured on a ma{s of native carbonate of Strontites, nd action enfues ; but if fome water be added, the acid commences to aét with ener- gy, and a folution, attended with a brilk effervefcence, is the confequence. Very little will be diffolved, though the fpar be finely powdered, if the acid be highly concentrated. A fimall increafe of temperature, it may be remarked, enables the ftrong acid to attack the folid fpar, and to accomplifh the folution. If you employ an acid previoufly diluted, the ebullition inftantly begins; for this purpofe, an equal quantity of water at leaft muft be mixed with the acid. If much lefs be added, the ef- fervefcence and folution will commence, but they will both foon ceafe. When the quantity of water is fufficient, the acid free from adulteration, and the {par pure, no refiduum is left, and a clear and tranfparent folution is obtained ; but if fomewhat lefs of the water be employed, the falt that is formed by the union of the acid and earth immediately affumes a folid cryftal- line form. It was by a folution carried on in this manner that I procured the moft regular, though by no means the largeft cryftals of this nitrate. 24. THE folution has a ftrong pungent tafte. It is perfectly neutral, and readily by evaporation yields cryftals. ‘Thefe are rarely produced in fo regular a manner that their form can be eafily afcertained. By a flow and fpontaneous evaporation, cry- ftals were formed that were hexagonal truncated pyramids. The moft perfect cryftals, obtained in the way a little ago defcribed, were octohedral, confifting of two four fided pyramids united by their bafes. Sometimes the apex is truncated, and the cry- ftals terminate like a wedge; often likewife the angles are trun- cated in different degrees, which gives a confiderable variety to the fhape of the cryftals, B2 25. THIS re ACCOUNT of a MINERAL 25. Tuts falt is very foluble in water. One ounce of diflil- led water at temperature 60 diflolved an equal weight. With the aid of a boiling heat, the fame quantity diffolved one ounce, feven drachms and fourteen grains. The folution, faturated in a boiling heat, parts not with the falt immediately on cooling, but depofits it flowly in the form of a confufed mafs of cryftals. The nitrate of Strontites in a dry air lofes its water of cryftaili- zation and efflorefces ; in a moift, it attracts humidity, and runs per deliquium. 26. Tuts, as all other nitrates, deflagrates on hot coals. Sub- jected to heat in a crucible, it decrepitates gently, and then melts. When the heat rifes to rednefs, it begins to boil, and the acid is diffipated. If a combuftible fubftance be at this time brought into contac with it, a deflagration, with a very beautiful vivid red flame, is produced. By the operation of the heat, the falt fuffers a complete decompofition, the acid is ex- pelled, and the earth remains in a ftate of purity, unlefs in- flammable matter has gotten accefs to it, in which cafe it will prove a carbonate. With Muriatic Acid. 27. Very fimilar phenomena to thofe already defcribed, as attending the action of nitrous acid on the Strontian fpar, are exhibited on pouring muriatic acid on this fubftance. When the acid is concentrated, and the fpar is in folid pieces, no ac- tion whatever, or very little, takes place. ‘The effervefcence is brifk, and the folution rapid, when the acid is diluted with about an equal weight of water. A gentle heat, applied to the ftrong acid. has the fame effect as dilution. 28. Tue folution in the weak acid is tranfparent and. free from colour, and affords cryftals moft readily. On diflipating part of the fluid by heat, and permitting the reft to cool, the muriatic falt cryftallizes in a beautiful manner. The crytftals are . i From STRONTIAN. 13 are delicate flender prifms, fometimes two inches long, having a foft filky appearance. If the refrigeration has been very gra- dual, the prifms will be formed lefs delicate, and of a more di- ftinguifhable fhape. All of them are hexagonal, fome having all their fides equal, others having two broad fides, with two in- tervening narrow ones, while another fort is feen with three broad alternating with three narrow fides. At one time they end abruptly, at another an obtufe trihedral pyramid terminates them, and now and then they are feen pointed like a needle. 29. By the facility of cryftallization, and by the peculiar form of the cryftals, this earthy falt may be eafily detected wherever it exifts in folution. For this purpofe, put a few drops on a plate of glafs, and the muriate will foon difcover itfelf by fhooting into its long flender needles, which are often difpofed in a radiated form. 30. THEse cryftals, after they are thoroughly dried, fuffer little change from expofure to air, yet when the atmofphere is greatly loaded with moifture, they are apt to deliquefce. Their folubility in water is great. At temperature 60, one ounce of diftilled water is capable of diffolving one ounce, four drachms and one fcruple. To the fame quantity of diftilled water, kept boiling on a fand bath, I added in fucceffive portions four ounces of the falt, which became fluid, and I imagine I might have added any quantity more with the fame event, as the tem- perature of the folution, when boiling, feems fufficient to ena- ble the water of cryftallization itfelf to diffolve the faline mat- ter. 31. Ir into a faturated folution, fome {trong muriatic acid be: thrown, a precipitation inftantly happens. The matter that falls down is the falt in fmall needle-form cryftals, and the fe-- paration of them from the water arifes from the force with which the acid attra¢ts the fluid, being greater than that exert- ed by the falt to retain its folvent. 32; THE ia ACCOUNT of a MINERAL 32. THE tafte of the falt is peculiar, fharp and penetrating. When urged quickly by heat, the muriate of Strontites under- goes the aqueous fufion, and by lofing the water of cryftalliza- tion, and with it 42 per cent. of its weight, becomes a white powder, which, as foon as the crucible is heated to rednefs, melts. A quantity of this falt was kept in the red heat of a {trong open fire, occafionally enlivened by bellows, for above an hour. It had been in perfect fufion, yet its acid was not expelled. It could not, however, when contained in a fmall {poon of platina placed upon charcoal, endure, without decom- pofition, the ftronger heat excited by the blowpipe. With Acetous Acid. 33- Orpinary diftilled vinegar diffolves the Strontian fof- fil, after being reduced to a very fine powder, but with no great energy- An effervefcence, as ufual, accompanies the diffolu- tion. The liquid acetite is tranfparent, and without colour. It changes, though flowly, the colour of violet teft papers to a green. By fpontaneous evaporation, it dries up into a friable falt, compofed of minute cryftals. Tuese are perfiftent, though expofed to the atmofphere. They render green the vegetable colours. They feem to be nearly equally foluble in hot and cold water ; for a quantity of water, kept in a ftate of ebullition, which diflolved them at the rate of 196 grains fer ounce, depofited no cryftals on cooling. With Oxalic Acid. 34. Tue Strontian mineral muft be in fine powder, elfe it will remain untouched by this acid. When finely pulverized fpar is thrown into oxalic acid, an oxalate of little folubility is generated, which falls to the bottom of the veffel, under the form , From STRONTIAN. 15 form of a white powder. This acid, poured into Strontitic wa- ter, unites with the earth, and precipitates with it. 35- Tuis is one of the moft infipid, and one of the moft in- foluble of the combinations into which Strontites enters. Ten grains were boiled in four ounces of diftilled water for fome minutes, there remained undiffolved fully nine grains. The clear liquor had the flighteft poffible degree of milkinefs produ- ced init, on the addition of fulphuric acid, or of carbonate of. potafs, By heat the oxalic acid is deftroyed, and the earth. re-- mains partly pure and partly united to carbonic acid.. With Farsatans Acid. 36. Wirn this acid the mineral exhibits appearances nearly fimilar to thofe now defcribed. There is however, for a fhort- period, an extremely feeble effervefcence. Here I may remark, that for the fake of promoting the union of Strontites with: the weaker acids, 1 frequently employ what I call the artificial: carbonate of Strontites, by which I mean this earth precipitated from an acid by an effervefcent alkali. On this powder the acid: of tartar aéts with vigour. When.dropped into Strontitic wa-- ter, it carries down the Strontites in union with it. 37. Tue tartrite is nearly infipid. I boiled ten grains of it in [four ounces of diftilled water; fix grains were diflolved. This folution, after it had ftood fome weeks in a clofe phial, depofited during frofty weather feveral fmall but very regular- cryftals, the form of which isa triangular table, having the: edges and angles fharp and well defined. Thefe cryftals under- go no alteration from expofure to the air. When acted upon by heat, they at firft fwell and are puffed up after the manner of borax, and at length with ignition lofe their acid, which is the: firft change that the powdery tartrite fuffers under. fimilar treats- ment. : With) 16 ACCOUNT of a MINERAL With Fluorie Acid. 38. ScARCELY any perceivable effervefcence happens when Strontian fpar is thrown into acid of fluor. It is brifk if the artificial carbonate be ufed, but little is diffolved, as the fluate falls to the bottom. Fluor acid occafions a milkinefs in Stronti- tic water by the formation of a fluate, which is poflefled of nearly the fame folubility as the preceding. With Phofphoric Acid. 39. Tuts acid attacks the fpar, though in a folid form, but the progrefs of the effervefcence and folution is exceflively flow. A bit, weighing two or three grains, was not completely diffol- ved in twenty-four hours, though the difengagement of carbo- nic acid went on without interruption. The folution continues clear as long as the acid is confiderably in excefs; but as foon as the point of faturation approaches, it becomes thick, from the depofition of a white powdery phofphate. When the acid of phofphorus is dropped into Strontitic water, a precipitate ap- pears, which is rediffolved when the acid comes to be redun- dant. The phofphate, if perfectly neutral, has little folubility in water. Ten grains of it, treated with four ounces of boil- ing diftilled water, left a refiduum of nine grains. With Succinic Acid. 40. Tue acid of amber, diflolved in water, aflaults, but with no remarkable aétivity, the artificial carbonate of Strontites. A clear folution refults, which, by fpontaneous evaporation, yields a cryftalline fuccinate, which is perfiftent in the air. 3 With Fron STRONTIAN. 17 = | With Acid of Arfenic. at. Tue arfenic acid diflolves with tardinefs fmall but felid pieces of the foffil. With the artificial carbonate the effervef- cence is lively. In either cafe, the compound continues dif- folved till the acid is almoft faturated, when the liquor grows thick, from the depofition of a white powder, which is the ar- fenicate. A precipitate is formed by pouring Strontitic water on acid of arfenic; but agitation makes it difappear. This happens till the acid is nearly faturated ; after which the preci- pitate will not be taken up, unlefs upon the addition of fuch a quantity of acid as fhall make it predominate. The arfenic acid being dropped into Strontitic water, a copious precipitate defcends to the bottom, which vanifhes when the acid comes to prevail. 42. Havine diluted a quantity of this acid aie about twice its volume of water, I threw into it the artificial carbonate to nearly perfec faturation. A clear folution refulted, which evaporated on a plate of glafs, gave a gelatinous fubftance, that by longer expofure to the air dried into a white powder. Cry- {talline forms fhowed themfelves on the infide of a glafs, which contained fome of the folution after it had ftood for fome time. It is fomewhat curious, and deferving of notice, that this folu- tion lets fall the greater part of the arfenicate it contains as foon as it is made to boil by the application of heat. Tue arfenicate fully neutralized is only in a fmall degree fo- luble in water ; an ounce of which, when boiling, takes up ra- ther more than.a grain. With Boracic Acid. 43- To the acid of borax diffolved in hot water, I added a _minute portion of artificial carbonate of Strontites; a flight VoL. IV. Cc effervefcence 18 ACCOUNT of a MINERAL effervefcence and folution took place; and this happened when fimilar fparing quantities were thrown in for two or three times, after which the powder united with gentle effervefcence, and fell to the bottom. I poured Strontitic water into a fimilar folution of the acid; at firft no difturbance of tranfparency was obfervable, but when the point of faturation was not far diftant, a copious precipitate appeared. This I wafhed with cold water, that feems to act little upon it, and diffolved it in boiling, of which it requires about an hundred and thirty times its own weight. The folution changes to a green, the co- lour of paper ftained with the juice of violets. With Carbonic Acid. 44. THE combination of Strontites with carbonic acid we have in the Strontian mineral, the properties of which I have been detailing. The earth, foluble in water, becomes fcarcely fo by uniting with this acid. With an excefs of acid its folu- bility increafes confiderably, as is the cafe with barytes and lime. The folution of Strontites is precipitated by water im- pregnated with carbonic acid, and the precipitate is rediflolved by the addition of more of the fame fluid. 45- STRONTITES, and all its combinations, poflefs a remark- able property, and one which I long confidered as peculiar to them: I allude to the quality of tinging the flame of combu- ftible bodies of a red colour. The muriate has this power in the moft eminent degree. Its effects are well exhibited by put- ting a portion of the falt on the wick of a candle; it caufes the flame to affume a beautiful deep blood-red colour. All the other compounds, and Strontites itfelf, occafion more or lefs of the fame appearance. The nitrate approaches the neareft to the muriate ; and it is in confequence of this property that the de- flagration of this falt with an inflammable fubftance exhibits fo brilliant and vivid a red flame. It isa pretty experiment to ex- tinguifh ‘ Frim STRONTIAN. ig tineuifh a candle by means of carbonic acid gas, as it iflues from a brifkly effervefcing folution of the fpar in muriatic acid. After the nitrate, comes Strontites in cryftals; the acetite holds the next place. Thofe that follow give but a faint tinge of red. I fhall enumerate them in the order of their power: Tartrite, fulphate, oxalate, fluate, arfenicate, carbonate, phofphate and borate; the effect of the two laft is extremely feeble *. 46. Ir is worthy of remark, that a certain portion of humi- dity is abfolutely requifite to enable thefe fubftances to alter the hue of the flame. By way of illuftration, dry by a gentle heat the moft powerful of them all, the muriate, and by that bring it to the ftate of a dry white powder. In this condition it will not affe& the flame; moiften it, and inftantly you reftore its former power.’ This holds true with regard to all the reft; fo much fo indeed, that thofe which have not much moifture in their compofition will not affeét the flame without an addition of humidity. This is the cafe with the fulphate, tartrite, oxa- late, phofphate, arfenicate, borate, fluate, carbonate and cal- cined fpar. Nay, itis even true with refpect to the acetitey though in a cryftalline form. , 47. Aux the combinations of Strontites with different acids, excepting the carbonate, are decompofed by the three alkalis in their ordinary effervefcent ftate, by virtue, in part, of a dou- ble ele@tive attraGtion. When a folution of carbonate of po- tafs, for example, is dropped into the muriate, at firft a tranf- parent gelatinous precipitate is formed, which, upon agitation, after further additions of alkali, acquires a white curdy appear- ance. Similar phenomena accompany the precipitations by the carbonates of foda and ammoniac ; no effervefcence attends any of them. ‘The precipitate, when dried, proves to be a white C2 fubtle * The beautiful experiment with the muriate was firft mentioned to me in the 1787, by an ingenious gentleman, Mr Asn, who was then ftudying phyfic at Kdin- burgh. 20 ACCOUNT of a MINERAL. fubtle powder, and is what I have hitherto denominated the ar- tificial carbonate. In diluted muriatic acid, I diffolved 200 grains of Strontian mineral, and then added falt of tartar, which had run per de/iquium as long as it occafioned any preci- pitate. By the teft of fulphuric acid, | difcovered that the al- kali had feparated the whole of the earth, which was well walhed, and afterwards dried before a fire, being towards the conclufion of the exficcation brought very near the bars; it weighed 198 grains. This deficit of two grains I afcribe to ac- cidental lofs, as during wafhing, by adhering to the filter, We. ‘The artificial carbonate pofleffes all the chemical qualities of the native, with this difference, that it parts with its acid more readily when urged by heat. 48. Tue pruffiate of potafs and of lime did not difturb the tranfparency of a folution of a pure colourlefs mafs of Stron- tian mineral in nitric acid. Sometimes, however, thefe fub- {tances threw down from folutions in the muriatic acid a {pa~ ring precipitate of a blue colour, which denotes the exiftence of a minute portion of iron in fome fpecimens. The precipitate is moft abundant when a coloured fpar has been employed ; whence | conclude, that the colour which the fpar occafionally exhibits is adventitious, and is owing to the iron it contains. 49. Wir fulphur, Strontites combines into an hepar. Equal weights of calcined Strontian mineral and flowers of fulphur were triturated together, and expofed to heat in a covered cru- cible. The heat was continued till a few minutes after the blue flame had ceafed to appear at the chinks of the cover. The mafs had been in fufion. Being pulverifed, part was thrown into muriatic acid; an effervefcence enfued, and the hepatic odour became offenfive. Boiling water was poured on the remaining portion; a yellow-coloured fluid refulted, which was decompofed by acids, and gave with acetite of lead a very abundant black precipitate. In the hamid way likewife a he- par may be formed. On -a mixture of equal parts of flowers of — From STRONTIAN. 24 of fulphur and cryftals of Strontites, I poured fome hot wa- ter, which I caufed to boil for fome time. A liquid hepar, of a dark yellowifh brown colour, was the. product, and fhowed the fame qualities as the preceding. 50. CrysTats of Strontites were diflolved, but fparingly by’ alcohol.. The tincture was of a yellow colour, and burned. with a reddifh flame.. 51. Havinc detailed all the properties of the Strontian mi- neral, and of its earthy bafe, with which I have made myfelf acquainted, my next object fhall be to confider, and, if pofli- ble, to determine, whether this earth be really different and diftinct from all thofe that are already known. There are two kinds to which the Strontitic. bafis bears in its properties no in- confiderable refemblance, I mean barytes and lime; yet it feems to me to differ as much from both of them as they differ the one from the other. In external appearance, it. muft be ac- knowledged, fome fimilarity is obfervable among the native: carbonates of thefe earths. The Strontian foffil refembles moft- the barytic fpar. Indeed this is fo much the cafe, that many perfons admitted it into their colleCtions as the. aérated barytes. Nay, a French chemift. of fome note, M. PeLtLerizr, informs us,; that having analyzed a mafs, which he received from the Honourable Mr.Grevit_e, he did. not publith the refult, for the reafon, ‘‘ qu’elle ne m’avoit fourni rien de particulier *.”’ 52. THESE two productions of nature agree in exceeding other earthy fpars in fpecific gravity ; in retaining their carbo- nic acid, unlefs when urged by a very intenfe heat; in dif- folving when, cauftic in water; in affording the pure earth. in cryftals; in diffolving in acids with nearly fimilar phe- nomena; in forming falts of difficult folubility with feve- ral. of the acids, and cryftallizable ones with the nitric and muriatic. In thefe refpects a ftrong analogy prevails: between them, yet it is but an analogy ; for in the points now’ enumerated,;, * Ann. de Chem. t. 10. p. 188. 22 ACCOUNT of a MINERAL enumerated, as well as in others, a confiderable difference aQtually prevails. 53- Tuer fpecific gravities differ, that of native carbonate of barytes being 4.338, while that of Strontitic fpar goes from 3.650 to 3.726. The laft mentioned parts with its acid fome- what more readily, and without being fufed itfelf, or acting fo powerfully on the clay of the crucible ; and when calcined, it imbibes moifture with much greater avidity, fplitting with more heat and noife. There fubfifts a greater difference be- tween the folubility of pure Strontites in hot and cold water than of barytes* ; moreover, the forms of their cryftals dif agree widely. Strontites generates with fulphuric acid a lefs ponderous and more foluble earthy falt than barytes. It is true that both barytes and Strontites form cryftallizable falts when combined with nitric or muriatic acids, but the cryftals have no fimilarity either in property or afpect. Thofe, into the com- pofition of which Strontites enters, fuffer changes from expo- fure to the air, which do not happen to the nitrate or muriate of barytes, and they are vaftly more foluble in water. In the figure of the cryftals alfo the difference is very remarkable. A {trong and weighty argument in favour of the diftiné nature of thefe earths is furnifhed by the circumftance, that folutions of Strontites in acids fuffer no decompofition from pruffiate of lime or potafs ; for here I put out of confideration the change that is occafionally produced when the minute portion of iron is prefent; while, as every body knows, a prominent and dif- criminating feature of barytes is its precipitation by either of thefe fubftances. A mark of diftinction not lefs decided is the quality that Strontites and its compounds poflefs of tinging the flame of combuftible bodies of a red colour; a property that does * T have, fince this paper was read, difcovered that the difference of folubility of barytes in hot and in cold water is fully as remarkable as that of Strontites. This mark of diftinétion confequently mutt be rejected. From STRONTIAN. 23 does not belong to barytes, the muriate of which gives a very faint greenifh hue. To thefe add, what afluredly carries great weight with it, that thefe fubftances do by no means agree in the order of their attractions. On the whole, I think it abun- dantly manifeft, that the foffil from Strontian is not aérated barytes, and that it has not this earth for its bafis. 54. Ir has been above remarked, that this mineral occafionally affumes the appearance of fome forts of calcareous fpar ; and it has likewife been noticed, that fome analogy prevails between the properties of their component earths. In no circumftance does this appear fo ftrongly as in the quality of tinging flame, which I have difcovered to belong alfo to the compounds of lime, though in a much fmaller degree. The muriate of lime gives the flame of a candle, when applied in the manner for- merly defcribed, a red colour, which is confiderably lefs vivid and brilliant than that produced by muriate of Strontites, and fhort of that occafioned by the nitrate of this fubftance. It is eafy, however, to fhow, that Strontites and lime materially dif- fer. The fpecific gravity of the Strontian far exceeds that of calcareous fpar, which is commonly about 2.700. The former retains its carbonic acid much more obftinately in the fire. But the incomparably greater folubility of the pure earth in hot water, and its cryftallizing, are characters of themfelves fuffi- cient to difcriminate Strontites from lime, and I {hall only fur- ther obferve, that Strontites forms a lefs foluble compound with fulphuric acid, yields a cryftallizable nitrate and muriate, and difplays a power of attraction different from lime ; whence I reckon it certain, that the earth of Strontian mineral is not lime. 55. I neep not draw a parallel between the appearance and properties ‘of this foffil and any of the other earthy bodies, as » it is not in the moft diftant degree like any of them. 36. Ir perhaps deferves notice, that the mineral I have been treating of, though different from the native carbonates of ba- } rytes 24 ACCOUNT of a MINERAL rytes and lime, holds a fort of intermediate fpace, and forms a kind of link between them. To illuftrate what I mean, I may obferve, that in fpecific gravity, fufibility, capability of decom- pofition by heat, and in the folubility of the compounds it forms, it ftands in the middle. Thus, heavier than calcareous and lighter than barytic fpar, it is more eafily melted than the one, lefs fo than the other. When fubjected to heat, it parts with its carbonic acid more readily than barytes, lefs fo than lime. The fulphate, nitrate and muriate of it are all more fo- luble than the fame falts of barytes, and lefs foluble than thofe of lime. In one refpect “indeed it exceeds both, and that is, folubility in hot water, which perhaps is fo great as may make fome perfons, over fond of nice diftinétions, deny it a piace among the earths altogether *. 57. Tuts kind of intermediate fituation fhall perchance in- duce fome to imagine, that this earth is a peculiar combination of the other two. At firft, I confefs, when this idea fuggefted itfelf to me, I did not deem it improbable ; but now, after full inveftigation, I muft rejeé&t the notion. This, I hope, I do with good reafon, fince I have found that, like the acknowledg- ed fimple earths, this fubftance bears repeated folutions, cry- {tallizations and precipitations, without fhowing the fmalleft difpofition to a feparation of principles; and fince the means that difunite an artificial mixture of the two earths, fuch as diffolving in muriatic acid and cryftallizing, or precipitating by pruffiate of potafs or lime, have no effect in occafioning a disjunction of its parts. 58. As the earthy bafis of the Strontian {par poffeffes re- markable qualities that are peculiar to it, and forms with acids combinations unlike thofe generated by the known earths, and differs from all of them in the order of its attraCtions, I can- ‘not hefitate to conclude, that it is an earth /w generis, a new Binh ee and. * Vide note to 53. meas neat t # , = ee a. & =r From STRONTIAN. 25 and diftiné genus. It belongs decidedly to the ancient order of them called alkaline or abforbent, of which the moft abun- dant fpecies, the calcareous earth, has been long known. To my illuftrious mafter in chemiftry, Dr BLack, we are indebted for eftablifhing the diftinét nature of magnefia. Dr Gaun -and Mr ScuEeEte have the merit of difcovering barytes. 59. CONSIDERING it as a peculiar earth, I thought it necef- fary to give it aname: I have called it Strontites, from the place where it was found; a mode of derivation, in my opi- nion, fully as proper as from any quality it may poflefs, which is the prefent fafhion, My reafon is, that I think there is lefs chance of difcovering two new earths in the fame fpot, than of finding two poffeffed of the fame property any where. The denomination, however, is of little moment, provided it be well underftood what it is intended to denote, and there be no room for miftake. 60. To complete the hiftory of Strontites, it remains for me to {tate what I have difcovered refpecting the order of its at- tractions. I fhall begin with pointing out the order in which the principal acids attract it, and then I fhall fhow the place due to its attraction among thofe of other fubftances for acids. 61. SuxpuHuric acid attracts Strontites with the greateit force ; for when added to a folution of the nitrate, muriate, . tartrite, arfenicate, fuccinate, fluate, acetite and borate, it in- ftantly caufes a difturbance of tranf{parency, and a white pre- _cipitate falls to the bottom. When poured upon the oxalate, which is fcarcely foluble in water, and permitted to remain for fome hours upon it, this acid expels the oxalic, and takes its place. I may here remark, that the precipitates formed by the fulphuric acid do not defcend fo rapidly as the ponderous ful- phate of barytes; they have oftentimes in their fall more the appearance of fulphate of lime, On this account, Strontites, though a good one, is by no means fo delicate a teft of the pre- fence of this acid as barytes, nor can it be employed altogether Worilv. D with 26 ACCOUNT o a MINERAL with the fame advantage in the purification of nitric and mu- riatic acids from the fulphuric. 62. Tue acid of fugar, or oxalic acid, follows the fulphuric. This acid takes the new earth from all the folutions above men- tioned, and with it f2!!s in a powdery form, excepting from the fluate. Iris acurious faét, that the oxalate is foluble in mu- riatic acid with partial decompofition. I obtained an oxalate by dropping the acid of fugar into muriate of Strontites, which I walhed well with cold water, and dried. I then introduced it into muriatic acid, that did not diffolve it till a very little di- {tilled water was added. The folution, in a few hours, had depofited a {mall quantity of cryftals, which I dried on blotting paper. They were perfiftent in the air, they diffolved in wa- ter, and imparted to it the tafte of oxalic acid. This fluid was not difturbed in its tranfparency by fulphuric acid, and it oc- cafioned in lime water a copious precipitate of very little fo- lubility ; whence I inferred thefe cryftals were oxalic acid, and their form did not contradié the conclufion. On evaporating the liquor from which they had been depofited, I procured a powdery oxalate and cryftallized muriate. The reafon of this partial decompofition I cannot at prefent affign ; it cannot be explained in the fame way that the partial decompofition of ful- phate of potafs or foda by nitric or muriatic acid is accounted for. . , 63. Tue third place belongs to the tartarous acid, which de- compofes and caufes a milkinefs in the folutions of the earth in nitric, muriatic, fuccinic, arfenic, boracic and acetous acids. 64. THEN comes the acid of fluor, which precipitates ‘the earth from its folution in all the acids I have tried, excepting the three already mentioned as exceeding it in force. It is re- markable, that a folution of fluate is not rendered turbid by oxalic acid, though it be certain, that the oxalic has the ftronger attraction; perhaps a triple compound is formed. 65. Nitric ) ee es? ae SOS ee! = : ’ . 3 From STRONTIAN, 27 65. Nrrric acid holds the next place). When this acid, ina {tate of concentration, is poured into a faturated folution of the muriate, a precipitate immediately defcends. This confifts of minute cryftals of the nitrate. An affufion of water reftores fluidity. The liquor on evaporation affords the nitrate in cry- ftals. 66. Muriatic acid, as ufual, fucceeds the nitric. As it forms a very foluble compound with Strontites, the decompofi- tions accomplifhed by it are made apparent by evaporation. The phofphateyof Strontites is diffolved readily by this acid. The liquor, when the moifture is diffipated by a very gentle heat, yields cryftals of the muriate and phofphoric acid in a concrete ftate. The arfenicate is taken up {till more readily ; and from the folution, by an evaporation not pufhed fo far as to deprive the arfenic acid of its humidity, are obtained cry- {tals of the muriate. The borate diffolved in this acid exhibits phenomena fimilar to the phofphate. By adding this acid to the acetite, and evaporating, we get the muriate. Succinic acid, if it do not rank before the two laft men- tioned acids, without doubt, holds the place immediately fol- lowing. 67. PHospHoric acid comes next in order. It makes no change in the combinations containing any of the acids already noticed, but inftantly throws down a precipitate from the ace- tite, arfenicate and borates With regard to the two laft of thefe, care muft be taken not to add more phofphoric acid than is fufficient, elfe the precipitate will be inftantly rediffolyed, and will elude obfervation. 68. ArreR phofphoric ftands acetous acid, which unque- ftionably has a feebler attraction than any of the preceding, and I think a greater than the acid of arfenic, becaufe this acid, dropped i into. the acetite, ‘difturbs not the tranfparency. Boracic acid follows the arfenic, and laft of all comes carbo- D2 nic 28 ACCOUNT of a MINERAL nic acid, which is expelled by all the others, as appears from the narration already given. Order of Attractions among the Principal Acids for Strontites. STRONTITES. Sulphuric acid. Oxalic. Tartarous. Fluoric. Nitric. | Muriatic. Succinic. Phofphoric. Acetous. Arfenic. Boracic. Carbonic. 69. THE attraction of the new earth for acids ranks high. For fulphuric acid, barytes has unqueftionably a ftronger at- traction than Strontites. I added barytic water to a folution of fulphate of Strontites; and though only an extremely minute portion of this earthy falt be contained in the fluid, yet an im- mediate milkinefs end precipitation was the confequence. This earth however comes next; for I find that, when I pour Stron- titic water into folutions of fulphate of potafs, of foda, or of lime, the liquor becomes turbid, and the Strontitic fulphate falls to the bottom. : 70. I HAVE not afcertained how the attraction of Strontites ftands with oxalic acid further than that the force of its attrac- tion for this acid is fuperior to that of potafs, and confequently of all thofe fubftances that are inferior to it. 3 71. THE —— ' From STRONTIAN. 29 71. Tue earth attracts tartarous acid more forcibly than al- kalis do. Add Strontitic water to tartrite of potafs, and tartrite of Strontites will defcend; but its attra@ion is weaker than that of barytes or lime, for the folutions of either’ of thefe earths renders tartrite of Strontites turbid. The fame place is due to this earth in its attraGtion for fluoric acid as with acid of tartar; barytes and lime exceed it, potafs is feebler. 72. WiTH refpect to nitric and muriatic acids, the order feems foméwhat different. Here fixed alkalis appear to predo- minate. Yet of this, after feveral trials, I was fomewhat un- certain, in confequerice of peculiar phenomena that occur. When abfolutely cauftic potafs is dropped into a diluted folu- tion of muriate of Strontites, tranfparent cryftalline flakes ap- pear ; but long before all the earth is.difengaged, the alkali ceafes to occafion more precipitation, and it may be afterwards added in quantity, without producing any vifible effed. If, however, an effervefcent alkali be now poured in, a copious. curdy precipitate will be formed. Two hundred grains. of Strontian fpar were diffolved in muriatic acid. To the folution, diluted with more than an equal quantity of diftilled water, L added potafs, till it no longer occafioned depofition. I permit- ted the precipitate to fubfide, and then poured in fome potafs, which caufed no vifible change. The clear liquor was decant- ed off, and the remaining portion filtered. The precipitate, when collected and weighed, amounted only to 24 grains. With the clear liquor, I mixed carbonate of potafs, and I ob- tained an abundant white precipitate This I wathed, and dried. ‘by a gentle heat; it weighed 170 grains. On another occafion, I diffolved a fimilar quantity of the mineral in the fame acid, and after dilution I added the alkali very flowly. The matter feparated aflumed the form of quadrilateral Jamellar cryftals, fome of which, unattached to any others, fhowed the wedge fhaped margin like an ordinary cryftal of Strontites ; frequently they adhered to each other, fometimes appearing in mica gures. 32 ACCOUNT of a MINERAL figures. I continued to pour in potafs as long as any precipi- tation followed, and I certainly: confumed more alkali than would have been fufficient to faturate the whole of the acid. The cryftalline depofite, when dried quickly, effervefced very feebly with muriatic acid ; it was much more abundant than the former; it weighed 74 grains. From the fupernatant h- quor, carbonate of potafs feparated effervefcent Strontites to the amount, when dry, of 132 grains. The matter thrown down by potafs, when diffolved in muriatic acid, cryftallizes in every refpect like ordinary muriated Strontites. It is alfo fo- luble in water, and generates Strontitic water. From thefe ex- periments it appears, that potafs precipitates only a portion of the Strontites, which is in the ftate of cryftals, and that this portion is variable in quantity, which Limagine in fome mea- fure depends upon the ftate of dilution. How this comes to pafs it is not eafy to fay. I am difpofed to afcribe it either to the prodution of a triple compound, or to the folubility of Strontites in pure alkali. The weight of the two precipitates, in neither experiment, exactly amounted to that of the {par employed ; nor was this to be expected. In the former it was deficient by fix grains, in the latter it exceeded by as much. The deficit of the one may arife in part from the lofs of matter adhering to the filter, but principally from the heat employed in drying, expelling too much moifture from the firft precipi- tate. 4 priori, it might be imagined, that there fhould always be a deficiency, fince part of the earth is difengaged in its pure {late, as invariably happens with lime. Inftead_ of this, how- ever, in the latter experiment there was rather an increafe of weight. This I impute to the cryftalline form in which the Strontites is feparated ; for in this ftate it is united to a greater weight of water than it contains of both carbonic acid and wa- ter when it is effervefcent. 73. Tne impracticability of precipitating all the Strontites from muriatic acid, fuggefted fome doubts whether the alkali 2 really oo a yg oe ss ST atl a From STRONTIAN. 3r really poffeffed a ftronger attraction or not. Thefe were remo- ved by the refult of the following experiments: I difiolved a quantity of nitrate of potafs in boiling water, and threw in fome maffes of recently calcined Strontites: The heat genera- ted commenced an ebullition, which I prolonged by the heat of a fand bath, the mouth of ‘the flafk being ftopped by a perfo- rated cork. During the cooling, cryftals of Strontites were de- pofited. I next diffipated by boiling much of the water of the clear fluid, managing the operation fo that the atmofpherical air fhould have as little accefs as poflibleé. By this procets I ob- tained cryftals of nitre, intermixed with a fmall quantity of cryftallized Strontites. I performed a fimilar experiment with a folution of muriate of foda, and the refult only differed in this, that the cryftals of common falt were depofited during the evaporation of the liquor, and thofe of Strontites, for the fe- cond time, during the fubfequent refrigeration ; whence the in- ference is deducible, that Strontites cannot detach the nitric or muriatic acid from the alkalis with which they are united in faltpetre and fea falt. 74. THE attraction of barytes for muriatic acid exceeds that of the new earth. Toa folution of Strontitic muriate I added fome native carbonate of barytes lately calcined and re- duced to fine powder.’ Soon marks of decompofition were ap- parent, and the liquor contifted of muriate of barytes. Mu- riated barytes, on the other hand, fuffers no change from the earth [have been defcribing. The attra@tion of lime for this acid is feebler than that of Strontites. Muriate of lime became muriate of Strontites. fome time after I had introduced the powder of calcined Strontian fpar into it. Ammoniac’ was in- ftantly difengaged from the muriatic acid by Strontites. 75. Porass attracts acetous acid more forcibly than Stron- tites, and diilodges it. 76. Puospaorie acid isone of *thofe’ that prefer Strontites to alkalis. Strontitic water immediately caufes a precipitation in: 32 ACCOUNT of a MINERAL in phofphate of potafs or foda. Strontites in its turn gives place to lime and barytes. 77. THE fame order as in the preceding is eioruetheal with re- gard to the acid of arfenic. 78. Borate of Strontites fuffers no vifible cintiesen from lime-water or potafs, but is turned muddy inftantly by bary- tic water. A folution of borax is decompofed by diflolved Strontites. or . 79. THE attra@tion of Strontites for carbonic acid is power- ful. It renders mild alkalis cauftic, and becomes thereby itfelf a carbonate. I was defirous of determining the relative attrac- tions of barytes, lime and Strontites for this acid, but found it not an eafy matter. The difficulty proceeds from all the three being entirely or nearly equal in power. BERGMAN was not able to decide between the two firft of them. In hopes of af- certaining this point, with artificial carbonate of Strontites in fubtle powder, I mixed a quantity of barytic and of lime wa- ter, and kept them in phials accurately clofed. I had the bot- tles fkaken very often during a week. At the expiration of this time, I decanted carefully from both the fupernatant fluid, and faturated it with marine acid. ‘The liquor of the one, treated in this manner, gave, on evaporation, muriate of ba- rytes ; from the other I obtained muriate of lime. Thefe ex- periments feem to fhow, that Strontites will not yield carbonic acid to either of thefe earths. Again, when Strontitic water, poured upon the carbonates of barytes and of lime, is managed in the fame manner as the former, the clear liquors, faturated with the fame acid, afford, both of them, muriate of Strontites. This earth confequently had not taken the fixed air from either. Since then neither lime nor barytes can attract carbonic acid from Strontites, and fince this acid will not defert either of thefe to combine with Strontites, I am led .to the conclufion, that the forces of their attraétion are equal, or very nearly fo. This alfo appears from the following experiments: Into a mix- ture From STRONTIAN. 33 ture of nearly equal parts of Strontitic and barytic waters, I threw diftilled water impregnated with a quantity of fixed air lefs than was fufficient to faturate either of the earths. I fhook the whole well for fome time, in the expectation that the earth, whofe attraction preponderated, would attach to itfelf all the acid, and become infoluble. On examination, however, I found, that the precipitate confifted of the carbonates of both. When a folution of lime, inftead of barytes was ufed, the event was fimilar. 80. STRONTITES precipitates metallic calces from their folu- tions in acids, but with no particular phenomena. When Strontitic water is poured into a folution of muriate of mercu- ry, a brownifh yellow precipitate, like to that produced by ba- rytic or lime water. prefents itfelf. The fame fluid caufes a dark green precipitate in fulphate of iron, a greyifh white in fulphate of zinc, a light blue in fulphate of copper, and a white one in acetite of lead. TABLE to fhow the Place due to Strontites in the Order of Attractions. : 4 Sulphuric Acid. Oxalit. Tartarous. Fluoric. Nitric. Barytes Barytes Lime Lime Barytes Strontites Lime 2? ~ Barytes Barytes Potafs Potafs Strontites Strontites Strontites ) Soda Potafs Potafs Potafs Strontites Lime Soda Soda Soda Lime Muriatic. Phofphoric. -Arfenic. Boratic. Carbonie. Barytes Lime Lime Barytes Lime Barytes Strontites otafs _ Barytes Barytes Lime > Potafs Soda — _Strontites - Strontites Strontites? ~~ Soda Strontites Potafs Potafs Potafs Lime Soda Soda Soda Vou. IV. E To a ACCOUNT of a MINERAL ee GLI ae To make a fmall addition to the hiftory of barytes, and to correct a miftake that has prevailed refpeting the native com- bination with carbonic acid, I beg leave to add a few words. 1. Aut the chemifts who have made native carbonate of ba- rytes the fubject of their experiments, concur in afferting, that the carbonic acid cannot be difengaged from it by heat alone ; and upon this fuppofed fact, a theory of pretty extenfive applica- tion has been founded. Dr WiTHERING, in his admirable paper, Phil. Tranf. vol. Ixxiv. p. 298. fays, ‘‘ It is very remarkable, that “ the terra ponderofa fpar in its native ftate will not burn to lime. “ When urged with a ftronger fire, it melts and unites to the cru- ““ cible, but does not become cauftic.” ‘‘ May we not conjec- ture then, that as cauftic lime cannot unite to fixed air with- out the intervention of moifture, and as this fpar feems to contain no water in its compofition, that it is the want of “* water which prevents the fixed air affuming its elaftic aérial “ ftate.”” This fuppofition becomes, in his opinion, ftill more probable from the circumftance, that the artificial aérated terra ponderofa, which contains water, lofes its fixed air by the ac- tion of heat. 2. Dr PriesTLEY adopted this notion, and adds his teftimony to the faé&t upon which it refts. In the Phil. Tranf. vol. Ixxviii. | p- 152. we have the following words: “ Terra ponderofa aérata ‘“* gives no fixed air by mere heat. But I find, that when {team is fent over itin a red heat in an earthen tube, fixed air is produced with the greateft rapidity, and in the fame quantity, as when it is diflolved in fpirit of falt, and making “ the experiment with the greateft care, I find that fixed air * confifts 7 ¥ 4 a are i From STRONTIAN. 35 * confifts of about half its weight of water.” From thefe ob- fervations Dr ParrsrLey infers. that water enters into the com- pofition of fixed air, nay, that it is this ingredient which is effential to the aériform condition of the acid. He extends the idea to all aérial fluids, and hence draws a futile argument againft Mr Cavenpisn’s glorious difcovery of the compofition of water. - 3. I is unneceflary to tranfcribe the words of Mr Watr junior, who {peaks on the authority of Mr Jostau WepcEwoob junior, to nearly the fame purpofe. or thofe of M. Sace, Four+ croy and PELLETIER, who ftrangely aflert, that this fubftance is abfolutely unchangeable by heat. 4. From this general opinion, however, I am obliged to dif- fent, having found, that the fixed air can be expelled from the native aérated barytes by heat alone, if fufficiently intenfe; a circumftance that muft prove fatal to the theory founded on its fuppofed impra¢ticability. The heat which anfwers this pur- pofe is that of 2 fmith’s forge, when the fire is fkilfully ma- naged. By its affiftance, I have oftentimes deprived the bary- tic {par of its acid either entirely or nearly fo. 5- I NEED not detail the particulars of more than of one expe- -riment. In feveral trials, however, it may not be improper to remark, I was difappointed, in confequence of the barytes, vehe- mently heated, acting as a flux on the clay of the crucible, cor- roding holes in it and making its efcape, leaving as its only ve- ftige a green-coloured vitreous glazing on the infide of the cru- cible. At firft I employed crucibles made of pure Stourbridge clay, but was, from the circumftance this moment mentioned, obliged to have recourfe to thofe compofed of black lead, which are able to refift and confine the heated fpar; yet fometimes I fucceeded even with thofe of clay. 6. A sotip and pure mafs of the fpar, weighing 338.4 grains, was put into a black lead crucible, having a lid of the E2 fame 36 ACCOUNT of a MINERAL fame fubftance fitted to it. The crucible, gradually heated, was kept in the {trong fire of a fmith’s forge for the fpace of half an hour, when it became very foft. On breaking it after it had cooled, indubitable proofs appeared of the mafs having undergone complete fufion. From being previoufly angulated, it now accommodated itfelf to the fhape of the crucible, and encrufted the bottom and fides of it a little way up. ‘the cruft externally, where it flightly adhered to the crucible, was of a dark greyifh colour, internally it had a greenifh fhade. The matter was light, {pungy and porous like pumice {ftone, and being carefully colleéted weighed only 261 grains. The fpar had therefore loft 77.4 grains, which is at the rate of 23 per cent. nearly. 47. Tue calcined mafs imbibed water with a hiffing noife and confiderable increafe of temperature, but without fwelling or fplitting like lime, and was foluble in this fluid. On dropping it into diluted muriatic acid, a very flight effervefcence took place; but this foon ceafed, and the diffolution proceeded in perfe@t quiet. The folution had a greenifh caft. 8. From another mafs, weighing 530.5 grains, I expelled 136.5 grains or 25.60 per cent. and ftill it was not altogether non-effervefcent. I however obtained it once abfolutely cau- ftic or free from carbonic acid, having employed a crucible of Stourbridge clay, which endures a ftronger heat than the black lead. But I could not in this cafe afcertain the lofs of weight, as part of the mafs had efcaped through a hole it had made for itfelf. 9. Even by the common blowpipe.and candle, a part of the acid may be difengaged. Suppofing that the heat excited by this inftrument, employed in the ufual way, would be very in- adequate to produce the defired effect, I tried pure air, in the manner I had feen M. LavorsiEr ufe it. This mode confifts in dire¢ting a ftream of oxygenous gas againft ignited charcoal, and, From STRONTIAN. 34 and produces an extreme intenfity of heat. By this heat the {par was rapidly melted, but finking into the pores of the charcoal, it eluded further impreffion. I then had recourfe to the ordinary blowpipe. The fmall mafs readily melted, and on being kept in fufion for fome time, boiled with fo much violence as to fcatter around it minute particles of the liquid matter. After two or three minutes, it was kept fluid with more difficulty; and, finally, it covered the furface of the charcoal with a thin powdery cruft. Though it ftill effervefced brifkly with muriatic acid, a portion of the fixed air had been feparated ; for a part of it, thrown into diftilled water, impart- ed to it the power of changing to a green violet teft-papers, and the water acquired a cruft on its furface from expofure to the air. 10. THESE experiments, I hope, fatisfaCtorily fhow, that the native carbonate of barytes can be decompofed by heat alone, and further afford proof of the infufficiency of the theory that has been deduced from the fuppofed impoflibility of accomplith- ing it. 11. I nave found that barytes is vaftly more foluble in hot. than in cold water, and that it is depofited from the former im the {tate of cryftals. To obtain thefe I commonly employ the calcined barytic fpar, and the mode I follow confifts in throw- ing into water, that has juft ceafed to boil, fome pieces of a re- cently burned mafs. The heat that is generated caufes the wa- ter to boil, and I prolong the ebullition for a little time. The clear part of the liquor being decanted off and permitted to cool, depofits fooner or later a quantity of cryftals. The fhape and appéarance of thefe vary confiderably, according to the ra- ‘pidity with which they have been formed, and this depends upon the greater or fmaller quantity taken up by the hot wa- _ ter over what can be retained by it when cold ; the moft fatu-. rated yielding cryftals the moft {peedily, the lefs fo not for feve-. tal days. 12, THE. 38 ACCOUNT of 4 MINERAL 12. Tue cryftal in its perfe€t condition feems to be a flatted hexagonal prifm, having two broad fides, with two intervening narrow ones, and terminated at either end by a quadrangular pyramid, which, in fome cafes, conftitutes the larger part of the cryftal. When the cryftallization goes on at great leifure, the cryftals are often diftiné and folid, of no inconfiderable magni- tude; but more commonly with a quicker depofition, they are more flender and delicate. and are attached to each other in fuch a manner as to aflume a foliaceous form of beautiful appear- ance, refembling fome of the fern tribe in their pinnated frons, to fpeak botanically ; but in this arrangement, a confiderable diverfity occafionally happens. 13. Tue cryftals obtained from calcined barytic f{par, in the manner now defcribed, diflolve in water, and impart the qua- lities of barytic water; they change vegetable colours to a green, they unite with acids without effervefcence, and gene- rate with the muriatic and fulphuric, compounds fimilar to the fulphate and muriate of barytes ; hence I infer they confift of pure barytes. 14. Tues cryftals are perfectly tranfparent and colourlefs, but when expofed to the air, become white, opaque and effer- vefcent, lofing during this change nearly 30 per cent. of their weight. Subjected to the heat of boiling water, they undergo the aqueous fufion and become fluid ; from which ftate, if al- lowed to cool flowly, they concrete into a folid cryftalline mafs. When a ftronger heat is applied, and continued till all the moi- fture is diffipated, there remains a white powder, lighter by one half than the cryftals employed, which, urged by the heat produced by the blowpipe, is melted with more difficulty than the native carbonate. 15. Tue folubility of thefe cryftals in water furprifed me a good deal. One ounce of diftilled water, at temperature 60, diffolves almoft twenty-five grains, while boiling water appears to | I be . From STRONTIAN. 39 be capable of diffolving any quantity of them, however great. This arifes from the circumftance, that the earth becomes fo extremely foluble at an elevated temperature, that the water of cryftallization itfelf, which fcarcely furpafles the weight of the barytes, when heated to the two hundred and twelfth degree, is able to accomplifh the folution of the earth without the affift- ance of more fluid. 16. In this amazing folubility barytes and Strontites nearly agree, but materially differ from lime, which, fo far as I can difcover, is diflolved as fparingly by hot water as it is by cold. If. S\ om 4 Trot ' , een - ‘ is . ‘ f = ‘ ii Honk ik sities ai nel ots) ert ached nd hd II. OpsERVATIONS on the NaTURAL History of Guiana: In a Letter from WiLLi4m LocHEaD, E/q; ¥.R.S. Epin. to the Rev. Dr WALKER, F.R.S. Evin. Regius Profeffor of Natural Fiifiory in the Univerfity of EDINBURGH. [Read March 3. 1794.] DEAR SIR, LLOW me at prefent to trouble you with a few gene- ral obfervations on natural hiftory, which I had an op- portunity of making while on a botanical excurfion, with my friend Mr ANDERSON, to the Dutch colony of Demerary. Gui- ana is a country but little known in Europe, though its animals and vegetables have added confiderably to the catalogue of na- tural productions. It is not however the organic kingdom which I mean at prefent to touch upon; all I aim at is to give you fome idea of the face of the country, as leading to the know- ledge of its formation and prefent ftate. It is not a field for the mineralogift, as its interior is unexplored. But to the geolo- gift, who wifhes to trace revolutions of the lateft date, it is not uninterefting to contemplate fuch a recent and fingular coun- try as Guiana. I NEED not inform you, that under Guiana is comprehended all the coaft of South America from the Amazons to the Oroo- _ noko ; that it trends nearly N. W. and. S. E..; that it is in gene- ral a very low and flat country, efpecially the Dutch or wefter- moft part of it; and that it is watered \by feveral rivers and creeks, which rife in a chain of mountains running nearly E. Vor. IV. F and t 42 NATURAL HISTORY and W. and dividing Guiana from the inland parts of South © America, which form the banks of the Amazons and its nu- merous branches. Coa/t.—No coaft can be more eafy to make than that of Gui- ana. The changed colour of the water indicates foundings long before you make the land, and you may run on in feven , fathoms before you can difcover it from the deck. The bottom is at that diftance a foft mud. All along the coaft near Deme- rary, you have only about two fathom at.a good league from the fhore ; to leeward of Effequebo, it deepens {till more gra- dually. In ftanding off or on five or fix miles, you will hardly deepen or fhallow the water as many feet. When a high fea fets in upon fuch a coaft, it is eafy to conceive, that at a very confiderable diftance from the land it muft be affected by the bottom. ‘The interval betwixt wave and wave becomes more diftiné. As they roll .on im fucceffion, the lower part is re- tarded, the upper furface accelerated, each billow of courfe be- comes {teeper and more abrupt, till at laft it gradually ends im a breaker, when it has come to the depth of only a few feet. Thefe rollers, as they are called, are the dread of feamen, efpe- cially betwixt Effequebo and Pomeroon, where the water is fhallow, and the bearing of the coaft very much north and fouth, expofes it fully to the action of the trade-winds. In {mall craft, thofe acquainted with the navigation do not hefitate to run along the coaft, even among the rollers themfelves ; but veffels drawing ‘from ‘eight ‘to twelve ‘feet water, efpecially if the {well be heavy and it falls calm, can hardly get‘off. If an- chor and cables fail, ‘they drift on till they are faft in themud, and there they will continue, fometimes.for weeks together, be- fore they ‘go to pieces. The fea-water ‘becomes ‘exceedingly thick and muddy within a few leagues ‘from the coaft of De- merary, as much or more do than the Thames is at “London. A ftranger would naturally take this for the difcharge of large flooded ~ —————E a a eee ——— Of GUIANA. 43 flooded rivers after a rainy feafon. By and by I fhall explain the true caufe off it. On approaching the continent of South America, a change on the face of the /€y will ftrike the attentive obferver. ~The clouds become lefs diftin@ from each. other, and the. intervals between them lefs:clear.; They are blended into one another, as it were, and © fuffufed more> generally over the atmofphere. They appear to be furcharged with vapour, or to have a fetongen difpofition to depofit it. THERE is a particular prevailing appearance of the heavens within: the tropics when. you are at a diftance from continents or very high iflands, which has fo often ftruck me that I won- der it has not been taken notice of. I call it a tropical /ky, and thus defcribe it. The clouds:in fine weather are in a fingle feries or ftratum, failing away regularly with the trade-wind. They are fmall and diftinctly feparated from each other. The inter- vals or: fky>above: them of a clear azure. The lower furface of the clouds. is, perfectly horizontal. As the temperature is commonly. very equal over the fea, the condenfation takes place every where at an.equal height'from, the furface of the water. In the clouds that are over-head, you. cannot indeed perceive this ; but it becomes more and more vifible as the eye recedes from the zenith. The lower limb of each diftant cloud. appears perfectly level.and:well: defined, brighter than the. fuperincum- bent part. - Ata diftance, nothing is to be feen but thefe. limbs clofer and cloferinygradation one behind, the other; and. the whole horizon round refembles the roof of a ftage;,with an in- finity of half dropt curtains as far as the eye can reach. In two voyages from Europe, I have met with this tropical fky as far,north as Cape Finifterre. It came with a fair wind, which continued with us like a regular trade-wind,accompanied with the fame appearance of the clouds, till we made the Weft Indies. In running down the. trade-winds, every one has an opportunity of verifying this defcription, and muft be, ftruck, with the beauties ) F 2 which 8 44 NATURAL HISTORY which this fky prefents at the fetting of the fun. The inhabi- tants of the lower iflands may alfo be well acquainted with it. In the higher ones, the attraction of the mountains ever forms fets of clouds of other appearances, as being produced by other caufes. With our prefent knowledge of meteorology, hardly any other caufe can be afligned for the phenomena above men- tioned, than the conftant equal temperature that every where prevails on the intertropical feas. One analogous fact however may be mentioned ; the exceedingly fmall range of the baro- meter in the torrid zone. Does the fame caufe regulate fo ex- actly the height of the clouds, and maintain the uniform fu- fpenfion of the mercury ? We might almoft fufpect it did, were it not well known, that the barometer varies as little upon con- tinents, and in the vicinity of mountains, in thefe regions as elfewhere, though the condenfation of vapours is in fuch cafes much more irregular. Upon the continent you will frequently obferve this tropical {ky alfo, efpecially in fine fettled weather ; but much more commonly you will find the fky there, and even before you make the coaft, covered with heavy large dark clouds in fome places, and in others, at a greater height, the ferene dappled iky, fo often feen in Europe. Winds.—TueE trade-wind generally prevails all the day long,. and on the fea-coaft feldom fails even at night ; but in lefs than fifty miles up the river it is a dead calm at night, and the breeze is not able to penetrate fo far till towards noon. Still farther up we had whole days of a ftark calm, and the heat very intenfe. Dews, fogs and temperature.—Tuer dews, following the law which they generally obferve, are very heavy when and wherever there is but little wind, and the hotter the day and evening, they fall the more copioufly ; they were of courfe more abundant up the river than near the fea-coaft. The exhalations in the day-time from Of GUIANA. 45 from a hot and mifty country covered with vegetables being very great, the condenfation occafioned by the abfence of the fun, and the cold accompanying that condenfation, are in pro- portion. Near the coaft the diurnal difference of temperature is but trifling, the conftant trade-wind preferving in the air nearly the fame medium of heat as in the body of the ocean; but far up the river the range of the thermometer was. very great. The heat of the day was intolerable. In the fhade it was fre- quently above 90°. This, when there is no breeze, forces you into the woods for fhelter.. Towards evening it cools; during the night the cold increafes, and is greateft about five in the morn- ing. The thermometer would then be from 72° to 74°. The body of the river being large enough to retain its heat, the eva- poration goes on from its furface through the night, and is condenfed into thick fog, which hangs over it, and is feldom difperfed before eight or ten next day. While the air was as above in the morning at 72°, the water along-fide gave 80° to 83°, and feldom rofe two degrees higher at noon-day. We had _an opportunity of verifying an obfervation made by the few inhabitants who live far up the river Demerary; that when it feels very cool'in the morning before day-break, they are fure of fine weather; when, on the contrary, it feels warm, they expect rain. They fleep in hammocks, and the houfes they have are pervious enough to the air, fo they are fenfibly affected by any change in its temperature. Seafons.—As to the feafons, it is not an eafy matter, from the accounts given by the colonifts, to afcertain them exa¢tly. All feem to agree, that fince cultivation has been fomewhat extended, they are not fo regular as before ; that the dry feafon encroaches on the rainy, and that during the latter, they have often feve- ral dry days in fucceffion, The account given by Dr Ban- CROFT was the one generally allowed; that it is dry about the equinox, and rainy about the folftices; that of confequence they 46 NATURAL HISTORY they have two wet and two dry feafons every year. We thought it difficult to reconcile this with the account given of the fea- fons of other countties in fimilar climates, and with what ac- tually takes place in the Carib iflands. I will give you my ideas on the fubjeét. It is within the tropics a very general rule, that the vicinity of the fun brings the rainy feafon. To the northward of the line therefore this muft be in our fummer months. It is another invariable law, that.as in lunar influences, fo in the change of feafons produced by the fun, fome time is neceflary after the maximum of the ‘caufe to produce the full effe&. The higheft tides are not till two or three days after the full and change: The greateft heat of the day is'two hours after noon, and the hotteft months in Europe are:July'and Au- guft, not June, when the fun is,higheft. Among the Weft India iflands, the full effect of the fun’s vicinity is ftill later. I have found Auguft, and more efpecially September, to be the hotteft months in the year, and they are accordingly the height of the rainy feafon. It begins thus: No fooner has the fun come to the northward, and begun to be vertical among the iflands in April and May, than his force is felt, the fly is more difturbed, the wind is more frequently from the fouthward and in fqualls, and now and then there are heavy fhowers. In June the fame effects continue, and increafé in July, when the proper rainy feafon may be. faid to begin, and’ continues in force more or lefs till the middle of O@ober. Auguft and Sep- tember, with part of July and October, when thefe effects are at their greateft height, are ftyled the ‘hurricane months, and by the French /’bivernage. During them, the full force of the great luminary which diftributes light and life, however necef- {ary, feems fometimes’too’ much for nature.’ She is opprefled and fickens ; her refpiration is difordered by intenfe heat ; fome- times calms, fometimes heavy {qualls ; the agitated elements vent themfelves in lightning, with thunder and torrents of rain, or are fometimes thrown out into thofe horrid: convulfions, hurri- canes, ——— Of GUIANA > “47 canes which feem to threaten inftant diffolution. Guiana is happily free from thefe fcourges of the Antilles. Their force has lately been partially felt at Tobago, which was thought be- yond-their reach. In Trinidad, the greateft ftorms they have hitherto experienced, do not deferve the name of hurricanes ; and to the fouthward, on the main of America, they are utterly unknown. The difference then. between Guiana and, 'the iflands is this: In the former, the rainy feafon fets in earlier, as indeed the fun is fooner vertical. Their principal rains are in the end of April, in.May, June and July. They are alfo fooner over ; for Auguft, September and October, and I believe ‘part of July, are commonly fair weather. But again, November in part, De- cember, January and February, reckoned dry months among the iflands, are in Guiana a fecond rainy feafon. The caufe of this I take to be as follows: North-eafterly winds, pretty tiff, cold, and bleak comparatively in thefe climates, are frequent among the iflands during the winter menths. They are well known by the name of Norths. They are often accompanied with rain, but it is not very heavy, nor thought of confe- quence enough to give the denomination of a rainy feafon. Thefe winds we know to reach as far as the coaft of Guiana; and there I have reafon to believe they are produétive of more ain than in the iflands. The face of a large continent, and its effects upon the atmofphere, may very probably make them give up more of their humidity than they do among the An- tilles, though, at the fame time, their force and bleaknefs may not be fo much felt. If this conjeCture hits the truth, the fol- lowing ought to be corollaries, and are left to future obferva- tion. In this rainy feafon, when the fun is near the fouthern folftice, their rams will be with pretty fteady northerly* breezes on the coaft. They may be.of longer continuance at a time, but they will not be fo heavy as thofe of fummer, and they will be chiefly on the fea-coaft, and probably will not extend a great way up the country. It remains even ‘a query with me, 3 whether 48 NATURAL HISTORY whether the rain that accompanies the norths among the iflands, efpecially thofe moft remote from the line, be not generally in a greater proportion than is commonly fuppofed. Country.—I WILL now endeavour to give you fome idea of the face of the country. Though, as is well known, Guiana is flat and fwampy, yet it affords to the attentive eye an in- terefting variety. The fea-coaft is little, if at all, raifed above the level of high water, and it continues at this level for many miles inland. It is properly an immenfe woody fwamp, never dry in the drieft feafon, covered with feveral feet of water in the wet. Next the fhore, as far as the brackifh water extends, it is covered with mangroves, which grow toa confiderable height, and form a thick fhade. They are elevated on their branchy intermingled roots from the bare wet clay or mud, on which there is fearcely one herb or plant, but which feems to be all in motion, from the prodigious number of crabs which make: their holes in it. Further on, when the under-water is frefh, you meet with a new fet of vegetables, principally {mall trees, which, from -their fituation, are obliged to adopt the habits of mangroves, having the bottom of their trunks fup- ported three or four feet above ground by their ramified roots. Several climbing plants are. mixed with them. Arunis, in great variety and profufion, emerge from the water, or embrace the {tems of the trees ; and feveral broad-leafed plants of the hexandria and triandria claffes, affift the Arunis in forming an herbage. In all this low part of Demerary, there is not one tree of a large fize, nor ‘among them all above two or three fpecies which can be applied to ufe as timber. Proceeding ftill up the river, its banks are found generally to raife themfelves above the level of the water; and when you have gone up one tide, (betwixt twenty and thirty miles), they are fo high, that there is no farther occafion for dams to keep the plantations from being overflowed at high water, as below; I canals. oo ee ee Oe Of GUIANA. 49 canals or ditches are fufficient to drain the land, which is full perfectly flat. The trees are here different in fpecies and larger in fize than below, and the woods are much more practicable. As they are drier, the ground has acquired a regular fort of fur- face, and there is neither that plexus of roots, nor the fame number of vines, (the common name in the Weft Indies for _ all climbing plants), to entangle thofe who choofe to traverie them. The foil here is generally a ftiff, cold, reddifh clay, mixed a-top with a portion of vegetable mould. Tue fand-hills prefent to the admiring eye a fcene very dif- ferent from what it had been accuftomed to below. The firft you meet with upon the Demerary, is upwards of thirty miles from the mouth of the river, and on the right hand afcending, or on its weftern fhore. There are of them further down in the country, but not clofe by the river-fide. This one is the extremity of a ridge which extends to the weftward {feveral miles. As you afcend the river, you meet with many more of the fame kind on both fides, whofe direction feems likewife to be eaft and weft, or nearly at right-angles with the average courfe of the ftream. They vary from 50 to 100, 150, or 200 feet of perpendicular height above the level of the river and the intervening flat country. ‘Their breadth and extent varies fometimes only a few hundred paces, fometimes many miles. Their length is great; with fome interruptions, I have reafon to believe they are generally continued from one fide of the colony to the other, only interfected in different places by the rivers and their branches. They confift of a pure filiceous fand, fo white that it dazzles the eyes, commonly fine grained and loofe, but not unfrequently mixed with little ftrata of coarfer pebbles, moftly quartz, and fometimes concreted into a proper fand-ftone. In the laft cafe, a black or reddifh tinge is iM many cafes communicated to it, from clay, decayed vege- tables, or other extraneous matter. There is no regular ftratifi- cation to be found in it, more than what is common to all Voz. IV. G fands, 50 NAPE RINE VETS TORT fands, the produce of depofitions of different dates, and as they are of different materials, thicker in one place, thinner in another, fometimes horizontal, but oftener inclined, and convex or con- cave according to circumftances. We could meet with no ap- pearance of fhells or other marine productions, but in a few places, pieces of broken vegetables buried in the fand where it was concteted. They were black as all the foflil vegetables that 1 have ever feen in fand-{tone. Upon, and by the fides of the fand-hills, grows the moft valuable timber of thefe colonies. The trees there are of a good fize, and very clear of obftructing underwood or vines. The Wallabba, (Parivoa grandiflora of Aublet); the Sipiri or green-heart, (a new fpecies of laurel) ; the Coumarou or Tonquebean-tree, Coumarouna odorata of Aublet ; the Mora, valuable for boat-timbers, and many others, whofe wood is equally hard and beautiful. ConTINUING to afcend the river, the fand-hills become ra- ther more frequent, but the intervals ftill remain a perfect flat, though now feveral feet above the level of the ftream, and the, foil is ftill a {tiff clay. Hitherto the river is deep all over, ge- nerally from two to five fathoms ; the bottom is mud or clay, and the fhores on either fide at low water covered with ooze. About 130 miles up, however, or juft before it begins to fhal- low, the bottom is covered with banks of a hard white or brown fand. It was a problem for fome time whence all this fand originated in fuch a country. It was foon folved. Lea- ving here the veffel that had hitherto carried us, we proceeded in a canoe ; and at about 160 or 170 miles diftance from the mouth of the river, we met with the firft proper hills of folid materials. The neareft to us was a rock of granite projecting into the ftream, whofe direétion it gave a change to at this place, and it ferved for a landing-place to the higheft piece of cleared land upon the river next to the poft-holders. It was part of a low ridge of the fame ftone which crofled the country, probably ta Berbia or beyond it, and was fucceeded by many other feries of . hills Of GUIANA. 53 hills more inland, and as far as we could examine them, of the fame materials. The granite was both of the red and the gray kinds, but chiefly of the latter. A number of feams or dikes croffed it here and there in all directions, not diftinétly fepa- rate, but firmly united to the reft, making as it were but one body with it, and confifting of the fame materials diffe- rently modified. ‘Their component parts were generally {fmail- er; they were more compact and clofer in the texture than what furrounded them; and where they had been equally ex- pofed to the action of the weather, they appeared to have born it much better than the furrounding granite. The origin of the fand was now accounted for. This ftone, in fome cafes ex- ceedingly firm and durable, is in others very liable to decay ; and the wafh of thefe enormous chains of hills was able to fur- nifh abundance of fuch fand as we had met with below. The granite afforded many varieties, indeed every fhade, from large and diftinét grained, to that whofe component parts of felt- fpar, {chorl or quartz, were fo {mall as to refemble pretty com- pact, compound lavas, or fome of our mixed whin-{tones in Scotland. All thefe varieties would be found at no great di- ftance from each other. I brought fome fpecimens, from Ti- ger’s berg, a hill about soo feet perpendicular height, which have every appearance of having undergone the action of fire. They refemble half-vitrified {corie, and would be taken for- them, but that they were actually broken off from the granite, and difcover all its parts in the fraGture. The fummit of this hill is irregular, with feveral pits and holes among the rocks. A little higher than it, and I fuppofe nearly about 200 miles from the fea, you meet what are called the Falls. They are only five or fix rapids, within the fpace of a mile or two, form- ed by ledges of very clofe-grained gray granite that run acrofs the river. There are breaks in each of them, through which -the dextrous Indians are able, in their light canoes, to pafs up at any feafon, even the drieft; and when the river is {welled by G2 the 52 NAFURAL HISTORY the rains, they become totally obliterated! Two days journey, or two and a half above this, is the great fall, where the ftream comes over the face of a rock, as we were informed, twenty feet high. Savannahs. —SAVANNAHS, ever fince the difcovery of Ame-. rica, have been known to occupy large {paces in the fouthern. parts of that continent. They are to be met with abundantly in Guiana, and are of two kinds very diftinét from each other, , the wet and the dvy. Of the former, many are extenfive as. the eye can reach, immenfe verdant plains occupying. the. whole face of a country, with or without a few ftraggling infulated. patches of wood. In the dry feafon, they appear. meadows. of Jong grafs or reeds, and are feldom pra¢ticable for any diftance, for the bottom is very rarely dry. In the wet feafon, they are all one entire plain of water, over the furface of. which the grafs ftill rifes, but which may be every where navigated in the cou- rialls or canoes. Towards the end of the drought, the Indians fet fire to them. The young growth which fucceeds attracts the deer, and the native, on the return of the half-deucalion days, purfues them in his little bark-acrofs their former plains. The foil upon thefe favannahs can neither be very deep nor very good ; yet water may be always commanded, and labour and induftry might convert thefe deferts into rice-fields. It is- a queftion whether the days of flavery willever fee that event. The culture of this ufeful vegetable, which in the eaft has. for ages been the ftanding food of millions, brings too moderate.a return, at leaft in an infant colony, for the rapacious agricultu- ral fyftem of the Weft Indies. Tue dry favannahs are neither fo frequent nor fo extenfive, yet we have paffed through fome of them feveral leagues in circumfe- rence. They are formed along the flats on the top'of the fand ridges, and covered by a very thin coat of verdure. They re- femble, exa@tly enough, fome of the bare moors in Scotland. Many Of GUIANA. 53 Many beautiful plants of the clafs gynandria are their chief orna- ments, as is alfo the orchis, which grows in fimilar fituations with you. Some Melaftomas, and more Rhexias, fupply the place, and bear fomewhat of the habit of the Erice ; for your Sedums and Saxifrages is the little Sauvagefia ; and in hollows of the fame f{a- vannahs, where moifture prevails, what I never could have ex- - pected to fee within five degrees of the line, and not more than go. or 100 feet above the level of the fea, the Drofera lifts its: humble head from a bed of the Sphagnum paluttre. i BeEsi1DEs thefe two. kinds, there are alfo what we may deno- minate alf-/avannahs, formed upon the tops of fand-hills, higher and more irregular than in the cafe of thofe juft de- fcribed. Some of thefe are alfo very extenfive. Few herbaceous- vegetables are to be met with upon them. Broad {paces of arid’. fand are interfeéted by clumps. of fhrubery. Nothing grows . to the height of a tree; but a particular fet of. plants, different . from thofe in other parts of the country, find fubfiftence-enough to rife to fifteen or thirty feet. How nature, after all her ef- forts, fhould have. failed to induce a foil: upon thefe, is furpri- fing. It appears chiefly owing to the great porofity of the fand, which every where admits- the decayed vegetable matter deftined for that purpofe, to be carried: down through it, and . filtered off by rain. Even thofe fand-hills which are covered by tall-trees, {till thew proofs. of this. The trifling layer of mould formed upon them is-exceedingly:thin. When cleared . they are very barren; and when you dig in. them to a great depth, you ftill find fmall portions of black vegetable earth dif- perfed among the: fand.. What corroborates the above fuppofi- tion, is the appearance of the fprings.. Abundance of. thefe are found -gufhing out copioufly round the verges of the hills ; and notwithftanding the extreme whitenefs' and purity of the fand from whence they flow, there is not one in an hundred whofe | waters are limpid. They come out not muddy, but of a. brownifh colour, very much like. the. water which runs from . peata.— 54 NATURAL HISTORY peat-moffes, and they are certainly tinged by the fame caufe. The rotten leaves of trees, and other decayed parts of vegeta~ bles on the hills, inftead of being colle&ed on the furface to form foil, are wafhed down into the fandy ftrata by every rain ; fo that the refervoirs of the fprings, and the water which pro- ceeds from them, is always coloured with thefe fubftances. There _ follows a corollary alfo from this general principle, and when compared with faéts I believe it will hold good :, The more the fand is concreted into ftone in any of the hills, the more and better will be the foil upon them. Where clay in fmall beds, or in a certain proportion, is mixed with the fand, the vegeta- ble mould will likewife be better retained, Rivers.—I wiLt next give you what general obfervations I have been able to make upon the rivers and creeks of this part of America. The courfe of nearly all thofe of Guiana is from fouth to north. They originate in a chain of hills running eaft and weft, which feparates Guiana from the country on the Ama- zons, and likewife gives rife, on its fouth fide, to the numerous branches which fall into that river. The Demerary is a confi- derable ftream, equal, if not fuperior to the Thames ; yet it is by no means among the largeft of them. The Effequebo is five times larger at its mouth, forming a whole Archipelago of iflands ; but its {tream foon divides, and, on account of rocks, fhallows and rapids, none of its branches are navigable fo high up as the former. Moft of the particulars I am now to give you muft be underftood as applying to the Demerary. The bar, if it may be fo called, is common to this with many other rivers, which difcharge themfelves into a fhallow fea; but full with circumftances in the prefent cafe which diftinguifh it from others, where the bottom is not mud but fand. It does not run like a fingle narrow ridge, acrofs, or nearly acrofs the mouth of the river, but it is of great extent, and is properly a con- tinuation of the mud-bank which runs all along the coaft. To the eaft and weft, and for two miles or more in the offing, you have a Of GUIANA. 55 have ten or twelve feet water with the utmoft uniformity, and ftanding in with the mouth of the river open, you neither deepen nor fhallow till you enter it, when you find two, three, four or five fathom, and it continues to average that depth for a long way, fo that any veflel which can enter, may, for draught of water, proceed up the river for 100 miles or more. Tue mouth of the Effequebo, from the fand-hills and rocks being very near it, is exceedingly different. Three large iflands prefent themfelves in a breaft, and divide its entrance into four channels. The length of thefe iflands is with the current, fouth and north ; and from the tail or north end of each of them, as alfo. from the banks of the main on either fide, run out fand-banks to a good diftance. They are perfectly firm, quick in very few fpots,. and the body of them is above the level of low water. On the eutfide of them you have the continuation of the mud-banks and fhallow water as above, only that the entranee of thefe channels is: {till fhallower than that of the Demerary.. The ftreafn of this river runs very brown and muddy, and the fea is {tained with it for fome leagues off. A ftranger naturally imputes this-to the wafhings of a large flat country, or the ftirring up of the muddy bottom by the tides. The latter may in part be a: caufe, though I believe it contributes. to it but very little, and the former, in a ftate of uncultivation, none at all. On afcend- ing forty miles or fo, you find the water clear again, or rather of a darkifh hue, and fo it continues above that. I was at firft at a lofs how-to account for this, but, from a number of cir- cumftances,, was foon led to conclude, that the thicknefs, and light brown colour of the water near the mouth of the river: and on the coaft, were almoft entirely the effect of cultivation. -Numberlefé ditches and canals have been opened by the inhabi- tants, which are receiving or difcharging water every tide, and each particular piece on a plantation is every way interfected with open little drains, which communicate with thefe ditches.. In digging and hoeing this clayey foil, much of it is fufpended: ins 256 NATURAL HISTORY in the water, and carried off by the current of the tides. Nothing can be more certain, than that all up the river, and in all the creeks which difcharge themfelves into it, the colour of the water is conftantly clear or blackifh, even in the rainy fea- fon, when it is fwollen. On confidering thefe circumftances, I have been led to this general conclufion, which is fubmitted to the proof of obfervation in different parts of the world. The reddifh brown colour, fo common in frefhes of rivers, in Europe, and we may add every where, is almoft entirely the effect of cultivation ; and the natural colour of rivers, even in the higheft and longeft continued floods, where all the country is ftill in woods or paftures, is ever that of a very dark brown, or blackifh, pretty much like that of the ftreams which rife among peat-moffes, but rather more diluted. It is compara- tively very clear, and depofits but a trifling fediment. The other is thick and opaque, and its fediment copious. Thus is man, in his little workings, made, in a fmall degree, one of the ’ engineers of nature. We cannot doubt, that entire ftrata will owe to him their exiftence, accumulated in a feries of ages at the bottom of the fea, and deftined, in future revolutions, to act a more diftinguifhed part. It may be curious too to con- fider the differences that may be expected betwixt the ftrata formed by thefe different depofitions, which may be fuppofed between them to have been the origin of moft of the clays upon our globe. Clay, earth or loam, ftirred up by the la- bourer, gives rife to the one; minutely decayed parts of ve- getables form the body of the other. Ir mutt alfo be obferved, that clearing the ground along the coaft, by cutting down the trees, and opening ditches for the difcharge of water, has expofed the land very much to the wathing of the fea. The roots of the mangroves formed a plexus able to refift its force ; and the former equal, and very flow deepening of the water, prevented its making a ftrong ; impreflion Of GUIANA. 87 impreffion on any place. The difcharge from the-ditches at low water cut out channels in. the mud, and left the fidés of thefe channels more expofed to the returning waves, which here beat continually upon a lee-fhore. We find therefore on the coaft, that the fea has made here and there confiderable en- croachments, which generally begin on the weft fide of the canals or ditches, as being the moft acted upon by the waves. The mouth of the Demerary itfelf furnifhes us with a ftrong inftance. ‘That river is now nearly twice as wide as it was when the country firft began to be cleared; the fea and the ftream together having fince that fwept away a large portion of land from the weftern fhore. Creeks.—A NUMBER of creeks fall into the Demerary on both fides, but fo fimall that they bear no proportion to the fize of the river. You can hardly diftinguifh their mouths in the woods which overhang the banks. They are fo narrow that it is difficult to run a fmall boat in them; yet you will find in them throughout from two and a half to four fathom water, and they run winding fo far back that it will take five, fix, eight hours, or more, to carry you up to their heads, where they terminate in fmall ftreams from among the fand-hills. The banks of the creeks at their mouths are of the fame height as thofe of the river clofe by, from five perhaps to twelve feet above the water in the dry feafon. As you afcend the creek, you might naturally expect to find them rife. It is however the very reverfe ; they become gradually lower and lower, till at laft all round them is a fwamp; and the trees on each fide in like manner become fmaller and fmaller, and of different fpecies from what they were. It is now in fhort exactly a mangrove fwamp, with this difference, that the water is ‘quite frefh, the vegetables are not the fame, and there are abundance of arunis and other low herbaceous plants. A little higher up, Vou. IV. H you 58 NATURAL HISTORY you lofe the wood altogether, and find yourfelf in a beautiful — deep canal, winding through a fpacious wet favannah, which is fometimes many leagues in circumference. The firft time we went up one of thefe creeks, (called Camouni), I was fur- prifed at this appearance, and thought it muft be a mere local circumftance peculiar to it. We found afterwards the fame in one or two more inftances, and were fatisfied upon enquiry, that it is common to them all. It was natural to look for an explanation of this phenomenon, and I foon found it in one of thofe laws, which probably extend to all rivers fubject to frequent inundations. It has been obferved, in particular, of . the Ganges *, that the banks of that river are higher than the adjacent lands at a diftance from the ftream, owing, no doubt, to the annual depofitions of mud, tc. during the {well of the river. Apply the fame rule to the Demerary, and the difficulty will be folved. The wet favannah behind, and the fwampy woods around them, are the body of the low country at its natural level, fcarcely a foot or two above the fea. Whatever additional height the land has in the vi- cinity of the river, from the time you have afcended about twenty miles or fo, is all acquired. It has arifen from the fedi- ment of the river during the rainy feafon,- when the country is overflowed fo as that all the lower part of it is under water. This depofition muft be always more copious, in proportion as it is nearer the ftream, where additional quantities are always brought, and where it is kept in motion both by the current and the tide. Every thing which we afterwards faw confirmed this theory, and nothing more directly than the canals which run out at right angles from the river. Some of thefe extend four miles, inward, and they prove to a demonftration, that the land becomes lower and lower the farther you recede from the * Account of the Ganges, &c.. Phil, Tranf. 1781, by M, RenvE.t. a ve Of GUIANA, 9 uy the river. ‘The maps of the colonies confirm it; for in all of them the main body of the low land of Guiana is laid down as favannah, and the woody country, which a ftranger or fuperfi- cial obferver would fuppofe to be the whole or much the greater part of it, is in fact only a border on the fides of the rivers and of the fea, but of confiderable breadth, more or lefs, in proportion to the fize of the adjoining river, or, which is generally the fame thing, to the acquired height and extent of the foil on either bank. It followed as a confequence, and, as far as we had opportunities of obferving, we found it to be the cafe, that the low land was fomewhat higher, and continued fo farther down, about the Effequebo than the Demerary ; the woods con- fequently were of greater extent. We found, befides, in the foil adjoining the Effequebo, at leaft upon the eaft fide, a mix- ture of fand. The river is full of fand-banks; and it appears, that the finer parts of even this lefs fufpenfible fubftance are raifed by the floods and carried among the adjacent woods to be depofited with the mud. The Mahayka, a fmall river or creek which falls into the fea about twenty or thirty miles to the eaft- ward of the Demerary, though it runs a long way up the country, and fpreads into many branches, has but a very nar- row, and often interrupted border of wood upon its banks; it runs through an immenfe favannah, and fo do its branches, with little or no wood, till they approach the fand-hills. The Deltas of the river of Oroonoko, and its numerous mouths, make a figure even in the map of the world. It is to be regretted, that its noble ftream has been fo long hid from {cience. What I learned in Trinidad from a gentleman, who had failed from its mouth to the Angufturas, about 300 miles up, confirms and illuftrates, in the fulleft manner, the above general rule. The weftern mouths of it oppofite Trinidad, are navigable only for launches drawing fix or feven feet wa-' H2 ter. = 69. NATURAL HISTORY ter. At and oppofite them, the bottom is fhallow and mud- dy, and the coaft a low mangrove {wamp, refembling, in all refpeéts, that of Guiana. You muft afcend thofe branches feveral days before you reach the main ftream; and in doing fo, you find the fame phenomena as in afcending the Deme~ rary, but in a ftill greater degree. At firft you have the man- grove, or fome fimilar fwamp, and behind it on both fides for about twenty leagues, the land, if you can call it fo, hardly emerging from the water. Afterwards the ground appears ; and, as you go up, rifes ftill higher and higher on the banks above the common level of the ftream. The trees become, in the fame manner, of different fpecies, and much taller than they were below, The channel in which you are, from being wide, grows narrower by degrees. It is from about one and a half to three-fourths of a mile broad near the entrance ; and, when it joins the main ftream, is not more than about 200 yards. It has then acquired a confiderable depth, and the banks may be about twenty feet high. Along the main ftream of the ri- ver, or Boca de Nafios, the gradual rife, and other circum- ftances attending it, are quite fimilar. All this height of the bank, I can make no doubt, is entirely acquired ground, form- ed by the fediment of the floods, greater near the {treams than at a diftance from them; and though I have no knowledge of the nature of the land in the deltas and their vicinity, I would not hefitate to fay, that great part of the interior body of each ifland, and moft probably of the main on either fide, where it is low country, confifts of nothing elfe than wet favannahs. Fiseds,—BrEFORE we leave the rivers, it may be proper to take notice of their floods. In no inftance of a large river does the univerfal law within the tropics fail, that they annually overflow their banks for a certain feafon. What was a prodigy x im Of GUIANA. 61 in the Nile-during the infancy of {cience, is now a well known phenomenon to every inhabitant of a continent in the torrid zone. From the fituation of the river Amazons, it amounts to a certainty, that the Demerary, Effequebo, and other rivers of Guiana, cannot originate very far up in the continent of South America. This is confirmed by what I could learn of the rife and duration of the floods of thefe two rivers. En- _ quiring about them at the plantations below, is to little pur- pofe, for there the floods are hardly difcernible; but by the poftholder and the fettlers fartheft up, I was informed, that they are there fenfible enough, and that, independent of all partial {wells from accidental rains, the Demerary generally rofe every year in the month of June, and continued high through July and part of Auguft." The rife there, upon the whole, might be about twelve feet; it is fufficient to lay the level parts of the country under water, and to render the woods, that cover them in feveral places, paffable in canoes. We could have wifhed for more exact information. This, how-. ever, was fufficient to prove, that the rivers. did not rife very far inland, elfe the floods would have been later in the year ; but at the fame time that they were of extent enough to fol- low the rule of all confiderable intertropical rivers, fo. as to have a flood im the rainy feafon, that is, in the months when the fun is wpon the fame fide of the line on which they have their- origin and courfe. THE great Oroonoko, | have been informed, begins to rife a little in May, it continues increafing through the fummer months, and the inundation is at its height in September. At: that time, as far up as the Angufturas, the rife is about forty feet perpendicular above the low water-mark. It diminithes as _ you defcend till about the mouth, where it is only a very few feet. Tides: 62 NATURAL HISTORY Tides are of the utmoft confequence to the inhabitants of the coaft of Guiana. They enable them to drain a country which otherwife could never have been cleared, and they af- certain their journeys which are made by water up and down the rivers, and even along the coaft. At the mouth of the Demerary, it is high water at about half paft five, at new and full moon. The rife in fpring tides, a littl way up, is twelve feet, or more, above low water-mark. The tide runs very rapidly near the mouth of the river, feldom lefs than four or five miles in the hour. It continues to run with force for a long way up, and was fufficient, without wind, to carry us up or down at 150 miles from the mouth. Above that it be- comes feebler ; and-for a confiderable diftance below the rapids, though there is a fenfible rife and fall of two or three feet, yet, even in the dry feafon, the current is conftantly down, only more gentle during the rife or flood, and there alfo the conti- nuance of the rife is very fhort, not more than two or three hours. Some obfervations upon the Soi/ of the different parts of the country, may be the fubjeét of a future communication. I will only add at prefent, what I think has more than con- jeCtural foundation, viz. That this moft recent of countries, together with the large additional parts {till forming on its coatft, appear to be the productions of two of the greateft rivers on the globe, the Amazons and the Oroonoko. If you caft your eye upon the map, you will obferve from Cayenne to the bottom of the gulph of Paria, this immenfe tract of fwamp, formed by the fediment of thefe rivers, and a fimilar tract of fhallow muddy coaft, which their continued operation will one day elevate. The fediment of the Amazons is carried down thus to leeward (the weftward) by the conftant currents, 2 which Of GUIANA. 63 which fet along from the fouthward and the coaft of Brafil. That of the Oroonoko is detained, and allowed to fettle near its mouths, by the oppofite iflands of Trinidad, and ftill more by the mountains on the main, which are only feparated from that ifland by the Bocos del Drago. The coaft of Guiana has remained as it were the great eddy or refting-place for the wathings of great part of South America for ages; and its own comparatively {mall ftreams have but modified here and there the grand depofit. W. LocHuHeEapD. IIL. ; a meaanean ca EES (2 sila Moabs hg ae Pips fp tik: ter a ie BBW iat ts ras swind miadte ie » ch) ‘igriameanaa bi Ws: Meth aang ny ame ‘yee Yay <4 pat" his any hey forts ‘ith fey eee ty Agagit to Lie Ah! Alpes, ibgaky 40th Crepe’ tensive “unig Lig soi uatoiae imtnaate te et : ‘3 the ath aa ae rae eS! OE maa) Re ies ree Cn: atgaa 3 Mivivie’r das “ihj alhtreg Pees: es Fat u ~ Piaget aN 7 Saal yitiic fh ibid apie ebewg fas nel) rt hh :, fy ; F eek Pe: a! date ed ss vary Bony FARA Cay! raed on ating Oia a eae ak te ay by Acoe gh Olde a ah eh ie Pola” ' aera " of af, aati Tepe! “fg AA Hl Pay ae ei! arert of ee AR ay hm ‘Fes 67 aie, HeMs iG? buy htciitetie b Ural scene od Nae : HE Ne: or tise nap tenteorie, Linnea Ee ene | paepeees wif Wi , ae ‘ge rigivi side SF CRG ie will vidio ad 4 | bth tade: “lh phe yn. ohetdpionad: pescad bis? i bans ea.) Oi ce caad mY shie.. Ady cary | id ase OMe ata ater Head er Y ae abe AN a Gon Mise i iaaat a: jai’ iy i pngite: eae “eet Nat a f TAS tes i ih ce : fut we © ws . f : me %, oH, Seeauiiiy ty, =f, i= i Sheet ye miko fe ay ot rs high. eiainy ee “thtbhe ME Vive] i ; Ny tet a bei te rs spi Sites steeds, . ; ; oe a (heat it , Plpacaas We Pita renee , Pe? f ; 7 nia Pg oe ; ‘ we We iets } x . ‘ - \ ji .. Pre. ~- ef t; a q ; Z eal P ( A TATA 4 oo i+ > , = ’ aes 2 MED x! } | EBs F s at roe \ us X ' apes or . fi ee | ¥ III. 4 /bort Paper on the Princiexes of the ANTECEDENTAL Catcuuus. By f4éMES GLENIE, E/qg; M.A. F.R.S,. Lonp. & Epin. [Read Dec. 1. 1794.] EVERAL of my friends have fuggefted to me the propriety of publifhing fomething of the kind now offered to the Society, obferving, that the great brevity with which the - Antecedental Calculus is written, and the very concife form in which it is delivered to the public, may lead fome to form erroneous opinions refpecting the principles on which it is founded. In compliance partly with their requeft, I have drawn up this fhort paper, which I hope will remove even the - poflibility of mifconception on that head, and convince every intelligent reader, that the antecedental calculus has the fame geometrical principles for its ground-work, that the formulz in the Univerfal Comparifon themfelves have, from which I origi-' nally derived it more than twenty years ago. In the third page of that treatife, | have fhewn from the © firft formula in the third theorem of my Univerfal Comparifon, that, when R and Q are any two given magnitudes of the fame kind, and A, N, B are any homogeneous magnitudes, the ex- cefs of the magnitude, which has to B a ratio having to the ratio of A+N to B the ratio of R to Q, above the magnitude, Vou. IV. I which 66 On the PRINCIPLES of the which has to B a ratio, having to the ratio of A to B the fame ratio of R to Q, is geometrically exprefled by J de e RRO. Re R R-Q. 4, RRQ RQ R R-QR nee a0 ee iiss Q- 2Q Q ez" Q Be=G) Qo or, which comes to the fame thing, that the expreffion, R.. KR. ERLG R R—Q ,R-2Q., A— Beek 3 — .—_—A ~N’?+ &c. CMR Pan TOS Cy Teas » exceeds the ree sits ou Nee geometrical expreflion, Fe oF pass Q RQ , AB R-Q Bae r= & tS © A 50D oO ATBh se. by the afore-. faid geometrical expreflion. In the fame page, I have fhewn, that the excefs of the mag- nitude, which has to B a ratio, having to the ratio of A to B the ratio of R to Q, above the magnitude, which has to B a ra- tio having to the ratio of A—N to B the ratio of R toQ is geometrically exprefled by R ,R-Q RRQ RaQ abet Se iii aie Naa >N* + &e. RO, , or, which comes to Ge the fame thing, that the expreflion, a R roy R-Q , A-B R-Q R2Q , AB) BEER AE Q cA. B + — ree a0 Senn B +&e. ex= Q ceeds ANTECEDENTAL CALCULUS. 67 ceeds the geometrical a AR _ RR ,R-Q@ R—Q ,R2Q Re a, ES ts A NTE : NG —— eee SCOT anon Quay SsiSlR ES aby oaNs . pk —Q. | Q -aforefaid geometrical expreflion. Ir is almoft unneceflary to obferve, that the two expreflions, which have refpectively to B ratios, having to the ratios of ( A+N to B, and A—N to B the ratio of R to Q, give us: ROR Reo R R—Q,, R-2Q _., ——— ~ N+ — .—>A ——SN’*+ + &e. 2508 2 for the geo- metrical magnitude, which has to B a ratio, having to the ratio of A=N to B the ratio of R to Q. But as this expreflion muft vary indefinitely with the endlefs variations in the quantity of the magnitude B, its geometrical ftandard of comparifon, fo, when we fuppofe it to become numerical, we get an indefinite number of arithmetical formule, referring to different ftandards of comparifon. For B may be then reprefented by I, 2, 3> 4 5 &e. 1, ¥2, V3 v 45 V5; &c. or &c. &c. fine limite. And in that particular cafe, when it is reprefented by 1 or unit, this geometrical formula gives the arithmetical one, (put- ting r and q for R and Q,) eet A NG A ee 8 IN +e, q z q 29 q q 2g 37 q which 68 On the PRINCIPLES of the which has to 1, or unit, a ratio having to the ratio of AXN to 1 the ratio of r tog. Init A, N, 7,9, may be any numerical or arithmetical magnitudes whatever, whole, fractional, furd or mixed. ‘This formula, or antecedent, is exactly what is com- monly called the Binomial Theorem. Ir we fuppofe B to be reprefented by 2, we derive immedi- ately from this geometrical antecedent or formula, the following arithmetical one : A op aA Re Re eee een carte ee ae A732. N344 &e. q q Zi 7, 29 q ay! =f 37 q which has to 2 a ratio having to the ratio of A+N to 2, the ra- tio of 7 to 4. To fuch arithmetical formule there is no end or limit. And this I take to be the tru and fyftematic method of deriving them, v/z. from geometrical antecedents or formule, when they are fuppofed to become numerical. WHEN 1 or unit is the ftandard of comparifon, its various combinations with itfelf and the other numerical magnitudes, do not appear in the formula or antecedent. This circumftance renders it of all others the moft commodious for common ufe in algebra and arithmetic, though the leaft calculated of any for fhewing the rationalia or ground-work of the various opera- tions in thefe two fciences. For when the formula or antece- dent fhows the different combinations of the confequent or ftandard of comparifon with itfelf and the other numerical magnitudes, it is a fort of language announcing or exhibiting the reafons of its formation. Ir is evident, that half the excefs of the two geometrical expreffions taken together, which have refpectively to B ratios, having to the ratios of A+N to B and A—N to B, the ratio of F au ig R to Q, above twice a: or twice the magnitude, which B—— A has = ANTECEDENTAL CALCULUS. 69 has to Ba ratio having to the ratio of A to B the fame ratio of _R to Q, is truly exprefled by R RQ R2Qye, R RQ RQ Rs sRaQaray ge, ee e and that half the difference of thefe expreflions is RA ig ae BerorE I proceed farther, however, in the confideration of thefe expreflions, it may not perhaps be improper to premife the few following lemmata, which are almoft too evident to re- quire demonftration. LEMMA I. Ir any ratio be compounded with its inverfe, or the inverfe of any ratio the fame with it, the compofition produces a ratio of equality. « For of the three magnitudes A, B, A, by the definition of compound ratio, (s. Euc. Simson’s edit.), the ratio of A to B, compounded with the ratio of BtoA, is the ratio of A to A, or a ratio of equality ; and if the ratio of C to D be equal. to, or the fame with the ratio of A to B, its inverfe, D to C, is equal to, or the fame with the ratio of B to A, (Prop. B. ibid.) : Therefore, (Prop. F. Euc. 5. Srmson’s edit.), the ratio of A to B, compounded with the ratio of D to C, is the fame with the 3 ratio 70 On the PRINCIPLES of the ratio of A to B compounded with the ratio of B to A, or a ra- tio of equality. Q.E.D. , LEMMA IL. Ir with the inverfe of any ratio there be compounded a ratio greater than it, the compofition produces a ratio of greater ine- quality, or a ratio of which the antecedent is greater than the confequent ; and if with the inverfe of any ratio, there be com- pounded a ratio lefs than it, the compofition produces a ratio of lefs inequality, or a ratio of which the antecedent is lefs than the confequent. Frrast, Let the ratio of C to D be greater than that of A to B. Then (ro. Eve. 5.) the magnitude, which BA DCE has to D the ratio of A to B, is lefs than C. | | If E therefore be that magnitude, the ratio of C to D, compounded with the ratio of B to A, is the fame with the ratio of C to D, com- pounded with the ratio of D to E, (Propofi- tions B, and F. 5. Evc. Sim.). Wherefore, the ratio produced by compounding the ratio of i C to D with that of B to A, is the fame with the ratio of Cto E. But fince C is greater than E, the ratio of C to E is greater than that of E to E, (10. Eve, 5.), or a ratio of equality. Q.E.D, SECONDLY, —— a ew ANTEGEDENTAL CALCULUS. gt Seconpty, Let the ratio of F to D be lefs than that of A to B. Then (ro. Euc. 5.) the magnitude, which B AD F E has to D the fame ratio with that of A to B, | | | is greater than F. If E therefore be that | magnitude, the ratio of F to D, compounded | with the ratio of B to A, is the fame with the | ratio of F to D, compounded with the ratio | | of D to E, (Propofitions B. and F. 5. Euc. | Sim.). Wherefore the ratio produced by | | compounding the ratio of F to D with that of B to A, is the fame with the ratio of F to E. But fince F is lefs than E, the ratio of F to E is lefs than that of E to E, (10. Euc. 5.), or a ratio of equality. Q.E.D. « LEMMA IIL. Ir any ratio be compounded with a ratio of equality, it is not altered thereby. For the ratio of C to D, compounded with the ratio of A to A, is the fame with the ratio of C to D, compounded with the ratio of D to D, (Prop. F. 5. Stm. Euc.), which, by the defini- tion of compound ratio, is that of CtoD, Q.E.D, TuEse three Lemmata are alfo evident from Formula 1. Theorem 1. Univerfal Comparifon, Cor. From this and Lemma 1. with the definition of com- pound ratio, itis evident, that if with any ratio there be com- pounded a greater one, there arifes a ratio greater than it; and that, if with any ratio there be compounded a lefs one, there arifes a ratio lefs than it. 1 ; LEM- 72 On the PRINCIPLES of the LEMMA Iv. Ir from any magnitude there be taken the half, and from the remainder its half, and fo on, the halves fo taken, be their number ever fo great, are together lefs than the magnitude. C D 1d, Ue |—————_——_—_—__|_|_-B A For let AB be any magnitude, AC the half of AB, CD the half of CB, DE the half of DB, EF the half of EB, and fo on. THEN it is manifeft, that AC, together with CD and DE and EF, &c. are lefs than AB, from which they are taken. Q.E.D. Cor. 1. The ratio of AB to the fucceffive halves AC, CD, DE, EF, &c. taken together, be their number ever fo great, is greater than a ratio of equality; and the ratio of any one of the terms to all the fucceeding ones taken together, be their - number ever fo great, is greater than a ratio of equality. Cor. 2. Hence it follows, that of any feries or fucceflion of terms, in which the half of each term has to the immediately fucceeding one a ratio of equality, each term has to all the fuc- ceeding ones, be their number ever fo great, a ratio greater than that of equality. Cor. 3. Hence it alfo follows, that if CD, inftead of one half, be one third of AC or CB, DE one fourth of CD, EF one fifth of DE, and fo on, the ratio of any term to all the fucceeding ones taken together, exceeds a ratio of equality more than the ratio it has to the fame number of fucceeding terms, be that number ever fo great, exceeds it, when each term has to the immediately fucceeding one the ratio of two to one, SCHOLIUM. oditting inet Pay ANTECEDENTAL CALCULUS. 73 Scuotium. In like manner is it fhewn, that, if AC bea third part of AB, CD of AC, DE of CD, EF of DE, and fo on, the ratio of each term to all the fucceeding ones taken together, be their number ever fo great, exceeds the ratio of two to one; and, in general, if the ratios AB to AC, AC to CD, CD to DE, DE to EF, &c. be refpectively the fame with that of A to N, that the ratio of each term to all the fucceeding ones, be their number ever fo great, exceeds the ratio of A—Nto.N. This is alfo evident from the well known method of finding the aggre- gates of geometrical progreflions; and if the ratio of AC. to. CD be greater than that of AB to AC, the ratio of CD»to DE greater than that of AC to CD, and fo on, the ratio of any term to all the fucceeding ones, be their number ever fo great, exceeds the ratio. of A—N to N, more, than the ratio it has to the fame number of fucceeding terms, exceeds: it, when each term has to the immediately fucceeding one the ratio of A to N. I now proceed to prove, that each of the general geometrical. expreffions in p. 3. Avtecedental Calculus, viz. RRO. RRO RQ, R RQ RQ RQ yey Ae Ae eee Ol 2 AO be 1S: ne (i ca Q and R RQ. RRQ RQ, R RQ RAQ RD ee Ne TAL ~N + — = : eS a ola arate ae gen er alii, RS . Q. Fake has to Na ratio nearer to the ratio of Q = Q- to B than any: Bows given or afligned ratio, or than by any given or affigned. mag- nitude, when A+N'and A-—N have either to A or B ratios: nearer to that of equality than any esta or afligned ratio, or Vou. LV. K 5 than. "74 On the PRINCIPLES of the than by any given, or afligned magnitude, and.R and Q are twe given magnitudes of the fame kind. PROPOSITION I. ‘In this cafe, the firft term in each of thefe general expref- fions has to twice the fecond, the fecond to thrice the thifd, the third to four times the fourth, the fourth to five times the fifth, and fo on, a ratio greater than.any given ratio. For, if this be denied, let C and D be two given homogene- ous magnitudes, and let the ratio of C to D be greater. In each; the ratio of the firft term to twice the fecond, is that ‘of A to SON, and its inverfe “BON, or (N+N. SS) . to A, is the ratio compounded of the ratios of R—Q to Q, and N to A, (For. 1. Theor. 1. Univerfal Comparifon). Now, the ratio compounded of this ratio, and that of C to D, is a ratio compounded of the three ratios C to D, R—Q to Q, and N to A. But, fince R and Q are given magnitudes, R—Q is a gi- ven magnitude, (4. Euc. Data), and the ratio of R—Q to Qa given ratio, (1. Data). Wherefore the ratio compounded of the ratios of C to D and R—Q to Q, is alfo given, (67. Data). This ratio, however, compounded with that of N to A, is the fame Ro with the ratio compounded of C to D, and a Nto A. But fince that of A to N is by the hypothefis greater than any given ratio, the ratio compounded of C to D and R—Q to Q; com- pounded with that of N to A, produces a ratio of lefs inequa- = N is lity, (Lemma 2.). Confequently, the ratio of A to greater than any given ratio CtoD. Wherefore, the fuppofi- tion, ANTECEDENTAL CALCULUS. 75 fition, that any given ratio C to D is greater than it, is ab- furd. AND, fince the ratio of the fecond term to thrice the third, is that of A to =: N, it is proved exactly in the fame manner, that this ratio is greater than any given ratio. And precifely in the fame way is it demonftrated, that the ratio of the third term to four times the fourth, is greater than any given ratio ; and fo on. Cor. 1. If R—Q be equal to Q, the ratio compounded of” C to D, and R—Q to Q; is the fame with that of C to D, (Lem- ma 3.) ; and if R—Q be greater or lefs than Q, the ratio com- pounded of C to D and R—Q toQ, is accordingly greater or lefs than that of C to D, (Cor. to Lemma 3.). | ako kad AR fa Rela oye oti ye | neon, ————_—_., . Cor. 2. T itudes, = hitiitea mia or. 2. The magnitudes, QR Go. @, peed Q: af R-2Q &c. ==.N, “SON, aN, &c. are lefs than any given or afligned magnitude. Cor. 3. The ratio of each term to all the fucceeding ones, be their number ever fo great, is greater than any given ratio, (Scholium to Lemma 4.). Cor. 4. The magnitudes atin, atan, &c. have refpectively to A-ratios nearer to that of equality than any given ratio, or than by any given magnitude. Cor. 5. The magnitude which has to B a ratio, having to the ratio of A to B the ratio of R to Q, has to twice the firft term, in each of thefe general geometrical expreflions, a ratio greater than any given ratio. K 2 ; PRO: 76 On thee PRINCIPLES of the ~ PROPOSITION IU. Tue ratio of each of thefe two general geometrical expref- Rees aiid ds bluatiea Bests 3S. fions to N, is nearer to the ratio of Q pka@ to B than any given or affigned ratio. For, fince the firft term in each has to twice the fecond a ra- tio greater than any given or afligned ratio, (Prop. 1.), and the fecond has to all the fucceeding terms, be their number ever fo great, a ratio greater than any given ratio, (Cor. 3. Prop. 1.) the ratio of the firft term to all the fucceeding ones is a fortiori greater than any given ratio, being greater than that of A to ? era eee pia) Q 4 R magnitude, ens is lefs than > which (Cor. 2. Prop. 1.) is lefs than any given magnitude, which is abfurd, In like manner is it demonftrated, that the: ratio of the fe- cond expreffion to N, is nearer to the ratio of its firft term to, N than any given ratio, Q.E. D. SCHOLIUM.. Ir the fame reafoning be applied to the expreflion, = ak-Qy batten saat La R30 ws + &e. cL 2 lla which is half Q the difference of the two geometrical expreffions that have refpectively to B ratios having to the ratios of A+N to B, and A—N to B, the ratio of R to Q, we get the ratio of the | firft term to twice the fecond, the fame with that of A ‘to RaQ Ra N’ Aeris) AS and the ratio of the fecond to four times the third, - ANTECEDENTAL CALCULUS. 79 third the fame with that of A to SS = , and fo on. THE general expreflion, (p. 5. Antecedental Calculus), gives AN +C.M+M.N So B the ratio, that is produced by compounding the ratio of C+N . to D with that of A+M to B, above the magnitude, which has to B the ratio compounded of the ratios of A to B and C to D. But it is demonftrated in the fame manner as above, that if A+M and C+N have refpectively to A and C ratios nearer to that of equality than any given or afligned ratio, or than by any given or afligned magnitude, this expreflion alfo has to A.N+C.M —— tio, or than by any given magnitude. And the demonftration is exactly the fame, when any number of ratios are compounded. In like manner, if the ratio of C+N to D be decompounded with that of A+M to B, we get the difference between the ex- preffion thence arifing, and the magnitude which has to B the ratio produced -by decompounding the ratio of C to D with that CD.M — AD.N c. C+N {trated, as above, that if A+M and C-+N have refpeétively to A and C ratios nearer to that of equality than any given or aflign- ed ratio, or than by any given or afligned magnitude, this ex- CcD.M — AD.N : preffion. alfo has te —~—gi———— a ratio nearer to that of equa- for the excefs of the magnitude, which has to a ratio nearer to that of equality than any given ra- of A to B, equal to But it is readily demon- lity than any given ratio, or than by any given or afligned mag- nitude. Ir is manifeft then, that in this calculus no indefinitely {mall or infinitely littl magnitudes are fuppofed, but only magni- tudes lefs than any that may be given or afligned, and ratios _Mearer to that of equality than any that may be given or aflign- peed: 80 On the PRINCIPLES of the ed, and that it is equally geometrical with the method of ex- hauftions of the ancients, who never fuppofed lines, furfaces, or folids, to be refolved into indefinitely {mall or infinitely little elements. The expreffion infinitely little magnitude indeed im- plies a contradiction. For what has magnitude cannot be infi- nitely little. THIs geometrical calculus, though it has no connection with the various modifications of motion, is equally convenient in its application with the method of fluxions, (which is unqueftiona- bly a branch of general arithmetical proportion, in which 1 or unit is the common ftandard of comparifon, as well as the con- fequent of every ratio compounded, or decompounded). EXAMPLE I. In the circle ATB, (Fig. I. Pl. I.) let the diameter AB be re- prefented by D, TE perpendicular to it by Y, and AE by X. Then (13. E. 6.) Y* is equal to the reGtangle DX—X*. But the antecedental of Y° is 2YY, and that of DX —X’* is DXK—2XX, (p. 6. Antecedental Calculus). Wherefore D—2X is to 2Y as Y to x, that is, as TE to CE, (p.g. nt. Gal.). Confequently CE is a third proportional to EO and TE. EXAMPLE To find the furface of the fphere of which ATBA is a great circle, (Fig. I. Pl. 1.). Tue furface of the fpherical fegment, cut off by the circle, of which TE is the radius, has to the fquare on any given line B, a ratio compounded of the circumference of faid circle to B, and of the antecedental of the curve AT to B, (Ant. Cal: p. 9.) But the antecedental of the curve is a fourth proportional to 2YD and | ANTECEDENTAL CALCULUS. 81 and x, (ibidem). Wherefore, if 2YXp reprefent faid circum- ference, the antecedental of the fpherical fegment is pDX, of which the antecedent is PDX. EXAMPLE IL. Ir it be required to draw a tangent to the parabola (Fig. s. Pl. 1.) ATG at the point T ; let the latus rectum be reprefented by L. Then L.X is equal to Y’, and L.X to 2¥Y. Where- fore L isto 2¥ (2TE) as Y to X, that is, (Ant. Cal. p. 9.) as TE to CE, which is confequently equal to twice AE. EXAMPLE IV. _ In finding the area of the parabola, fince K ods equal to 2yY a L, we get the antecedental of the area, or YX, equal to aVY 2¥3 . . . 2 —z7> the antecedent of which is —, or its equal —XXY. 3L 3 . OTHERWISE: THE ratios of the antecedentals of the area AET, and the rectangle under AE, and any given line B to the fquare on B, are YX and BX to B’. But YX is equal to = , the antece- : +s 2y3s ‘ dent of which is Sah its equal a x XY; and the antece- dent of BX is BX. Wherefore the area of the parabola is two thirds of the rectangle AE, ET. Vot. IV. xe -L E X- 82 On the PRINCIPLES, &c. EXAMPLE V. So to divide a ftraight line AB, that the rectangle under the two parts AC, CB {hall be the greateft poflible. Cc ste RB . Ne Let AB bereprefented by A, AC by X, and confequently CB by A—X. Then the rectangle AC, CB is equal to AX—X’, the antecedental of which is AX—oXX, which, when fup- pofed equivalent to nothing, (according to Ant. Cal. p. 7.) gives A equal to 2X, or AC equal to CB. To multiply examples would be ufelefs. I will take an op- portunity, as foon as I conveniently can, of applying this cal- culus to feveral phyfical problems of importance, and particularly fome refpecting the refiftance of fluids ; and will fhew, that as it furnifhes a much greater variety of ways for exprefling antece- dentals than the fluxionary calculus does for fluxions, fo it wilt open new and extenfive rules for finding antecedents, as yet altogether unknown in the inverfe method of fluxions. AtTuHouGH the notation be in reality of no importance, I prefer X, Y, &c. to x Y, &c. as more indicative of the ori- gin of this mode of reafoning, which was derived from an exa- mination of the antecedents of ratios in general geometrical comparifon. ; es : 2 As - IV. Os- ie he. * IV. OzsERVATIONS on the TRIGONOMETRICAL TABLEs Of the BraAauMINS. By FoHN PLarraiR, F. R.S. Evin. and Profeffor of Mathematics in the Univerfity of Edinburgh. [Read April 6. 1795.] 1. PN the fecond volume of the Afatic Refearches, an extract is given from the Surya Siddbanta, the ancient book which has been long, though obfcurely, pointed out as the fource of the aftronomical knowledge of the Brahmins. The Surya Siddhanta is in the Sanfcrit language: It is one ofthe Saftras, or infpired writings of the Hindoos, and is called the Jyotith, or Aftronomical, Saftra. It profeffes, as we learn from Mr Davis, the ingenious tranflator, to be a revelation from heaven, communicated to MreyaA, a man of great fanctity, about four millions of years ago, toward the clofe of the Satya Jug, or of the Golden Age of the Indian mythologifts; a period at which man is faid to have been incomparably better than he is at pre- fent ; when his ftature exceeded twenty-one cubits, and his life extended to ten thoufand years. INTERWOVEN, however, with all thefe extravagant fictions, this fingular book contains a very fober and rational fy{tem of aftro- nomical calculation ; and even the principles and rules of trigo- nometry, a fcience of all others the moft remote from fable, and the leaft fufceptible of poetical decoration. It is on the con- La ftruction 84 OBSERVATIONS on the ftruction of the tables contained in this trigonometry, that [ - now beg leave to offer a few remarks. 2. Ir is neceffary to begin with obferving, that the cir- cumference of the circle is here divided into 360 equal parts, each of which is again fubdivided into 60, and fo on. The fame divifion was followed by the Greek mathematicians ; and this coincidence is the more to be remarked, that it re- lates to a matter of arbitrary arrangement, and one by no means neceffarily connected with the properties of the circle. There are indeed fome very obvious properties of that curve, that make it, though not neceflary, at leaft convenient, that the number of parts, into which the circumference is divided, fhould be a number divifible both by 3 and by 4, that is, that it fhould be a multiple of 12 ; but nothing more precife can be determin- ed from the nature of the curve itfelf. The agreement of two nations, therefore, in dividing the circumference of the circle precifely in the fame manner, as it cannot well be attri- buted to chance, muft be fuppofed to refult from fome communi- cation having taken place between them, if it were not that ano- ther very probable caufe may be afligned for it. In Greece, and no doubt in every other country, the divifion of the circle, i 1to equal parts, is of a much older date than the origin of trigono- metry, and muft be as ancient as the firft circular inftruments ufed for meafuring angles in the heavens. The inventors of thofe inftruments naturally fought to make the divifions on them correfpond to the fpace which the fun defcribed daily in the: ecliptic ; and they could eafily difcover, without any very pre- cife knowledge of the length of the folar year, that this might be nearly effected by making each of them the 36oth part of the whole circumference. Accordingly the famous circle of OsyMANDIAS, in Egypt, defcribed by HERopotus, was divided into 360 equal parts. ; THIS TRIGONOMETRY of th BRAHMINS. 85 . Tris principle may therefore have guided the aftronomers, both of the Eaft and of the Weft, to the fame divifion of the circle, without any intercourfe having taken place between them. It has certainly directed the Chinefe in their divifion, though it has led them to adopt one different from the Hindoo and Egyp- tian aftronomers. They divide the circle into 365 parts and 4, which can have no other origin than the fun’s annual motion: and fome fuch divifion as this; may perhaps have been the firft that was employed by other nations, who changed it however to the number 360, which nearly anfwered the fame purpofe, and had befides the great advantage of being divifible into ma- ny aliquot parts. The Chinefe, again, with whom the fciences became ftationary almoft from their birth, have never attempt- ed to improve on the method that firft occurred to them. 3. THE next thing to be mentioned, is alfo a matter of arbi- trary arrangement, but one in which the Brahmins follow a method peculiar to themfelves. They exprefs the radius of the circle in parts of the circumference, and fuppofe it equal to. 3438 minutes, or Goths of a degree. In this they are quite fin- gular. Protemy, and the Greek mathematicians, after dividing the circumference, as we have already defcribed, fuppofed the radius to be divided into 60 equal parts, without feeking to af- certain, in this divifion, any thing of the relation of the dia- meter to the circumference :. and thus, throughout the whole of their tables, the chords are exprefled in fexagefimals of the ra- dius, and the arches in fexagefimals of the circumference. They had therefore two: meafures, and two units; one for the circum- ference, and another for the diameter. The Hindoo mathema- ticians, again, have but one meafure and one unit for both, vz. a minute of a degree, or one of thofe parts whereof the circum-- ference contains 21600. From this identity of meafures, they derive no inconfiderable advantage in many calculations, though. it muft be confefled, that the meafuring of a ftraight line, the radius,, 86 OBSERVATIONS on the radius, or diameter of a circle, by parts of a curve line, namely, the circumference, is a refinement not at all obvious, and has probably been fuggefted to them by fome very particular view, which they have taken, of the nature and properties of the cir- cle. As to the accuracy of the meafure here afligned to the radius, viz. 3438 of the parts of which the circumference con- tains 21600, it is as great as can be attained, without taking in fmaller divifions than minutes, or 6oths of a degree. It is true to the neareft minute, and this is all the exactnefs aimed at in thefe trigonometrical tables. It muft not however be fuppofed, that the author of them meant to affert, that the circumference is to the radius, either accurately or even very nearly, as 21600 to 3438. I have fhewn, in another place*, from the Inftitutes of AxBArR, that the Brahmins knew the ratio of the diameter to the circumference to great exa¢tnefs, and fuppofed it to be that of 1 to 3.1416, which is much nearer than the preceding. Cal- culating, as we may fuppofe, by this or fome other proportion, not lefs exaé¢t, the authors of the tables found, that the radi- us contained in truth 3437’. 44”. 48”, &c.; and as the frac- tion of a minute is here more, than a half, they took, as their conftant cuftom is, the integer next above, and called the radius 3438 minutes. The method by which they came to fuch an accurate knowledge of the ratio of the diameter to the circum- ference, may have been founded on the fame theorems which were fubfervient to the conftruction of their trigonometrical tables +. 4. THESE tables are two, the one of fines, and the other of verfed fines. The fine of an arch they call cramajya or jyapinda, and the verfed fine wtcramayya. They alfo make ufe of the co- fine or bhujajya. Thefe terms feem all to be derived from the word jya, which fignifies the chord of an arch, from which the name * Tranf. R.S. Edin. vol. II. p. 185. Phyf. Cl. +See Note, § 6. TRIGONOMETRY of the BRAHMINS. 87 name of the radius, or fine of go°, viz. trijya, is alfo taken. This regularity in their trigonometrical language, is a circum- ftance not unworthy of remark. But what is of more confe- quence to be obferved,'is, that the ufe of fines, as it was un- known to the Greeks, who calculated by help of the chords, forms a ftriking difference between the Indian trigonometry and theirs. The ufe of the fine, inftead of the chord, is an improve- ment which our modern trigonometry owes, as we have hither- to been taught to believe, to the Arabs ; and it is certainly one of the acquifitions which the mathematical fciences made, when, on their expulfion from Europe, they took refuge in the Eaft. But whether the Arabs are the authors of this invention, or whether they themfelves received it, as they did the numerical characters, from India, is a queftion, which a more perfect knowledge of Hindoo literature will probably enable us to re- folve. No mention is made in this trigonometry, of tangents or fe- cants; a circumftance not wonderful, when we confider that the ufe of thefe was introduced in Europe no longer ago than the middle of the fixteenth century. It is, on the other hand, not a little fingular, that we fhould find a table of verfed fines in the Surya Siddhanta; for neither the Greek nor the Arabian ma- thematicians, had any fuch, nor had we, in modern Europe, till. after the time of PeTiscus, who wrote about the end of the cen- tury juft mentioned. 5- NExT, as to the extent and accuracy of thefe tables. The firft of them exhibits the fines to every twenty-fourth part of the quadrant, that is, the fine of 3°. 45’, and of all the multiples of that arch, viz. 7°. 30, 11°. 15’, &%c. up to go°. The table of verfed fines does the fame. In each, the fine, or verfed fine, is exprefled in minutes of the circumference, but without any frac- tions of a minute, either decimal or fexagefimal ; and, agreeably to the obfervation already made, when the fraétion that ought ta 88 OBSERVATIONS on the to have been fet down is greater than +, the integer next greater is placed in the table. Thus the fine 3°. 45° being, when accu- rately exprefled in their way, 224’. 49”, is put down 225’; and fo of the reft. The numbers, therefore, in tliefe tables, are only fo far exact as never to diifer more than half a minute from the truth, and this very limited degree of accuracy gives no doubt to their trigonometry the appearafice of an infant fcience: But when, on the other hand, we confider the principles and rules of their calculations, rather than the numbers actually calculated, we find the marks of a {cience in full vigour and maturity: and we will acknowledge, that the Hindoo mathematicians did not fatisfy themfelves with the degree of accuracy above mentioned, from any incapacity of attaining to greater exactnefs. TuHErR rules for conftructing their tables of fines, may be re- duced to two, vrz. the one for finding the fine of the leaft arch in the table, that of 3°. 45’, and the other for finding the fines of the multiples of that arch, its triple, quadruple, tc. Both of thefe Mr Davis has tranflated, judging very rightly, that it was impoflible to give two more curious fpecimens of the geometri- cal knowledge of the Hindoo philofophers: the firft is extracted from a commentary on the Surya Siddhanta; the other from the Surya Siddhanta itfelf. 6. WiTH refpect to the firft, the method proceeds by the con- tinual bifection of the arch of 30°, and correfpondent extrac- tions of the fquare root, to find the fine and co-fine of the half, the fourth part, the eighth part, and fo on, of that arch. The rule, when the fine of an arch is given, to find that of half the arch, is precifely the fame with our own: “ The fine of an arch being given, find the co-fine, and thence the verfed fine, of the fame arch ; then multiply half the radius into the verfed fine, and the {quare root of the produét is the fine of half the given arch.” Now, as the fine of 30°, was well known to thofe mathemati- cians to be half the radius, it was of confequence given: thence, by en x TRIGONOMETRY of th BRAHMINS. 97 by the rule juft laid down, was found the fine of 15°, then of 7°. 30, and laftly of 3°. 45’, which is the fine required. Thus the fine of 3°. 45’ would be found equal to 224’, 44”, as above obferved, and, the fine of 7°. 30’, equal to 448’. 39”, and, taking the neareft integers, the firft was made equal to 225, and the fe- cond to 449*. 7. WueEN, by the bifections that have juft been defcribed, the fine of 3°. 45, or of 225’, was found equal to 22°’, the reft of the table was conftructed by a rule, that, for its fimplicity and elegance, as well as for fome other reafons, is entitled to particular attention. It is as follows: “ Divide the firft jya- pinda, 225’ by 225; the quotient 1, deducted from the divi- dend, leaves 224’, which added to the firft jyapinda, or fine, gives the fecond, or the fine of 7°. 30’, equal to 449’. Divide the fecond jyapinda, which is thus found, by 225, and deduct 2, the neareft integer to the quotient, from the former remain- der 224’, and this new remainder 222’, added to the fecond jya- - pinda, will give the third jyapinda equal to 671’. Divide this laft by 225, and fubtract 3, the neareft integer to the quotient, from the former remainder 222’, and there will be left 219, M which, * By fuch continual bifections, the Hindoo mathematicians, like thofe of Europe before the invention of infinite feries, may have approximated to the ratio of the - diameter-to the circumference, and found it to be nearly that of 1 to 3.1416 as above obferved. A much lefs degree of geometrical knowledge than they pofleffed, would inform them, that fmall arches are nearly equal to their fines, and that the fmaller they are, the nearer is this equality to the truth. If, therefore, they afflumed the radius equal to 1, or any number at pleafure, after carrying the bifection of the arch of 30, two fteps farther than in the above conftruction, they would find the fine of the 384th part of the circle, which, therefore, multiplied by 384, would nearly be equal to the circumference itfelf, and would aétually give the proportion of 1 to 3.14159, as fomewhat greater than that of the diameter to the circumfe- rence. By carrying the bifections farther, they might verify this calculation, or eftimate the degree of its exattnefs, and might affume the ratio of 1 to 3.1416 as more fimple than that juft mentioned, and fufficiently near to the truth, 98 OBSERVATIONS on the which, added to the third jyapinda, gives the fourth; and fo on unto the twenty-fourth or laft.” Ir is not immediately obvious on what geometrical principle this rule is founded, but a flight change in the enunciation will remove the difficulty. The remainder, it muft be ob- ferved, from which the quotient is always directed to be taken away, is the difference between the two fines laft computed; and hence the rule may be exprefled more generally: Divide any fine by 225, and fubtract the quotient, or the integer neareft the quotient, from the difference between that fine and the fine next lefs ; the remainder is the difference between the fame fine ~ and the fine next greater ; and therefore if it be added to the former, will give the latter. If then, (fig. 3. Pl. I.), GA, GC, GE, be three contiguous arches in the table, of which the dif- ferences AC, CE, of confequence are equal, and of which the fines are AB, CD, and EF, the rule, as laft ftated, gives us CD—AB— = for the difference between CD and EF, and therefore EF=CD-+CD—AB — > =2CD— — AB, and al- fo EF+AB=CD(2—=)=cp(22). But 225 is the fine of the arch 3°. 45’, and 449 of twice that arch, as already fhewn; and, therefore, according to this rule, if there be three arches, of which the common difference is 3°. 45’, the fine of the mean arch will always have to the fum of the fines of the ex- treme arches, a given ratio, that namely, which the fine of 3°. 45° has to the fine of twice 3°. 45’, or of 7°. 30°; now, this is a true propofition ; and therefore we are in polleffion of the principle on which the Hindoo canon is conftructed. 8. THe geometrical theorem, which is thus fhewn to be the foundation of the trigonometry of Hindoftan, may alfo be more generally enunciated. “ If there be three arches in arithmetical progretlion, the fine of the middle arch is to the fum of the fines of ——— ee ade. al a a 70 TRIGONOMETRY of th BRAHMINS. 99 of- the two extreme arches, as the fine of the difference of the arches to the fine of twice that difference.” This theorem is well known. in Europe ; it is juftly reckoned a very remarkable pro- perty of the circle ; and it,ferves to fhew, that the numbers. in a table of fines conftitute a feries, in which every term is formed exactly in the fame way, from the two preceding terms, viz. by multiplying the aft by a certain, conftant number, and fub- tracting the laft but one from the produc. 9g. Now, itis worth remarking, that this property of the table of fines, which has been fo long known in the Eaft, was not ob- ferved by the mathematicians of Europe till about two hundred years ago. The theorem, indeed, concerning the circle, from which it: is deduced, under one fhape or another, has been known to them from an early period, and may be traced up to the writings of Euciip, where a propofition nearly related to it forms the 97th of the Data: “ If a ftraight line be drawn with- in a circle given in magnitude, cutting off a fegment containing _ a given angle, and if the angle in the fegment be bifected by a ftraight line produced till it meet the circumference ; the ftraight lines, which contain the given angle, fhall both of them together have a given ratio to the ftraight line which bifeets the angle.”” This is not precifely the fame with the theorem which has been fhewn to be the foundation of the Hindoo rule, but differs from it only by affirming a certain relation to hold among the chords of arches, which the other affirms to hold of their fines. It is given by Evcurp as ufeful for the con- ftruction of geometrical problems; and trigonometry being then unknown, he probably did not think of any other applica- tion of it. But what may feem extraordinary is, that when, about 400 years afterwards, ProLemy, the aftronomer, con- ftructed a fet of trigonometrical tables, he never confidered Ev- cLip’s theorem, though he was probably not ignorant of it, as having any conneétion with the matter he had in hand. He, M2. therefore, 100 OBSERVATIONS on the therefore, founded his calculations on another propofition, con- taining a property of quadrilateral figures infcribed in a circle, which he feems to have inveftigated on purpofe, and which is ftill diftinguifhed by his name. This propofition comprehends in fact Evcxip’s, and of courfe the Hindoo theorem, as a par- ticular cafe; and though this cafe would have been the moft ufeful to Protemy, of all others, it appears to have efcaped his obfervation ; on which account he did not perceive that every number in his tables might be calculated from the two preceding numbers, by an operation extremely fimple, and every where the fame; and therefore his method of conftructing them is infinitely more operofe and complicated than it needed to have been. Not only did this efcape ProLemy, but it remained un- noticed by the mathematicians, both Europeans and Arabians, who came after him, though they applied the force of their minds to nothing more than to trigonometry, and actually enriched that fcience by a great number of valuable difcoveries. They continued to conftruct their tables by the fame methods which Protemy had employed, till about the end of the fix- teenth century, when the theorem in queftion, or that on which the Hindoo ruleis founded, was difcovered by VirTa. We are however ignorant by what train of reafoning that excellent geo- meter difcovered it; for though it is publithed im his Treati/e on Angular Sections, it appears there not with his own demon- ftration, but with one given by an ingenious mathematician. of our own country, ALEXANDER ANDERSON of Aberdeen. It was then regarded as a theorem entirely new, and I know not. that any of the geometers of that age remarked its affinity to the propofitions of Evcitip and Protemy. ‘It was foon after applied in Europe, as it had been fo many ages: before in Hin-- doftan, and quickly gave to the conftruction of ‘the trigonome- trical canon all the fimplicity which it feems capable of attaining. From all this, I think it might fairly be:concluded, evenif we had. a : ] be TRIGONOMETRY of the BRAHMINS. 101 had no knowledge of the antiquity of the Surya Siddhanta, that the trigonometry contained in it is not borrowed from 5 7 Greece or Arabia, as its fundamental rule was unknown to the geometers of both thofe countries, and is greatly preferable to that which they employed. Io. CONSIDERABLE light may perhaps hereafter be thrown on this argument, if it be found that the Surya Siddhanta con- tains a demonftration of this rule. It does not appear, however,. from the fragment we are. in’ poffeffion of, that any explanation ' of the rule is given, either in that work, or in the commentary. Indeed I am not certain that the Surya Siddhanta contains any thing but rules and maxims, or that the author of it condefcends. to give any demonftrations of the propofitions which he enun- ciates. He may have felt himfelf relieved from the neceflity of doing fo, by his claim to infpiration ; and as he probably valued himfelf more on the character of a prophet, than of a geometer, he may rather have inclined to exercife the faith, than the rea- ‘fon, of his difciples. However that be, by the rule above explained, the Brah- mins have computed a fet of tables, limited indeed in their accu- racy, but extremely fimple and compendious. ‘The rule is eafily remembered by one who has been accuftomed to- numeri- cal calculation, and is fuch, that, by help of it, he may at any time compofe for himfelf a complete fet of trigonometrical tables, in a few hours, without the affiftance of any book what- ‘ever. For the purpofe of rendering it thus fimple, the con- trivance of meafuring the radius, and all the fines, in parts of ‘the circumference, feems to have been adopted: if we follow any other method, the rule, though it remain the fame in reality, will affume a form much lefs eafy to be retained in the me-- mory*. It has the appearance, like ai onbes things in. the a 83 i fcience: '* Tuts feems to me the moft probable reafon that can’ be affigned forthe mea- faring of the radius, and the other ftraight lines in the circle, in parts of the circum- ference, 102 OBSERVATIONS on the fcience of thofe eaftern nations, of being drawn up by one who was more deeply verfed in the fubjeét than may be at firft ima- gined, and who knew much more than he thought it neceflary to communicate. It is probably a compendium, formed by fome ancient adept in geometry, for the ufe of others who were mere- ly practical calculators. 11. Ir we were not already acquainted with the high anti- quity of the aftronomy of Indoftan, nothing could appear more fingular, than to find a fyftem of trigonometry, fo perfec in its principles, in a book fo ancient as the Surya Siddhanta. The antiquity of that book, the oldeft of the Saftras, can fcarce be accounted lefs than 2000 years before our era, even if we fol- low the very moderate fy{tem of Indian chronology laid down by Sir Witti1am Jones *. Now; if we fuppofe its antiquity to be no higher than this, though it bears in itfelf internal marks of an age {till more remote J, yet it will fufficiently excite our won- der, to find it contain the principles of a fcience, of which the firft rudiments ference. It is remarkable that the Hindoos fhould have been thus led, at fo early a period, to put in practice a method, the fame in the moft material point, with one which has been but lately fuggefted in Europe as an important improvement in tri- gonometrical calculation. In the Phil. Tranf. for 1783, Dr Hutton of Woolwich propofed to divide the circumference, not into degrees, as is ufually done, but into decimals of the radius; and he has pointed out how the prefent trigonometrical ta- bles might be accommodated to this new divifion, with the leaft poffible labour, in a paper which difplays that intimate acquaintance with the refources, both of the na- merical and algebraic calculus, for which he is fo much diftinguifhed. His plan is, in one refpeét, the fame with the Hindoo method, for it ufes the fame unit to exprefs both the circumference and the diameter; in another refpeét it differs from it, vz. in making the radius the unit, while the other affumes for an unit the 36oth part of the circumference. Dr Hutton’s plan has never been executed, though it cer- tainly would be of advantage to have, befides the ordinary trigonometrical tables, others conftruéted according to that plan. * Afiatic Refearches, vol. II. p. r11, &&c. + The obliquity of the ecliptic is ftated at 24° in the Surya Siddhanta, as in all the other aftronomical tables of the Hindoos which we are yet acquainted with. (Tranf. TRIGONOMETRY of th BRAHMINS. 104 rudiments are not older in Greece than 130 years before our zra.. The bare exiftence of trigonometrical tables, though they belong undoubtedly to a very elementary branch of fcience, yet argues a {tate of greater advancement in the mathematics than may at firft. be imagined, and neceflarily {uppofes the application of geome- trical reafoning to fome of the more difficult problems of aftro- nomy and geography. As long as the furveying of land, and the ordinary menfura- tion of furfaces and folids, are the only praétical arts to which the geometer applies his fpeculations, he will naturally content himfelf with conftructing his figures and plans by means of a fcale, and an inftrument for meafuring angles, as by doing fo he may attain to all the accuracy he can defire. But when, in the figures that are to be thus delineated, the fides happen to be extremely unequal, and fome of the angles very acute, or very obtufe, graphical operations become inaccurate, and a very {mall error in the meafuring of one thing produces an enormous error in the eftimation of fome other. Lines, therefore, that extend over _a great tract of the earth’s furface, and much more thofe that extend to the heavens, cannot be compared with the fmaller lines, which we have an opportunity of meafuring, by the bare con- ftruction (Tranf. R. §. Edin. vol. 1]. p. 164.) Mr Davis concludes from this, (Afiatic Re- fearches, vol. II. p. 238), that if the obliquity diminith, at the rate of 50” in a hun- dred years, the Surya Siddhanta is at prefent about 3840 years old, which goes back nearly 2000 years before the Chriftian zra. But the diminution of the obliquity of the ecliptic, is fuppofed confiderably too rapid in this calculation. According to: Mayer it is 46” in a century; and according to De la Grance, (Mem. Berlin 1782), at a medium no more than 30”. This laft is moft to be depended on, as it proceeds on an accurate inquiry into. the law of the fecular variation of the obliquity, that variation being by no means uniform. Let us however take the mean, viz. 38”, and the obliquity at the beginning of the prefent century having been 23°. 28’. 41”, we fhall have 5020 years for the age of the Surya Siddhanta, reckoned from that: date, or: about 3300 years before CuristT, which is near the zra of the Caly Yug.. 104 OBSERVATIONS on the ftruction of triangles and parallelograms ; and when ever fuch comparifons are to be made, fome other method mutt be fought for. It was precifely in fuch circumftances, that the inventive genius of Hirrparcuus fuggefted the application of arithmetic to afcertain thofe ratios among the fides and angles of figures, which pure geometry afforded no method of exprefling. This union of geometry and arithmetic did not happen, however, till each of thefe fciences feparately had made great progrefs ; for before the days of Hrprarcuus, Euciip, ARCHIMEDES, and Aproton ius, had all flourifhed in fucceflion, and had pro- duced thofe immortal works, of which the luftre has not been ob- {cured by the higheft improvements of later ages. In the progrefs of fcience, therefore, the invention of trigonometry is to be confi- dered as a ftep of great importance, and of confiderable difh- culty. It is an application of arithmetic to geometry, with which we are now too familiar, to perceive all the merit of the inventor; but a little reflection will convince us, that he, who firft formed the idea of exhibiting, in arithmetical tables, the ra- tios of the fides and angles of all poflible triangles, and contrived the means of conftructing fuch tables, muft have been a man of profound thought, and of extenfive knowledge. However ancient, therefore, any book may be, in which we meet with a fyftem of trigonometry, we may be aflured, that it was not written in the infancy of fcience. 12. As we cannot therefore fuppofe the art of trigonometri- cal calculation to have been introduced till after a long pre- paration of other acquifitions, both geometrical and aftro- nomical, we muft reckon far back from the date of the Surya Siddhanta, before we come to the origin of the mathemati- cal fciences in India. In Greece, the conftellations were firft reprefented on the fphere, if we take a medium between the chronology of Newron, and that which is now ge- nerally . TRIGONOMETRY of the BRAAMINS. Tos nerally received, about 1140 years before the Chriftian xra* 5 and Hierarcuus invented trigonometry 130 years before the fame xra. Even among the Greeks, therefore, an) interval, cf Jat leaft:1000 years, elapfed from: the firft obfervations in aftro- nomy, to the invention of trigonometry; and we have furely no reafon to fuppofe, that the progrefs of knowledge |has beey more rapid in other countries. A THOUSAND years therefore muft be added to the age of the Surya Siddhanta, which we fuppofe here to be 2000 before Curist, in order that we may reach the origin of the {ciences an ‘Hindoftan, and this brings us very nearly to the celebrated era of the Caly Yug, to which M. Bartry has already referred the conftruGtion of the aftronomical tables of that country. And here, I cannot help obferving, in juftice to an author, of whofe talents and genius the world has been fo unfeafonably and fo cruelly deprived, that his opinions, with refpect to this zra, appear to have been often mifunderftood. It certainly was not his intention to affert, that the Caly Yug was a real era, confidered with refpect to the mythology of India, or even that at fo remote a period the religion of Brahma had an exift- ence. The religious and civil inftitutions of Hindoftan, as they now exift, may be all pofterior to this date, and their antiquity is “probably to be determined from principles that are not the ob- jects of aftronomical difcuffion. All, -I think, therefore, that M. BarLiy meant to affirm, and certainly all that is neceflary to his fyftem, is, that the Caly Yug, or the year 3102 before our ra, marks a point in the duration of the world, before which m7 N the * The {phere of Curron and Musaus was conftrusted, according to Newton, ‘about the year 936 before Curist, (NEwTon’s Chron. chap. i. § 30). According to the fyftem generally received, the ancient fphere, defcribed by Eupoxus, was conftruéted about 1350 years before Curist, (Dr Prarrarr’s Chronolegy, p. 37). The medium is 1143. 106 OBSERVATIONS, &. the foundations of aftronomy were laid in the’ Eaft, and thofe obfervations made, from which the tables of the Brahmins have been compofed. On this, however, and on many more of the particulars of the hiftory of thofe remote ages, great additional light will un-. doubtedly be thrown, by the complete tranflation of the Surya Siddhanta. From the fpecimen which Mr Davis has given, we can neither doubt of the importance of fuch a work, nor of his abilities to execute it; and we truft, that, to the zeal and libe- rality of our brethren of the Afiatic Society, the learned world will foon be indebted for the pofleflion of this ineftimable trea-- fure, > PR ates V. Some GEOMETRICAL PorisMs, with EXamPLEs of their APPEICATION to the SoLuTION of Propitems. By Mr WILLLAM WALLACE, Affifiant-Teacher of the Mathematics in the Academy of Perth. Communicated by Mr PLAYTFAIR. [Read March 7. 1796.) ‘HE nature of thofe mathematical propofitions, which were called Porifms by the ancient geometers, is now no longer a matter of uncertainty. The relation which they bear to other mathematical truths, the way in which they may at firft have been obferved, the kind of analyfis to be employed in their in- veftigation, their application to the folution of problems, have all been confidered by fome eminent mathematicians of the pre- fent age. THESE propofitions appear to have been held in high eftima- tion by the mathematicians of antiquity, becaufe of their great ufe in the analyfis of difficult problems, as we learn from the writings of Parpus of Alexandria: And fome {pecimens, which late inquirers into this fubjeét have given us, of their applica- tion to the folution of problems, feem to juftify his very high character of them. — Tue following paper contains fome porifms intimately con- nected with each other, and which feem capable of being ap- plied to the folution of a number of geometrical problems. Ex- N 2 amples 108 GEOMETRICAL PORISMS. amples of their application are added, fome of which are pro- blems that have been long known, and others are new ; but the conftructions of the former, it is believed, differ from any hi- therto publifhed.. Although»there are feveral of thefeexamples, in appearance, little related to each other, yet their folutions are effected by the fame general principle, which is alfo the founda-. tion of all the porifims. . PROP. I. PORISM, Fig. 4, ¢. PLT. Let AB, AC, be two ftraight lines given by pofition, let B, C,. be given points in thefe lines, a point H may be found, fuch, that any circle whatfoever pafling through A, the in- terfe€tion of the given lines, and H the point which may be found, fhall cut off from the given lines fegments BD, CE, adjacent to. the givem points, and: having .to-each other the given ratio of « to i Suppose the porifm to be true, and that,the point H is found. If a circle be defcribed through H,.A, and B one of the given points, it muft alfo, pafs through C the other given point, that the propofition may be univerfally true. Therefore H is in the circumference of a given circle. Join BH, CH, DH, EH. The angle DHE is equal to DAE, that is, to. BHC, (fig. 4.) or DHE is the fupplement of DAE, (fig. 5.) and therefore equal to BHC ; hence BHD is equal to CHE, but BDH is equal.to CEH, there- fore the triangles BDH, CEH, are equiangular, and BH is to HC as BD to CE, that is by hypothefis in the given ratio of « to 8; therefore if BC be joined, the triangle BHC is given in fpe- cies, and BC being given, BH and HC are given; therefore the ‘point H is given, which was to be found. __ Ie the fegments BD, CE, cut off from the given lines, lie in the fame direction with refpect to AB, AC, (fig. 4.) the point H will a GEOMETRICAL PORISMS. Iog will be in the fame fegment of the circle with the angle BAC; but if BD, CE, lie in contrary directions to AB, AG, (fig. 5.) then H will be in that fegment of the circle upon which BAC ftands. Tue point H will be found by the following conftruction : Defcribe a circle through the poimts A, B,C. Join BC, which divide at G, fo that BG may be to GC in the given ratio of BD to CE, that is of « to 8, and if the fegments to be cut off are to lie in the fame direction with AB, AC, find F the vertex of the fegment upon which the angle BAC ftands, (fig. 4.) ; but if BD, CE are to lie in oppofite direCtions, (fig. 5.) find F the vertex of the fegment BAG, and in either cafe join FG, which produce to meet the circle in H the point to be found ; that is, if any circle be defcribed through H and A to meet the given lines in D and E, BD.is to CE as @ to @. Join HB, HC, HD, HE. The tri- angles BDH, CEH are. fimilar, for the angle BDH is equal,to CEH, and becaufe the angle BHC is equal to DHE, therefore BHD is equal to CHE; hence BD is to CE as BH to. HG, that is, (becaufe HG bifects the angle BHC), as BG to GC, or as a; -to p. Ir is-evident that the point H may be alfo. found, by taking ' any fegments BD, CE, in the given ratio of a to #8, and defcrib- ing a circle through the points D, A, E, to meet the circle BAFC in H the point required. If the given lines be parallel, and the ‘points B, C, alfo the ratio of BD to CE, (fig. 6.) given as before, ‘the indeterminate circle will be:changed into a ftraight line paf- fing through a given point H, which will be without the given lines, or between them, according as BD, CE, are to lie in the - fame, or in-contrary, dire@tions with AB, AC. ” PROP. IE. + fe) GEOMETRICAL PORISMS. PROP. I. PORISM, Fig. 7. PLI. Let AF, AG be two ftraight lines given by pofition, a point Hi may be found, fuch, that any circle whatfoever defcri- bed through it, and A the interfeétion ‘of the given ines, to meet them in D and E, fhall cut off from them feg- ments AD, AF, whofe fum fhall-be a given line M. Suppose the porifm to be true, and that the point is found, and circle deferibed as above, let given points B, C be fo taken, that BA and AC-may be together equal to DA and AE, that is, by hypothefis to the given line M, then BD will be equal to CE. If a circle be defcribed through the given points A, B, C, by hy- pothefis it will meet the circle paffing through A, D, E, in H the point which may be found. Join BH, CH, DH, EH. The angle BHC is equal to DHE, each being the fupplement of BAC, ‘therefore BHD is equal to CHE; now, HDB is equal to HEC, and BD is equal to CE, therefore the triangle HBD is equal to HCE, and BH is equal to CH, alfo DH to EH ; hence the angle BAH is equal to CAH, and H is in a ftraight line bifefting the angle FAG, but it is alfo in the given circle BAC; therefore the point H is given, as was required. Hence this conftruction: Take B and C two given points, fo that BA and AC may be together equal to M, and through A, B, C defcribe a circle. Draw AK bifecting the given angle FAG, and meeting the circle ABC in H the point required, that is, if any circle be defcribed through H and A, to meet the gi- ven lines in D and E, the fum of DA and AE {hall be equal to the fum of BA and AC, that is, by conftru¢tion to the given line M. The fynthetical demonftration follows readily from the preceding analyfis. : PROP, IU. Pa SS Se _ GEOMETRICAL PORISMS. Its PROP. Ill. PORISM, Fig. 8. PL IL. Let AF, AG be two ftraight lines given by pofition, a point H may be found, fuch, that if any circle be defcribed through it, and A the interfeGtion of the given lines, to meet them in. D and:F, the difference between AD and AE fhall be equal to a given line N. ‘THE analyfis of this propofition will differ in nothing material from the laft, and the point required may be found thus: Take- B and C, two given points, fo that the difference between BA and AC may be equal to N.. Through the points A, B, C, de- fcribe a circle. Draw AK bifecting the angle contained by FA one of the given lines, and AL the other line produced at their - interfection, and AK will meet the circle ABC in H the point which may be found ; that is, if any circle be defcribed through . H and A, to meet the given lines in D, E, the difference between - AD and AE is equal to N the given line. Jorn AH, BH,CH, DH. The triangles HCE; HBD are equal to one another in every refpect, for if BC be joined, the angle HBC is.equal to HAL, that is, by conftruction to, HAB, there- fore HB is equal to HC; in the fame way it appears that HD ig equal to HE ; now, the angle DHE is, equal to DAE, that is to BHC, therefore BHD is equal to CHE, hence BD is equal to CE, and the difference between DA and AE is the fame with. the difference between BA, AC, which $24 conftruction is equal, to the given line M.. THEsE two laft. propofitions the sh confidered ‘as particular eafes of the following propofition. PROP. Iv... 1r2 GEOMETRICAL PORTSMS. PROP. IV. PORISM, Fig. 4, 5. PLL. ‘Two ftraight lines AB, AC being given by pofition, and two ~ lines P, Q_ being given in magnitude, a point.H may be found, (fig. 5.) fuch, that any circle deferibed through it and A the interfeCtion of the given lines, to meet them in D, FE, thall cut off from them fegments AD, AE, fo that PXAD+QXAE, fhall be equal to a given fpace. Alfo, the fame things being fuppofed, a point H may be found, (fig. 4.) fo that Pk AD —QXAE, fhall be equal to a given fpace. Let given points B, C, be taken in either cafe agreeing with the hypothefis of the propofition, or fo that PX AB+Q x AC, ( fig. 5.) may be equal to PXAD+Q XAE, -and’ fo “hat PXAB—QXAC may be equal to PX AD—Q XAE, (fig. 4.) then, tm both cafes, PX BD will be equal to Q XCE 3; there- fore BD is to CE as Q to P, that is, in a given ratio, and the points B, C being given, the point H may be found, (Prop. 1.). Consrruction. Let given points B, C be taken as above direCted, and if PX AD+Q AE is to be a given fpace, (fig. 5.) find a point H, (Prop. 1.) fo that any circle defcribed through A and H may meet the given lines in D, E, fo that BD, CE may lie in contrary directions to AB, AC, and have to each other the given ratio of Q to P, then PX BD will be equal to QXCE, and adding the common fpace PXAB-+QXAE to each, we get PX AD+QX AE, equal to PX AB+Q* AC, that is, to the given fpace, as was required. But if Px AD—Q XAE is to be a given fpace, (fig. 4.) find H, (Prop. 1.) fo that any circle pafling through H, A may cut off fegments BD, CE, in the given ratio of Q_ to P, and lying towards the fame parts with AB, AC, then PXBD is equal to Q xCE, BP eye GEOMETRICAL PORISMS. 113 Qx CE, and Px AD—Q x AE, will be equal to Px AB—Qx AC, that is, by conftru¢tion to the given ‘pace. LEMMA, Fig.-9. Pl. IL. Ir circles be defcribed through A and C any two angles of a triangle ABC, to meet each other at D a point in AC, and the remaining lines AB, BC, in E and F; their other in- terfeGtion H, the remaining angle B, and the points EF, F, are in the circumference of a circle. Jorn DH, EH, FH. The angle AEH is equal to ADH or CFH, that is, BEH is equal to BFH, hence the points H, B, D, F areinacircle. Q. E. D. PROP. V. PORISM, Fig. to. Pl. IL. Ler AB, AC, BC be three ftraight lines given by pofition, a point H may be found, fuch, that if any circle be defcri- bed through H, and B the interfection of any two of the given lines, to meet them in D and F, and if DF be joined. ’ meeting the remaining line at E.. The line DF fhall be divi- ded. at E, into fegments having to each other a given ratio. Suppose that the point H is found. Join HA, HB, HC; join alfo HD, HE, HF. Since, by hypothefis, a circle may pafs - through the point which is to be found, the interfeftion of any two of the given lines, and the points where DF meets thefe lines, therefore the points H, A, D, E are in a circle, and the an- gle HEF is equal to HAD or HAB; now the points H, B, D, F are fuppofed to be in a circle; fince therefore in the triangle ABC, circles pafs through two of its angles A, B, and meet each other at D, a point in AB, (Lemma,) the points H, C, E, F are O alfo s| 114 GEOMETRICAL PORISMS. alfo in a circle; therefore the angle HCF is equal to HEF, that is, (as has been fhewn), to HAB; hence the point H, which may be found, is in acircle paffing through the points A, B, C, what- ever be the given ratio of DE to. EF. Let this circle be defcribed. Becausk the points H, A, D, E are in a circle, the angle HAC is equal to HDE, and becaufe H, C, EF, F are in a circle, the angle HFE is equal to HCA; therefore the triangles AHC, DHF are fimilar. In the fame manner it appears, that AHB is fimilar to EHF, and CHB to EHD. . Let AC be divided at K, fo that AK. may be to KC, in the given ratio of DE to EF, the point K will thus be given. Join HK meeting the circle in G. The triangles AHC, DHF being fimilar, and -having AC, DF, fimilarly divided at K, E, the tri- angles AHK, KHC will therefore be fimilar to DHE, EHF, which have been proved fimilar to BHC, AHB; therefore the angle AHB is equal to CHK or CHG, and the arch AB is equal to CG, hence G is a given point, and K being given, the line GH will be given by pofition; therefore the point H is given which was to be found. Construction. Defcribe a circle through the points A, B, C, let AB, BC, be the lines upon which D and F, the extremities of the indeterminate line, are.to be placed, and let AC be the line which is to meet it in E, fo that DE may be to EF, in the given ratio of de toef. Find K, fo that AK may be to KC as de to ef, draw BG parallel to AC, meeting the circle in G, join GK meeting the circle in H, the point which may be found ; that is,. if any circle be defcribed through H, and B the interfection of any two of the given lines, to meet them in D and F, and if DF be joined, meeting the remaining line at E, the line DF fhall be divided at FE, fimilarly to the given line def. Ler AH, BH, CH be joined, alfo DH, EH, FH. The angle HDF or HDE is equal to HBF, that is, to HAE, the points H, A, D, E are therefore in a circle, now the points H,‘S; DD, 2 are. GEOMETRICAL PORISMS. i's are in a circle, therefore (Lemma.) the points H ,U; E, F are alfo ina circle. The angle HDE is equal to HBC, that is, to HAK, and fince HEF is equal to HCF, therefore HED is equal to HCB, that is, to HGB or HKA; hence the triangles HDE, HAK are fimilar, and fince HFE is equal to FICK, the triangles HEF, AKG are alfo fimilar ; therefore DE is to EF as AK to KG, that is,as detoef, Cor. 1.~ The lines DH, EH, FH contain given angles, and have to each other the given ratios of AH, KH, CH. Cor. 2, The line DF cuts off fegments DA, EK, FC from _ the given lines, adjacent to given points in them, and having to each other the given ratios of HA, HK, HC. For the angles HDB, HEK, HFC are equal among themfelves, and fince BCH or BGH, that is, AKH, is the fupplement of each of the angles HCF, HAD, HKE, the angles HAD, HKE, HCF are equal a- mong themfelves, therefore the triangles HAD, HKE, HCF are fimilar, and AD, KE, CF are proportional to the given lines AH, KH,CH. | PROP. VI. PORISM, Sipe ets Pt is Ler AB, AC, BE, DE be four ftraight lines given by pofi- tion; a point P may be found, fuch, that if any circle be defcribed through it and B, any of the fix interfeGtions of the given lines, to meet the lines through whofe interfe@tion . At paffes in G and L, and if GL be joined, meeting the re- ; Maining lines in H and K, the fegments GH, HK, KL have given ratios to one another, which ratios are to be found. Because, by hypothefis, the points P, A, G, H are in a circle, and alfo the points P, F, H , K, it will appear, as in the analyfis of laft propofition, that P is in a circle defcribed about the tri- angle ADF; in the fame way it will be found, that P muft be in circles defcribed about each of the triangles ABC, DBE, O2 FCE. 116 GEOMETRICAL PORISMS. FCE. Therefore, that the propofition may be univerfally true, thefe four circles mutt interfeét one another at the fame point. Axsour any two of thefe triangles, as ABC, DBE, let circles be defcribed, the point P muft be at their interfection. Becaust ADF is a triangle, and through two of its angles A, D, circles are defcribed, meeting each other at B, a point in AD, therefore (Lemma.) P, their other interfeCtion, and the points F, C, E, are in a circle; and becaufe FCE is a triangle, and circles pafs through C, E, two of its angles, and meet each other at B, a point in CE, therefore (Lemma.) the points P, A, D, F are in a circle. Thus, it appears, that circles defcribed about each of the four triangles ADF, ABC, DBE, CFE, pafs through the fame point P as was to be inveftigated. It remains to inquire, whether the ratios of GH, HK, KL to one another be given. Join PB, PC, PE, alfo PG, PH, PK, PL. The angle GPH is equal to GAH, that is, to BPC, and PGH is equal to PBC, therefore the triangles BPC, GPH are fimilar, and the an- gle PHK is equal to PCE; but HPK is equal to HFK, that is, to CFE or CPE, hence the triangles HPK, CPE are fimilar, and PKL is equal to PEL. Now, if PN be drawn, fo that the angle BPN may be equal to GPL, that is, to the given angle GBL, it is evident that the point N is given, and will be in a circle paf- fing through P, and touching AG at B; the angles NPE, LPK will thus be equal, and the triangles NPE, LPK fimilar. Since, therefore, the triangles BPC, CPE, EPN are fimilar to GPH, HPK, KPL, it follows, that BN, GL are fimilarly divided by the given lines CH, EK, therefore the ratios of GH, HK, KL are the fame with the given ratios of BC, CE, EN. Construction. About ABC, DBE any two: of the four triangles formed by the given lines, let circles be defcribed, they will meet each other at P, the point which is to be found. THROUGH GEOMETRICAL PORISMS. Ti7 Turovcu P and B, the interfection of any two of the given lines, let a circle be defcribed to touch one of them at B, and cut the other at N, the line BN will be given, and the ratios of GH, HK, KL, the fame with the given ratios of BC, CE, EN to one another. Tue fynthetical demonftration follows readily from the ana- lyfis, and for the fake of brevity is here omitted. Cor. 1. The lines PG, PH, PK, PL, contain given angles, and have to each the given ratios of PB, PC, PE, PN. Cor, 2. The line GL cuts off from the given lines, fegments BG, CH, EK, NL, adjacent to given points, and having to each other the given ratios of PB, PC, PE, PN. For the points P, A, G, H, being in a circle, the angle PGB is equal to PHC; and fince P, F, H, K, are ina circle, the angle PHC is equal to PKE, which in like manner will be found equal to PLN. Now, the angles PBA, PCF, PEF, PNB are equal among themfelves, there- fore their fupplements PBG, PCH, PEK, PNL are equal, and _ the triangles PBG, PCH, PEK, PNL are fimilar, therefore BG, CH, EK, NE are proportional to the given lines BP, CP, EP, NP.. ly PROP. VI. THEOREM, Kg. 12. PI. II. Ler PGAB, PFAC, PEAD, &c, be any. number of given _ eircles, each of which pafles through the fame two points A, P ; from A, either of thefe points let a ftraight line, given by pofition, be drawn, meeting the circles at B, C, D, t&c.. and another meeting them at E, F, G, &c. Let ftraight lines GB, FC, ED, t¢c. be drawn, joining thefe points, fo as, to form, with the lines paffing through A, triangles GAB, FAG, EAD, fc. in each of the circles. If, through P, the common interfection of the circles, and Q. the interfection of 118 GEOMETRICAL PORISMS. of any two of the lines, a circle be defcribed to meet them in K and L, a line joining KL, and meeting the remaining lines, will be divided by them into fegments HK, KL, LM, MN, We. having to each other given ratios. Ler Q, R,S, Sc, be the remaining interfections of GB, FC, ED, ce. Becaufe GRE is a triangle, and circles PGAB, PH AD pafs through G, E, two of its angles, and meet at A, a point in GE, the points P, R, B, D, are in a circle, (Lemma.) in the fame way it appears, that circles may pafs through P, 8, C, D, and P,Q, B,C, tc. Becaufe it is now proved, that in the tri- angle CDS, a circle may pafs through P, C, B, Q, and. another through P, D, B, R; therefore the points P, S, R, Q, are ina circle. (Lemma.) Thus it may be fhewn, that circles defcribed about each of the triangles, formed by the intercepted fegments of the ftraight lines, will all pafs through the fame point Py From P draw ftraight lines to the points of interfection of one of the given lines, with all the others, as PA, PB, PC, PD, tc. Join PH, PK, PL, PM, PN, €c. Since P, Q, K, L, are in a circle, the angle BKP is equal to CLP ; now, the angles PBG, PCF, are each equal to PAG; therefore the angles PBK, PCL, are equal, and the triangles PBK, PCL, fimilar ; hence KP is to PL as BP to PC; now the angle KPL is equal to KQL, that is, to BPC ; therefore the tri- angles KPL, BPG, are fimilar, and the angle PLM will be equal to PCD. But the points P, S, C, D, having been proved to lie in a circle, if PS be joined, the angle PCD will be equal to PSD, therefore PLM is equal to PSD or PSM, hence the points P, S, L, M are ina circle. In the fame way it may be fhewn, that P, G, H, K are in a circle, as alfo P, D, M,N, &%. and that the triangles PAH, PDM, tc. are each fimilar to PBK and PCL, and hence that PHK is fimilar to PAB, and PLM to PCD, te. Through P defcribe a circle to touch AG at A, and meet AD in Pe Hee GEOMETRICAL PORISMS. 11g in V, which will be a given point, fince GA, AD, are given a pofition. Join PV, the angle PVA is equal to PAE or PDS, that is, (P, D, M, N being in a circle) to PNM, and PDV is equal to PMN, the triangle PMN is therefore fimilar to PDY ; and fince the angle PVA is equal to PDS, alfo PNV to PMD, the triangles PDM, PVN are fimilar. Thus it appears, that HN and AV are fimilarly divided by the lines BK, CL, DM, Gc. ; now, the points A, B, C, D, V, %c. are given; therefore the ratios of HK, KL, LM, MN, ec. to one another are given. Q. E. D. Cor. 1. The lines PH, PK, PL, PM, PN, &c. contain given angles, and have to each other the given ratios of PA, PB, PC, PD, PV, te. Cor. 2. The line HN cuts off from the given lines, fegments HA, KB, LC, DM, VN, &c. adjacent to given points, and hav- ing alfo to one another the given ratios of PA, PB, PC, PD, PV, tc. ; for the triangles PAH, PBK, PCL, PDM, PVN, ‘tc. have fee: proved equianeular ; and therefore AH, BK, CL, DM, VN, oc. are proportional to PA, PB, PC, PD, PV, We. *. PROP. VIII: * Tr may be proper to remark here, that,.in the preceding propofitions, the ftraight lines given by pofition, as well as the indeterminate ftraight line, which is cut by them into fegments, having to each other given ratios, and which alfo cuts off from them fegments adjacent to given points, and having to each other given ra- tios, are tangents to a parabola, of which the point thatiis required to be found is the focus; This confideration fuggefls fome.curious propofitions, relating to tangents to. the parabola. Some of them have been obferved by Dr Hat.ey, in his tranflation of the Seo Ratzonis of APPOLLONIUS. One very obvious application of the propofitions above hinted at, is to defcribe- - parabolas that fhall pafs, through given points, and touch ftraight lines given by pofis tion. 120 GEOMETRICAL PORISMS, PROP. ‘VOL VP OR TSM, Fig. 1's. -piei Ler CA, CB, AB be three ftraight lines given by pofition, a point H may be found, fuch, that if through H, and B, C, any two of the interfections of thefe lines, there be defcribed circles HBEF, HCDE, to meet each other at E, a point in BC, and the remaining lines at Dand F. If DE, EF, DF be joined, the triangle DEF {hall be fimilar to a given triangle def, and fhall have its angles upon the given lines in a given order. Because circles are defcribed through C, B, and meeting each other at E, a point in CB, therefore their other interfection H, the remaining angle A, and the points D, F, are in a circle. (Lemma.) Let a circle be defcribed through H, C, A,’to meet CB in G, and another through H, B, G, to meet AB in K, Join HA, HG, HK, alfoHD, HE, HF. The angles ADH, GEH, KFH, are equal to one another, and the angles CAH, CGH, BKH are equal, therefore HAD, HGE, HKF are equal, and the triangles HAD, HGE, HKF are fimilar ; therefore DH is to HE as AH to HG, and EH is to HF as GH to HK; now, the angles DHE, EHF are equal to DCE, EBF, that is, to AHG, GHK; hence the quadrilateral HDEF is fimilar to HAGK, and the triangle DEF is fimilar to AGK; now, the an- gles EDF and DEF are given by hypothefis, therefore GAK and AGK are given; but A is a given point, and AK is given. by pofition, therefore AG and the point G are given; therefore GK and the point K are alfo given, and H, the interfection of . the given circles GAC, GBK, will be given, which was to be found. Construction. Take a given point, which, to render the conftruétion more fimple, may be at A, one of the interfections of _ ae GEOMETRICAL PORISMS. 121 of the given lines. Let AG, GK be fo drawn as to form a triangle AGK, fimilar to the given triangle def, and having its angles placed upon the given lines, in the given order. Through A, G, any two of its angles, and C, the interfection of the lines upon which they are placed, defcribe a circle; through G, K, and B, the interfecétion of CG, AK, let another circle be defcribed, meeting the former in H, the point to be found, which will alfo be ina circle paffing through K, and touching CA at A. Tue demontftration follows eafily from the preceding analyfis. Cor. tr. The lines HD, HE, HF contain given angles, and have to each other the fame ratios, with the given lines HA, HG, HK. Cor. 2.. The lines AD, GE, KF have alfo to each other the given ratios of HA, HG, HK. PROP. IX. THEOREM, Fig. 14. Pl. III. Ler Ea, Ed, Fe, Gd, tc. be any number of ftraight lines _ given by pofition. Let P be a given point. Through P, and E, the interfection of any two of the given lines, let a _circle be defcribed to meet them in A and B ; through P, B, and H, the interfeGtion of BJ, with one of the remaining lines, let a circle be defcribed to meet that line in C. Through P, CG, and K, the interfection of Cc, with one of the remain- ing lines, let a circle be defcribed to meet that line in D, and fo on if there be more lines. Join AB, BC, CD, &ec, DA. The rectilineal figure ABCD, tc. is given in fpecies. TAKE 4, a given point in EA, through P, E, a, defcribe a circle to meet EB in 4, through P, H, 4, defcribe a circle to meet HC in c, through P, K, ¢, defcribe a circle to meet KD in d, and fo on if there be more lines. Join Pa, PA, alfo PB, Pd, PC, f } P Pe, 122 GEOMETRICAL PORISMS. Pc, PD, Pd, &%c. Becaufe the points P, E, A, B, are ima circle, the angle PAa is equal to PBJ ; now PaA is equal to PLB; for PaE is equal to PdE, the triangles PaA, PJB are therefore fimi- lar. In the fame manner it may be fhewn, that PdB is fimilar to PcG, and that again to PdD, tc. Therefore PA is to PB as Pa to Pé,-and PB to PG as Pd to Pc, and PC to PD as Pe to Pd, ‘8c. ; now the angles APB, BPC, CPD, t&c. are equal to AEB, BHC; CKD, &c, that is, to aPb, bPc, cPd; tc. therefore if ali, be, cd, 8c. Ad be joined, the retilineal figure PABCD, tc. is fimilar to Pabcd, tc; and leaving out the fimilar triangles PAD, Pad, the reétilineal figure ABCD, &c. is fimilar to abcd, ‘sc. Now the points P,; E, a, being given, the circle pafling through them is given; therefore 4 is a given point; in like manner ¢, d, tc. are given points; therefore the figure abled, Wc. is given; therefore ABCD, tc. to which it is fimilar, is given in fpecies. Q. E. D. Cor. 1. The lines PA, PB, PC, PD, €c. contain given an- gles, and have to each other the given ratios of Pa, P4, Pc, Pd, te, Cor. 2. The fegments Aa, Bd, Cc, Dd, tc. of the given lines, adjacent to the given points a, J, c, d, tc. have alfo to each other the given ratios of Pa, Pd, Pe, Pd, &c. Cor. 3. If there be any number of ftraight lines given by pofition, there may be innumerable reétilineal figures fimilar to one another, and having their angles upon the ftraight lines given by pofition. PROP. X PORISM, Fig. 15. Pl Il. Ler A and B be two given points in the circumference of a given circle. Let C bea given point in KC, a ftraight line given Na icnse snp irnin seid —_— GEOMETRICAL PORISMS. 1.23 given by pofition. There may be found a ftraight line KD given by pofition, and alfo a given point D in that line, fuch, that if AE, BE be inflected to any point in the cir- cumference of the given circle, they fhall cut off from KC, KD, fegments FC, GD, adjacent to the given points, and having to each the given ratio of « to £. Suppose the line KD, and the point D to be found. If AH, BH be inflected to the circle, fo that AH may pafs through C, then BH mutt pafs through D, the point which may be found, otherwife the propofition would not be univerfally true. Now, C being given, the point H, and the line BH, will be given by pofition. Let AL be drawn parallel to KC, then BL muft be parallel to KD, the line to be found ; hence it appears, that the angle GKF is equal to ALB, that is, to GEF; therefore the points E, K, G, F are in a circle, and the angle DGB is equal to CFA; now DBG is equal to CAF; therefore the triangles DBG, CAF are equiangular, and AC is to BD as CF to DG, that is, by hypothefis, as « to 8; now AC is given, and BH is given by pofition, therefore the point D is given, but BDG is equal to the given angle ACF, therefore DG is given by pofi- tion. ConstrucTion. Join AC, meeting the circle in H. Join BH, and, as @ is to B, fo let AC be to BD. Through H, D, CG defcribe a circle to meet FC in K. Join DK; then D is the given point, and DK is the line given by pofition, which are to be found ; that is, if AE, BE be inflected to any point in the circumference, to meet the-given lines in F, G; CF fhall be to DG as AC to BD, orasato@. The denial asion,i is ably de- rived from the es, Tue foregoing propofitions, in one point of view, may be confidered as exhibiting innumerable folutions of certain geo- metrical problems of the indeterminate kind, to each of which, Piz if 124 GEOMETRICAL PORISMS. if fome condition, unconnected with the hypothefis of the pro- pofition, be added, there will be formed a problem perfectly li- mited in its nature. Tue method of applying the porifms to the folution of many problems is obvious enough ; and, as fome of thefe may be of a very extenfive nature, and fuch as many others can be reduced to, therefore the utility of the porifms will by this means be greatly extended. The condition that may be joined to the hy- pothefis of each porifmatic propofition, it is evident, may be greatly varied ; And, hence, it were eafy to form abundance of problems, differing from any hitherto propofed: but this would extend the paper to too great a length. We {hall therefore on- ly give a few examples, of which, let the firft be the Sectio Ra- tionis of the ancient geometers. PILALES, O80, cba Bove Bae. 76. Pl dnt, Two ftraight lines AB, AC are given by pofition, and two points B, C are given in thefe lines. It is required to draw a line through P, a given point, without them, to meet them in D and E, fo that BD may have to CE the gi- ven ratio of M to N. Because the ratio of BD to CE is given; if a circle be de- fcribed through the points A, B, C, there is given a point H in the circumference, fuch, that the points A, H, D, E are ina circle, (Prop. 1.) therefore if HD, HA be joined, the angle HDP is equal to HAE, that is, toa given angle; now H and P are given points, therefore D is in the circumference of a gi- ven circle, but it is alfo in AB, a line given by pofition ; there- fore D is a given point, and PE is given by pofition, which was to be found. Con- —— . eee oe GEOMETRICAL PORISMS. 125 Construction. Through A, B, C defcribe a circle; inflec& BH, CH to the circumference, fo that BH may be to CH in the given ratio of BD to CE, or of M to N*, thus H will be a given point. If the fegments BD, CE to be cut off, are to lie in the fame direétion with AB, AC, the point H muft be found in the fame fegment with BAC; but if they are to lie in contrary di- rections, then H muft be taken in that fegment upon which BAC ftands. Join AH and PH, upon which defcribe a feg- ment of a circle, that may contain an angle equal to HAC, which is given. This circle may cut AB in two points D, 2d. Join PD and £90, meeting the remaining line in E and ¢; thefe lines cut off fegments BD, CE, or Bd, Ce, having to each other the given ratio of BH to HC, or of M toN. Jorn HD, HE. Becaufe the angle PDH is by conftruction. equal to HAE, the points A, H, D, E are in a circle; therefore the angle HEA is equal to HDA, that is HDB is equal to HEC; now, HBD is equal to HCE, for HBA is equal to HCA, there- fore the triangles HCE, HBD are fimilar, and BD is to CE as BH to HG, that is, by conftruétion, as M to N. ‘Ir is evident that this problem may admit of four folutions in general, if there be given no limitation with refpect to the di- rection in which the fegments are to be cut off from the given lines ; but the data may be fuch as to render it capable of three and alfo of two folutions only, THE next example fhall be the Seétio /patii of the ancients. PROP. XII. PROBLEM, Fig. 17. Pl. Ii. Two ftraight lines AB, AC are given by pofition, and two points B, € are given in thefe lines. It is required to draw a. * THE manner of doing this has been fhewn in Prop. t. 126 GEOMETRICAL PORISMS. a ftraight line through P, a given point, without them, te meet them in D and E, fo that the rectangle BD, CE may be equal to a given {pace. Suppose that DE is drawn as required. Join PC which will be given in pofition and magnitude. Draw PF parallel to AC, and take F, fo that the rectangle CP, PF may be equal to the given {pace, the point F will therefore be given; draw FL pa- rallel to CP, meeting AB in K, and PD in L, then FL and the point K will both be given by pofition. The triangles LFP, PCE are fimilar; therefore LF is to FP as PC to CE, and the rectangle LF, CE is equal to the rectangle FP, PC, which, by hypothefis, is equal to the rectangle BD, CE, therefore FL is equal to BD ; now, B and F are given points, and BK, FK are lines given by pofition ; therefore (Prop. 1.) if a circle be de- {cribed through K, B, F, there is a given point H in the circum- ference, fuch, that K, H, L, D are in a circle; therefore, if this point be found, and HD, HL, HK joined, the angle HDL is equal to HKL; therefore HDP is equal to HKF, that is, to a given angle; but H and P are given points, therefore D is in the circumference of a given circle; but it is alfo in a ftraight line given by pofition ; therefore D is a given point, and PD is given by pofition, Construction, Join P andC, either of the given points in the given lines; draw PF parallel to CA, and take F, fo that the given {pace may be the rectangle CP, PF. Draw FL parallel to CP, meeting AB in K, and through the points F, B, K defcribe a circle. Find H in the circumference, fo that BH may be equal to FH. Join HK and HP, upon which defcribe a feg- ment of a circle, that may contain an angle equal to HKF; this circle may meet AB in two points D, 3. Join PD and Pd, meet- ing a GEOMETRICAL PORISMS. 127 ing AC in Eand« The re¢tangles BD, CE, and BQ, Ce, are each equal to the given rectangle FP, PC, Let ED meet FK in L, join HL, HD. Becaufe by conftruc- tion the angle HDP is equal to HKF; therefore HDL is equal to HKL; therefore-the points H, K, D, L, are in a circle, and the angle HLK is equal to HDK, that is HLF is equal to HDB, now HFL is equal to HBD, alfo HF is equal to HB; therefore the triangles HFL, HBD are in all refpects equal, and FL is equal to BD. Again, the triangles LFP, PCE are fimilar, therefore PL is to FPas CP to CE, and the rectangle FL, CE is equal to the rectangle FP, PC, but FL is equal to BD, therefore the rec- tangle BD, CE is equal to the re¢tangle FP, PC, that is to the given fpace. In the fame way it may be fhewn that the rec-- tangle Bd, Ce is equal to FP, PC. PROP. XII, PROBLEM, Fig. 18. Pl. IV.. Four ftraight lines DB, DF, CG, BG are given by pofition, it is fequired todrawa line to meet them in the points N,O,P,Q; fo that the line NQ may be divided at thefe points, fimilar-. ly to a given divided line 2 op q.. . Suprose the line NQ drawn as required. Becaufe DB, DE,. BF are three ftraight lines given by pofition, and that NQ is di- vided by one of them. at O into fegments, having to each other - a given ratio, if a circle be defcribed through the points B, D, F, there is & given point E in the circumference, fuch, that the points KE, B;N;Q are in a circle, (Prop. 5.). Again, becaufe CB, GG, BG are three lines given by pofition, and NQ_ is divi- ded by one of them at P into fegmenits, having to each other a ®iven ratio, if |a Cirle be deferibed through B, GC, G, there isa given point A, in the circumference, fuch, that A, N, B, Q are in a circle, (Prop.'s.) | Thus it appears, that there afe given: three 128 GEOMETRICAL PORISMS. three points A, EF, B ina circle, paffing through N and Q, there- fore NQ is given by pofition, - Construction. Let DB, BG be the lines upon which the extremities of NQ are to be placed. About the triangles BDF, BCG, defcribe circles, draw BH parallel to FD, meeting the circle DBF in H, and draw BK parallel to CG, meeting the circle CBG in K. In DF find L, fo that DL may be to LF as no to 09, and in CG find M, fo that CM may be to MG as np to pq, jom HL meeting the circle DBF in EF, join alfo KM meeting the circle CBG in A. Through the points A, E, B defcribe a circle meeting DB, BG in N and Q, join NQ_ meet- ing the other lines in O and P, and NQ fhall be divided fimi- larly to 74q. Ir has been proved in Prop. 5. that the point E being found as above, if any circle pafs through E and B, and meet DB, GB in N and Q, the line joining NQ_ fhall be divided at O, fo that NO will be to OQ as DL to LF, that is by conftruction as no to og. Likewile, that the point A being found as above, if any circle be defcribed through A and B, to meet DB, BG in N and Q, the line NQ_ being drawn, fhall be di- vided at P, fo that NP will be to PQ as CM to MG, that is by conftruction as 1p to pg. Hence, it is obvious, that NQ_ is divided fimilarly to 2 q. Ir may be remarked, that the preceding conftruétion points out very clearly, a circumftance which appears to have efcaped the notice of fome Mathematicians that have given folutions of the problem,with a view to its application to Aftronomy. It is that the given ratios of NO, OP, PQ, to one another may be fuch as to render the problem indeterminate. Now, this it is evident will be the cafe, if the points A, E fhall both fall at £ the interfeCtion of the circles. This cafe forms Prop. VJ. of this paper, fo that it may be fufficient to add here, that the ratios which _ SE ee es oe > GEOMETRICAL PORISMS. 129 wwhich render the problem indeterminate, are thofe which are required to be found, in the propofition juft now quoted, PROP, XIV. PROBLEM, Fig. 19. Pl. IV. Turee ftraight lines AB, AC, BD are given by pofition, and P is a given point. It is required to.draw PE to meet BD in E, and PG meeting AB in F, and AC in G, fo that the angle EPG may be given, and fo that EP may have to FG the given ratio of « tof. Suppose the lines drawn as required. In GP take PH equal- to FG, therefore the ratio of EP to PH will be given, now the angle EPH is given, therefore His in a ftraight line given by pofition, (Apoll. Loci Plani, Lib. 1. Prop. 6.) let this line be LC. Bifecét PF in K, then becaufe P is a given point, and AB is given by pofition, the point K will be in a ftraight line given by pofition, (Loci Plani, Lib. 1. Prop. 4.) let this line be LM. Becaufe GF is equal to PH, and FK to PK, therefore GK is equal to KH, ‘but the lines ML, MC, CL are given by pofition, therefore, (Prop. 5.) a given point N may be found in the circumference of a circle pafling through M, C, L, fuch, that the points N, M, G, K are in a circle, therefore if this point be found, and NG, NM joined, the angle NGK or NGP is equal to the given angle NML, now N and P are given points, there- fore G isin the circumference of a given circle, but it is alfo in a ftraight line given by pofition, therefore the point G is given. Construction. Find LC a ftraight line given by pofition, fuch, that if PE, PH be drawn meeting BD, CL, and contain- ing an angle EPH equal to the fupplement of the given angle EPG, 130 GEOMETRICAL PORISMS. EPG, the ratio of EP to PH may be the fame with the given ratio of « to . (Loci Plani, Prop. 6. Lib. 1.) Find alfo a ftraight line LM given by pofition, fuch, that PF drawn to any point in AB, may be bifeéted by itin K. Through L, M, C, the interfetions of the given lines LM, AC, LC, defcribe a cir- cle. Draw CO parallel to LM, meeting the circle in O; bifec&t ML in Q; join OQ meeting the circle in N ; join NM, and infle&t NG, PG to AC, fo that the angle NGP may be equal to NML; draw PE, fo that the angle EPG may be fuch as is re- quired. Let GP meet CL in H, and AB in F, alfo LM inK ; join NH, NK, NL. Since NGP is equal to NML, the points N, K, G, M are in acircle, and the angle NKH is equal to NMG or NMC, that is to NLH;; therefore the points N, K, L, H are ina circle, and the angle NHK is equal to NLQ; now NKH is equal to NMG or NOC, that is (OC being parallel to ML) to NQL; therefore the triangles NKH, NQL are fimilar. In like manner it ap- pears, that NKG, NQM are fimilar ; ‘therefore ML and GH are fimilarly divided at Q and K, but MLis bifected at Q; therefore GH is bifeéted at K ; now PF is alfo bifected at K; therefore GF is equal to PH, and EP is to FG as EP to PH, that is, by conftruction, as @ to 6. PROP? 2V.° Peo BYE Me rie: 2b. Pity. TureeE ftraight lines AB, AC, BC are given by pofition, and three points D, E, F are given in thefe lines. Itis required to draw a ftraight line GHK to meet them, fo that DG, EH, FK may have to each other the given ratios that P, Q R have among themfelves. Suppofe EE EE ae —_— SC as GEOMETRICAL PORISMS. > LR Suppose that the line is drawn as required. Becaufe the ra- tio of DG to EH is given, there is given (prop. 1.) a point M in the circumference of a circle paffing through A, D, E, fuch, that the points A, M, G, H are ina circle. If. this point be found, and MG, MH, MD, ME joined, the angle GMH is equal to GAH orto DME. Alfo if MA, DE be joined, the angle MHG is equal to MAG or to MED. Therefore the triangle MHG is fi- m ilar to thegiven triangle MED, and the angle MHG is given. In like manner, becaufe the ratio of EH to FK is given, there is given a point N in the circumference of a circle pafling through E, C, F, fuch, that N, C, H, K are in a circle. If NH, NK, NE, NF, NC, EF be joined, it may be proved, in the fame way, that the triangle NHK is fimilar to NEF, hence the angle NHK is given. Now, the angles MHG, NHK being each proved to be given, the angle MHN is given, and the points M, N being alfo given, the point H is in the circumference of a given circle; but it is alfo'in a ftraight line given by pofition ; therefore the point H is given, and the angles MHG, NHK being given, the line GK is given by pofition, which was to be found. Construction. Through the points A, D, E defcribe a cir- cle, and infle@ DM, EM to the circumference, fo that DM may be to EM as'P to Q. Defcribe alfo a circle through C, E, F, and infleét EN, FN to the circumference, fo that EN may be to FN as Q to R. Join DE, EF, and inflet MH, NH to the ftraight line AE, fo that the angle MHN may be the fupplement of the fum of MED and NEF; draw HG, fo that the angle MHG may be equal to MED; then NHK is equal to NEF. Join MG, MA. Becaufe the angle MHG is equal to MED or to MAG, the points M; A, H, G are in a circle; hence the angle MHE is equal to MGD ; now MEH is equal to MDG; for MEA is equal to MDA; therefore the triangles MEH, MDG are fimilar, and DG is to EH as DM to ME, that is as P to Q. Q2 In 132- | GEOMETRICAL PORISMS. In like manner it may be proved, that becaufe the angle NEF is equal to NHK, the points N, C, H, K are’in a circle, and hence that the triangle NEH is fimilar to NFK.; hence EH is to FK as EN to FN, that is.asQ toR. Therefore GHK is drawn as required, PROP. XVI. PROBLEM, Fig: 20. PI. IV. Ir is required to defcribe a triangle DEF fimilar to a given triangle def, having one of its fides EF pafling through P a given point, and having its angles in a given order up- on three ftraight lines: AB, AC, BC given by pofition. THE conftruétion of this problem follows readily from the 8th propofition, as follows’: Draw AG, GK, fo as to’ form a triangle AGK, fimilar to the given triangle de f, and having its angles: upon the given! lines in the given order. Turoucu A, G, any two of its angles, and C, the interfection of the lines upon’ which they are placed, defcribe a circle. Through G, K,.and B, the interfeGtion of GC, KA, defcribe 4 circle meeting the former in H. From: the points’ H, P' infle& HE, PE to CB, fo that the angle HEP may be equal to HGK;, let PE meet AB in F. Through H, C, E defcribe a circle to meet CA in D; join DE, DF, and: the triangle DEF fhall be fi- milar to AGK or to def. Join HD, HF, HA, HK, HB, HC. Becaufe, by conftru&ion, the angle HEF is equal to. HGK of to HBX, the’ points H, By E, F are in a circle, and the angle FHE is equal to FBE or KHG, therefore the triangles EHF, GHK are fimilar.. In lke manser, becaufe a circle pafles through H, G; D, E, the angle DHE4s ‘equal to DCE or AHG, and’ HDE is’ equal! to’ HCE or HAG, therefore: the GEOMETRICAL PORISMS. 1353 the triangles EHD; GHA are fimilar. Now the triangle HEF was proved fimilar to HGK. Therefore the quadrilateral HDEF is fimilar to HAGK, and the angle DEF is equal to AGK +, alfo DE is to EF as AG to GK} therefore the triangle DEF is fimi- _lar te AGK or to def, as was required. - / PROP. XVI: “PROBLEM, Fipe'21. PI VS A and B are two given points in the circumference of a gi- ven circle. C and D are two given points in ftraight lines CE, DE given by pofition. It is required to inflect AF, BF to the given circumference, meeting the given lines in G _ and H, fo that the rectangle CG, DH may be equal toa given {pace. Because A and B are given points in the circumference of a given circle, and D is a given point in a line DE given by pofi- tion, a line LM, and a point M in it, both given by pofition, may be found, (prop. 10.), fo that BF, AF being infle@ted to amy point in the circumference, meeting the given line DE in H; and the line LM, which may be found in N, the ratio of DH to MN, may be given. Suppose the line ML found, fo that MN may be equal to DH, then the rectangle MN, CG is equal to DH, CG, which by hy- pothefis is given. Now A is a given;point, and C, M are given points in ftraight lines given by pofition. Therefore the pro- blem is now reduced to the 12th propofition of this paper. Construction. Join B and D, the given point, in the line whofe fegment is to be intercepted by BF. Let BD meet the circle in K; join AK, and take AM equal to BD. Through the points D, M, K defcribe a circle cutting DE in L, and AK in M. Join LM, and from the point A (by prop. 12.) draw a {traight line to meet CE in G, and LM in N, fo that the rec- tangle 134 GEOMETRICAL PORISMS. _ tangle MN, CG may be equal to that which is to be contained by CG, DH. Let AN meet the circle in F; join BF meeting DE in H. ; THE angle HDB is equal to LMK or AMN, and the angle DBH is equal to MAN; now BD tis equal to AM ; therefore the triangles BDH, AMN are in all refpects equal, and DH is equal to MN. ‘Therefore the rectangle DH, CG is equal to MN, CG, that is, (by conftruction), to the given {pace as requi- red. Ir is eafy to fee, how, in like manner, by drawing AGN, fo that CG may be‘to MN in a given ratio, (prop. 11.), the lines BF, AF fhall cut off fegments DH, CG, having to each other a given ratio. me poi t Th pp andres tinier poem Speen arnt net n= ’ ry } te +7 . 1 ar ; ee Se if : ZS | | bE peep pana a Nase eet Aaa ‘ a“ ¥' i ray} NC H ox ey Pails Scab haste nian ne eee ie OS EO eats 1 a q ] \ gd ta its tad * 7 S46 V. DETERMINATION of the LATITUDE and LoncitupDE of the OBSERVATORY at ABERDEEN: Jn Two LETTERS from ANDREW Mackay, LL.D. & F. R. S. Epin. to Foun PLarrair, F. R.S. Evin. and Profeffor of Mathematics in the Univer/ity of Edinburgbh.. EBT) TE Reo [Read 2d Dec. 1793-] DEAR SiR, Aberdeen, 18th September 1793 OME time ago I promifed to fend you the refult of a feries of obfervations, made to determine the fituation of this place. Having, however, been much hurried of late, I am only able at prefent to tranfmit you the determination of the latitude, deduced from a feries of obfervations of the fun’s meridian ze- nith diftances. With refpect to the longitude, as foon as it is in my power, I will reduce fome obfervations of occultations, and of the late folar eclipfe, and fend you the refults. Tue following obfervations of the fun’s meridian zenith di- ftances were made with a moveable quadrant of two feet radius, conitruéted by Mr Maccuttoca of London. This qua- drant has two feparate fets of divifions: the quadrantal arc of the ‘inner fet is divided into ninety degrees as ufual; and the exterior arc is divided into ninety-fix primary aiviaoud' ; each of j } | “ which - * 136 DETERMINATION of the LATITUDE which is fubdivided into eight equal parts; and the vernier gives one thirty-fecond part of a fubdivifion, or 13’,18. A micrometer {crew is attached to the vernier, which ferves to re- gulate the motion of the index, and by which, the excefs in fe- conds above the next lefs divifion of the vernier is fhown. Eacu zenith diftance was read off, at leaft, three times, both from the ninety and ninety-fix arcs, and the means of each were taken. Thefe ferved as a check on each other ; however, the zenith diftance, as given by the ninety-fix arc only, is ufed for obvious reafons. The ninety-fix arc was found to be about 12” lefs than go° ; and the error of the line of collimation at the vertical radius was about a fecond and a half, fubtra¢tive. As the tranfit inftrument and quadrant were placed in adja- cent rooms, it was therefore in my power to obferve both the fun’s tranfit and zenith diftance the fame day; however, the paf- fage of the fun’s weft limb over the fifth wire, and that of the eaft limb over the firft wire, were by this means loft. Hence, alfo, the zenith diftance of one limb only of the fun could be obferved ; and the true zenith diftance will be affected by the error of the fun’s femidiameter, as given in the Nautical Alma- nac, and by the irradiation, which according to M. pu SEjJour, exceeds three feconds. THE middle wire in the telefcope of the quadrant fubtended an angle of no lefs than 20°,6; therefore, as it was fcarce pof- fible to bring the fun’s limb exadtly to the middle of the wire, I conftantly made the lower edge of the wire a tangent to the fun’s apparent lower limb. The zenith diftances in the follow- ing table are the differences between thofe obferved and the fe- midiameter of the wire, the tenths of a fecond being neglected. Tue fifth column of the table contains the error of the line of collimation, combined with that of the ninety-fix arc, taking it for granted that this arc is accurately divided. In column fixth is the fun’s femidiameter, from the Nautical Almanac, to the I neareft oS 'e to eo BT ee — ey “ce eatin cies Cee wa = es ' And LONGITUDE of ABERDEEN. 137 neareft fecond: The next column contains the aggregate of the three preceding columns, and is the fun’s apparent central ze- nith diftance. The eighth column contains the mean refraction, anfwering to the apparent zenith diftance of the fun’s limb ; hence the allowance for the contraction of the femidiameter at low altitudes is avoided. The next column contains the mean refraction reduced to the true, by the application of the correc- tions depending on the heights of the barometer and thermo-- meter, as they are found in Table VIII. of my book on the Longitude: In column tenth is the fun’s parallax; and the quan- tities in the two laft columns, applied to thofe in column feventh, give thefe in column eleventh, being the true zenith diftances of the fun’s centre. The following column contains the fun’s declination, reduced to the meridian ofthis place; and in the laft column is the latitude. Voz. IV. R Obferved. Fg 138 DETERMINATION of the LATITUDE Obferved Diftances of the Sun’s Upper Limb- from the Zenith of the Obfervatory, Err, ge Sun’s Semid, add. Zen. ditt. Red . Appar. Zen.|M.Ref.|Ref. (Par. diftance. — | diftance. B May 17.29.78 ]48° 137° 26' 46" + ‘15’ 51" 137° 42‘ go" lo! 44" sae 43 19" h June 3.130-15 ]624 134 295513 115 49 134 45 47 10 39 5 46 21 © — -4.]3026 60 |34 22 56.) 3 | 15 48 |34 38 47 ]}0 5 39 21 YD — 5430-36 {er 134 T6143 175 48 134 32 5 ]9 5 32 38 B — 7-]30-23 {59 [34 4 0/3 | 15 48 J34 19 st lo 5 20 24 uw — §.{29.09 [55% 133 5845 )3 | 245 48 134 14 36]0 5 Th — 10.]29-83 |54% |33 49 9} 3 | 15 48 134 4 51 Jo 5 @ — 11-]3000 153 (33 44 4013] 15 48 434 © 31 Jo 5 D — 12.|29.98 1542 ]33 40 47 | 3 | 15 48 433 56 38 lo 5 YU — r5-]30-05 |58 133 31 36) 3 115 47 133 47 26 {0 5 © — 18.}37-06 [55 133 262013 | 15 47 133 42 19 }0 5 D — 19.13005 156 135 25 30 ]3 115 47 133 41 20 }0 5 gd — 20.]30.08 |60 |35 24 45} 3 |15 47 |33 49 45 |o 5 3 — 21-}30.05 63 133 24 3713 115 47 133 40 27 |0 5 YU — 22./29-89 |65 133 2453 |3 | 15 47 133 4° 43 lo 5 bh — 24-|29-79 }65 [33 26 4213 | 15 47 133 42 32 |o 37 36 © — 25.29.86 ]66 133 28 10 | 3 15 47 |33 44 © ]9 37 |o0 36 3 — 27.|29.65 58 |33 32 28] 3 [15 47 133 48 18 Jo 38 Jo 37 @ July 2.}30.00 [57 133 501313 |25 47 |34 6 39 38 |o 38 D — 3:129-71 ]63 133 545613 |15 47 134 10 46 }o 38 jo 37 S — §-130-29 }615 134 5 5213 |25 47 |34 22 42 |0 38 Jo 38 h — 1$-|30-31 |66 }34 22 36 |3 | 15 47 134 38 26 Jo 39 Jo 39 ad — 18./30.31 163 135 52 56 | 3 15 47. |36. 68 46]0 41 jo 41 Q — 21.|30.02 |$7 |36 26 30 | 3 15 48 |36 42 21 |0 42 |o q2 Q—.2 5 3 6 34.|0 43 J|o 42 2f Aug. 5 4 42 18 }o 47 |o a 2 — 4-|29- 4 58 70 48 |0 47 h-— : 4 14 20]0 48 Jo 47 h ie 4 5 59 9}]1I oO jo 59 o — 30. . 5 ES LOVE Bivin B YU — 3i./29- 4 5 3649 |t 4 |r 2 } Sept. - 5 QO 44 (5 5 |r 3 g¢ — 5.|29. 5 2716 |r 9 |x 10 3 — 20. 5 6 II 14 |t 24 |x 25 z — 21. 6 34 48 |r 25 |r 25 —— 27. 16-2 158 55 14 |% 337 |2 3 Od. 18. 16 7 }66 541242723 |2 “4 gif 16 10 |69 43 15 |2 3% |2 37 h Dec 1617 |79 7 38|4 43 |4 50 Oo 1618 |80 254]5 9 |5 11 2 — 15. 16 19 |80 22 57 |5 19 |5 O — 1. 16 19 |80 27 3515 21 |5 34 Seas 8o 31 18/5 23 15 45 © — 24.| 39.24 80 29 23]5 22 |5 qr ») G 80 2747/5 21 |5 43 > Apr. 30. 29.56 Tre Zenith | Latitude, 42 38 14 5r jo Q May 4.}29.81 Ate Gise 49 |o Dee: 30.06 38 27 36 44 |o 3 — 22.29.87 ° & June 12. | 30.12 41 35 ° — 15.|29-61 32 31 33 48 «1 ° ==) 26-| 29.66 29 53 33 45 43 c Sept. 1.] 30.52 48 53 I 19-|29-25 55 42 13 T 22. 129-49 56 52 15|1 26 |r 23- 129-49 57 15 39 {1 28 {1 Od. 18. ] 29.48 WHOAPH YOSHI s10 CEKVIN QAAIAanaKHHHUwW/AEaR OoOWDvow/o”o HID 24 |29.71 Ry ap) 7 29 |1 28 28.]29.98 59 12 46 |1 35 |r 36 66 49 5 {21% |2 10 23-|29.41 68 36 5 23 «12 23 Dec. 16. | 29.59 8 a1 80 24 49 20 15 33 — 21. /29.93 14 48 80 31 16 23 15 39 — 22./29.85 1455 80 31 23 23 15 4° 1738. n ~ um OOS mmm [IN OUNUU| AA wow bo [19070 0 BNSF] AAA ani in it in inn an we wan ut Pp i h. Uy w 2) eas) BOT ST 3ST i 24 18 ComPruTATION of the Apparent Time of Conjun¢tion at Green- _ Ob. ecliptic, Sum, - Alt, nonag. Vou. IV, : wich, on the Spherical Hypothefis. 5s. ° ’ ” Moon’s true longitude at beginning, 2 13 19 37 at ending, Computed parallax in longitude, - + “30 15 : Moon’s apparent longitude nearly, - 2 13 49 48 Moon’s equat. hor. parallax, - 60 33.0 Sun’s horizontal parallax, - - 8.7 ’ Difference of parallax of fun and moon, 60 24.3 . he ’ “w” App. time beg. 19 24 46% Sun’s R. A. 4 §t 302 R.A. meridian, © 16 17 6 : Arch, - 6 16 17 v. fine, 0.0297853 co-fecant, q Latitude, 51 28 4o co-fine, 9-7943612 fecant, 23 28 3 fine, 9.6001327 714 56 43 co. v.s. 034322 26563% 9.42427G2 45 34 9 v. fine, 299953 fine, s. ae es ek n 2 14 18 59 - 22 32 2 14 41 31 Q.001097r 0.2056388 98537566 Long. 146 DETERMINATION of the LATITUDE 7 ° , “ Long. nonag. 29 32 39 Moon’s app. long. 73 49 48 Diff. - 44 17 9 fine, Alt. nonag. 45 34 9 fine, Diff. hor. par. 60 24.3 fine, Par..in long. 3° «7.0 fine, h. ’ u" App.timeend. 21 I 24 Sun’s R. A. Anstey R. A. mer. I 53\ 15 6 Arch, 2 ee Pe v. fine, fecant, 9:8440037 98537566 co-fine, 8.2447766 fine, 7-9425369 P.inlat. 42’ 17.1, 0.168 5046 co-fecant, Latitude and obl. 74 56 43 co. v.S. 034322 9-3944939 365593 9.5629985 Alt. nonag. 53 7 26 v.fine, 399915 Long. nonag. 46 43 15 Moon’sapp.long. 74 41 3£ Dift.) 4 Non. 27 58 16 fine, Alt. nonag. 46 43 15 fine, Diff. hor. par. 60 26.2 fine, Par. in long. 22 34.2 fine, Moon’s true mot. in long. in ob. int. = Sun’s true mot. in long. 4 a Moon’s true rel. mot. in long. = Par. in long. at beginning, = - z at ending, = 2 App. rel. mot. in longitude, x fine, fecant, 9.6711972 9-9030547 co-fine, 8.24 50042 fine, 4.81472561 P. in lat. 36’ 16.”9, 59 22.0 ‘True mot. in lat. 3.51.0 Par. in lat. at end. 55 31.0 Sum, 30 7.0 Par. in lat. at begin. + 22 34.2 App. mot..in lat. 0.0604925 9-8451277 8.2447766 8.0899043 0.0552648 0.2056388 99930547 —_— 0-1639583 9.7782140 8.24 50042 8.0232182 / ” 5,393 36 16.0 41 46.3 42 17.1 30:8 Apparent F : 2 f ‘ St ——— = CUP And LONGITUDE of ABERDEEN. Mu Apparent mot. in lat. 30.8 1.4885 507 Apparent mot. in long. 47 58.2 3-4591210 Apparent inclination 36'47", tang. 8.0294297 co-fine, Moon’s apparent mot. in relative orbit, 2878.’’3 - : thal’ row Moon’s femidiameter at begin, 16 30 atend. 16 30 Sun’s femid. Augmentation, - + 9.0 + 12.5 Irradiation, Inflexion, - — 35 — 3-5 Cor. femid. Corre&ted femidiameter, 16, 35-5 16. 39.0 Sun’s femidiameter; - 15 45.0 15 45.0 ‘Sum, - 2 32 20.5 32 24.0 wu Sum of femid. at end. 1944.0 - - ar. co. log. at begin. 1940.5 ar.co.log. 6.7120864 App. mot. in rel. orbit, 2878.3 ar. co. log. 6.5 408639 Sum, i 6762.8 Half, - 3381.4 log. 35290965 Remainder, - 1437-4 log. 3-1575776 19.9396244 21 6 59 _ co-fine, 9.9698122 Central angle at begin. 42 13 58 - - fine, \ ° , a” Central angle at end. 4qz 8 21 fine, ° , "” ° , vw _ Central angle at begin. 42 13 58 atend. 42 $ a1 App.» inclination, 36 47 App.in. 36 47 Arch, - 42 50.45 co-s. 9.8652142 Arch, 41 31 34 co-S — Sum of femidiameters, 32 20.5 32879136 fumfem. 32 24 2342.8 3+1531278 24 15.4 147 3-4591210 9-:999975% 3-4591459 , ” 15 48.5 3-5 —_— 15 45.0 6.7113037 3-2879136 98274625 9-8266798 9-8742810 3-2886963 3.629773 Part 148 DETERMINATION of the LATITUDE Par. in long. at begin. Sum,’ - Rel. mot. in long. Obferved interval, Int, bet. beg. and conj. App. time of beg. App. time of conj. ° ’ ” 30 «(7-0 atend. 22 34.2 — —_—— | 53 49.8 3-5091756 Dik I 41.2 2.0051805 > 55 3E ar.co. 6.4774254 6.4774254 1 36 37% 3-7632408 3-7632408 a Tad Uo eg f 33 41-4 3-7498418 bet.end & con. 2 56.1 2.2458467 Ig 24 46.5 Apparent time of ending, 21 I 24. —— 20 58 27.9 20 58 27.9 Computation of the Apparent Time of Conjunction at Aberdeen, App. time of begin. Eftimated longitude, Reduced time, - - 2.13 30 8 at end. Moon’s true long. Par. in long. nearly, h , ” - 19 33 19 App. time of end. 3 + 8 36 19 41 55 - + 24 49 Moon's app. long. nearly, 213 54 57 Moon’s hor, parallax, Sun’s Diff, hor. par. App. time of begin. _Sun’s right afcenfion, Right afcen. meridian, 69 33.3 8.7 - 60 24.6 - 19 33 19 App. time of end. - 4 5% 34 © 24 53 oP 20 49 29 + 8 36 26.5845 214 16 57 + 19 45 2 14 36 42 60 34.8 8.7 60 26.1 20 4y 29 4 51 47 I 41 16 Now, with the right afcenfion of the meridian at the begin- ning, increafed by fix hours, or 65 24’ 53”, the latitude of the place of obfervation 57° 9° 0”, and the obliquity of the ecliptic 23° 28’ 3”, the altitude of the nonagefimal is 41° 39 6”, and its longitude 35° 46 6”; hence the moon’s apparent diftance from the nonagefimal is 38° 8’ 51”, with which the altitude of the ee ee ee eee ee And LONGITUDE of ABERDEEN. 149 the nonagefimal, and difference of the horizontal parallaxes of the fun and moon, the parallax in longitude is 24’47”.9, and in latitude 45’ 8”.2. Acain, with 75 41’ 16”, the fum of the right afcenfion of the meridian and fix hours, the latitude and obliquity of the ecliptic, the altitude of the nonagefimal, is 47° 17’ 40”, and lon- gitude 48° 8’ 35”; the apparent diftance of the moon from the nonagefimal is, therefore, 26° 28’ 7; from whence, the altitude of the nonagefimal, and the difference of the horizontal yO al- Jaxes of the fun and moon, the cag in sas cao is 19° 47".6, and parallax in latitude 40’ 59”.3. THE true motion of the moon in longitude is 46 48”.2, and that of the fun 3’ 2”.1; hence the moon’s relative motion in longitude is 43° 46’.1 ; from which, fubtracting the difference of the parallaxes in longitude 5’ 0%.3, the remainder 38’ 45”.8 is the apparent relative motion of the moon in longitude. THE true motion of the moon in latitude, in the obferved in- terval, is 4’ 20’.4; from which, fubtracting 4’ 8.9, the diffe- rence of the parallaxes in latitude, the remainder is the: moon’s apparent motion in latitude. Now, with the apparent motions of the moon in longitude and latitude, the apparent inclination is found to be 17’ 0”, and the apparent motion of the moon in its relative orbit is 2325.8. Wirn the altitude and longitude of the moon at the begin- ning and end of the eclipfe, the augmentation of the moon’s fe- midiameter at the beginning is g”.o, and at the end 11.4; hence the moon’s femidiameter, corrected by the augmentation and inflexion, is 16’ 35”.5 at the beginning of the eclipfe, and 16 37.9 at the end; and the fum of the femidiameters of the fun and moon, at thofe times, are 32 20’.5, and 32 22”.9 re- f{pectively ; with which, and the moon’s apparent motion in re- lative orbit, the central angle at the beginning of the eclipfe is 53 150 DETERMINATION of the LATITUDE 53° 15’ 20", and at the end 53° g 39’; hence arch firft is 53° 32 20”, and arch fecond 52° 52’ 39’. Wirth thefe arches, and the fum of the femidiameters of the fun and moon at the beginning and end of the eclipfe, arches third and fourth will be found equal to 19’ 13’.2 and 19! 32.6 re{pectively. Now, the fum of arch third, and the parallax in longitude at the beginning is 44 1’.1, and the difference be- tween arch fourth, and the parallax in longitude at the end, is. 15.0. Now, with this {um and difference, the moon’s true re- lative motion in longitude, and the obferved interval, the diffe- rence between the beginning of the eclipfe and the conjunction is 15 16’ 36’.1, and between the end and the conjunétion 26’.1. Hence the apparent time of conjunétion, inferred from the be- ginning, is 204 4g’ 55’.1, and from the end it is alfo 205 49' 55’-1, But the apparent time of conjunction at Greenwich is 20% 58'27’.9; hence the longitude of Aberdeen in time is 8’ 32”.8 weit. Computation of the Apparent Time of Conjunétion, on ; the Spheroidal Hypothefis, at Greenwich. . o a” |Site hk. ; Appt. time of beginning, 19 24 46} Appt.time of ending, 2 I 24 Sun’s right afcenfion, 4 51 302 4 51 47 ; Right afcen. meridian, o 16 17 ¥ $3) 0x Moon's true long. 2 13°19 39 2 14 18 59 _ Eft. par. in long. + 30 10 22 5x Geen app: long. 2 13 49.47 2 14 41 50 3 foon’s hor. par. 60 33.0 60 34.9 2 Reduétion, — 96 96 Reduced hor. par. 60 23.4 60 25.3 And LONGITUDE of ABERDEEN. 154 . ° B) ladé a) tite Sun’s hor. par. 8.7 8.7 Difference, = 60 14.7 60 16.6 Altitude nonag. - 45 46 19 53 20 35 Long. nonag. - 29 21 19 46 35 16 Par. in long. - 30 14.6 22 46.9 Par. in hat. - 42 1.2 35 19-5 Moon’s true rel. mot.inlon. | 5§ 31.0 Moon's trie mot. in lat. 5 30-3 Diff. par. in longitude, 4 247.4 Diff. par. in latitude, 6 2.1 D’s app. rel. mot. in long. 48 3.3 App. mot. in lat. 31.8 App. inclination, - 37 55 App, mot. in rel. orbit, 48 3.5 Moon’s femidiameter, 16 30.0 16 30.0 Augmentation, - + 9.0 + 12.5 Inflexion, Z — 3.5 a ER Corrected femidiameter, 16 35.5 16 39.0 Sun’s femid. — Irrad. - 15 45.0 15 45-0 Sum, - 32 20.5 32 24.0 Central angle, - 42 7 "6 42 I 30 App. inelination, 37 55 37 55 Arch firft, - 42.45 2 Arch fecond, 41 23 35 Arch third, 23 44.9 Arch fourth, 24 18.4 Par. in long. at beginning, 30 14.6 Atend 22 46.9 Sum, - 53 59-5 Ditference, © ~ I 31.5 Hence interval between h. ’ ” Interval between the end and yp, ” ” the beg. and conj. I 33 58.3 conjunétion, oO 2 39.2 App. time of begin. 19 24 46.5 App. time of ending, 21 I 24,0 | App: time of conj. 20 58 44.8 20 58 44.8 , At Aberdeen. | 5 : ses Trevi rt se Hispape 4 App. time of beginning, 19 33 19 App. time of end, 20 49 29 ; Sun’s right afcenfion, - 4 51-34 4 51 47 Right afcen. of meridian, © 24 53 I 4t 16 Moon’s Rye Ss, ° , uu” &. ° en Ge, Moon’s true longitude, 213 30 8 2 14 16 57 Eftimate par. in longitude, + 24 55 + 19 54 Eftimated apparent long. PV Cai Seae | 2 14 36 51 Moon’s hor. parallax, 60 33-3 ~ 60 348 Redudtion, a — IL — IL. Reduced parallax, - 60 22.2 60 23.7 Sun’s hor, par. - — 84 8.7 Difference, - 60 13.5 60 15.0 Altitude nonag. - 41 50 6 47 29 32 Longitude nonag, - 35) 4353 47 59 26 Par. in longitude, : 24 55.4 19 54.2 Par. in latitude, - 44 522 40 42.6 Moon’s true rel. mot. in long. 43 46.1 Moon’s true mot. in lat. 4 20.4 Diff. pare in longitude, - 5 1.2 Diff. par. in latitude, 4. 9.6 App. mot. in longitude, = - 38 44.9 App. mot, in latitude, 10.8 App. inclination, - 15 58 App. mot, in rel. orbit, 38 44.9 Moon's femidiameter, 16 30.0 16 3c.0 Augmentation, - + 9.2 + 11.6 Inflexion, — = - — 355 — 35 Corrected femidiameter, 16 35.7 16 38.1 Sun’s femid, — Irrad, 15 45.0 E5 45-0 Sum, - - 32 20.7 ~ 32 23-8 Central angle, - 53 16 36 53 10 55 App. inclination, - 15 58 15 58 Arch firft, - 53 32 34 Arch fecond, $2) 54.557, Arch third, - Ig 13.2. Arch fourth, 19 31-7 Par. in longitude, - 24 55-4 IQ 54.2 Sum, < = 44 8.6 Difference, 22.5 DETERMINATION of the LATITUDE Hence And LONGITUDE of ABERDEEN. 153 \ h. 7 # h, / " Hence the interval between Interval between the end the beg. and conj. is - 1 16 49.2 and conjunétion is _ 39-2 App. time of beginning, Ig 33 19. 5S 3 58.3 Ln59s3q I 59.0 33 35:0 44 ASIC, I 20 46 16 51.3 1319.3 (ca ee 3 32.0. Moon’s true mot, in latitude, Diff. par. in latitude, Appt. mot. in latitude, Appt. mot. in orbit, At emerfion, Arch fecond, Arch fourth, Difference, Interval between the emer. and conjunction, Appt. time of emer. 5 38.5 12 31 45. 12°26 6.5 AT ‘And LONGITUDE of ABERDEEN. 157 -At Aberdeen. 8. ° ‘ uv Moon’s true long. at immer. 2 29 52 49 Eft. par, in long. - + 20 45 Appt. longitude nearly, 3 © 13 34 Moon’s true latitude, 20 17 Eftimated par. in latitude, 37 6 Appt. latitude nearly, - 57 23 Moon's horizontal parallax; 61-923 Reduétion, __.- - — 11g Reduced parallax, : 61 0.8 Latitude Aberdeen, - 57 9 9 Reduétion, = 13 41 Reduced latitude, - 56 55 19 Altitude nonag. . 53 21 52 Longitude nonag. - 65 24 42 Par. in longitude, - 20 32.8 Par. in latitude, - Ba) 7.3 )’s true mot. in long. - 4° 44.8 Diff. of par. in longitude, 7 44.5 Appt. mot, in longitude, 33 9-3 Appt, inclination, - 328 4 Central angle at immer. IO 51 14 Arch firft - 7 23:10 Arch third, - 16 41.1 Par. in longitude, - 20 32.8 Sum, - - 37 13-9 Interval betweentheimmer. h. ° “ and conj, - © 59 27.2 Appt. time of immer, mu 18 8 Appt. time of conj. 12 17 35.2 App‘. time of conj.at Gr, 12 26 6.5 / s.1 9 fh TF 3 © 33 34 — 12 34 3-0) 46 8 24 2 35 18 “59 20 61 10.6 — 113 At emer. ——_—— 60 59°3 oe , ”f 55 3° 39 76 0 36 12 48.3 35 22.1% 3 45-4 I 45. 2 0,0 33 39 Io 5° 35 14 18 39 16 19.2 12 48.3 True mot. in latitude, Diff. parallax in latitude, App*. mot. in latitude, Mot, in app*. orbit, Atemer. Arch fecond, Arch fourth, Difference, Interval between the emer. and conj, Appt. time of emer, 3 30.9 h. ‘ ut o § 368 12 23 12 cee ee 12 17 35.2 Longitude 158 DETERMINATION of the LATITUDE 44 @ 9Th Longitude in time, = = 8 31.3 Long, on fpherical hyp. by occult. 8 32.2 Long. by folar eclipfe, _—- 8 36.6 byeclipfe, 8 32.8 Mean, - - 8 33.9 Mean, 8 32.5 Ir we fuppofe, with Mefirs pu Szyour and La Lanpe, that the difference between the equatorial and polar diameters is zie Of the equatorial diameter, in that cafe the longitude will be 8’ 33’.6. ’ ‘DETER- a eee Aid LONGITUDE of ABERDEEN. 159 DETERMINATION of the Longitude of the Obfervatory at Aberdeen, by Obfervations of the Lunar Eclipfe of roth September 1783, made at Aberdeen and at Chiflehurft in Kent, 19” in Time Eaft of the Royal Obfervatory at Greenwich. | Apparent Time of Obfervation at Names of Spots. Bj ° > s ic) Aberdeen. | Chiflehurtt. Ariftarchus, Kepler, Copernicus, Manilius covered, Tycho covered, Menelaus covered, Dionyfius covered, Plinius covered, Mare Crifium E, end, W.end, “ 45 Total darknefs, 10] 10 46 34 \O CO O~rs3 CO OO~T COM”D _ Sum, Mean, Ariftarchus, Kepler, Copernicus, Plato E. end, Tycho E, end, W. end, Menelaus, Dionyfius, Plinius, 3 | Mare Crifium E. end, | 13 7 10.7 i W.end, |.13 12, 20,8 20.7 18.6 49-6 25.6 53-6 39-4 3264 51-4 2433 32.2 9 ° ) 8 8 8 8 8 8 9 8 Som, a 95-5 Mean per egrefs, : 5,68 ‘Mean per ingrefs, _ "s 23.17 17 31.85 Diff, mer. Aber. and Chiflehurft in time nearly, 8 45.92 Longitude of Chiflehurft in time,E. 19. Longitude of Aberdeen nearly, - 8 26.92 Change of equation of time in 8’ 26”.9 +12 Longitude of Aberdeen, = 8 26.8 W. 160 DETERMINATION of the LATITUDE DeETERMINAT#ON of the Longitude of the Obfervatory at Aber- deen by a Chronometer, conftructed by Mr Arnotp of Lon- don*, THE chronometer was fet to mean folar time at Greenwich, 16th June 1788, and loft 7’.5 in eleven days. It was fent to Aberdeen by fea; and being compared with the Obfervatory clock, 15th July, it was found to be 7’ 26’.6 faft, and was lofing 644 daily: It is hence probable that the motion of the {hip had altered its rate. Now, fuppofing this alteration to have com- menced when the fhip left London, which was on the 8th of July, its error at that time, for the meridian of Greenwich, would therefore be 15’.0; from this time, till 15th July, it loft 44’.8, (=6’. 4X 7,) its rate being fuppofed uniform. Hence its error, for the meridian of Greenwich, 15th July at noon, was — 59’.8. But its error, for the meridian of the Obfervatory at Aberdeen, at the fame time, was + 7’ 267.6. Hence the longi- tude of Aberdeen, in time, is 8’ 26’.4 weft. Tuis laft method of afcertaining the longitude of Aberdeen, although it agrees very well with the former, yet it is not to be fo much depended on, as there are fome fuppofitions intro- duced which may be objected to. From a comparifon of the preceding refalens it may be prefu- med, that the longitude of this place, in time, is probably not lefs than 8’ 18’, as deduced from the obfervations of the eclipfes: of the firft and fecond fatellites of Jupiter, nor greater than 8' 367, as inferred from the folar eclipfe of 3d June 1788. The diffe- rence between thefe limits is only 18” in time ; which in this latitude does not amount to two miles and an half. Upon ac- count of the near agreement of the refults of the folar eclipfe and occultation, as well-as from other obfervations, I am led to | believe * Sex Theory and Praétice, of finding the Longitude, &c, vol, I- p. 208. ene ee 4 4nd LONGITUDE of ABERDEEN. 161 believe that 8’ 32" or 2° 8' is not far from the exact longitude of this place. Hence the latitude of the Girdlenefs is 57° 8’, and longitude 2° 6' W. and the latitude of Greigfnefs 57° 7' 20’, and longitude 2° 6' W. alfo. Tue latitude and longitude of Aberdeen, as determined above, differ confiderably from the fame as given in moft books of geography and navigation, where indeed they are ufually ftated with great inaccuracy. Mr Downie, to whom, at his requetft, I communicated the refult of my obfervations, has, in his New Pilot, placed Aberdeen nearly as above, and of courfe has laid down the adjacent coaft, with much more precifion than had been formerly done. This was in 1793; I then fuppofed the longitude 2° g' W. which is 1’ greater than the above determi- nation, Vor. IV. : U . I. Foe “agama aa meen! “obypigat Pams six ono ant Sor!ti 8 *s *¢ spt ited ae A dori BARS ool! to. obasiel ‘ofy song i Poe Pee AcuilfisrD toabositel ot ban .W 'd “> sbutigaol ee is V7 ds obutigao’ sa (a7 clad seve aE ceed ‘YW sbieargnl Beis? sbininlan 40 eilocd Home’ ab Wavig” es -— ond’ tttott ue de Sb Aizen» " bounty elhititer ote yoy bostide sted w ‘ mobs giver | bos vlqen ‘HHedepert ai its (atkodwr" oy are dtl AME “on urioedt Yeotg ec + ak etal ont nud sponne edo, sein 4 glifver oils Borpsitisetenos bial tid Suds to ‘ban, sods ba ‘efinan fro9lyisdA beowliy « ‘9 ss fail aads doiltsoig: Soot’ Monge Asiw, Asoo Thssibs gt ay ody DehoqquY goda 1; goyr at “aio edt stiob homo ” med | uGiterob oveds Sah: iad ines % as dard or @ °€ sbetigaol ” a % t ‘ Tem | " yo poe” tee nck PEL oe ities ely aga Salar eee, a y ’ y P A it, ¥ ‘ : , yer OF 25 Pryor vie TEE » : : \ F 4 nig agit? ‘ * ip ; ‘ed " Te paints tA Laraegtig j are Leese BN eed ¢ OOF 3 , . ‘ oie s : here: ace face ditions Tore y 2 3 % 1 ed whatil f U VE do mires 3: ¥ . ‘Mia Pre » 4 ” ; mae 4 POE 4 vs " oe 5 3 fs 2 ee Tier F pa P oe > Aan rite H rE dirt » ot fi ‘ 7. i \ z > 4a poset Py Rat Lea ae 1:4 4 ae na ee. ae ce ; , tie areas ae ; ; : Wy , ee / . + " « ah > east (ACRE 3 yy ! tlh tin AH ane wy ks : ; . Mbt ne See hares ARR a te ibis ee Ohi a eae mate 4 at a a Ce. Oe Oy 4 3 dvi Y hag f ah * ” ‘ “ v y 1 f ‘ he ys 7 ve A, ony y 7 : ‘ ' ¥ * ’ * : oe 7 ¥ ax VI. An Account of certain Motions which Small Lighted Wicks acquire, when fwimming in a Bason of OIL; together with OBSERVATIONS upon the PHENOMENA tending to explain the PRINCIPLES upon which fuch Mo- TIONS depend: Communicated in a Letter from PATRICK WILSON, F. R. S. Epin. and Profeffor of Practical Aftro- nomy in the Univerfity of Glafgow, te foHN PLAYFAIR, F. R. S. Epin. and Profeffor of Mathematics in the Uni- verfity of Edinburgh. [Read May 5. 1795.] Dear Sm, Glafgow College, April 28. 1795. Now fit down to give you fome account of the little hydro- ~ ® ftatical lamp, which I fo briefly mentioned to you in a for- mer letter. As I am far from being fure whether what I have -to offer upon this fubject may be entitled to the notice of the Edinburgh Royal Society, fo I will refer this point to your determination, after you have had leifure to confider the con- tents, ee ; Tue phenomena, treated of in the fequel, were quite new to: _. me a few months ago, and, fo far as I know, have not hitherto: _ been attended to, or defcribed by any body elfe. "What I have «called the Hydrofatical Lamp, confifts of a fmall circular patch of common writing paper, about three eighths of an inch in dia-. “meter, having about a quarter of an inch.of foft cotton thread: U2 ftanding 164. MOTION of Small Lighted WICKS ftanding up through a puncture in the middle to ferve asa wick ; and the phenomena, in queftion, are certain motions which fuch minikin lamps acquire, when lighted and made: to {wim in very pure falad oil. A sHALLow glafs bafon, with fides rifing nearly perpendicu- lar, of a common eglafs falver, will conveniently contain the oil for thefe experiments. As foon as the lamp is lighted, it will immediately fail brifkly forward, in fome direction, till it meets the fide of the veffel, and afterwards will take a circular courfe, always bearing up to the fides, and fo will perform many revo- lutions. SomeETIMEs the circulation is from right to left, and fome- times in the contrary direction, according as that point of the paper bafe, which in the direct failing kept always foremoft, turns away from the fide of the glafs a little to the right or to the left hand of that which comes to be the point of contact. This turning away, of what may be called the LEADING PoINT of the bafe, is diftinétly obfervable by a partial rotation of the lamp round the wick as an axis, as foon as it arrives at the fide of the veffel. Sometimes, though rarely, the leading point itfelf attaches to the fide, and forms the vinculum, in confequence of the well known corpufcular attraétion between the elevation of oil around the bafe, and that belonging to the fides of the glafs; and when the vinculum fo correfponds to the leading point, the Jamp will be found to ftand ftill, without any tendency to cir- culate. WueEn the little wick has any fenfible excentricity upon the circular paper bafe, the lamp will fail fo as to make that part of the bafe which lies neareft to the wick the /fern ; and if the bafe of the lamp be clipped of an oval form, and the wick placed in the longer axis excentrical, that end of the bafe, neareft the wick, will alfo keep hindmoft, when the lamp fails acrofs the falver. In the fame manner, if the bafe be ; an a When fwimming in a BASON of OIL, &. 165 an equilateral triangle, having its wick in the perpendicular which bifects any of the fides, either the vertex or fide will be- come the /ern, and keep hindmoft, according as the wick is placed neareft the one or the other. Lamps, fo conftructed, are found ; alfo to circulate upon their arrival at the fide of the veflel, when / the leading point turns away from_the glafs, as it Bee ae happens. WuatTeEVER be the caufe of the failing of the lamp directly foreward, the perpetual circulation, after it arrives at the fide, feems to proceed from the force, which formerly impelled it, {till ating in the fame manner, but in a direétion inclined to that of the corpufcular attraction, which forms the vinculum ; and it is evident, that this inclination will be greater or lefs, ac- cordin as the leading point is more or lefs averted from the glafs. “When it fo happens that the leading point and vinculum coincide, it fhould feem that both forces, juft now mentioned, muft urge the lamp in a direction perpendicular to the fide of the glafs; in which cafe it muft ftand {ftill, agreeable to obfer- _-vation, : - THE next thing which I had occafion to take notice of, when th amp failed in a direét courfe, was, a feemingly very active repulfion between its {tern and the oil at the furface contiguous to it. This became manifeft, when very fine charcoal duft was are {cattered around the lamp. As it then proceeded in its courfe, it marked out a fpreading or diverging wake behind it, y ts entirely clear of all duft, in confequence of the particles being _chaced backwards, and laterally with a motion much more than merely relative. Desi1rous of learning how this difperfion of the duft would take place when the lamp was ftationary, I conftructed one of a fine wafer, and with an excentric wick, confifting of a foft cot- ton thread doubled; and to prevent the wafer or bafe from catching fire, 1 footed its upper furface with gold leaf. When thig 166 MOTION of Small Lighted WICKS this was made to reft immoveably upon the oil, the duft retired in all diretions, fo as to leave the fpace, adjacent to the wafer quite free from every particle. But here it was obfervable, that this difperfion of the duft, by the feeming repulfion of the bafe of the lamp, was much more rapid at that fide which lay | neareft to the wick than at any other part, and leaft of all fen- fible at the fide diametrically oppofite. THE circumftances laft mentioned, feem fufficiently to account both for the progreflive motion of the lamp, and for the general law of this motion, formerly defcribed. For, regarding this dif- perfion of the duft, as yet, only in a general way, and as the ef- fect of fome repulfion between the bafe and the oil contiguous to it, the facts above mentioned plainly indicate, that, in all cafes, this repulfion is ftrongeft at that part of the b: nation the wick or flame : and as action and rea¢étion are equal and con- trary, the lamp mutt therefore be impelled, in the direction of a | line drawn through the wick, towards that part of the bafe moft remote from it, and where the reaction is the leaft. Bor in order to obtain a ftill more competent knowledge of P the phyfical caufe of thefe motions, it feemed now neceflary to inquire more particularly into this apparent repulfion between __ the bafe of the lamp and the furrounding oil, as indicated Oe 4 the difperfion of the duft, in the manner above defcribed : here the following confiderations prefented themfelves. a Tus oil in the bafon, when of an uniform temperature, has all its parts in a ftate of equilibrium and of reft. When the 4 lamp is hghted, it is evident we have a very active caufe intro duced, tending to deftroy that equilibrium. This caufe is the 4 flame, which broods over a fmall portion of the oil, and is fepa- rated from it only by the intervention of a piece of paper or a waffer. The oil, in fuch circumftances, in confequence of be- ing violently heated, muft fuddenly increafe m: volume, and mutt now, on account of the decreafe of its fpecific gravity, be preffed. ne See ae — ee fe When fwimming in ga BASON of OIL, &c. i67 _preffed upwards by a force fufficient to raife part of it above the general level. . But this heated portion of oil, in its endeavour thus to rife up, will meet with a refiftance equal to the weight of the incumbent lamp, which will determine it, in feeking a vent, to flide out from under the bafe in a thin /uperficial fream; and it feems to follow, with equal certainty, that this conftant ftream will flow moft readily and moft copioufly towards that fide of the bafe of the lamp where the refiftance is leaft, or where it has the fhorteft way to prefs forward; that is, from under the wick or flame, to the edge of the bafe which is the neareft, according to what we have feen to be agreeable to the pheno- - mena. But, from the laws of motion, it is certain, that the re« action of this ftream of rarified oil, thus iffuing moft rapidly and moft copioufly from a particular fide of the bafe, muft im- pel the lamp in the cofitrary direction, and make it fail in the manner we have feen. It may further be remarked, that the heated oil, fo retreating from the flame, and endeavouring to rife fomewhat above the general level, in confequence of its dimi- nifhed fpecific gravity, may more or lefs lift up that fide of the _ -bafe neareft the wick, and aid the reaction of the recoiling ‘ftream, by making the lamp {ail in the oppofite direction, as_ it were down-bill. * -"Tuat the rarified oil under the bafe has really a conftant _ ‘tendency to rife above the general level, feems undeniable, from the following facts, namely, that after any of the lamps has burned a little while, and has got its, bafe foaked with the oil, as foon as the flame is blown out the lamp finks to the bottom ; and even a lamp, with its bafe made of a thin lamina of talck, fails very well till the flame is extinguifhed, and then it imme- diately finks. ; _ AGREEABLE to thé explanation which.has now been attempt- ed, I found, that when a topical beat was applied to the furface of the oil, by bringing the point of a poker, dully red hot, near- 168 MOTION of Smail Lighted WICKS ly into contact, there was foon produced a fuperficial ftream or efHux from the iron in all directions, which cleared the face of the oil from the charcoal duft, in a wider and a wider circle, till « at laft the whole particles were crowded together at the confines of the bafon. WueEN the oil in this experiment was fhallow, having gold leaf beat into very minute parts mixed with it, an oppofite ftream was obferved below, fetting in towards the poker in all directions, and then rifing upwards. But this general tendency of all the parts of the fluid of moving in queft of an equili- brium, is illuftrated in a very entertaining manner as follows : Into a tea-cup or punch-glafs, nearly filled with pure water, pour a defert fpoonful of very clean falad oil, with minute particles of gold leaf in it. If the water be cold, the oil, when poured on at the centre, leifurely and continuedly, will reft upon the furface in the form of a lens, and remain infulated or equidi- ftant from the fides of the veffel. A little lamp, when put up- on this lens of oil, and lighted, will fail and circulate as larger ones do in the bafon. If it be now made to ftand ftill, it is very amufing to obferve the minute particles of the gold _per- petually thrown out brifkly at the ftern in the fuperficial cur- rent, whilft the particles in the fund of the lens creep in all di- rections towards the lamp, and at laft rife up under the bafe towards the flame, as the great centre of attraction, till they are caught by the retreating fuperficial ftream, in which they ra- pidly trend off to fome diftance, when again they fink to renew. the circulation. WHEN a patch of paper, or a wafer, or fuch light body, fwims upon the oil in the bafon, the point of a hot iron held near to it makes it flit its place, and move away by a feeming repulfion ; but, in reality, by the heat generating a fuperficial ftream, flowing from the iron in all directions. AGAIN, | | When fwimming in a BASON of OIL, &c. 169 Acain, if upon oil of turpentine, xther, alcohol, or any of the inflammable fluids poffefling much tenuity, you throw a wafer much heated, it will immediately glide away, and con- tinue in motion till it cools; when the ftream, which iffued ~~ from fome part of it moft copioufly, ceafes. Double rum, melt- ed tallow, bees wax, and rofin, alfo afford the fame continued efflux at the furface, upon a topical application of heat, and the fame phenomena as the oil does, when little lamps are made to fwim in them. It is fomewhat remarkable, however, that though the inflammable fluids all agree in this, yet the topical application of heat, at the furface of water, does not produce fi- milar effects. For if the point of a poker nearly red hot be held very clofe to the furface of water in a bafon, the particles of the charcoal duft do not at all glide away as they do in the cafe of oil, but feem to acquire only a flow irregular circular motion, _ which in time fpreads wider, whilft the floating motes or particles of duft keep nearly their relative places ; and the fame thing hap- pens, though the point of the iron touches the water, fo as to make it fimmer. I Do not well know how to account for this, unlefs it may be a confequence of the known much lefs expanfibility of water _ by heat, compared to that of the inflammable fluids, and which may be fo inconfiderable as not to deftroy the equilibrium, fo far as to produce an efflux from the lighter and expanded fluid immediately under the heated body. Poflibly, too, the parts of the water, as foon as heated, may tranfmit the furplus tempe+ rature to the contiguous colder water much more rapidly than the inflammable fluids do in like circumftances, and thereby re- fift the high temperature, neceflary to that degree of expan- fion, which would difturb the equilibrium, and produce an ef. flux ; not to mention that the maximum of this temperature can never, at any rate, exceed 212°, the boiling point of water. VoL. IV. x THAT 170 MOTION of Small Lighted WICKS Tuart the equilibrium, however, amongft the parts of water, is difturbed by the local application of heat, though in a much fmaller degree that what obtains among the inflammable fluids, appears from an experiment I was led to make with a {mall thin cup fwimming on water, and fo contrived as to carry and feed with oil a wick, placed a little way down from the lip in the infide, fo as to be on a level with the water. ‘The confe- quence of this conftruction was, that the cup moved upon the water very flowly, but always with the flame evidently ftern- moft. The fame cup, when taken from the water, and put in- to a bafon of {trong rum, failed a great deal fafter, and accord- ing to the fame ufual law. I am much afraid, that by this time I have wearied you by fuch a detail of minute facts and circumftances, and by thofe frequent repetitions which every new fubject more or: lefs re- quires. And | ever remain, Dear Sir, Your moft obedient faithful fervant, Pat. WILson., P. S. SHoutp you be inclined to repeat any of the experi- ments, the following directions and mifcellaneous obfervations may be attended to: The thread I made ufe of for the wicks was of that foft kind commonly employed in the flowering of muflin. After making the puncture in the bafe, you put through a bit of the thread, which clip fhort off below, and with a pin force in the burr gently round the thread, to give the bafe a proper hold of it. Then clip away the fuperfluous thread above, leaving the wick about a quarter of an inch long; and fo the lamp is completed. Set it then upon the oil, by taking hold of the wick, that the paper bafe may not be bent or diftorted by handling sh” ao ne ee eS oh Whea fwimming in a BASON of OIL, &. 171 handling it; and, after the wick is touched with a drop of oil, it is ready for being lighted. For this purpofe, a bit of pack thread, which has been fteeped in oil, is a cleanly and conve- nient match, and fheds no impurities on the oil, as a candle or wax taper would do, WHEN you want the lamps to circulate, the oil muft be very pure, and brought into full contact with the fides of the glafs. The oil, and the bafon or falver, fhould all be allowed to come to the fame temperature, between 55° and 60° of Fahrenheit. For if any part of the brim be much hotter than the reft, the lamp, on arriving there, will leave the fide, by the current iffu- ing from the heated part forcing it away. Sometimes the lamp, when failing, veers a little into a diffe- rent direction, by the bafe altering or warping by the fcorching heat of the flame, which determines the ftream to flow out moft copioufly at a different part of the bafe.. In the melted greafe which lies round the wick of a common candle when lighted, there are fometimes obferved atoms, which have been left by the fnuffers, moving to and from the flame continually. Thefe motions have been conceived by fome as occafioned by attractions and’ repulfions, in confequence of an electrical quality imputed to the flame. It fhould feem, howe . ever, that they depend merely upon oppofite currents at the fur- face, and immediately below the furface of the melted greafe, according to the principle above explained. X2 VIL. Teh ete | yx > ih mo 2 oii ty ex sings, vad’ | ; ay ( to, ae AP Sage gettin ss: 2M. Spabgiana, Bie Tate. orl amis Sir cepieg: Bic sicgitlbinsil dmg dacs ls pat aight: ait.” herdyil 2 zatind ach hiesre bit . rs yO? bo dutlexslaae eae nae bagead) aod @ nd ddider' Bighid?? 2% nog slbirna. nun abi -iitieandeaeint brikgrtigborl isan a acndt SAMO” 4 bi 3 Oh late San 3 ier oth re bantes ‘a oul a2talinrtio, oat salt af. icnn: 20% cal . Diets. odd It ise toihs. bt Pep seivo. it, gah 24! ge oil hee ee “rn on beyolls ie: q doodkagorla: to mastedks ft. brtg uber raced y a6 ~~. brs 5 yp awe pi a! es ott» oale@s ari pian: orks aneaty. sport, Ams .90\ seigdh, 283. Yo, s3eq ee, i tel, 3: et ait. ods typo iio redtanirinm, focal: a coe Tea? ane gens aR ti aniyrot tiaq hotrod zh) cot yar, és aii ¢ onaint efit fe 1agy; ‘youliad iougiz epnal oxy, eben: 8 sninspoot ont ed, anger. vo nastils Shed, 443 24g eras How: Teds. ‘bik os, s67 Sh. salt, gicigmsab dide’ acuml als 19 Loy yan ted, ats Yo Vtg agate Ya thicdagae foasecto> i te. ee wots bagen qil bide shesry boston oft 9 doider acnins bovmido npttuidacbOd 9 wis oforty bouigi msslw est oust odd: moth ham os penyort erpRiom wilson ESL nib . ag aitied 6. havisoing: ds eid svad enonder sted Tw oie : wa net 290k wpayney A, anoMaget fas moificis Pied an | =worl nosh. bigodt 21, rani eds 9 bouqent yilesp: leatifela.. wuld suld. te Bnet Oey ep OMtiog it-eietsis, boogeh collate AEE She <. hinlome wal fo sehr nots aver elesnribspencht? Sas Site yee a saihtqas’ avods: Pes att on “ei wae ¥ - ‘- es at F on pe I Hi rir aS eae ROR gaan %S hide hy * wy s - 84 y: Fey = 5 £ my are 4 - af ver coe :; ~ me - i Faw Si 4 wee, PME 2 et a % > . . es 1 VII. An Account of a Sincutar Hato of the Moon. Com- municated in a Letter from WILLIAM HALL, E/q; of White- Hall, ¥. R.S, Evin. to Sir FAMES HALL, Bart. F. R. S. Epin. [Read May 2. 1796.] DEARSIR JAMEs, Whitehall, near Berwick, April 2. 1796. SEND under cover the reprefentation of a very fingular Halo. of the Moon, (See Pl. V.), feen here on the night of the 18th of February laft, about 10 o’clock, and this I have hitherto delay- ed, in order, if poffible, to gain farther information in the neigh- bourhood concerning it. Durinc the fhort continuance of the fmall halo, which did not exceed 10 minutes after I got notice of it, I could not lay my hands on any other inftrument to take the angles, but a S1s- soNn’s theodolite, which, unluckily, having been conftructed fo as not to admit of a vertical angle fo great as the moon’s alti- tude then was, I laid it afide, not recollecting that it might have meafured feveral of the fmaller angles. But I obferved fundry marks, from which I took the angles as exa¢tly as I could next day. , THE moon was about S. W. and her altitude nearly 54°,. - which of confequence was alfo the altitude of the limb of the greater halo, where it was higheft, and where it pafled through. ‘ the 174 ACCOUNT of a SINGULAR the moon ; the altitude of its oppofite limb was 14°; fo that its diameter fubtended an angle of no lefs than a hundred and twelve degrees. Tur diameter of the fmall halo, which appeared to be a per- fe& circle, with the moon in its centre, I found, after repeated trials, was under 12°, and more than 8° ; but as the different diameters of the large halo were not meafured, it cannot pofi- tively be affirmed that it was an exact circle; on the contrary, its limb did not feem to interfeé the {mall circle quite fo much at right angles, as the circular arch delineated in the plan, It may therefore have been fomewhat eliptical. Tue fmall circle was remarkably bright, particularly at Weft Re/lon, about five miles to the northward, the only other place where the halo was obferved, and where it was thought to fend forth flame. The {mall halo alfo continued there much long- er than here, where fome thin fleecy clouds foon put an end to it, but the large halo continued with us near an hour. Tue weather about this time was, for the feafon, remark- ably mild, particularly on the day of the halo. The fky was pretty clear all that day, and alfo in the evening; but at the time of the halo there was a fmall degree of hazinefs, particu- larly towards the north, which did not however prevent the moon from fhining with brightnefs ; and the ftars were even vifible within the circle of the fmall halo: there was little or no wind. Tue circles or belts of both halos are reprefented in the plan, nearly of their apparent breadth, or perhaps a little broader ; the light of both was whitifh, and confiderably bright, without co- lour; that of the large circle was the paler of the two, particu- larly where it paffed through the fmall circle: to the northward it was fomewhat obfcure. By means of the angles taken as above, after having afcer- tained, on a vertical circle of the heavens, the fituations of the moon, ee. ee ee eS HALO of the MOON. 175 moon, of the fmall halo, and of the north-eaftern limb of the large halo, whofe fouth-weftern limb pafled through the moon, the whole was projected on the horizontal plane, as in the figure already referred to. ‘The moon, a little more than half, is pla- ced in the centre of the fmaller halo; and both halos are repre- fented in their true fituations, relatively to the horizon, and in the circular fhape which they appeared to have, though they ought perhaps to have been fomewhat-forefhortened, and thrown into an elliptic form. Tuts halo, as you will fee by the above defcription, appears to be of the kind called by the learned a Corona 5 and as it fomewhat refembles the famous one of the fun, obferved at Rome in the year 1629, and defcribed by ScHEINER*, it deferves the more attention, efpecially as the great halo, on the prefent occafion, having its fouth-weftern limb elevated to the height of 54°, and its north-eaftern deprefled to within 14° of the ho- rizon, was in an oblique pofition, not eafily reconciled with the theory of Huycens, which feems to require that fuch circles fhould be equally elevated above the horizon all round. It alfo fhews, that ScHEINER’s original plan of the halo at Rome, which reprefented it as oblique, may have been right, and that HuyceEns’s correétion, which makes it parallel to the horizon, _ was probably an erroneous conjecture. I am, Dear Sir JAMEs, Your humble fervant, Witt. HALL. * Smitn’s Optics, vol, I. § 534 VIL ardatee ed : i tt te 5 hee Ran 6 iy Syet $i) oi a8 or alg iaintoshod ee ao beta Zap hos stole - a gley lest coi sear eat 3 s gb SRY | oPtstst: yi Ssiqht vis delat Pod tek. Petes walicent cay 10%: 2135 ot SP Bike sins 20 add ot evautat uasntadas al be nt 5 9 a atl agro 2. AVR ot hase Biel iitiwitse cd) 2altstir god er . ae als bas eabit ae dé: shit yenres ht nip <2, ri. - ee cami an SEALER FHI ae iv r, A om . mh, as Pee ra 76. ans Lidinburyh Vidi pillpage 7 PAT: S y ee xX SS Ni N y NY . S Y aa o yy Xs 5 Sa s 2 ai ve > . ‘ ‘ ‘ ca me a . ag ~ - \ . eg So a VIII. 4 New Series for the RecTIFIcATION of the Exxipsis ; together with fome OBsERVATIONS on the EVOLUTION of the Formuta (a* + b+ — 2ab cofo)".. By JAMES Ivorr, A.M. Communicated by oHN PLAYFAIR, Pro- felffor of Mathematics in the Univerfity of Edinburgh. [Read Nov. 7. 1796.] Dear Sir, AVING, as you know, beftowed a good deal of time and attention on the ftudy of that part of phyfical aftronomy which relates to the mutual difturbances of the planets, I have, naturally, been led to confider the various methods of refolving the formula (a?-+ 4* — 2ab cof¢)* into infinite feries of the form A+Bcofg+Ccof29+ &c. In the courfe of thefe in- veftigations, a feries for the re¢tification of the ellipfis occurred to me, remarkable for its fimplicity, as well as its rapid conver- gency. As I believe it to be new, I fend it you, inclofed, to- gether with fome remarks on the evolution of the formula juft mentioned, which, if you think proper, you may fubmit to the confideration of the Royal Society. I am, Dear Sir, Your’s, &c. Dovciastown, near Borfen,2 James ious ~ 20th O&tober 1796. Io Mr Fohn Playfair, Pro- Seffor of Mathematics, Sc. Von, IV. ¥¢ Let 178 RECTIFICATION of the ELLIPSIS, &c. Let ¢ denote the excentricity of an ellipfe, of which the femi- tranfverfe axis is unity, and a the length of the femicircle, ra- dius being unity: Then, I—yY1—: if we pute = nef yee g half the periphery of the ellipfis will be Te v.12 77.17. “ 17. 1°. 37.5 ——— e° SES (th eth Se “84 &c), the coefficients ty es fquares of the coefficients of the radi- Cal Woy ee THE common feries is, Tomik I.I 1.3 Tae BEG aX (x ee gt et - * — ee. ). PN UES 2.4 24 2.4.6 2.4.6 Tue firft of thefe feries converges fafter than the other on two accounts: firft, becaufe the coefficients decreafe more rapidly ; and, next, becaufe ¢ is very fmall in comparifon of ¢, even when ¢ is great: Thus, if ¢ be e e will be and ¢ = = In order to point out the way in which the preceding feries was difcovered, let us fuppofe (a* + 4 — 2ab cof 9) =A +. Bcofg+Ccof2e + &c.; and to determine the’ coefliicients, A, B, C, &c. let us, with. M. DE LA GRANGE, confider the quantity (a? + 4° — 2ab cof ¢) as the product of the two imaginary expreflions (a cy TX Sn *), and - (a a a Lo a where ¢ denotes the number ‘whofe hy- perbolic logarithm is unity. Then, by expanding the powers. (a — bce? Se 3 and (a —be~? ieee into the fe- ries a”( I SNe 2 cPV HF Bc PY HE ere SMT F + &c.) and Micros. RECTIFICATION of the ELLIPSIS, &c. -179 and a” ( I— Sh eas 20/8 a __—_— ——__ a, 21—t — NIT. A? 4 > Y= &c. I.2 I. 2.3 we have a=7,6= THEN multiplying thefe two feries together, and putting + mof—t1 —mo/ —1 : +¢ . Pd 2cof{m@ for its imaginary value c we fhall find, on equating the terms, 2 4 b* 3 Yis\y 7 RD (« + a7. = +Roty. a &c. ); B= — 2a" X (« 4 ab 54 py S+ &e. ), and fo on. Or the feveral feries for A, B, C, &c. the firft deferves parti- cular attention, on account of the fimplicity of the law of its terms. It deferves the more attention, too, that the whole fluent f 9 (a*-+ b> — 2ab cof¢)", generated while 9 from o becomes = a, half the circumference of the circle, is = A+ z: all the other terms of the fluent then vanifhing. SUPPOSE now, in an ellipfis, the femi-tranfverfe = 1, the ex- centricity = «, and ¢ an arch of the circum{cribing circle, rec- koned from the extremity of the tranfverfe: then the fluxion of the correfpondent arch of the ellipfis, cut off by the fame ordinate, will be = 9 V1 —«* col%9. In this expreffion, I write S45 cof 29, for cof.*9: and put . / e* e* - ae SR SSS SET OES TERE Loe Sees a the refult, 9 ¥ 1 — 7 — 7 cof29 = 9 Va + * — 240 cof2¢9, a and d being indeterminate quantities. e2 . e* To determine @ and J, we have a? + 4*=1 — —,and 2ab = =; whence a+ 5= t,anda—b=V1—-fothata =**¥ ITE and pe v¥ as 2 Ya = i 180 RECTIFICATION of the ELLIPSIS, &c. I ruus obtain 9 V1 — & cole = 9 V a+ 4 — 2ab cof29: and, taking the whole fluent, while 9 from o becomes = a, it is manifeft, from what has been premifed, that the femiperiphery of the ellipfis is = ae 1 Sa hy Tarte so Os ) eXeX (4b oe at ae ee ae DO C0 - b or putting >= = the femiperiphery of the ellipfis = oe x = oP reste CST (1+ he? + iets + Soeb et’ + &c) In this feries, as was before obferved, ¢ is a fmall fraction even when s is very confiderable, and. the. coefficients are more fimple in the law of progreffion, and converge fafter, (ef- pecially in the firft terms), than in the common {eries. Ir we fuppofe the ellipfis to be infinitely flattened, in which cafe ¢ = 1, ande= 1, and the: femiperiphery = 2, this feries Pives, 2. = >< ( 1+ 5 tee ae also sleacoibies &c:), and fo ICD if apes a. yt ge 2 2 eT ok aaa a a But, we may remark, that as we have here obtained the fum of the fquares of the coefficients of the binomial when the ex- ponent is +; fo, from the fame fource, we may determine the fum of the fquares of the coefficients correfponding to any other exponent, at leaft by a fluent. For taking the whole fluent when @ = a, we have: no fla + be ste ea Gof @) 9a" a (1-fer.% +. ath y*. zt Be. ) and fo when 4 = 1, andd=1,. S (CAB 2ab cole)" 91 4 at + Bt Pt Bees Ko Now,, RECTIFICATION of th ELLIPSIS, &c. 181 Now, when 4 = 1, and d= 1,/9 (at + js —2abcofe) genx . ‘i 9 (fin®),” becaufe 2 (Gn2) = 1 — cof¢: we thus obtain 2° Xf o (fing) ype pete + &e. @ the whole fluent to be taken when ¢ = z, or @ =<. IF we put « = fin £ we fhall have Un x7? % Y til ogteer = = wabiet ch Gt ch vizh&e, {a the whole fluent to be taken when « = 1; and in this formula m is any number fractional or integral, pofitive or negative; and a, 2, y; &c. the coefficients of the binomial raifed to a power of which the exponent is 7. _ WHEN 27 is a whole pofitive number, HIF % + 3e Sune ee (28—= 1), ; f Stat ae See in the cafe when x = 1: (i—x AiO ence . ag pee(ane— 2) : And fo, 2” x EAS OED a rt ot + Bett Bees pnw: eo Meet ee ne eee is no other than the coefficient of 25 4. Ow 2n the middle term of a ipineenial, raifed to the power exprefled by on: Hence we have a very curious property of thofe numbers: viz. that the fum of the /quares of the coefficients of a binomial, the exponent being n, is equal to the coefficient of the middle term of a binomial, of which the exponent is 2m. ANOTHER remark, which I have to offer on this fubje€t, may be confidered not only as curious, in an analytical point of view, but as, in fome meafure, accomplifhing an, object that has much engaged the attention of mathematicians. __ In the computation of the planetary difturbances, it becomes 3 neceflary to evolve the fraction (a* + 4? — 2a) cof °) into. a: feries 182 RECTIFICATION of the ELLIPSIS, &e. feries of this form, A+ Bcofe + C cof29 + &c. The quan- tities @ and J reprefent the diftances of the difturbing planets from the fun; and when thefe bear fo great a proportion to one another, (as in the cafe of Jupiter and Saturn, or Venus and the ate Jes - : Earth), that the fraction - is large, it becomes extremely difficult to compute the coefficients A, B, &c. by feries, on account of the great number of terms that muft be takenin. This matter not a little perplexed the firft geometers who confidered this fubje&t, and they were obliged to approximate to the quantities fought by the method of quadratures, and by other artifices. Two things are to be attended to with regard to the quanti- ties A, B, C, &c. The firft is, That it is not neceflary to com- pute all of them feparately by feries, or by other methods: They form a recurring feries; and the two firft being fo computed, all the reft may be derived from them. The fecond thing is, That the quantities A and B having been computed for any exponent a, the correfpondent quantities are thence derived, by eafy for- mulz, for the exponents n+1, n+2; 2—1, n—2; andin general for the exponent 2+ m, m being any integer number, pofitive or negative. From thefe remarks, it follows, that the whole difficulty lies in the computation of the two firft quantities, A and B; and that we are not confined to a given exponent 7, but may choofe any one in the feries, n+-1, n +2, &c.; n—1,2—2, Ke; that will render the computation moft eafy mh expeditious. Tuus, in order to compute the quantities A and B, for the 3 . exponent — =, M. pE La GrancE makes choice of the expo- I . o . nent ee which, in the whole feries of exponents + 3, -b > =: “5 26 3, &c. is the moft favourable for computation, on ac- count of the convergency of the coefficients of the feries for A and B. In Se a en ee ee ee aoa RECTIFICATION of the ELLIPSIS, &c. 183 In confidering thefe fubjeéts, however, I have fallen upon a ‘method of computing the quantities A and B for the exponent — + by feries that converge fo faft, that, even taking the moft Oa: cafe that occurs in. the theory of the planets, two or three terms give the values required with a fufficient degree of exattnefs. “This is what Iam now to communicate. ‘WE are then to confider the expreffion, (47+ *—2ad cof9) eB : : for the fake of fimplicity in calculation, = oY a + 6* —2ab colo I write = = c, throwing out a altogether ; and I fuppofe z —A+Bcofe+Ccof29+ &c. Yate —ecole) Ler ¥ be an angle, fo related to ¢, that fin ()— ¢) = c fin yp: It is obvious, from this formula, that ~ = 9 when fin po, that is, when » is equal to 0, or to a, 2a, &e. WE have then, cof() — o) = =V1i—c? fin and taking ierfiacsdohe. aieice a: > CW) — W¥G—e fing) * MEST gorisi : 14f E — 7 fin. >i) — ce cof p whence 9 = x Vt —c* fin * » Bur (¥1— ¢? fin?) —.¢ cof)? = 1 —¢ fine) + c* cof? me cof vr e* fin *y Sate? — 2c? fin xp — 2c cofy V1 —c? fina, (becaufe c* cof?) =c* —c?fin?4) = 1 + c? wot x (cfind X fin + cofp ¥1 —'c? fin 74). | Now, if we write for -cfin 7 its equal,fin () — 9), and for ¥1 — c? fin 7p its equal, cof (x) —'9), we thall have ofiny) X fin + cof x ¥i—c? fin *y = fin() —@),x find + cof x cof — 9) =. cof@: which being fubftituted, there comes out (vi—e BE eter by =1+c¢? — 2 cof. Our * 184 RECTIFICATION of the ELLIPSIS, &c. Our fluxional formula thus becomes ¢= p year = eeniees wy he niCe es es SES A Yi—e? fin *p Yitc* —2ccoi9g Y (oct fin 7 I nExT transform the quantity / 1 — c? fin ?¥ as in the in- : ni Ss ; I—/1—c? utting ¢) = —~—_, veftigation for the elliptic feries, and putting a ane sooo 8 Vi te? + 20 col 2p ? —¢? 2 =. ANC Oe eee ! find YI fin?) = I+¢ Vi+c*—2ccoig — Gte)y ; Vite? +2¢ cofap Now, taking the fluents when ¢ = a, and y = a, we fhall have /- paiee cae =AXq@: And according to the me- d oy j thod of M. pE tA GRANGE, MELE ONE =a (1 + ae + sea et Bic}: Hence A = (1 + c) X (1 ap. Eatge +5 Fz + &c.)- And in this value of A, c’ will : be a fmall fraétion, even though c be large; and the feries will therefore converge very faft. But, eine the cog of A dire€tly m a feries, we have Az=i+5 a =a; ct ke. And fo 1+ 4c? + 23h 2ruAz + &. = (14+) X (1 + Sl? + — ct &e.). Now, 2 the two feries being exactly alike, it is evident that we may transform the one, as we have transformed atid and that, if —V/1—c* 1 42 Trg? lan es Se < we fhall have 1 ++ 3: cf? put > 1 Bea we put Cc — 2.4? (1 +c’) x (x + a +- — 3” i's ob &e,): whence A =(1-+¢’) (rt+o)(r+he cf? fF 3- 3-4 + &e,)s Ir RECTIFICATION of the ELLIPSIS, &c. 185 Ir is manifeft. we may proceed in this manner as far as we VI gy ta Sey arr SastetASeya/ rec and fo on, we fhall have the value of A in an infinite product, =(r1te)xXQ4+¢)x te) ite) X &e, the quantities c', c’, cl", c, &e. converging very rapidly. NotHinG more feems to be wifhed for, with regard to the ‘ computation of the quantity A: fince we can, by methods fuf- ficiently fimple, exhibit the value of it in feries that fhall con- verge as faft as we pleafe. By a fimilar mode of réafoning, I pleafe, and that, if we put¢” = : x : I ‘ 12,32. : 2 gt 2 find~the> feries 09 97? = i Sa vy of &e. (which occurs in determining the time of a body’s defcent in the arch’ of a’ circle), = (1c) & (i+ = cz =, ct ane e° + &c.) where ¢ = fate fo that the famma- tion of this feries alfo is accomplifhed by the method above. I HAVE now only,to explain the method of computing B. For: this purpofe I refume, ft SS =A + B cofp + C cof29 + &c.. Multiply by 2 cof, and there refults 2 cof Yate sels — B+ (2A + C) cofp + &c. . nehence it is manifeft that the whole fluent ; ; 2clexe . ‘ —————————— wh n 18 3 it oiae ae ok ola o— 4, ee toB Xa FRoM the preceding savenipaibn We hae pee Wt +o? — 2c cof se and cofg@ = c fin 7. Vise es fin 74, -> Won, IV. Z whence 186 RECTIFICATION of th ELLIPSIS, &c. : 20 c009 — 2d fn *y- Mi whence Vite wie oe Reepor nad + 24coft. 7 Again, I ote (1+) ; 2fin?¥ = 1 — cof2, and ————— —-— 4, Vi—e* fin 7d Jit? +2¢ cola ? "3 t—/i1— 2 pe Th Lae BS being = > wae thefe fubftitutions being made, we get 29 cof et (rte’)b ee SC i: +e) cofryp Vitec? —2ccu1g Vitec + 2c colow WV ipo + 26 cal ay + 2 cof. I SUPPOSE now, pra =A'—B'cof2ab-fe'cof4p— &e. it is evident, from what goes before, that, taking the fluents of the above fluxions, when 9 and } = a, we fhall have B X a =cx(1+¢c)x (a+) xz, and foB =¢ X (1+¢') xX aa 8 {A +5): Tue values of A’ and B’, in feries according to the method of M. DE LA GRANGE, are 3? N=rthc24++ d+ poe co + &e, I visit I 1-3 3 EOS Dey 2 ee 8 a aber oS + &e.) Wr4 2.4.6 which feries converge very faft, on account of the {mallnefs of c' in refpect of c. Ir, however, it be required to find the value of B by feries ‘}} more converging, we may eafily do fo: For it is manifeft that B and B’ are fimilar functions of ¢ and c’; and that if we 5 4/ On os Aa 1—fi—c* SRY SSA = ap 5 and fo on, and put a eg A’, make c’” = rh a RECTIFICATION of the ELLIPSIS, &c. 187 - A’, A”, &c.; BY’, B”, &c. to denote the correfponding values of A’ and B’, we fhall have Bac.(1+c)(A +5) B= c.(1$¢) (A + 5) BY = cr ej (Ao) &e.,: Now, remarking that A’ = (1 +c”) A’; Av = (1+ 0") A", &c. we have the following values of B: Bocx(1 +2). (1 +e): ejay = 4a) +0")B". Boex(rt i425) (1 +e) (1be Crp AN pee (10) (afe") (a+ eB. And we may proceed in this manner to find the value of B in feries that fhall converge as faft-as we pleafe. As the quantities ¢’, c”, c’’, &c. diminifh very faft, the feries A’, A”, A” will approach rapidly to unity, and B’, B’, B” will decreafe rapidly to nothing : Hence we have ultimately, Boe X(t, ++ & ans 4 &e, ) x (te') (the?) (be) &c. i or, fince A= (1 +’) (1 $c’) (a a c") &e.: B=exX (1+ £45 +e wey Bic.) XA. We fhall beft fee the degree of convergency of the quantities e, c', c”, &c. if we take the infinite feries by which they are de- rived one from another. Now,.if y = = tov then alfoy= + C 8 . . . . tat oy a+ &c.: whence it is obvious, that in the feries of quantities c, c’, c’, &c. the fourth part of the fquare of Z.2 = 188 RECTIFICATION of the ELLIPSIS, &c. any term is nearly equal to the following term, and the rapidity _ with which the feries decreafes is therefore very great. THE method, then, that refults from the preceding inveftiga- tions for computing A and B, is fhortly this : L— V¥i—c* I1+vVvi—c z T*< z ; r*: ca z ere =; c!? + = ct =e er cS + &c. = M Put c = : and compute ah Gh ee se PE) bore pe Ss bee and rigart 2.4 1 Fiomme? + &c. = N. Then A = (1 +c’) X M, and Boe X (1 +c’) Xk (M+N). Tut feries M and N will converge fo faft, even in the moft unfavourable cafe that occurs in the theory of. the planets, that the firft three terms will give the fums fufficiently exact ; and it will therefore not be neceffary to have recourfe to the more converging feries A” and B”’. Sucu is the method that I had firft imagined, for facilitating thefe fort of computations. I have fince found, however, that by means of the common tables of fines and tangents, the quan- tities A and B may be computed in a ftill eafier way from the expreflions, A=(1+c) (1 +c’) (1 +0") &e. Bo=cx(1+¢ ES HES St &e.) X A. 1—cofm For if c= fin m, then/1 —¢* = cofmand ¢ = arm =u. o confequently 1 + ¢’ = fec? =. In like manner, if _m c= finm’, c’ = fin m’, &c. we fhall have fin m' = tan? >; fin m’ RECTIFICATION of the ELLIPSIS! &e. 189 ey, > i fin m’ = tan? . vad foion: And 1 -- c¢ = fec? = patie f m!! ' fec? =, and fo on. Thus: A = fec? = x fec? x fec? ™ x &e. S nt To find the logarithm of A, we have then only to add toge- ther the logarithm fecants of the angles os Z, = &c. to dimi- nifh the fum by as many times the radius as there are fecants, and to take twice the remainder. As the angles.m,m', m’, &c. decreafe very faft, it will feldom be neceflary to compute more than two or three of them. Tue feries (1 +- oye. Cp os ' puted from the tables; becaufe is ee of ¢5¢”, c’", ec. be- ing the fines of the angles m',.m’, &c. are all aay in the ta- bles. As an example, let c = 0.72333: which is the fraction that arifes from dividing the mean diftance of Venus from the fun, by the mean diftance of the Earth; and this is the moft unfa- ‘vourable cafe that occurs in the theory of the planets: Then to - gompute A, I find, in the table of natural fines, that 0.72333 cor- _refponds to 46° 19° 48+”: we have therefore m = 46° 19! 483” . _L. tan = = |. tan 23° 9! 54%” = 9.6313206 |L. fec = = 10.0365070 c c a 5 ot &e ji is alfo readily com- 2 L. fin m' = 9-2626412 Lm 100 32°57 = L. tan = 1. tan 5° 16’ 284” = 8.9652949 |L. fec = = 10.0018429 2 L.finm’ = —_7.9305898. L. m= 0° 29 18” L, tan 190 REUTIFICATION of th ELLIPSIS, &c. L. tan w= 1, tan 0° 14 39” = 7.6295664 |L. fec = = 10,.0000039 2 —_———-——— __- 0.0383538 L.finm" = = 5.2591328 2 As m" will only be a few feconds, it may| L. A = 0.0767076 be neglected. Hence A = 1.19318 To compute B,letS = 1 + £455 4 &e. I = 1.000000 “bs ¢) te]. finn; &, 9.262641 5 c .= 0.091540 L. c? = 1, fin m’ = 7.9305898 ae = 0-000390 - Leg. 168 == PRETO RSaNO S = 1.091830 B=cXSXA. L. ¢ = 1.8593365 L. S = 0.0381948 L. A = 0.0767076 . L. B = 1.9742389, and B = 0.942408 IX. Eee es IX. 4 Snort Mrinerarocicat Description of the Moun- TAIN Of GIBRALTAR. By Major ImMriz. Communicated by the Reverend JOHN WALKER, D. D. Profeffor of Na- tural Hiftory in the Univerfity of Edinburgh, [Read Fuly 3. 1797-] HE mountain of Gibraltar is fituated in 36°. 9’ north lati- tude, and in 5°. 17’ eaft longitude from Greenwich. It is the promontory which, with that of Ceuta upon the oppofite coaft of Barbary, forms the entrance of the Straits of Gibraltar from the Mediterranean ; and Europa Point, which is the part of the mountain that advances moft towards Africa, is generally regarded as the moft fouthern promontory in Europe. The form of this mountain is oblong; its fummit a {harp craggy ridge; its direction is nearly from north to fouth; and its greateft length, in that direction, falls very little fhort of three miles. Its breadth varies with the indentations of the fhore, but it no where exceeds three quarters of a mile, The line of “its:ridge is undulated, and the two extremes are fomewhat high- er than its centre. ‘Tue fummit of the Sugar Loaf, which is the point of its greateft elevation towards the fouth, is 1439 feet ; the Rock Mortar, which is the higheft point to the north, is 1350; and the Signal Houfe, which is nearly the central point between thefe two, is 1276 feet above the level of the fea. The weftern : fide 192 MINERALOGICAL DESCRIPTION fide of the mountain is a feries of. rugged flopes, interfperfed with abrupt precipices. Its northern extremity is perfectly perpendicular, except towards the north-weft, where what are called the Lines intervene, and a narrow paflage of flat ground that leads to the ifthmus, and is entirely covered with fortifi- cation. The eaftern fide of the mountain moftly confifts of a range of precipices; but a bank of fand, rifing from the Medi- ~ terranean in a rapid acclivity; covers a third of its. perpendicu- lar height. Its fouthern extremity falls, in a rapid flope, from. the fummit of the Sugar Loaf, into a rocky flat, of contiderable extent, called Windmill Hill. This flat forms half an oval, and. is bounded by a range of precipices, at the fouthern bafe of which a fecond rocky flat takes place, -fimilar in form and ex. tent to Windmill Hill; and alfo, like it, furrounded by a pre- cipice, the fouthern extremity of which is wafhed by the fea, and forms Europa Point. Upon the weftern fide, this penin- fular mountain is bounded by the bay of Gibraltar, which is in length nearly eight miles and a half, and in breadth upwards -of five miles. In this bay the tide frequently rifes four feet. Upon the north the mountain is attached to Spain by a low fandy ifthmus, the greateft elevation of which, above the level of the fea, does not exceed 10 feet, and its breadth, at the bafe of the rock, is not more than three quarters of a mile. This ifthmus feparates the Mediterranean, on the eaft, from ie bay of Gibraltar on the weft. Tus mountain is much more curious in its botanical, than in its mineralogical produétions. In refpect to the firft, it con- neéts, in fome degree, the Flora of Africa with that of Europe. In refpe@t to the latter, it produces little variety ; perhaps a few fubftances and phenomena that are rare, but none that are pecu- liar. ; THE principal mafs of the mountain rock confifts of a grey, denfe (what is generally called primary) marble; the different beds Pea ade Bis ep — o Of GIBRALTAR. 193 beds of which are to be examined in a face of 1350 feet of per- -pendicular height, which it prefents to Spain in a conical form. Thefe beds, or ftrata, are of various thicknefs, from 20 to up- wards of 40 feet, dipping in a direction from eaft to weft, near- ly at an angle of 35 degrees. In fome parts of the folid mafs of this rock, I have found teftaceous bodies entirely tranfmuted into the conftituent matter of the rock, and their interior hollows filled up with calcareous fpar ; but thefe do not occur often in its compofition, and its beds are not feparated by any interme- ~ diate ftrata. In all parts of the globe, where this {pecies of rock conftitutes ‘large diftri€ts, it is found to be cavernous. The caves of Gi- braltar are many, and fome of them of great extent. That which moft deferves attention and examination is called St Mi- chael’s Cave, which is fituated upon the fouthern part of the "mountain, almoft equally diftant from the Signal Tower and the Sugar Loaf. Its entrance is 1000 feet above the level of the fea: This entrance is formed by a rapid flope of earth, which has fallen into it at various periods, and which leads to a {pa- cious hall, incrufted with fpar, and apparently fupported in the centre by a large maffy ftalatitical pillar. ‘To this fucceeds a long feries of caves of difficult accefs. The paflages from the one to the other of thefe are over precipices, which can only be paffed by the affiftance of ropes and fcaling ladders. I have, myfelf, paffed over many of thefe to the depth of 300 feet from the upper cave ; but at that depth the fmoke of our torches be- came fo difagreeable, that we were obliged to give up our pur- fuit, and leave caves ftill under us unexamined. In thefe ca- vernous receffes, the formation and procefs of ftalaGtites is to be traced, from the flimfy quilt-like cone, fufpended from the raof; to the robuft trunk of a pillar, three feet in diameter, which rifes from the floor, and feems intended by nature to fupport the roof from which it originated. » Von, IV. Aa THE 194 MINERALOGICAL DESCRIPTION . THe variety of form, which this matter takes. in its different fituations and direétions, renders this fubterrancous feenery ftrikingly grotefque, and in fome places beautifully picturefque. The ftalactites of thefe caves, when near the furface of the mountain, are of a brownifh,yellow colour ; but, as we defcend- ed towards, the lower caves, we found them begin to lofe their darknefs of colour, which by degrees fhaded off to a whitith. yellow. i tide sor dsivw. ask ball Tue only inhabitants of thefe caves are bats; fome of which are of a largefize. The foil, in general, upon the moun) tain of Gibraltar, is but thinly fown ; and in) many parts that thin covering has been wafhed joff by, the heavy autumnal rains, which have left the fuperficies of the rock, for a confider- able! extent;, bare »and ,openyto/ infpection,, , In thofe fituations, an obferving eye'may trace the effects.of the flow,-but conftant, decompofition of the rock, caufed: by its expofure to! the air, and: thecorrofion. of fea-falts, which, -in the: heavy gales of eafterly: windsy are depofited with the fpray-on:every part of ithe moun-! tain: “Thofé uncovered! parts of the mountain :rockalfo expofe to’ the eye a phenomenon-worthyof:fome iattention}ias ititends clear ly todemonftrate, that; howéver high the \furfacesof sthis -rock may now be elevated! above =the sleweliiof ithe» fea, ut -has ! once! beén the bed of! agitated waterse This - phenomenon >is to ‘be obfenvedl inemahy! partssof the: rockyiand is conftantly food! iny the bedssof dorrents.> [It trified ftate, and inclofed in the folid calcareous rock; but thefe are miftakes, which could only arife from inaccurate prides 93 and falfe defcription. In the perpendicular fiffures of the rock, and in fome of the caverns of the mountain, (all of which ‘afford evident: proofs ‘of their former communication with the furface), a calcareous concretion is found, of a reddifh brown ferruginous colour, with an earthy fracture, and confiderable induration, inclofing the bones of various animals, fome of which have’ the appearance of being human. Thefe bones are of various fizes, and lie in all dire€tions, intermixed with fhells of {nails, fragments of the calcareous rock, and particles of {par; all of which materials are fall to be feen in their natural uncombined ftates, partially feat= tered over the furface of the mountain... Thefe having been fwept, by heavy rains at different periods, from the furface into the fituations above defcribed, and having remained for a long feries of years in thofe places of re{t, expofed to the permeating action of water, have become enveloped in, and cemented by, the calcareous matter which it depofits. Tue bones, in this compofition, have not the fmalleft appear- ance of being petrified; and if they have undergone any change, it’ is more like that of calcination than that of petrifaction, ‘as the moft folid parts of them generally admit of being cut and fcraped down with the fame eafe as chalk. Bones combined in fuch concretions are not peculiar to Gi- braltar: They are found in fuch large quantities in the country of rke OFA DG MOB RA LT Ay Re 199 of Dalmatia, and upon its coafts.in the iflands of Cherfo and Ofero, that fome naturalifts have been induced to. go fo far as to affert, that there has been a regular ftratum of fuch matter in that country, and that its prefent broken and interrupted appearance» has: been caufed by earthquakes, or other convul- fions, experienced in that part of the globe. But, of late years, a traveller, (Abbé Atpertro Fortis), has given a. minute de- fcription of the concretion in which the bones are found in that country’: And by his account it appears, that with regard to fituation, compofition and colour, it 1s. perfe@ly. fimilar to that found at Gibraltar.!> By his defcription, it alfo appears, ;that the two mountain rocks of Gibraltar. and Dalmatia confift: of the fame fpecies of calcareous {tone ; from which it: is. to be prefu- med, that the concretions in both have been formediin the fame manner ‘andyabout: the fame periods. f . vPerkHars ifthe fiffures and caves of the ie om: eesti were {tills more minutely examined, their former communica- tions with the furface might yet be traced, as in thofe defcribed above ‘and; in'that'cafe, there would ibe at leaft a.ftrong proba- bility}that the materials of the concretions.of that country have been ‘brought ‘together by the fame accidental caufe, which, in my opinion, has ‘collected: thofe found in the caverns of Gibraltar. T have traced, in:Gibraltar, this concretion, from: the loweft part of aodeep perpendicular fiffure, up:to:the furface of the moun- tains» Ascit: approached! to the i furface; the ‘concretion became lefs firmly combined, and,'whem it! had:no ‘covering of the calca- reous!rock,aifmall degree lof adhefion, only remained, which was, evidently produced by thecargillaceéus-earth, in its compofition,, having: been:moiftenedsby taim and: baked by thefua. >| - ~) Precdepth;sav whiely thefe materials had: been, penetrated | by. that! proportion! of» ftalaCtitical miatter;.capablesiof (giving:.to. the: concretion |its:greateft: adhefion and:folidityy Lfoundsto.vary ac- cording: tovits fituation, and to:the! quantity! of:«mattér to:be com-: ot bined: 200 MINERALOGICAL. DESCRIPTION bined. In fiffures, narrow and contracted, I found the concretion pofleffing a great degree of hardnefs at fix feet from the furface; but in other fituations more extended, and where a larger quan- tity of the materials had been accumulated, I found it had not gained its greateft degree of adhefion at double that depth. In one of the caves, where the mafs of concretion is of confiderable fize, I perceived it to be divided into different beds, each bed being co- vered with a cruft of the ftalactitical fpar, from one inch to an inch and a half in thicknefs, which feems to indicate, that the materials have been carried in at various periods, and that thofe periods have been very remote from each other. Ar Rofia Bay, upon the weft fide of Gibraltar, this concre- tion is found in what has evidently been a cavern, originally formed by huge unfhapely mafles of the rock, which have tum- bled in together. The fiffure, or cavern, formed by the difrup- tion and fubfidence of thofe maffes, has been entirely filled up with the concretion, and is now expofed to full view by the outward mafs having dropped down, in confequence of the en- croachments of the fea. It is to this fpot that ftrangers are ge- nerally led to examine the phenomenon ; and the compofition, having here attained to its greateft degree of hardnefs and foli- dity, the hafty obferver, feeing the bones inclofed in what has fo little the appearance of having been a vacuity, examines no further, but immediately adopts the idea of their being incafed in the folid rock. The communication from this former chafm, to the furface from which it has received the materials of the concretion, is {till to be traced in the face of the rock, but its opening is at prefent covered by the bafe of the line wall of the garrifon. Here bones are found that are apparently human ; and thofe of them that appear to be of the legs, arms, and ver- . tebre of the back, are fcattered among others of various kinds and fizes, even down to the fmalleft bones of {mall birds. I found here the complete jaw-bone of a fheep; it contained its full of GIBRALTAR. 201 full complement of teeth, the enamel of which was perfeét, and its whitenefs and luftre in no degree impaired. In the hollow parts of fome of the large bones was contained a minute cryftal- lization of pure and colourlefs calcareous fpar; but, in moft, the interior part confifted of a fparry cruft of a reddifh colour, {carcely in any degree tran{parent. Ar the northern extremity of the mountain, the concretion is generally found in perpendicular fiffures. The miners there, employed upon the fortifications, in excavating one of thofe fif- fures, found, at a great depth from the furface, two ikulls, which were fuppofed to be human ;, but, to me, one of them, if not both, appeared to be too fmall for the human fpecies. The bone of each was perfeétly firm and folid; from which it is to be prefumed, that they were in a ftate of maturity before they ‘were inclofed in the concretion. . Had they appertained to very young children, perhapsithe bone would have been more porous, and of a lefs firm texture. The probability is, that they belong- ed to a fpecies of monkey, which ftill continues to inhabit, in confiderable numbers, thofe parts of the rock which are to us inacceffible. THIS concretion varies, in its compofition, according to the fituation im which it is found. At the extremity of Princes Lines, high in the rock which looks towards Spain, it is found to confift only of a reddifh calcareous earth, and the bones of fmall birds cemented thereby. The rock around this {pot is in- habited by a number of hawks, that, in the breeding feafon, neftle here, and rear their young; the bones in this concretion are probably the remains of the food of thofe birds. At the bafe of the rock, below King’s Lines, the concretion confifts of pebbles of the prevailing calcareous rock. In this concretion, at a very confiderable depth under the furface, was found the un- der parts of a glafs bottle, uncommonly fhaped, and of great - thicknefs ; the colour of the glafs. was of a dark green. Won, IV: Bb, Ex 202 MINERALOGICAL DESCRIPTION iy many parts of the rock I have found concretions, in which there are no bones of any kind; and on the elevated ‘parts of the mountain, where the flopes are rapid, I have found a breccia, (if 1 may fo call it), entirely confifting of fnail-fhells, combined in a mafs of opaque ftalactitical fpar of a yellowifh brown co- lour. The various progreflive augmentations of this matter were to be traced in various fhades of the fame colour, which, like the zones of the antique alabafter, curve round, and fol- low the form of the fhell. The purer matter of this {par has penetrated the fhells, and in their interior hollows has formed a lining of fmall cryftals, generally colourlefs and perfe@ly tranf- parent. f I nave beftowed more time in endeavouring to defcribe the compofition, and the real fituation, of this concretion of bones, than the fubject, in the eftimation of many, will feem to de- ferve, and indeed more than it deferves in my own opinion; but where an erroneous opinion has obtained a footing, in confe- quence of inaccurate obfervations and partial defcription, it is the duty of every new obferver to endeavour to correct it.’ ea * fy X. Description of a THERMOMETER, which marks the great- eff Decree of Heat and Coup, from one Time of Ox- SERVATION. to another, and may alfo regifler its own “Heicut at every InsTANT. © By ALEXANDER KEITH, Eq; F.R.S. & F. A. S, Evi. | * [Read Auguft 3. 1795-].. YHERMOMETERS have hitherto been defective for meteo- “rological purpofes, i in fo far as they only point out the de- gree ‘of heat at the moment of infpecting them, but do. not fhow what the difference of temperature has been, from the time of ‘one obfervation to that of another: Nor has any inftrument Been yet conftruéted, fo far as I have been able to learn, which will record the intermediate degrees of heat. 1 “Tuer ingenious Ropert Hook, in the end of the laft century, mentions his intention of making a thermometer for the above purpofe ; but it does not appear that it was ever executed: Nei-- ther does he explain how it was to have been done. Tuk thermometer, invented by M. James Six, as defcribed in the 72d volume of the Philofophical Tranfactions of the Royal Society of London, is made to fhow its. greateft rife or. fall from ‘one period of obfervation to another. This is done by. means of two {mall pieces of black glafs, which float on two different Bb2 furfaces 2) oY Weg DESC REP FON. of a furfaces of mercury, within two glafs tubes hermetically fealed. Thefe floats, when raifed to their greateft height, adhere to the fide of the tube, by means of a fpring of glafs, and become fta- tionary, although the mercury falls. After the obferver has taken a note of the temperature, he, by a magnet held in jis hand, draws down the float to the furface of the mercury, in con- fequence of a fmall bit of fteel wire inclofed in the float, and the inftrument is prepared for another obfervation. This is an in- genious invention, but requires too delicate workmanship to be fit for common ufe ; befides, it cannot be made-to record the degrees of heat at intermediate periods. The thermometer, lately invented by Dr RuTueERFOoRD of Balilifh, and defcribed in the 3d volume of the Tran/actions of this Society, is alfo an ingenious contrivance, but has the fame defet of marking on- ly the extreme points, to which the liquor has rifen or fallen, in two feparate glafs tubes. SEVERAL years ago it occurred to me, that an air thermo- meter might be ufed for the purpofes required, providing the weight of the atmofphere could be excluded, or a counter-ba- lance formed to it; and as the whole inftrument could be made to rife and fall by the temperature of the atmofphere alone, it might be adapted to a piece of clock-work, which would record the degrees of heat at every inftant through the year: And accord- ingly I read to this Society a defcription of the inftrument. But having formed another inftrument, of a more fimple con- ftruction, to anfwer the fame purpofe, I beg leave to give a de- {cription of it. AB is a tube about 14 inches long, (Pl. VI.) and three-fourths of an inch caliber, of thin glafs, fealed or clofe at top. To the bot- tom, which is bent upwards, there is joined a glafs tube 7 inches ‘long, and four-tenths of an inch caliber, open at top. The tube AB | ee ee -— ee eC lL Se a ta i en a ay ees 7 a= THERMOMETER. 205 AB is filled with the ftrongeft fpirit of wine or alcohol, and from B to E is filled with mercury. Ir will be evident, from infpection, that if the fpirit of wine is expanded by heat, the mercury in the fmaller tube will rife, and, if the f{pirit of wine is contracted by cold, the mercury will fall: And although they are both fubjected to the preflure of the atmofphere, yet, as liquids are incompreflible by weight in __ any perceptible degree, neither the fpirit of wine nor mercury will be altered in bulk by the different weight of the atmo- {phere. ED is a feale of brafs or ivory, about 65 inches long, divided in the ufual way. E is a fmall conical piece of ivory or glafs, of a proper weight, made to float on the furface of the mercury in the fmaller tube: to which float is joined a wire, reaching to H, having a knee bent at a right angle, which raifes one index, and depreffes ano- ther index, according as the mercury rifes or falls, which wire fhall be termed the float-wire. II is.a glafs tube, 7 inches and a half long, clofed at top and - open at bottom, fo wide as to flide eafily over the fcale, and, by means of a brafs rim cemented to it, is made to fit exactly to the circular bafe of the fcale, fo that, when this tube is put on, it covers the whole fcale and indexes, and defends them from wind or rain. This cover need not be taken off, except when the inftrument is to be prepared for an obfervation. _ Tue operation of the float and indexes will be better under- - ftood from fig. 2. which reprefents them of the full fize. FG is the fcale fixed to a circular piece of wood or brafs, through which the top of the fmall tube is made to pafs. From G to K is a piece of the fmalleft harpfichord wire, or rather of the fmalleft gold wire, ftretched along the {cale, fixed at the ends by two brafs pins. LL 206 DESCRIPTION of a LI. are two indexes, formed of thin black oiled filk, pierced by the fmall wire in fuch a manner as to {lide upwards and downwards with a very {mall force, not more than two grains. H, the knee of the float-wire before defcribed, is made to en- compafs the {mall wire between the two indexes, fo that, when the float rifes, the upper index is moved upwards, and, when it defcends, it leaves the upper index ftationary, and pufhes down the lower index, which is alfo left ftationary, when the float rifes. Wuen the inftrument is to be prepared for an obfervation, the one index is to be pulled down, and the other raifed, by means of a bit of wire bent for the purpofe, until both indexes touch the knee of the float-wire: And, when it is again obferved, the upper index will point out the greateft degree of heat, and the lower the greateft degree of cold, fince the time they were fet. : Ir this thermometer is to be adapted to a piece of clock-work,. in order to record the degrees of heat at each hour and minute of time, it ought to be made of larger dimenfions. ‘The large ‘tube may be 4o inches long, and not increafed in diameter, but the fmall tube ought to be enlarged in diameter, and not in ‘length. By enlarging the tube, which contains the {pirit of wine, in length only, it will be affe&ted by heat and cold in as fhort a time as that before defcribed. Ir is wunneceflary at prefent to explain the clock-work. It is fufficient to fay, that a hollow cylinder of any light fubftance, 7 inches long, and 5 inches diameter, is made to revolve upon a vertical axis once in thirty-one days or a month; a piece of fmooth or vellum paper is put round this cylinder, pafted only at the joining, but fo as to make it adhere clofe to the cylinder; on this paper are drawn thirty-one equal perpendicular divi- fions, numbered at the top 1, 2, 3, &c. to correfpond to the thirty-one days of the month, each of which is fubdivided into ‘fix parts, to anfwer to four hours. The length of this.cylinder | 4S THERMOMETER. %07 is divided. by lines furrounding it, or zones, in fuch number as correfpond to the feale of FAHRENHEIT’s thermometer, viz. from ‘oto roo degrees. Thefe divifions ought to be engraved on cop- ' perplate,’ and a great number of impreflions thrown off on fmooth or vellum paper, in mis that one may be ready to put on each month. Fic. 3. MN reprefents the cylinder covered with one of thefe impreflions. PP is the fcale fixed to the frame on which the cylinder turns. This fcale is divided into 100 of FAnREN- HEIT’S degrees, exactly correfponding to the divifions of the cy- linder. Q isa pee of black-lead pencil, joined to the end of the flot-wire in the place of the knee before mentioned. This pen- cil is made to prefs lightly on the cylinder, by means of the {mall weight R. And as the pencil rifes or falls by heat and cold, it will mark the degrees on the fcale of the cylinder ; and the cylinder being conftantly revolving, the divifion for each day and parts of a day will fucceflively be marked by the pen- cil, which will leave a trace, defcribing an undulated line, di- - ftinétly delineating the temperature of each day through the -month. Thefe papers, when taken off and bound together, will make a complete regifter of the temperature for the year ; or, if they are pafted to one another, they will form a thermometrical chart, by which the variations of heat and cold, during the year, may all be feen and compared by one glance of the eye. By infpecting fig. 3. the effect of the inftrument may be feen. It appears that the paper had been put on the cylinder the firft day of the month, at midday, when the thermometer ftood at 45°; that it fell gradually till midnight to 25°; thereafter it rofe till the 2d at 1 P. M. when it ftood at 42°; then it de- fcended at midnight to 35, &c.; that on the 4th, at midday, it rofe to 50; and at noon, the roth of the month, it ftands at Ao". Ir 208 - DESCRIPTION, €&e. Ir three inches be added to the length of the cylinder, it may be made to delineate the variations of the barometer as well as the thermometer, and thereby to form a complete chart or view of the progrefs of both of them. And if inftruments of this kind were kept in different parts of the country, and their charts compared together, it would afford much information with re- gard to meteorology. 22S Phil, Tran Vel 4% Fat HP. 208 Fig. 22 oe | | ae {[ i fo iL | AN rn my | Ih) AYA ql uel; TT. | | al bal | | iN { Ti XI. Description of a Barometer, which marks the Rise and Faux of the MERcuRY from two different Times of OspsERVATION. By ALEXANDER KEITH, E/q; F.R.S. & F. A. S. Epin. [Read Fan. 5. 1796.] N Augutt laft, I read to this Society the Defcription of an Air Thermometer, intended to record the various degrees of heat at every inftant; and mentioned my intention of conftrudt- ing a barometer, which would, in the fame manner, record the variations of the weight of the atmofphere: Both which I pro- f pofed to adapt to one piece of clock-work. Tuts piece of machinery appearing too complicated and ex- __-penfive for general ufe, I contrived a thermometer, which marks the extreme points of heat and cold from any two times of ob- fervation. Of which inftrument I alfo lately read an account, and produced the machine itfelf. _ 1 now intend further to lay before this Society the defcrip- tion of a barometer upon fimilar principles, of a very fimple con- ftru@tion, which alfo marks the variation of the atmofphere . from one time of obferyation to another. ' Vou, IV. Cow: Fic. 1. 210 DESCRIPTION of .a Fic. 4. ABCD is a glafs tube, bent in the manner repre- fented, open at D, and hermetically fealed at A. From A to B is 8 inches long, and about 3 of an inch caliber. From B to C 31% inches long, and about § of an inch caliber. And from C to D 4+ inches long, and + inch caliber. THE tube is filled with mercury, the length from B to E be- ing 29+ inches. When the tube is hung perpendicular, the © mercury will fall from B to E, leaving a vacuum in the upper half of the tube from B to A. When the atmofphere becomes heavier, the mercury falls in the tube DC, and when lighter it _ rifes. The range of the fcale is about 3 inches, being equal to that of a common barometer of the beft conftru€tion, which has a bafon with a very broad furface. This inftrument moves in a direction contrary. to the common barometer, the one rifing while the other falls. Fic. 5. reprefents the tube DC, with the fcale placed above it, of half the real dimenfions. F is a piece of ivory or glafs, of a co= nical {hape, of a proper weight, made to float on the furface of the mercury, having a wire fixed to it reaching toG. From Hto H is a piece of fmall harpfichord-wire, or rather gold-wire, {tretched along the ivory or brafs plate on which the fcale is en- graved. II are two indexes formed of the thinneft black oiled filk, pierced in fuch a manner by the {mall wire as to move up- wards and downwards upon it with a very fmall force, not more than two grain weight ; and thefe indexes, being not the weight of half a grain, they do not defcend the wire by their own weight, but remain where they are placed. THE wire fixed to the float, (which we {hall call the float-wire), has a knee bent at a right angle, and made to encompafs the fmall wire between the two indexes, fo that, when the float rifes, the upper index is carried up, and, when it falls, it leaves the upper index, and pufhes down the under index, In Bo AORIO ME F EER: ari Tw order to ’prepare this barometer for an obfervation, the “one index is to be brought down, and the other raifed, until both touch ‘the knee of the float-wire. THE next time the inftrument iis obferved, the upper index will point out the greateft depreflion of the mercury, or light- nefs of the atmofphere, and the lower index the greateft rife of the mercury or weight of the atmofphere, from the time the {cale was prepared. Iq 2% By this means the variations of the atmofphere are much more truly pointed out than by the common barometer. For it often happens, that, during tempeftuous weather, or be- fore it, the mercury both rifes and falls within the {pace of a few hours, or during the night time, which variations cannot be difcovered by any of the barometers prefently in ufe. Durinc the late very high winds, in November and Decem- ber laft 1795, I have frequently obferved the mercury to rife and fall within the {pace of two or three hours before the wind begins ; and, during tempeftuous weather, it will fall very confi- derably, and foon after rife higher than before, and ofcillate, or rather undulate, upwards and downwards, the undulations be- coming gradually lefs, until the atmofphere is more fettled; which fhows, that, like other fluids, when put in agitation, it undulates till it come near an equilibrium ; for it appears fel- dom to be in a ftate of perfe& tranquillity. THE fudden fall and rife, or even the rife and fall of the mer- cury, always denote an extraordinary agitation in the atmo- {phere. And therefore, to foretell tempeftuous weather, it be- comes of importance to obferve how many degrees the one in- dex is removed from the other; for example, at night, I take note of the common barometer as ftanding at 297 inches, and when I examine it in the morning find it at the fame height ; from which I naturally conclude, that, as there has been no agitation of the mercury, there will be calm or fettled wea- Ce2 ther. 212 DESCRIPTION gO, &&. ther. But, if I ufe the barometer before defcribed, and examine it in the morning, I find the common barometer has deceived me ; for although the furface of the mercury ftands at 29; in- ches, yet I obferve, that one of the indexes has been raifed +, and the other lowered 35 during the night. Hence, inftead of denoting calm weather, it fhows that, the mercury having been agitated, tempeftuous weather is to be expected. THE regifter of the weather, kept from an inftrument of this kind, will be much more fatisfactory than thofe hitherto ufed, and regifters kept at different places can be more accurately com- pared with one another. THE levity of the atmofphere, at great heights, might alfo be difcovered, by fufpending this inftrument to an air-balloon. XIL. XII. Meteororocicar Asstract for the YEARS 1794, 1795, and 1796. Communicated by FoHN PLAYFAIR, ¥. R. 8. Eptw. and Profeffor of Mathematics in the Univerfity of Edinburgh. [Read at the Meetings in Feb. 1795, 1796, & 1797-] HE Journal of the Weather, of which an abftract is: here , communicated, has been kept in a houfe in Windmill Street, on the fouth fide of Edinburgh. The latitude of Edinburgh College, as deduced from a feries of aftronomical obfervations made at Hawkhill, is 55°. 57’. 5” nearly. Wind- mill Street is about 500 yards farther to the fouth. Tue barometer ufed in thefe obfervations is a portable one, of the conftru€tion invented by Dr Linn, phyfician at Windfor; the mercury was boiled in the tube, and the fcale is divided in-- to the five-hundredth parts of an inch. The place where it ftands is 265 feet above the level of the fea, or of the mean high-water mark at Leith. The height of it is marked every morning at 10 o'clock, as well as that of a thermometer, in the. fame room, which gives the temperature of the mercury. Tue thermometer, which gives the temperature of the air, is | placed on the outfide of a window that looks towards the N. W.. about 214 METEOROLOGICAL ABSTRACT. about 18 feet above the furface of the ground; and though, in a town, it is impoflible to prevent local caufes from affecting the thermometer, yet the current of air is generally fo confiderable as to prevent thefe wregularities from rifing to. any great a- mount. THE regifter contains the ftate of the thermometer for three different hours of the day, viz. 8 A. M. 1o P. M and alfo about 2 o'clock, when the thermometer is higheft. The hour of this laft obfervation is not however fixed ; it is fuch as to give near- ly the greateft heat of the day, and varies from 1 to half patft 2, or even 3 0’clock, The abftraét contains the greateft and leaft heights of the thermometer, that have been obferved at any of thefe hours in the courfe of each month: It contains alfo the mean of the morning, mid-day, and evening obfervations ; and likewife the mean of all thefe means, as being nearly the me- dium temperature of the whole month. THE rain is put down for 1794 and 1795 from a rain-gage kept in Edinburgh, and for 1796 from one kept in the Botanic Garden with great accuracy, under Dr RUTHERFORD’s particu- lar infpection, The Botanic Garden is half-a-mile north of Edinburgh, and about roo feet above the level of the fea. In the remarks, reference is fometimes made to the Meteoro- logical Journal kept fome years ago at Hawkhill, near Edin- burgh, of which an account is given in the Phi/o/ophical Tranj- actions of London 1775, p. 462. METEO- er METEOROLOGICAL ABSTRACT. 215 METEOROLOGICAL TABLE For 1794. ie 2 ‘ rs £ e = s L is C=) we ee a & s ap S 8 aa r-) ae og Cet ge S = ede See ene fe ieee ie fee eT ihe tee g: | §8 | se] 3] #8} es) ) ee] § ea |Ss | o8 |] 4 !se |] s6 158 | 54 19 January, 29.661 | 49.30| 51-5 | 21-0 | 39.32] 41.43 | 41 20 140.65 | 1-40 |February, | 29.397] 59-0 |54-25135-5 | 43-5 | 46.00] 44.30].44.10 2.145 March, 29.631] 51.00] 53-0 | 38.5 | 44-43 | 48.09] 45.93| 46.15 0.995 April, 29-595 | 55-25 ]64-5 | 39-25] 49.50] 52.98 | 48.30] 50.26 | 2.150 May, 29-752 | 56.32 |62.0 | 42.0 | 50.22] 56.16] 47.22 | 51.20 1.910 June, 29.884 | 64.50} 73-0 | 48.5 | 60.4 | 62.30] 57.40] 60.70] 1.07 July, 29.768 | 66.70) 75.0 | 52.0 |61.7 | 66.42} 58.61 | 62.24 | 2.12 Augutt, 29-720 | 64.32 | 72.0 | 49.0 | §9.98 | 63.03] 55-40] 59.47 | 1-84 September, | 29.662 | 58.72 | 64.0 | 41.0 |-54.99] 57.45 | 52.06] 54.08 | 3.14 Oftober, | 29.516] 54-85 | 62.0 | 36.5 | 50.26] 52.43 | 47.29 | 49.66 | 3-53 November, | 29.416 | 48.90 | 53.5 | 32-5 | 43-58]45-54 | 43.47] 44-19] 4.51 December, | 29.691 | 48.58:| 50.5 | 26.25 | 47.33 | 42.50] 40.10 | 41.31 | 3-92 Means, 29.641 | 55.72 49-79 | 52-84 | 48.34 | 50.32 | ——- Total Rain, 28.73 Rik i ACR. 1K: Se Tue weather in January and February 1794:was very mild and open. The prevailing winds were from S. W. and S. 5. W.; ufually a brifk iteady gale, but fometimes more violent, particularly in February. The thermometer was as high as 50x ih January, and 54 in February ; and once in January. fo low as 21, only for a fhort time, however, during a N. W. wind; the froft lafted fome days. Very little fnow fell. The temperature of thefé months was 6° or 7° above the mean: of the Hawkhill obfervations. There was a great déal of clear weather, and, though ‘the atmofphere was moift, there fell but little rain. ; Marcu and April continued to maintain a fuperiority of 3 or-4 degrees in tem- perature above the fame months in ordinary feafons. March was very dry, and the wind frequently in the eaft. In the end of April, the weather was fqually, with the wind varying from §. W. to 5. E. . Is 216 METEOROLOGICAL ABSTRACT. In May the heat fell down nearly to the common average of that month, viz. 50%, fo that it feemed cold, compared with the reft of the feafon, The wind was often in the eaft, and the nights cold. June and July were very favourable; warmer than the mean by 1 or 2 de- grees. In June, the temperature was remarkably uniform; and the wind was moftly in the weft. The weather in July was alfo fine ; the wind moderate, and generally weft. | Tae Harveft began with Auguft; the weather tolerable, though more rainy than ufual, and colder. The temperature of this month is almoft 2° below the mean. Tue wind was generally weft; but a furface wind was to be obferved at the fame time blowing from the eaft. This is often obferved with us in the fineft weather : it feldom fails to happen at the time of the great changes of the wind from the eaft to the weft. SEPTEMBER was rainy ; its temperature rather below the mean, yes eafterly winds about the middle and end of the month. OcToBER rainy ; the wind variable, though moftly S. W.; the barometer low ; and the mean temperature 49°. 66, a very little under the mean. NovemseEr was warm for the feafon, though rainy, with the wind variable, and often very high from 5. W. DecEMBER was alfo warmer than ufual, by nearly two degrees: The wind was eafterly till near the end of the month, when it changed to the N. E: A goad deal of {now fell on the 25th; and, on the laft day of the year, the thermometer, in the evening, was at 26: The weather clear, with little wind. On the whole, the mean temperature of this year exceeded that of ordinary fea- fons by almoft 2°. This excefs of heat is very confiderable ; but, as it fell chiefly in the winter months, it was not attended with any particular advantage. The rain that fell was 28.73 inches. METEO- METEOROLOGICAL ABSTRACT. 217 METEOROLOGICAL TABLE ror 1795. Months. May, 3 Sues a july, % Aug. Sept. O&. Nov. Dec. ae Means, >. Totals, ’ Inches. | Inches. = Fi “1 a 3 3 Jan.. »|30.306]28.88 5}29.89 1142.046.0 16, 5]31-11|32-80]32-20|31.7¢ Feb. |30.450|28.636|29.484|41-8]14 0.¢|27,0130.14]30.89)28.46129.83 March, 30-125/28.992]29.5 73146. 5l15 1-5|26.0139.92142.96]3 7-80] 40.23 ‘wy April, |30.146|28.948]29.503]52.0l|56.5]39.0]47.09|49. 5 2|44-73]47-21 39-320/29.27 5129-91 3}5 5-110 5.5139.5]50-98]5 3-83]47-03| 50-34 30-272/29.128)/20.74 315 7.5116 7.0142. 5/54-40]57-17|50-5 4154.06 30-238]29.286]29.806|60.21172.0]50.0|60.42|02.85|54-9715 9-41 30-040 29.210|29.674|64.2]173.5152.0]61.11164.21158-58/51.3¢ Tete 29-944]28.3.40]29,280)5 7.515 3.5144.5|5 3-66]5 5.5 5|51-48}5 3.56 30.490|28.47 5129.570147.5|15 1.5/2 5+2/40.60]4 1.61/39-27| 40.49] 30.220/29.080/29.560150.5115.5.7136-014 5.4.3146-23/42-96| 14.87 p- of Merc. in Barometer. | Greateft Height of Mean Height of Ther. Mean Height of Ther, Mean Height of Ther. at Noon. Mean Height of Bar. Leatt Height of ‘Ther. 8 A.M. 10 A, M. Greateft Height of the Bar, at 10 A. M. Leaft Height of the Bar. at10 A.M. Mean of the three laft Columns. Quantity of Rain, | Days of wefterly wind. | Days of erlterly wind Ther. in the Air. Mean Tem Inches. . ' moo WB GU com = sis Yin ~~ OL | nl nwa 2.1I¢ 1.200] 18} 13 3-920] 10 2.520] 15] 16 3-620] 24) 7 2/29.31.4]29.8 5 3162.0]173.c|5 3.2159.85]53.48)5 7-0310.00} 1.120] 21] 9]. 4.87] 23} 8 4-580 4 | 3.8%c} 25] 6 47-9¢|50.04 Tue mean temperature of the whole year is 47.75. hace §-729]23|234 |. | | BN AL Ro RS Tue winter of 1795 was remarkable for the feverity and continuance of the cold. The year began with a tharp froft, which had fet in on the 26th of the pre- . round to the S. W. and was followed by a thaw. On the roth the froft returned, the wind varying’ from N..W. to N. E. with heavy falls of {now between the 15th and 20th. On the 20th the cold became very. fevere ; and on the 22d the thermometer, about 8 in the evening, ftood at 142°, the loweft that I obferved it du- ring the whole feafon. This intenfity of the cold lafted, however, but a fhort time, 4 __ for by 10'0’clock the thermometer had rifen to 163°. On the fame night, in the Bo- Vou. IV. ! | : ceding month, but which lafted only till the 3d of January, when the wind came tanicali Dd 218 METEOROLOGICAL ABSTRACT. tanical Garden, which lies between Edinburgh and the Frith, and is about 150 feet lower than the place where I obferved, a thermometer, which marks its loweft point, according to the conftru&tion deferibed in the 3d volume of thefe Tran/actions, fell as low as 5°. The cold at Glafgow, on this night, was ftill more intenfe. Mr Profeffor Wilfon, who watched the motions of the thermometer, with his ufual dili- gence and accuracy, found it ftand at zero, from xx at night till 3 in the morning, when it began to rife, and about break of day was at 10°. Tue night preceding this was alfo obferved, in fome places, to be remarkably — cold. At White Hall, in Berwickfhire, 7 miles W. N. W. of Berwick upon- Tweed, and about 38 E. 5. E of Edinburgh, Mr Hatt obferved the thermometer, in the open air, about ro that evening, at 6° below zero. This was the greateft cold that I have heard of being obferved in Scotland ; and is, at the fame time, an exam- ple of the locality of thefe great colds. The weather at this time was clear; the wind very gentle, between N, N. W. and N.N. E.; a great deal of {now had fallen from the xsth to the zoth, and lay at this time more than a yard thick on the ground. From about the 22d the intenfity of the cold relaxed gradually for feel days; the thermometer was a degree aboye freezing on the 24th. From that time the cold increafed ; on the 2gth the thermometer was at 16° in the evening; in the Botanic - Garden at 4°; and at Glafgow, on the afternoon of the 3oth, it was between 4° and zero for feveral hours together. This was again followed by a relaxation of the cold, though not fo confiderable as before. On the sth and 6th of February it was again very cold, the thermometer here was at 19°, at Glafgow it defcended to zero. Arrer another remiffion the cold became very fevere on the 13th, both here and at Glafgow. This was fucceeded by a fimilar change, only the remiffion was longer and more confiderable, fo that a good deal of {now was melted on the 24th and 26th; but on the 27th and 28th the cold once more became fevere, the ther- - mometer ftanding at 19 and 20 degrees. It continued much in this ftate till the 3d of March, when the wind came about to the S, W.; the thermometer rofe in the evening to 4oi°; and a very moderate thaw fucceeded, which carried off the fhow, without any of thofe great inundations which did fo much mifchief in the fouthern part of the Ifland. Tue whole duration of the froft was 52 or 53 days; and the medium tempera- ture, during that time, 29°.6. The alternate intenfions and remiffions of the cold, all the while were very remarkable; our climate feemed to lofe nothing of its ufual in- conft.ncy, and its viciflitudes were only lower down in the feale cf heat. By this means, however, many of the bad confequences of a long and fevere winter were prevented. The infides of houfes were never fo much cooled, that fpirits or beer, or even water, was frozen in them. The room where my barometer is kept, though without fire, was never colder than 37°, and this only for a few days in the end of January. From the fame caufe, the mills in the country were rarely {topped ; and, except from the blocking up of the roads by the fnow, almoft no inconvenience was experienced. The : { . METEOROLOGICAL ABSTRACT. 219 The roads were rendered impaffable, both from the depth of the {now, and the degree of thaw which now and then took place, by which they became {flippery, and uneven inthe extreme. The whole {now that fell, reduced to water, mea- fured 6.607 inches, which, had it fallen at once, would have covered the ground to the depth of about 7 feet. Tue feverity of this winter extended over all Europe; and, on the €ontinent, the freezing over of the Rhine and the Meufe was accompanied with circum{tances that will be long remembered. a Tue barometer was above 30.3 at the beginning of the froft, and continued high till the end of January, notwithftanding the heavy falls of fnow, which came almoft all from eaftand N. E. On the 31ft of January it fell greatly, with fnow; and, during the firft 12 days of February, it was generally below 29 inches. ~ It ‘ftood at 30.4 on the 17th, from which it fell gradually till the thaw, when it was un- der 29.5. ‘No-conneétion could be traced between the ofcillations of the barome- ter, and the intenfions and remiffions of the cold. From the breaking up of the froft on the 34, till about the 20th of March, the {now did not difappear entirely, even in the’ plains; it ufually froze a little in the night, and the medium temperature was under 38°. On the difappearance of the f{now, the thermometer rofe fuddenly about 10°, which muft be afcribed to the cea- | fing, at that time, of the abforption of the latent heat, that had raken place during the - melting of the fnow. Tue {pring which fucceeded was tolerable ; and the temperature of the latter part of March, the whole of April, and the beginning of May, rather above the mean. About the roth of May the wind, which had for fome time been in the 5. W. came to the eaft and N. E.; the weather, of courfe, was cold, and continued fo, with the wind generally N. E. all the month of June, and till the 24th of July. June and July were alfo very rainy months. The wefterly winds prevailed in Au- guit, and the weather was good, though a confiderable quantity of rain fell. Sep- tember was uncommonly favourable; and the crop, which was extremely late, owed much of its maturity to this month. It proved, however, very fcanty, and was got in but indifferently, O&ober being a very rainy month. Novemser was cold, and very wet: On the 18th the rain was remarkably heavy, and was followed by the greateft floods that had been known for feveral years. In December the weather became much milder, and fomewhat lefs rainy ; but, on the whole, the rain of this year very much exceeded the average, and amount- ed to 35.729 inches. N. B. In the two laft columns of the table for this year, it is marked whether the wind blew from the weftern or eaftern femicircle. The fouth wind is fuppofed to belong to the firft of thefe; the north wind to the fecond. METEO- 220 METEOROLOGICAL ABSTRACT. METEOROLOGICAL TABLE ror 1796. oo” yu = S ov ny o vo 7) S Z 3 3 & Aa [3 3 cae ¢ 2 5 =| Me eet 7 ue Ss 3s > z ‘S S Jo. eefo. [se] oapee je gee ae TEo + a ff Ps Bea | Ss eat 2 [s 2. | oS. |e | $8 82128 | as | me |e 1s 3 is ls He | es | Ps PL PRS pee leo | eA Po ie a Bs IE LB “2s a Heyer heo[me le }talme los ee |s [Se . 28 g af cod 226 € ep Bis ie eae ee =| aaie’ ae) eo ao ae En =e ee Wa Wd f'5 JS s/e.8 o oo oO 5 2 oO oo =o A=, ft fe 1 ee | Se Se hee ts 6 |$2 1/92 | 32 |SS|8e cc) S68 | SA [SSSR 1SE [SRA 125 | Sh 15254 26 |e 47-38)52-71147.10/48.1 estas fab fe ee THE mean temperature of the whole year is 48°. 1. Rh) Miva Ree Ress Tre winter of this year was remarkable for its mildnefs, and, compared with that of the former year, may give an idea of the two extremes between which the win- ters of this part of the Ifland will generally be confined. About the middle of January, the thermometer ftood for 10 days conftantly above 50°, day and night; and the mean temperature of the month, viz. 45°. 6, is at leaft 11° above the medium, and nearly the fame with that of the ordinary January of Marfeilles. This extraordi- nary 4 ; METEOROLOGICAL ABSTRACT. 225 nary degree of warmth was maintained by a high wind, that blew conftantly from S. W. and S. S. W. bringing with it the air and temperature of the fouthern parts of the Atlantic. This wind prevailed over fuch an extent of the ocean, and blew with fuch violence, that it forced back a fleet of Britifh men of war, afier it had endeavoured, in vain, for fix weeks, to make its paflage to the Welt Indies. Ir muft be remembered, that the great cold of the preceding winter was with awind N.N. E. and fometimes N. N. W which blew very moderately. Ow’ the 23d of January there was a hurricane from S. S. W. that blew down trees and unroofed houfes: The barometer fell very low, and did not rife to its ordinary height for more than ten days. In March the weather was cold, 5° below the middle temperature of February ; eaft winds prevailed, and the premature appearances of vegetation, produced by the mildnefs of the preceding feafon, fuffered a fevere check. April was more fa- vourable ; but in May the weather again became cold, with eaft winds, remarkably dry and parching. The grafs every where fuffered extremely from this month. On the 30th there was a hurricane at London, and at Portfmouth onthe 31ft. On both thefe days the barometer here was very low, 28.53, though the wind was no more than a brifk gale at 5. W. In June the mean temperature was not fo high by 2° as in ordinary fea- fons. The wind, though weft, was ufually from the northern points of the femi- circle. Juzy was worfe than June, and its mean temperature 3° under that of a tole-. rable feafon. Great apprehenfions were entertained for the crops, which, without the fine weather that fucceeded in Auguft, muft have been ruined. The heat of this * month, which was at a medium about 614°, was not fo remarkable for being great.as for being uniform ; the thermometer, for a great part of the month, was not below 63°, even in the night. There was a great deal of funfhine, and the wind almoft con- ftantly W. 5. W. i Be ic Tue firft half of September was little inferior to Auguft. On the 21/t, the wind, from the S. W. came round to the N. E.; a confiderable fall of rain follow- ed, and the weather became colder, and continued to be fo in O&ober: the medium temperature of which was 3 degrees lower than the average. A smaxtT froft fet in on the 29th of November, and next morning the thermo- meter ftood at 26°. This froft continued till the 1eth of December, with an intenfity very unufual fo early in the winter. On the evening of the sth: the ther- mometer was at 21°. Between the roth and 13th the froft had almoft difappeared; but it returned on the 14th with confiderable feverity, and continued till the 28th, when it broke up entirely. The thermometer was at 19° on the 26th, and in many places lower. The fame froft was felt in England, where there were local colds of much greater intenfity, the thermometer, in fome places, having been as low, it was faid, as =o. A tract of very mild and open weather began on the 31ft of December. Vou. IV. Ee THE: ‘ 222 METEOROLOGIGAL ABSTRACT. Tue mean temperature of the whole year is 48°,1, about } of a degree greater than the common average. e Tue greateft fingularity in this year is its drynefs. The whole rain amounted to no more than 19.395 inches, not much above the half of what fell in 1795. This quantity of rain was, however, perfeétly fufficient for the purpofes of vegetation, as the crop of corn was very plentiful. END OF PAPERS OF THE PHYSICAL CLASS: II. PAPERS. OF THE LITERARY CLASS. T. On the Onicin and Paincipyes of GoTuHic ARCHITECTURE. By Sir JAMES HALL, Bart. F. R. & A. SS. Evin. _ [Read April 6. 1797.} PN Ou CT Che ONG after the arts of ancient Greece and Rome had been loft, and before any effeCtual attempt was made to revive them, a ftyle of building, known among us by the name of Gothic Architeture, began to appear in Europe. Ar firft, a few only of its peculiar forms were employed, _ which, im fome old buildings, are to be met with, intermixed with the remains of a ftill more ancient ftyle. Afterwards, ri- fing by degrees into favour, it fupplanted, in all the depart- ments of architecture, every other {pecies of defign, and main- tained an unrivalled dominion during three hundred years. a2 iy 4 On GOTHIC ARCHITECTURE. In the early part of the fixteenth century it underwent a fud- den reverfe of fortune; not, however, (I am inclined to think), from any difcovery of its defects, or any inquiry into its me- rits, but entirely frorn the general temper of the times. A paf- fionate admiration of the works of antiquity, which had then recently attracted the attention of the moderns, produced a con- tempt for whatever was not profeffedly formed upon the models of Greece and Rome. At the fame time, an indifcriminate ha- tred againft every production of the middle ages, ftrongly felt by men juft emerging from the gloom of that period, led them to overlook the merit of this very brilliant exception to its gene- ral barbarifm. Bur the excefs of thefe impreflions has of late very much abated ; authors of the greateft eminence have teftified a refpect for Gothic architecture, by advancing various fyftems to ac- count for its forms ; and, whilft they acknowledge the fuperior excellence of the works of the ancient Greeks, they allow that, in airy lightnefs, and in bold grandeur of effect, thofe of the Gothic {tyle have not been furpafled, if ever equalled, by the moft ce- lebrated of our modern produétions. The period, too, in which it prevailed, being at a diftance from our times, and that di- ftance being magnified in our imagination by the obfcurity of its hiftory, we are inclined to rank its monuments with the works of remote antiquity, which feldom fail to excite even a greater intereft than thofe poflefling the charm of novelty. In concurrence with thefe favourable fentiments, my object, in the following Effay, is to reftore to Gothic architecture its due fhare of public efteem, chiefly by fhewing, that all its forms may be traced to the imitation of one very fimple original ; and, confequently, that they are connected together by a regular fyf- tem: thus proving, that its authors have been guided by prin- ciple, and not, as many have alleged, by mere fancy and ca- price. HaAvING a ee EE as — Oe On GOTHIC ARCHITECIURE. — 5 _Havine endeavoured to inveftigate the theory of Gothic ar- ‘chitecture, I fhall prefent a view of what I have been able to colle& concerning its hiftory; and, without pretending to dif pel the very deep obfcurity which ftill furrounds this curious fubject, I fhall venture to fuggeft fome hints, which may be of fervice in guiding the refearches of antiquaries. By this hifto- rical view, I hope, likewife, to refute an opinion, which has contributed greatly to difcredit the Gothic ftyle, namely, that it prevailed only in barbarous times ; fince I fhall fhow, that, al- though it made its firft appearance in a period of that defcrip- tion, it, continued to flourifh, while the arts of defign were ad- vancing in excellence, and {till maintained its pre-eminence, when they had attained to the higheft degree of modern {plen- dour. ; Last Ly, by inftituting, between the Gothic and other ftyles, a comparifon, founded upon the general and fundamental prin# ciples of architecture, I fhall endeavour fairly to appreciate its merits, and to fhow the high eftimation to which it is entitled, in point both of beauty and of utility *. BEFORE * Tus plan is now nearly completed, the whole Effay being written out, and ac- ‘companied with a fet of drawings fufficient to render it intelligible, but by no means in a ftate for publication. To bring them to fuch a ftate muft be a work of much labour and time, efpecially fince the nature of the fubjeét has hitherto compelled me to execute all of them with my own hands. : I HAVE judged it advifeable, therefore, to lay before the Society a part of the Ef- fay, which requires but few drawings, while it announces the fundamental and ef- fential views of the theory; referving the full illuftration of it to another occafion, when I hope to produce the whole in a feparate work. In the thean time, it may not be improper to obferve, further, with refpect tomy general plan, that the firft part, comprehending the theory of Gothic architeéture, has been arranged under three fubdivifions; the firft of thefe contains a view of its elements, all its forms being reduced to their fimpleft ftate ; the fecond treats of the deviations from thofe elements, which, in the courie of pra@lice, have been occafioned by various circumftances ; and, the laft, combining the other two, contains an exa- mination 6 On GOTHIC ARCHITECTURE. BEFoRE we enter upon this inquiry, which is chiefly directed towards the inveftigation of a principle of Imitation, it will be proper to premife a few obfervations, on the mode in which the forms of nature have been introduced into: works of art ; a fubje@ which hitherto feems not to have met with the atten- tion it deferves. AtTuoucu the connexion between beauty and utility be ftill involved in fuch obfcurity, that we are unable to decide con- cerning the univerfality of that connexion, of one thing we are certain, that, in a work intended to anfwer fome ufeful purpofe, whatever vifibly counteracts that purpofe always occafions de- formity. Hence it is, that, even where ornament is principally intended, the oftenfibly ufeful object of the work, “if it have: any fuch, muft be provided for, in the firft mee: in preference to every other confideration. But, in moft ufeful works; fome parts. occur, the fhape of which is quite indifferent with refpect to the propoféd utility, and which, therefore, the artift is at liberty to execute as he plea-. fes; a liberty, which has opened a wide field to the tafte and invention of ingenious men of every age and country, who: have turned their attention to the compofition of ornaments; and whofe exertions have been more or lefs influenced by the ftate of civilization in which they lived. It would feem, however, if we may judge by thofe various efforts, that little has been effect- ed by mere human ingenuity ; fince we fee, that recourfe has been had, almoft univerfally, to Nature, the great and legitimate: fource of beauty; and that ornament has been attained, by the imitation. mination of the monuments of the art now in exiftence, and an application of our principles to every part of them. Tue prefent publication confifls of the introduétion to the whole Effay, together: with the elementary part, illuftrated by fix plates. SSS On GOTHIC ARCHITECTURE, “| imitation of objects, to which fhe has aan a determinate and characteriftic! form. Tuus, among the Greeks, in the period of their higheft re- finement, we find the: handles of vafes in the fhape of vine branches, or of ferpents: twifted round each other. Some urns of ancient Egyptian workmanfhip: terminate in the head of am owl. The heads of our fhips are decorated with figures of men and of animals; and the hatchets and canoes of -Nootka Sound are covered with rude i images of various natural objects. THE imitation, laisnisstenits in fuch _ differs from that in a _ ftatue or in a picture. In the one, the fole object is to reprefent fome natural object; whereas, in the other, the forms of -nature have been partially adopted, and modified in various ways, in order to fuit the ufeful deftination of the work. In this man- ner, artifts) of every age have been led to fele&, among the forms of a natural object, fuch as anfwered their purpofe, to the exclufion of the reft; and have exhibited modified imitations of nature, which, being juftified by the circumftances of the cafe, do not fuggeft the idea of mutilation. Thus we meet _ with the foot of a table executed like that of a lion, or the hilt of a {word like the head of an eagle, without afking what has become of the body of the animal, and without being ftruck with any impropriety in the omiffion. FREQUENTLY, ‘where the materials employed are themfelves pofleffed of variety and elegance, the objeét of ornament has been fufficiently attained, by allowing the natural forms, in whole or in part, to remain in the finifhed work. For inftance, cups are made of ‘hells, of cocoa nuts, or of oftrich eggs, the character and beauty of which depend upon the natural form of the materials. And in the cafe of the bottles, ufed by the Roman Catholic pilgrims, an example occurs of an utenfil, in which the 8 On GOTHIC ARCHITECTURE: the natural form has undergone little or no variation, fince it confifts of the hard outward fkin of a gourd, of the fame fhape in which it grew upon the plant*. Tuts laft clafs of forms has been introduced, by Imitation, into works compofed of fhapelefs materials. Thus we have fil- ver cups in the form of thofe made of fhells, and fruit-difhes of f{toneware in the form of bafkets. The ancient Peruvian va- fes of pottery are executed in exact imitation of gourds; a prac- tice which had probably fucceeded the ufe of gourds as bottles. In fuch cafes, the defect of real character in the object is fup- plied by a fi€titious one, which, in the hands of a man of genius, is often productive of the moft happy effects ; fince it enables him to confer upon his. work the merit of confiftency, and truth of character; qualities, which influence the mind of the fpec- tator as powerfully, when founded on fiction as on: reality. For we judge of fuch a work, as we do of a romance, in which we are {carcely lefs interefted than if we believed it to be. true. ; WE may now confider the application of thefe principles to every kind of ornamental architecture.. As ftone is not natu- rally poffeffed. of any peculiar fhape, and as the ufeful obje& — propofed, by ftructures formed: of it, may be accomplifhed in | various ways, very great latitude is left to the invention ‘of the artift. We fee, accordingly, that, in every country where much, refinement has. been. introduced, great pains have been beftowed, in ornamenting ftone buildings, with. figures repre- fenting various natural objects. It, would feem, that the la- utude has even been too great; for experience fhews, that’ the ) artift * Even in this cafe, however, the natural form undergoes a certain degree of modification, by the device employed to produce the neck of the bottle. The fruit, while {mall-and tender, is furrounded with a ftring, which-remaining during. its, growth, prevents the part, thus bound, from {welling with the reft. . ¥ 2 >. Oa GOTHIC ARCHITECTURE. 9 aruft has fucceeded beft, where his imagination has been cir- _ cumfcribed, and forced into a regular channel. For this purpofe, recourfe has frequently been had to the de- vice laft mentioned ; the building being executed in imitation of a ftructure, compofed of materials, which naturally poffefs a determinate and characteriftic form. Such was the method fol- lowed by the architeéts of ancient Greece, who conftructed tem- ples, and other public edifices, in imitation of a ruftic fabric, compofed of {quare beams, fupported upon round pofts or ftems of trees; and who derived the numerous ornaments of that beautiful ftyle, from circumftances which would naturally take place in fuch a ftructure*. Vou. IV. ; b A * Tuar they really did imitate a building of wood, is ftated, in the cleareft man- ner, in the work of Vitruvius, particularly in-his chapter, ‘* De Ornamentis Co- lumnarum.” He there fpeaks of archite€tural work in ftone or marble, as a re- prefentation, (zmago ), and ef the timber fabric asa reality, (7 veritate), as will appear by the following quotation. _ Trav, in Grecis operibus, nemo fub mutulo denticulos conftituit, non enim: poffunt fubtus cantherios afferes effe. Quod ergo fupra cantherios et templa in ve- ritate debeét efle collocatum, id in zmaginibus, fi infra conftitatum fuerit, mendofam habebit operis rationem. Etiamque antiqui non probaverunt neque inftituerunt in faftigiis mutulos, ‘aut denticulos fieri, fed puras coronas; ideo quod nec cantherti nee afferes contra faftigiorum frontes diftribuuntur, nec poffunt prominere, fed ad ftillicidia proclinati collocantur.. ‘¢ Ira quod non poteft in veritate fieri, id non putaverunt in imaginibus factum, poffe certam rationem habere. Omnia, enim, certa proprietate, et a veris nature deduGtis moribus, traduxerunt in operum perfectiones. Et ea probaverunt, quorum explicationes, in difputationibus, rationem poffunt habere veritatis.” In one refpeét, this paflage is extremely obfcure, but, in another view, it is fuffi- ciently clear to anfwer the prefent purpofe. The obfcurity arifes from the difficul- ty, or rather impoffibility, of difcovering the meaning of feveral of the technical terms employed, thefe being very rarely ufed by authors, and relating to a mode of building different from any now prattifed. But, whilft commentators differ as to the precife meaning of the words cantherius, affer, and templum, as ufed in this paffage, they all agree in confidering them as denoting parts of the timber frame of a roof. At the fame time, mutu/us and denticulus are well known terms of architecture, and appropriated 10 On GOTHIC ARCHITECTURE. A FarnT and diftant refemblance, however, of the original, has generally been found to anfwer all the end propofed by the imitation ; a refemblance, which may fometimes be traced in the general diftribution of the edifice, fometimes in its minute parts, and not unfrequently in both. But the forms of nature, thus introduced, have been greatly modified by thofe of mafonry. For though ftone is by nature fhapelefs, yet, in the courfe of practice, many peculiar forms have been long eftablifhed, and currently employed, in working it; fuch as ftraight lines, plain furfaces, f{quare angles, and va- rious mouldings ufed to foften the effet of abrupt termina- tions ; all of which, originating in motives of mechanical con- venience, and of fimple ornament, had, in very early times, been appropriated to mafonry, and confidered as effential in every finifhed work of {tone ; fo that, when the imitation of na- ture was introduced, thefe mafonic forms ftill maintained their ground, and, being blended with the forms of nature, the two clafles reciprocally modified each other. TuIs combination of art with nature, of which we fee the moft perfect example in the Corinthian capital, produces what are appropriated to buildings of ftone. The latter part, which relates to the principle of imitation in general, is fufficiently clear. The paflage, in Englith, is nearly as fol- lows : “ Tuus, in the works of the Greeks, denticles were never placed under a modil- lion, becanfe it is impoflible that the afferes can be under the cantherii. If, then, what is fituated over the cantherii and templa zz reality, be exhibited as under them in the émétatzon, the principle on which the work proceeds is belied. * Iw the fame manner, the ancients never approved of, or direéted, the introduc- tion of modillions or denticles in the frontifpiece, but preferred a plain cornice; for this reafon, that neither the cantherii nor afferes lie towards the gable, nor can they project beyond it, but are placed with an inclination to the guttur. “ Tuus, they efteemed it a departure from principle to exhibit, in an imitation, what could not occur in reality. For in finifhing their works, they introduced every ornament in an appropriated manner, and according to a real analogy borrowed from nature ; and they approved of nothing, which could not be theoretically ac- counted for, on the principle of its refemblance to truth.” On -GOTHIC ARCHITECTURE. It are called architeftonic forms, in which the variety of nature, being fubjected to the regularity of art, the work acquires that peculiar character, which, in a natural obje¢t, we confider as of- fenfive, under the name of FORMALITY ; but which, in archi- tecture, we admire as a beauty, under the name of sYMMETRY: thus, we reprobate the formality of an avenue, and praife the fymmetry of a colonnade. > Suc is the nature of architectonic imitation; a device, which probably originated in accident, but to which architecture is in- debted for its higheft attainments. I was firft led by Mr Byres, a very refpectable member of this Society, to obferve, among the remains of antiquity at Rome, many beautiful examples of the application of thefe principles by the ancients; and though my view of the fubject was then very obfcure, the theoretical folution of the queftion not having occurred till long after, I was fully aware of the very great practical advantages which they had derived from the em- ployment of the principle of imitation. _ Occurrep with this view of ancient art, as I was travelling through the weftern provinces of France, in my return from Italy, in the end of 1785, I was ftruck with the beauty of many Gothic edifices, which, far from appearing contemptible, after the mafterpieces of art I had feen in Italy and Sicily, now pleafed me more than ever. I was thus induced to believe, that thofe extenfive works, poffefled throughout of fo peculiar a character, and fo eminent for unity of ftyle, could not have been carried on, -unlefs the architeéts who built them, like thofe of ancient Greece, had been guided, in their execution, by fome peculiar principle; and being diffatisfied with all the theories of the art which I had heard of, I undertook the inveftigation, which has given rife to the following Effay *. : b2 CoNcEIVING | * AFTER ftating my own views at full length, 1 fhall enumerate and examine the various opinions of others on the fubject of Gothic architeture, no lefs than five in 12 On GOTHIC ARCHITECTURE. Conceivine that fome ruftic building, differing widely from the Grecian original, might have fuggefted the Gothic forms, I had made it my bufinefs to fearch for fuch a one, when the following accidental circumftance greatly affifted my {fpecula- tions. Ir happened that the peafants of the country through which I was travelling were then employed in colleGting and carrying home the long rods or poles which they make ufe of to fupport their vines, or to {plit into hoops ; and thefe were to be feen, in every village, ftanding in bundles, or waving, partly loofe, upon carts. It occurred to me, that a ruftic dwelling might be conftructed of fuch rods, bearing a refemblance to works of Gothic archite@ture, and from which the peculiar forms of that ftyle might have been derived +. This conjeéture was at firft employed to account for the main parts of the ftructure, and for its general appearance only; but after an inveftigation carried on, at different intervals, during the courfe of thefe eleven years, with the affiftance of fome friends, both in the collection of ma- terials, and in the folution of difficulties, I have been enabled to in number. At the time here alluded to, I was acquainted with an opinion, which I have fince found to have originated with Dr Warzurron, that the Gothic ftyle was copied from an alley of trees, I was aware of the advantages of this theory in fome effential points, yet it always appeared to me unfatisfaftory in many others; and I conceive it to be at beft far too vague to ferve as a guide ‘to the arrift. + Tuts refemblance, though very obvious in many cafes, has not, to my know- ledge, been obferved by any one but the late Mr Grose ; to whom it feems to have occurred ina tranfient way. He makes ufe of the fhape of a bower to aflift his de- fcription of a Gothic roof, (Antiquities of England and Wales, p. 75.) ; but he does not go fo far as to afcribe the architectonic forms to this origin ; a view, which pro- bably, would not have efcaped him, had he not been preoccupied with a different one; for he confiders the rudiments of a Gothic arch as formed ‘ of two flat {tones with their tops inclined to each other, and touching.” I did not meet with this paf- {age till feveral years after I had undertaken the prefent inquiry, and had carried it a confiderable length. On GOTHIC ARCHITECTURE. 13 to reduce even the moft intricate forms of this elaborate ftyle to the fame fimple origin. In the prefent ftate of the queftion, the following inquiry _ mutt be confidered as falling under the denomination of, what is called by Mr Stewart *, “ Theoretical Hiflory,’ and by fome French authors, “ Hi/foire raifonnée ; being an attempt to trace, _ by conjecture, the fteps through which an art has paffed, in attaining the ftate in which we obferve it. Indeed it is probable, that few inveftigations have been undertaken, which more com- pletely correfpond to that definition, fince, in ‘moft fubjects of this kind, many fteps of the progrefs are known, and nothing is required but to fill up, by theory, the interval between them; whereas, in the prefent cafe, as all direct teftimony is wanting, and as.no fteps of the actual progrefs of the art have come to our knowledge, our opinions on the fubject, hitherto, can only amount to prefumptions, founded upon the correfpon- dence of the theory with the monuments of the art now in ex- iftence ; and, the more numerous and complicated the cafes are, in which this coincidence takes place, the greater probability there is in favour of the fyftem. But, though fuch be the adtual fituation of the inquiry, we may hope to fee it, hereafter, affume a different form; for, fhould the conjecture, brought forward in the following Effay, carry with it fufficient plaufibility to excite a fpirit of refearch among perfons beft qualified to purfue the fubject, there is rea- fon to expect, that difcoveries may be made, of a literary or ar- chiteCtural nature, by which its truth or falfehood will be efta- blifhed beyond difpute. Wuart has juft been faid will, it is hoped, ferve as my apo- _ logy for having advanced a fyftem, which, ftrictly fpeaking, is founded on conjecture alone; and, on the other hand, for having enumerated a multitude of particulars, many of which might ’ * BrocRapuicaL Account of Mr Smitn. 14 On GOTHIC ARCHITECTURE. might juftly be confidered as fuperfluous, were the theory fup- ported by direct teftimony. OF THE ELEMENTS OF GOTHIC ARCHITECTURE. Wuen we enter a Gothic church, our attention is firft at- tracted by a double row of cluftered pillars, compofed of an af- femblage of, long and flender fhafts, which, reaching from the ground nearly to the fummit, there feparate and f{pread in all di- rections, forming the ribs or groins (as they are called) of a vaulted roof. In the meeting of thefe groins, and in the win- dows of the fides and ends, we fee the form of the pointed arch, the principal characteriftic of Gothic architecture. Sucu buildings have, I conceive, been executed in imitation of a ruftic dwelling, conftructed in the following manner : Suppose a fet of round pofts, (PI. I. fig. 1. & 5.), driven firmly into the ground in two oppofite rows, the interval between the neighbouring pofts in the fame row being equal to that between the rows, and each poft being raifed above the ground to a height equal to three of thofe intervals. THEN a fet of long and flexible rods of willow, being ap- plied to each poft, (fig. 2. & 6.), let them be thruft into the ground at its bafe, and bound to it by two tyings, one near the ground, and another at two-thirds of its height; the rods being left loofe, from this laft point upwards, and free to be moved in any direction. Let three rods be connected with each outfide corner poft, (as A or H of the ground-plan fig. 6.), and five with each On GOTHIC ARCHITECTURE. 15 each of the others, (as B or G), and let their pofition be fuch as to cover the infide of the poft, (as marked by little circles in ‘ fig. 6.}, fo that, when feen from between the rows, the lower part of each poft fhall be concealed from the view, and prefent the appearance of a bundle of rods, (fig. 2.). Tunes being thus difpofed, the fkeleton of a thatched roof may be formed, by means of the loofe ends of the rods. This is reprefented complete in Plate II. figure 15. & 46.; but the ftructure being rendered intricate, by the mixture of different fets of forms, I have, for the fake of diftinctnefs, defcribed each of them feparately, and have reprefented them by feparate draw- ings, with each of which a ground-plan is connected. A rop from one of the pofts, being fo bent as to meet a fimi- lar one from the poft immediately oppofite to it, in the middle of the {pace between them, let the two rods be made to crofs each other, and iet them be bound together at their crofling, (Pl. I. fig. 3.). Thus-will be produced the exact form of the. Gothic arch. The fame being done with each pair of op- pofite pofts, and a fet of pointed arches being formed, let them be connected together by means of a ftraight pole, laid upon the forks of the crofling-rods, and bound to each of them, (fig. 7. & 11.). : THEN let a loofe rod be brought from each of any two con- tiguous pofts inthe fame row, fo as to form a pointed arch, fi- milar to that juft defcribed, and nearly of the fame height. This being done with every two contiguous pofts, (fig. 8- & 12.), and a new fet of pointed arches being thus produced, ftanding op- pofite to each other in pairs, let each pair be bound by a hori- zontal pole lying on the oppofite forks, and crofling the lon- gitudinal pole, defcribed above. Two of the reds of each corner poft, and three of thofe of each of the others, being thus difpofed of, we have one of each corner poft, and two of each middle .poft {till to em- ploy ; 16 On GOTHIC ARCHITECTURE. ploy; which is done as follows: A pair of thefe unoccupied rods being brought from any two pofts which: {tand diagonally to each other, (A and F, fig. 6.), and made to meet in the middle, not as in the firft cafe, crofling in an angle, but fide by fide, forming a femicircle, and joined together after the manner of a hoop, (fig. 4.) ; and the fame being done with every pair of dia- gonal pofts, (fig. 9. & 13.), the whole rods will have been employ- ed. Eacu of the three fets of arches having thus been feparately defcribed, (fig. 7, 8, & 9,), the complete ftructure, in which they are all combined, may eafily be underftood, (Pl. I. fig. ro. and 14., and Pl. Il. fig. 15, & 16.). In this manner a frame would be conftructed, fit to fupport thatch or other covering, and fuch a one has probably been often ufed. It would feem, however, that, for the fake of {trength, the number of rods has been increafed in each clufter, by the introduction, between every two of them, of an additional rod, which, rifing with them to the roof, {till continues its middle pofi- tion, as they {pread afunder, and meets the horizontal pole at an intermediate point. This is fhown in Plate III. figure 19, which is drawn with its covering of thatch; and the fame is ex-. prefled in the correfponding ground-plan, figure 20. From the imitation of a dwelling, fo conftructed, we may now trace the three leading characteriftics of Gothic Architec-— ture, the pointed arch, the cluftered column, and the branching roof, (Pl. Il. fig. 17, & 18., and Pl. III. fig. 21, & 22.) *. i : THE * Iw buildings of ftone, the arch or groin, which joins the diagonal piers, is very generally a real femicircle, fike that in the willow ftruéture juft defcribed; as I have found to be accurately the cafe at Beverley and Melrofe. This rule of execu- tion, with the deviations from it, which we meet with occafionally, will be fully confidered in a fubfequent part of the Effay; in which it will be fhown, that in thé ufaal roof, where the diagonal groin is a femicircle, it becomes the regulator of all the reft, determining their height and form in every refpett, — OO ee ee at 3 On GOTHIC ARCHITECTURE. 17 THE ruftic fabric might thus be covered completely, but would not be habitable, unlefs the openings of the fides and ends were clofed, {0 as to refift the weather. This might eafily be accomplifhed, by means of bafket-work, covered, as is. {till practifed in many countries, with a mixture of clay and ftraw. In order to furnifh ribs for the bafket-work, a fet of upright rods would be thruft into the ground below, and bound to the arch above, dividing the opening into fpaces reach- ing from top to bottom, (Pl. IV. fig. 2 3-), which, being filled up with twigs wattled through them, would be entirely clofed, (fig. 24.), and the work would be tolerably ftrong. It might however be thought advifeable, for the fake of greater f{trength, to fplit all the upright rods, down to the level of the points at which the main rods of the opening feparate from their re{pec- tive pofts ; or, to borrow a term from architecture, down to the level of the impofts of the arch ; and then to carry the half rods, fo fplit, acrofs the reft, in fuch a manner as to afford the opportunity of repeatedly binding them to each other, (fig. 25.), Bur were the {paces all fhut in this manner, the houfe would be rendered abfolutely dark. It would therefore be neceflary to provide for the admiffion of light, which might be done, without materially weakening the ftructure, by omitting fome of the wattled work in the middle, fo as to leave part of the ribs open and bare, (fig. 2 Igy THESE naked ribs feem to have fuggefted the forms of the flender bars of ftone, called Mullions, which conftitute the frame- work of the glafs, in’ all Gothic windows ; the moft common example of which may be feen in (fig. 27.) THE window, in the fabric of ftone, as well as in that of wil. low, being very con{picuous, would naturally become an obje@ of attention in point of beauty. Accordingly we find, that, in the compofition of Gothic edifices, much pains have been beftowed in ornamenting the windows, by the introduction Vou. IV, C : of 18 On GOTHIC ARCHITECTURE, of a number of figures, which are often extremely elegant, and fometimes furprifingly complicated, though without confufion; for they can all be traced to fome variety or modification of the fimple elements juft laid down; as will be fhown, when we treat of the more complicated works of Gothic ar- chite@ture ; at prefent, it is neceflary to mention only one other defign. a In this window, (fig. 26.), the halves of the neighbouring rods are brought to meet, but not to crofs, and are bound together fo as to touch each other, back to back ; next, the halves of each rod being brought together again, they are bound face to face; then again feparated, and bound a fecond time back to back, with the halves of the neighbouring rods; and fo on, till the whole fpace is filled with a fet of regular and equal compartments, bounded by waving lines, (fig. 26. & 29.). Tue form of the Gothic door may be traced to an origin fi- milar to that of the laft mentioned window. One pair of rods, (fig. 31.), being brought from the pofts which form the upright fides of the door, are made to meet in a pointed arch, in the manner defcribed above; then, another pair of rods, longer than the firft, and connected with the fame pofts, are brought to meet above them, and are bound together face to face, like the half rods in the laft mentioned window; the {pace between the two pairs of rods being occupied by a circu- lar hoop. Tue reprefentation of the upper pair of rods, when drefled with fome fmall ornaments, as in many Gothic buildings, pro- duces a moft elegant effet. Figure 33. is a door of St Mary’s, Beverley, reduced from a drawing taken on the fpot, at my defire, by Mr J. HALFrEenny. Tue form of the fteeple, however various and apparently dif- ferent from what has hitherto been mentioned, can eafily be re- duced oe | (See pd ry a re, eae te cy a, a On GOTHIC ARCHITECTURE, 19 _ duced to the fame principles. The common fteeple, or fharp pointed fpire, feems to have for its origin fimply eight long and ftraight poles thruft into the ground, one in each of the angles of an oétagon ; and fo inclined, that they all meet in a point, directly over the centre of the bafe, and raifed above it four or five of its diameters, the rods, thus placed, forming together a very acute octagonal pyramid, (fig. 34.). The original object of a ftructure of this kind would probably be mere ornament, as it is not calculated to anfwer any purpofe we know of, un- lefs it were to fapport a bell. Perhaps the firft works of this _ kind, even thofe executed in ftone, were placed upon the ground; but asa fpire is feen to beft advantage from a diftance, an ar- chiteét would naturally think of raifing i it in the air, by placing it on the fummit of a tower; which is the cafe sie all the {pires of this kind Ihave feen. Figure 35. is a view of the {pire of Tuxford in Nottinghamshire. _ Besrpes the re¢tilineal {pire, we fometimes meet with others of a curved form, which may be accounted for in a manner no lefs fatisfattory, as fhall be fhewn in a fubfequent part of this Eiey _ Havine now taken a view of all thofe parts of Gothic ar- chite@ure, which conftitute its folid mafs, it remains, in order to complete the elements of the art, that we confider two fets of fmall, ornaments, which very often occur, and which, though not red neceflary in theory, nor univerfally obferved in practice, arife naturally, from) the principles already laid down, and contri- bute very, much, to. give to Gothic architeCture that peculiar j a? appearance by. which. it is diftinguifhed. Both thefe orna- ments; maybe traced to. the effeds of time upon the mate- rials employed, in the conftruction of our ruftic fabric ; one fet being connected, swith the vegetation of the rods, and the other with their death and confequent decay. 2, As 20 On GOTHIC ARCHITECTURE. As it would frequently happen, that the willow rods, thruft into the ground, would ftrike root and grow, the architect feems to have taken advantage of this circumftance, by reprefenting them as decorated with buds and tufts of leaves, whenever he thought that fuch ornaments could be introduced with good ef- fect. Tuts practice has been very generally followed in the execu- tion of the door, as in that exhibited in figure 33. the upper part of which is a reprefentation of living rods, covered with tufts of leaves, like thofe in actual vegetation, (fig. 32.). Upon the fpire, too, a fet of {mall projections, placed at regular intervals, often occur, as in that of Bunny, in Nottinghamfhire, (fig. 37.), which feem to be the reprefentation of buds fpringing from the poles of the original, (fig. 36.). TueEse ornaments, known by the name of Crockets, when placed on the floping part of doors, fteeples, pinnacles, &c. and of Finials, where they form a tuft on their fummit, univerfally and unequivocally reprefent foliage. The leaves, it muft be owned, however, feldom refemble thofe of trees, but more com- monly fome plant of the cabbage kind. On this occafion, the artift has ufed the freedom to deviate from the ftrictnefs of the imitation, and has contented himfelf with adhering to the gene ral idea of foliage. But, in fo doing, he has been in a great meafure juftified by the circumftances of the cafe; for the fo- liage of a tree, efpecially that of the willow, being compofed of a multitude of fmall and detached parts, could not, without much difficulty, be executed in ftone, and would produce a very frail and perifhable work, which could only be placed with ad- vantage in very protected fituations. He has thus been indu- ced, in moft cafes, to choofe fome plant having a maffy and compact form, better adapted to fculpture. This however is not without exception, as we do meet fometimes with croc- kets On GOTHIC ARCHITECTURE. ae kets formed of the leaves of various trees, efpecially of thofe of the vine ; as may be feen in York-Minfter in feveral places; par- ticularly in that very interefting collection of pediments and pinnacles, furrounding the infide of the nave and its aifles. Thefe are executed with amazing delicacy and elegance, and with fuch fertility of invention, that, though eighty-eight in number, not only every two of the pediments, but every two crockets on the fame pediment, differ from each other *, ‘Upon * One of thefe pediments, with its pinnacles, crockets, and finials, executed on a large fcale, may be feen in that beautiful colleétion of the ornaments of York-Minfter, now publifhing in numbers by Mr HatFrenny: in which work, likewife, are many other things applicable to the prefent fubje&. I am happy to have it in my power to bear teftimony to the faithful accuracy with which the objetts are there reprefented, from having examined feveral of the originals in that view, in the courfe of laft fum- mer, (1796), particularly that of Plate XLI, of which I made a drawing myéfelf, in company with Mr Hatrrenny; fo that I can vouch for its exaétnefs in every tefpe&t. Ihave been induced thus particularly to mention the fubje@, by a fufpi- _ cion mentioned in Mr Hatrrenny’s feventh number, concerning the accuracy of his drawings ; fome gentlemen having imagined, that he had placed the fculpture in too advantageous a light. To this he anfwered, that “in truth he has not been able, “ in many inftances, to come up to the fpirit and elegance of the originals.” A de- claration no lefs true than it is modeft. Iam well convinced that the gentlemen, with whom this fufpicion has originated, have not been much accuftomed to exa- _ mine our Gothic buildings of eminence, fince, in any of thefe, they would have met with numberlefs works, executed in too high a ftyle of defign to admit of embellifh- ment in the prefent ftate of the arts. Nor is it wonderful that fuch fhould be the cafe, when we reflect, that they belong to the 14th and 15th centuries; during which, a feries of artifts flourifhed in Italy, who, in point of chafte defign, and care- ful imitation of nature, have never fince been equalled, though they had not attain- ed to many of the refinements which were introduced in the fubfequent age. Thefe artifts travelling over Europe, contributed greatly to the ornament of the Gothic edi- fices which were then building, as we learn from many curious fads collected by Lord OrrorD, in his Anecdotes of Painters. I sHALL enter more fully into this fubject, when I {peak of the Hiftory of Gothic Architeéture ; and I am led to touch upon it now, though out of place, in order ‘to call the attention of men of tafte to the fate of numberlefs beautiful ornaments of the a2 On GOTHIC ARCHITECTURE. Uron the monument of King Joun I. and Queen PaitipPa, in the church of Batalha, are two canopies of frittered-work, conftruéted in a manner which I fhall endeavour to explain in a fubfequent part of this Eflay. The lower part of each of them confifts of an arch of contrary flexure, like that of the door of St Mary’s, Beverley, (fig. 33.), but ornamented in a manner fomewhat different, having, in place of the crockets, a fet of leaves, in form and arrangement, greatly refembling thofe of. the willow *. WHOEVER the Gothic ftyle, which are daily perifhing by the exertions of a miftaken zeal in their favour. Every year, great fums are beftowed in dreffing up the old churches, in many parts of England, much to the detriment of thefe noble edifices. In fome cafes, this is done by befmearing the building with white or yellow paint, which chokes and confounds all the delicacy and elegance of the fculpture. This evil, however, is not of the deepeft kind; fince, here, the original forms of the work remain entire, and may be again reftored to their purity, when a better tafte prevails. But an in- jury of a much more ferious nature is occafioned by the operation of chipping, in which the mafon, with a barbarous hand, actually goes over the whole work, and chifels off the furface to a certain depth, leaving but a poor fhadow of the original form. By both operations, the building acquires the harfh and glaring appearance of new work; which, however, is removed in a few years, by the influence of the weather, and the edifice recovers its former grandeur, as far as colour is concerned. But the havock committed by chipping is quite irreparable; for the feulpture, when once removed, can'return no more. I dave been told, in vindication of this Sect that the forms of the old work were reftored exactly as they originally ftood. An idea. worthy of the fimplicity of Mummivs the Roman general, who demolifhed Corinth. As if it were in the power of every ftone-cutter to replace a mafter-piece of the rs5th century ! ; I was happy to find, at York, that a. different fpirit prevailed in the operations carrying on in the Minfter. In all thefe repairs, the ancient feulpture has been moft fcrupuloully refpetted ; and, in many places, the ftone has been carefully freed from, its load of paint, fo as to reftore it to its original purity. For thefe attentions, the: public is greatly indebted to the good tafte and judgment of the Rey. Mr Eyre, one of the refidentiaries. * Sez Mr Morpny’s admirable ‘publication; 2 work to which I fhall have very often occafion to refer, when I {peak of the more complicated forms of Gothic architecture. cacti atti a et On GOTHIC ARCHITECTURE. 23 WHOEVER pays any attention to Gothic architeture, mutt obferve, in the upper part of moft windows, an ornament pro- jecting from the bars, formed by two curved lines meeting in a point. It would be difficult to defcribe this form in words, but it may be underftood eafily by figures 27, & 28. of Plate IV. which reprefent two contiguous windows of St Mary’s, Bever- ley ; in one of which the bars have been executed plain, and in, the other they have been ornamented in this manner. Figure 30. is the window that lately ftood in the chapel of Holyroodhoufe at Edinburgh, and figure 29. the fame general form executed quite plain, as it fometimes occurs. As this ornament has not, that I know of, been charaéterifed by any peculiar name, I fhall apply to it that of cu/p, by which mathematicians denote a fic gure of the fame kind *. Bee Tr was long before any fatisfa@tory explanation of this form occurred, though the frequency of its appearance, and the uni- form manner in which it is introduced in all Gothic works, deft little room to doubt that it had an origin, in common with the more fubftantial forms of the ftyle. At laft a friend fug- gefted to me, that it may have been borrowed from the appear- ance affumed by the bark of the rods, when about to fall off, in confequence of decay. With this view, having attended particularly to branches in a fimilar fituation, I have met with feveral facts, which tend to confirm this conjecture. The dead branches: of every kind of ‘tree, after being expofed to the weather during three or four years, throw off their bark, which, immediately before it drops, curls into various fhapes, = owing _ * AssemBraces of thefe cufps are {poken of in the defcriptions of Gothic works, by the names:of trefoil, quadrefoil, femi-trefoil, &c: but no proper word has been ufed to defcribe the form, wherever it occurs, or however combined. This, 1 truft, will fufficiently apologife for the liberty I have taken, of introducing a new term into architeture. ; A\n application of the word cufp, as ufed by mathematicians, may be feen in Dr Smitu’s Optics, Vol. I. P. 172. where he ufes it in defcribing the cauitics formed by reflection. — a 24 On GOTHIC ARCHITECTURE, owing to the unequal contraction of its different layers. This takes place varioufly in different woods ; in fome, the bark bends inwards, in fome outwards, in fome acrofs the branch, and in fome lengthways. I have had occafion to obferve, that, univer- fally, the bark of the willow bends concave outwards, and length- ways with refpect to the branch. One of the firft diftind ex- amples I met with, of this kind, was on a rail at St Mary’s Ifle in Galloway, in the fummer of 1792, (Pl. V. fig. 38.). The rail had been made entirely of frefh willow, and the pofts had all ftruck root, having then the third year’s growth upon them; the hori- zontal bars had died of courfe, and were in the act of lofing their bark. This, in fome places, was feen feparated from the wood at one end, and adhering to it at the other, forming a gentle and continued curve with the mafs of bark, which ftill remained at- tached to the wood; fome pieces of bark, a few inches im length, had feparated at both ends, and remained adhering only by the middle ; in fome places two contiguous pieces of rifing bark met, and exhibited a fhape very much refembling that of the cufped ornament which I have juft defcribed. In the fummer of 1795, I faw, at the fame place, a ftill more f{triking example of this, upon an upright poft of willow, (fig. 40.), in which - the two pieces of curling bark formed, together, a cufp from nine inches to a foot in length. In a few days,'the under © piece of bark fell off; but the upper one remained for, more than a month, lying clofe to the wood during rain, and rifing from it when the weather was dry. — Figure 39. reprefents a large branch, which I cut from an old willow, having the curled bark-upon it, and which, being kept dry, ftill retains its fhape. ~ THERE is great reafon to fuppofe, that this accident has fug- gefted the cufped ornament : For if we fuppofe a window of the willow houfe, (fig. 41.), in the fame ftate of decay with the rails juft mentioned, to have come under the obfervation of an archi- tect -On GOTHIC ARCHITECTURE. 25 __ teét.of. genius, in the habit of borrowing all his ideas from a houfe of this kind, and eager to feize upon whatever con- ‘tributed to add. beauty or novelty to his work, it is natural to believe, that he would take advantage of the circumiftance, by imitating, in ftone, the curling bark; and this. being executed with that regular fymmetry, which architecture beftows. up- on the natural objects it reprefents, (fig. 42.), would produce a light and. elegant effect, and the ornament-would foon become general. We, know that to fuch accidents, the! architecture of the ~ Greeks was indebted for many of its pr incipal embellifhments ; of which the origin of the Corinthian cqapisal is a ftriking and _ authentic ‘ugreasene Sacrt that all the effential parts of Gothic architeAure could thus be explained, by tracing its origin to the imitation of a very, fimple ruftic edifice, I was defirous of fubmitting the theory to a kind of experimental teft, by endeavouring actually _ to conftruét aybuilding ;fuch.as has been defcribed. With the help. of a very ingenious country workman*, I began this in fpring 1792, and completed it, in the courfe of the winter fol- lowing, in a manner which far furpafled my expectation, and which has already met with the approbation of feveral Mem- bers of this Society. ;The method of con{truction anfwered fo - well in practice, that I doubt if a better could be followed, with -fuch fimple materials ; and fo primitive is the mode of execu- tion, that I believe, with a little ingenuity, the whole might be executed without the help of a {harp inftrument, or of any ma- terials but fuch as the woods afford. A set of pofts of afh, about three inches in diameter, were pla- _ced in two rows, four feet afunder, and at the interval of four Vou. IV. d feet: * Joun WHITE, cooper, in the village of Cockburnfpath, in Berwickhhire.. 26 On GOTHIC ARCHITECTURE. feet in the rows. Then a number of flender and tapering wil- low rods, ten feet in length, were applied to the pofts, and form- ed in the manner already defcribed, into a frame, which being covered with thatch, produced a very fubftantial roof, under which a perfon can walk with eafe * Tuts little ftruéture exhibits, in sinners, all the characte- riftic features of the Gothic ftyle. It is in the form of a Crofs, with a Nave, a Choir, and a north and fouth Tranfept. The thatch, being fo difpofed on the frame, as not to hide the rods of which it is compofed, they reprefent accurately the pointed and femicircular arclies, and all the other peculiarities of a groined roof. The door is copied from that of Beverley. The windows are occupied by a number of defigns, executed, (by means of fplit rods), in exact refemblance of thofe which actually occur in vari- ous Gothic edifices. Round each window is a border of compact wicker-work, which, by deepening the fhade, adds greatly to the general effect. At a little diftance ftands the {pire, formed of eight ftraight poles of willow planted in the earth, and ri- fing in an o@tagonal ‘pyramid to the height nearly of twenty feet. Various other Gothic forms are likewife introduced, which being of the more complicated kind, will be explained in a fub- fequent part of this Effay. THE appearance of the whole, whether feen from within or from without, bears, I flatter myfelf, no {mall refemblance to a cathedral. In the courfe of fpring and fummer 1793, a great number of the rods ftruck root, and throve well. Thofe of the door, in particular, * Tue roof, being proteéted from the weather, is ftill in perfe& prefervation, though it has now ftood about five years; but the windows and other parts, which are more expofed, are going faft to decay, though they have been often repaired. Soon after the work was finifhed, a very accurate drawing of it was made by an ingenious young artift, Mr A. Carsz, which it is propofed to engrave for the il- luftration of this Effay, when publifhed at full length. On GOTHIC ARCHITECTURE. 27 particular, produced tufts of leaves along the bent part, exactly -where they occur in f{tone-work; the vegetation did not however reach, as had been wifhed, to the very fummit, but was. more than fufficient to juftify an artift in the execution of doors like ‘that of Beverley, (fig. 33.). Three of the rods of the fteeple, alfo, fent out buds, at {mall intervals, to the height of eight . or ten feet from the ground, fo as, at one ftage of their growth, to refemble the budded {pire already defcribed. I HAVE likewife had the fatisfaction, in the courfe of laft au-. tumn, (1796), of finding one entire cufp formed by the bark in a ftate of decay, in a place correfponding exactly to thofe we fee executed in Gothic works. In this manner, all the original forms of . Gothic architeCture may be accounted for. But they feldom occur in the ftate of fimplicity, which, in order to facilitate their defcription, I have hitherto fuppofed ; for, in a Gothic edifice, they are for the moft part complicated by varieties in execution, and by inter- mixture with each other. They have been modified, likewife, and fometimes difguifed, by the circumftances attending the tranfition from wicker-work to mafonry, which have occafioned changes, both in the general defign of thefe works and in the execution of their minute details. I fhall endeavour to fhow, however, (in the work I have already announced), by an exa- mination of the actual monuments of the art, that the moft intricate of thefe forms may be traced to the fame fimple ori- ginal. But to accomplifh this, it will be neceffary previoufly to inveftigate the tranfition to Mafonry; an inquiry too exten- five to be comprifed within the limits of an academical memoir. “J ‘ 2 5 cs by 4 rae ye BP; ‘ ' ‘ : a . , "4 ¥ Se bt git *: > ee do'oaeht: vila ‘py Aa! sab aobldl 3 q0Ach, ach baiaizoops oil a Hpisiggh bas uopigbite aheapararied Bpaezilgaivo ghisbsae ‘eons ies ‘ave ed 2 hiaedso Bank sdacw toed yore sh Hipob, to st _ at NTF hi alee bolas oils, abgigen dts C30: a f, ak ya) po +o. Lee gt Be soe ad si Use ebug se sak Aaa . I]. |. woiidisisbarbedriemailiant , igabte ae ist: Snasyadt oitifie, didsoD> syai: “20 bioepitvein eine sia febg de dee be ent ewe = he ay f x #e eT s . ast he sae + ae SS pats > e > ee . i Wd ah _ Pur Trans, E ow: VotW. Lit Caps fojuce p. 28 Plate I ” Plate Il TL Beuge se ‘ ir Py Laws “sys Pa. “ x q - “ an ae ~ rS o hre ' ' * - Plate 1 ~ ES TER ATHMCRAES. oa cca rrr ao Ta "ays f AS) cn ae Syd - aye r Pe eld aay =i ay iC > x OE ese eter —\25n. te 4 = ‘es een Fast ee Hh ai Plate V Ti @10TY TT. aol, Po eee ee ———————————— ee : t ‘ ‘ . “4 = > “ ’ ’ é 1 v ; ' » ‘ + . a ¥ ‘ i a 4 { - ot - .? . a Clk’ . AY 4 9 q r= » - ‘ ¢ . ad : , > + re a eS hee : ; ¢ 76 4 . ? . A © 4 wae . ; eo . * ‘ < s ‘ ; < a) * ’ . s 4 , ‘ 1 * iy - at + ak >i > ‘ . F . I. M. CHEVALIER’S TABLEAU de Ja PLaine de TROYE i/- luftrated and confirmed, from the OsseRv ations of /ub/e- quent TRAVELLERS, and others. By ANDREW DALZEL, M. A. F.R.S. Epin. Profeffor of Greek, and Secretary and Librarian in the Univerfity of Edinburgh. [Read Sept. 4. 1797.] “A S the Members of this Society afforded to M. CHEVALIER d an early and warm encouragement and patronage, and readily gave his Tableau ‘de la ‘Plaine de Troye a place in their Tranfactions*, aswell) as admitted the author to a feat among their number ; and as that paper, fince the time of its publica- tion, has excited a good deal of intereft and fpeculation, they will, no doubt, hear with pleafure, that it has now received, at leaft in all its material circumftances, a moft ample and fatisfac- tory confirmation. | Tue author, previous to his departure from England, in May 1796, had exprefled an anxious:defire that a fecond edition of the Englifh verfion of ‘his Effay fhould be publifhed, improved from fome materials I had colle€ted, and by fuch amendinents as he fhould communicate. But as this could not be done, without See Vol. III. Lit.-Cl. p. 1, &c. 30 TABLEAU de la PLAINE de TROLE without a new arrangement with the bookfellers, and as an ob- ftacle occurred which rendered a delay neceflary, I have thought that it would, in the mean time, be agreeable to’ the Society to have a fhort Abftract of the moft material contents of the Eflay, as now confirmed by fubfequent travellers, laid before them, preceded by an account of the manner of its firft reception, of the comnmunications of thofe travellers, and of certain objec- tions that have been made to it; and followed by an Appendix, containing the papers and letters referred to in the foregoing detail. Account of the Reception which the Defcription of the Plain of Troy at firft met with. M. Cusvatier, after his return from the Eaft, and before he came to Edinburgh, vifited Paris, where he found the late M. PAbbé BartrueLemy, author of the Travels of the Young Anachar- Jis, to whom he gave fome account of his excurfions into the Troad. That celebrated and ref{pectable {cholar was fo much plea-. fed with the light he received, on this occafion, concerning that famous claflical region, that he introduced M. CHEVALIER to a party of his friends by the title of /e Reffaurateur de la Troade : and it is probable that, if he had been favoured with M. CuEva- LIER’s information previous to the publication of his great work,, he would have embellifhed his book with a more fatisfactory de-. {cription of the Troad, than he found him{elf able to.do from the imperfect and inaccurate accounts formerly given of it, In the year 1792, when the Differtation. in queftion, which. the author had read in French before this Society, was publifh- ed in the Englifh tranflation of it, which, at his own defire, and. with the approbation of the Council of the Society, I had made, it feemed to give great fatisfaction to claffical readers in gene- ral. ILLUSTRATED. and CONFIRMED. 31 ral. In Germany, even before it was publifhed, it had found a warm fupporter in the celebrated Profeflor HEyNE of Gottin- gen, with whom the author became acquainted, in a tour he made in that country, foon after he had read the original of his ‘paper in the meetings of this Society. Having no copy along with him, when he went into Germany, he endeavoured to give Mr Heyne an idea of his refearches in the Troad, as diftin@ly as he could from recolleétion, aided by fome travelling journals which he had retained in his cuftody. He found the fubject extremely interefting to Mr Heyne, whofe attention had been for fome time particularly turned to the poems of Homer, of which he had projected a new edition upon the plan of his Vir- gil, fo favourably received by the Public. At the united defire of the author and Mr Heyne, with the approbation of the Council of this Society, I firfttranfmitted a printed copy of the tranflation, with notes, to Gottingen, before the work could be publifhed here, and afterwards a copy of the maps, immediately upon their being finifhed by the engraver. Mr Hexyne was highly gratified with M. CHevacrer’s dif coveries, and pleafed with what he confidered as the very liberal manner in which they had been conveyed to him. That his countrymen might partake of the fatisfaCtion he had received, he employed Mr DorNEDDAN, a young promifing {cholar, to tranflate into German the De/cription of the Plain of Troy from the Englifh verfion. The greateft part of the notes, which I had fubjoined, were alfo tranflated by the fame ingenious {cho- lar ; a preface and further illuftrations by Mr Heyne_ himéfelf, with an Effay on the Topography of the Iliad, and a Differtation by Mr Kastner on the Height and Shadow of Mount Athos, were added ; and the whole publifhed in Germany in an oc- tavo volume, almoft as foon as the Englifh verfion, with notes, appeared in England*. It * See Appendix, No. I. 32 TABLEAU de la PLAIN de TROY It had been perufed alfo, before publication, by feveral gen- tlemen of learning and tafte in this place, who had defired to fee it; fome of whom expreffed their fatisfaGtion in converfation, and others in writing: and, after publication, I received letters from feveral eminent claflical fcholars in England, by whom M. Cuevattier’s labours were highly approved of. . Some of thefe teftimonies I have hae to preferve*, Bur though M. Cuevatier’s refearches, thus given to the public in Englifh and in German, and afterwards in the French original in the third volume of the Tranfactions of this So- ciety, were received in the moft favourable manner: by claflical {cholars in general; yet fome, who had long before acquiefted in the account of the prefent appearance of this claflical region given by the late Mr Woop, could not conceive how that: inge- nious obferver fhould have’ gone ‘fo ‘completely aftray on the’ ground as had been alleged ; and were difpofed to think, that an enthufiaftic admiration of Homer, common to M. CHEV A- LIER with many perfons of fenfibility and tafte, might have prefented to his fancy circumftances, and fcenes and’ appear- ances, of which a cool and unbiafled examiner might not have perceived the reality. Of the Communications of fubfequent Travellers, and of certain Ob- jections that have been made. I nap reafon, therefore, to confider it as a fortunate circum- ftance, that, towards the end of the year 1793, Mr RoBerT Liston, my own moft.intimate friend. ever fince a very. early period * In acard from Mr Home, author of Douglas, &c. (who ftill takes great delight in ftudying his favourite poet Homer, particularly the Odyfley), I find the follow- ing expreffion: ‘“ I have read over your tranflation of M. CuEvauier’s Difcourfe, “‘ which is the moft fatisfactory inveftigation and criticifm I ever read.” See Ap- pendix, No. IV. ILLUSTRATED and CONFIRMED. 33 period of life, was, after being employed in various honourable public miffions, appointed by his Majefty Ambaflador to the Su- blime Porte. Having the pleafure of meeting with him previous to his departure for Conftantinople, I requefted that he would en- deavour to find an opportunity of paying a vifit to the Troad, with M. CHEVALIER’S book in his hand. This I found to be al- ready his own inclination, as he ftill retained a fondnefs for claf- fical learning, in which he had greatly diftinguifhed himfelf, when a ftudent formerly at this Univerfity. I only regretted that my own fituation rendered it impracticable for me to accept of a moft kind and tempting invitation to be the companion of his voy- age. In the courfe of our correfpondence, after he had been fome time at Conftantinople, I had the {fatisfaction to receive from him a fhort letter, inclofing two others from Dr SisTHorPE and Mr Hawkins, written immediately after an excurfion they had made to the plain of Troy, and confirming the principal circumftances of M. Curva ier’s-difcoveries. He afterwards tranfmitted extracts from another letter of Mr Hawkins rela- tive to the fame fubject, to all of which I fhall have occafion to neferi*. In the beginning of laft year Mr Bryant publithed his OJ- JServations upon a Treatife entitled, A Defcription of the Plain of Troy, by M. CHEVALIER, of which he did me the honour to fend me a copy, accompanied with a letter. It appeared that this ~ learned gentleman had, antecedently to the publication of M. CueEvaLrer’s Effay, been engaged in the compofition of a Di/- Jertation concerning the War of Troy, and the Expedition of the Gre- cians, as defcribed by Homer, fhewing that no fuch Expedition was ever undertaken, and that no fuch City of Phrygia exifted: but finding that the new Defeription of the Plain of Troy, by gaining credit in the world, might be likely to prevent the fuccefs of his learned labours, he deemed it advifable to employ his ta- Vor. IV. e lents *See Appendix, No. V. 34. TABLEAU de laPLAINE de TROYE lents in-an attempt to invalidate and remove this obf{truction, in order to pave the way for his Di//ertation ; which now at length has likewife made its appearance, and of which I have alfo re- ceived a copy from the learned author. I am now ready to admit (as, in a fhort correfpondence with Mr Bryant, on the firft glance of the former of thefe produc- tions, I promifed to do, if afterwards, upon a careful perufal of that pamphlet, I fhould fee good caufe), that he has difcovered what now appear to me to be inaccuracies and inadvertencies m feveral parts of M. CHEVALIER’s performance, and fome errors in the notes which I had written. For, wpon topics and inveiti- gations, where hypothefis muft fometimes take place, and where arguments may not always be conclufive, it is not to be wonder- ed at if a perfon of Mr Bryant’s learning and fagacity fhould have detected a few improprieties and inaccuracies. But after a careful perufal, which I have now given both tohis Od/erwations, and his Difertation, | cannot bring myfelf to go along with him inv his views of this fubje@t; nor can I be perfuaded, by any thing Mr Bryant has written, to give up the pleafure received from remarking the ftriking fimilarity between thofe fcenes, which ftill exift, and the defcriptions ‘which occur in the poems of Homer. ‘This fimilarity has been traced by Mr Heywe, in a moft convincing manner, in his Effay on the Topography of the Iliad 3 a valuable piece of inveftigation, which of itfelf appears to me completely to refute all Mr Bryawt’s radical objeGtions to M. Cuevarier’s Eflay*. I fhall therefore decline following the learned gentleman through the minute parts of his elaborate performances, which indeed I want time as well as inclination to do: but fhall content myfelf with introducing a few remarks upon his Od/ervations. I moft readily refign every attempt at framing an anfwer to his Differtation ; as I find he has met with two antagonifts much better qualified to enter the lifts with him * See Appendix, No. III. ILLUSTRATED and CONFIRMED. 35 him than I.am, the acute and ingenious Mr WaKEFIELD *, and ‘a learned anonymous reviewer in the Briti/h Critic +. Mr Liston being to return from his embafly at the Porte, towards the conclufion of the year 1795, 1 was glad to find, by a fhort letter, that he himfelf had made an excurfion to the Troad; and underftanding that a new edition of M. CuEva- LIER’S Effay was projected, he defired it might be deferred till he fhould come. home, as he had fome obfervations to commu- nicate which would render the work more perfect. When I met with him at Edimburgh he was yery much hurried, owing to his being under the neceflity of fetting off foon for America, as his Majefty’s Plenipotentiary to the United States. He never- - thelefs devoted a few hours to the revifal of M. CuEVALIER’s Effay, whilft I fat by him and took notes of his remarks. As a great many of thefe confifted of fmall alterations of various parts of M, Cuevarigr’s defcriptions, with a view to condenfe them where they feemed too diffufe, and to correct them where they feemed inaccurate, it would be tedious at prefent to enter into a particular detail. But, in the cafe of a new edition of the Effay, I am perfuaded that they would be extremely ufeful. It may be fufficient, here in this Introduction, to fay in gene- ral, that Mr Liston confirmed, from his own infpedtion, all the great points of M. CugvaLizr’s refearches and difcoveries, af- ter {pending many hours in walking oyer the ground. He faw the fuppofed fite of Ancient Troy, the fources of the Scamander, and the place where that river is now diverted into its new channel. In fhort, I found that Mr Liston, along with a great defire to render every thing as exact and accurate as poflible, had alfo caught that fort of intereft in the fubject, which is fo e2 natural _ ™ See “ A Letter to Jacoz Bryant, Efg; concetning his Differtation on the “War of Troy: by GinBert WaKkEFIELD, B. A. Lond. 1797. 26 pp. 4to. + For May and June 1797, vol. ix. 36 TABLEAU de la PLAINE de TROYE natural to a claffical mind, when engaged in furveying or de- {cribing fuch pleafing fcenes. In fome parts of M. CnEvALIER’s map, alfo, he found fome inaccuracies, which he was enabled to rectify, both from his own obfervation, and from another map with which he had been furnifhed. This laft he expeéted to be fent after him from Conftantinople, and intended it fhould contribute to the improvement of M. CHEVALIER’s in the new edition of the Effay*. Of all this I apprized M. Cuevatier, in a letter diret- ed to him in London, which found him about to fet off for the Continent. Previous to his departure, I received from him two letters in anfwer; extracts from which will be found in the Ap- pendix }. BuT one of the chief inducements for bringing the fubject before the Society at this time, is the recent publication of a very ingenious work, entitled, Con/fantinople, Ancient and Mo- dern, with Excurfions to the Shores and Iflands of the Archipelago, and to the Troad. By James Dattaway, M.B. F.S. A. late Chaplain and Phyfician of the Britifo Embaffy to the Porte. This learned author has been at great pains in afcertaining the: topo- graphy of the Troad; and the refult of his inveftigations there has produced the fulleft confirmation of all the material parts of " M. Cuevarrer’s Effay, and a total but refpectful diffent on the part of the author from Mr Bryanv’s fcepticifm on this fub- ject. To this book, therefore, I fhall, in the aoe paper, have frequent occafion to appeal. ABSTRACT * Tus map I have never received, owing to fome omiffion which I cannot ex- plain. In the mean time, this paper is accompanied with a fiall one, fomewhat amended, chiefly from that given by Dr Datiaway, the author of the book pre- fently to be mentioned. + No. VI. OWT Yo 41/19 site WTAE, Trans. R.S. Edin. to tace page 7 Lit. Cl. © tee Kewy an ez Mi ? s= | Hectoris Tian. Sm, le of = allo HELLESPONT ay | Olympic stadia Geog. miles, 6o.to a dé cman: TOPOGRAPHICAL SKETCH ofthe PLAIN of TROY. ILLUSTRATED and CONFIRMED. 37 ABSTRACF of the moft material Parts of M. CHEVALIER’S Effay, with the Confirmation of Jubfequent Travellers. “In giving a fhort Abftract of M. Cuevaxrer’s inveftigations, I fhall not follow the order in which he himfelf proceeded, but that which feems to convey the cleareft idea of his difcoveries and obfervations, now that they have been made. For the cafe is quite different with a perfon, who gives a detail of the man- ner in which he himfelf advanced in the courfe of inveftigating objects, of which he had at firft but an imperfect notion, where the direct path leading to them was yet obfcure and unknown, and where he had to form conjectures that were fometimes er- roneous ; and with one who points out or elucidates fuch ob- jects after they have been difcovered, and their relative fituations afcertained. AFTER M, CHEVALIER had formed the refolution of explo- ring the Afiatic coaft, where the Hellefpont unites with the fEgean Sea, with a view to afcertain the true topography of the Iliad, he happened to land firft at Cape Baba, the ancient pro- montory of Le¢ctos, ‘Thence he proceeded to Alexandria 'Troas, the ruins of which he examined, and has given an account of; and this account Mr Liston in converfation, and Dr DatLaway in his book, (p. 326.), have agreed in confirming ; but of which a sot detail would be here unneceflary*. The * Tue Turkith name Efe Stamboul; the warm baths called Lidga Hamam ; the hill on whofe declivity thefe are fituated, and which is covered with tombs, whofe farcophagi of white marble the Turks break down and make bullets of, for fupply-. ing- 38 TABLEAU de la PLAINE de TROYE The Plain. In advancing from Alexandria Troas, along the coaft, M. CHEVALIER’S attention was particularly attracted by a twmulus, or barrow of immenfe fize, at a confiderable diftance*. This is now called Udjek Tepe, from Udjek, the name of the adjacent village. From the top of this at noon, (Ch, III.), he took a re- trofpect of the ruins of Alexandria, now at the diftance of more than four leagues ; towards the north he faw a large plain, en- compafléd with delightful hills; to the eaft the foot of the moun- tains of Ida; and to the weft the Agean Sea, the iflands of Te- nedos, Imbros, Samothrace, Lemnos, and all the way to the fummit of Mount Athos. Dr Da.taway remarks, that “ from the high ground near “ Alexandria Troas, the view of Tenedos, and of the fea, with “ Udjek Tepee, a vaft tumulus above the plain of Troy, on the “right under the horizontal line, is particularly pleafing.” (p. 326.). And that “ in the progrefs the country foon be- “ comes lefs woody, and {preads into a wide heath, from whence “ the whole plain of Troy is feen,” Wuen M. Cuevatier, in the courfe of his mveftigation, ar- rived at the eaftern extremity of this extenfive plain, on the emi- nence above the modern Turkith village called Bounar-ba/hi, and where he at laft concluded the citadel of ancient Troy to have been placed, he obtained a view of the whole extent of it; and it feemed to him of a femicircular fhape +. “ Of the two chains = “ce of ing the Caftles of the Dardanelles ; the aqueduct of Heropes Atticus; the circuit of the wall ftill almoft entire ; the thickets of Valonea trees; are all likewife re- marked by Dr DaLtiaway, or were mentioned to me by Mr Liston. The for- mer obferves, that “ the whole {ite is now a thick foreft of Valonea, or dwarf oak, “peculiar to the Levant.” Of this fhrub the latter brought away fome feeds. * See the Map. + Mr Liston adds, ‘* on each fide.” " ILLUSTRATED and CONFIRMED. 39 “of hills which embrace it, one appeared to run in a direction “ towards the promontory of Yeni-cheybr,” (or Sigeum), “ and “the other towards the point of Jn-Tepé-Gheulu,” (or Rhee- teum). The part of the hills to the right, reaching between the villages of diché and Jchiblac, appeared more cheerful than the reft, and which he had no doubt compofed the Callicoloné of Homer. From this ftation he defcried “ the iflands of Te- “ nedos and Imbros, Samothrace and Lemnos, the high top of “ Mount Athos, and the Thracian Cherfonefus beyond the Hel- “ lefpont.” (Ch. 1V.). As to the foil of the plain, he obferved it.to be “ of a rich and blackith colour, and of great fertility.” The village of Bounar-ba/bi he reckoned to be “ at the diftance “ of four leagues from the fea.” (Ch. XVII). Mr Hawsgins and Dr SisruorPeE took horfes at Koum- baleh on the coaft, and croffed the plain to the village of Bounar-ba/hi, in three hours, “ an extent,” fays Dr Sintuorre, “ of nine “ miles*.” Mr Hawkins, in his fecond letter to Mr Liston, affures him that Tenedos is to be feen from the hill of Troy, qed that even “ the whole coaft of the Hland 9 is vifible, from the ‘northern to the fouthern point.” , Dr Datuaway remarks, that “‘ the whole plain of Troy, _ “ from the height faid to have been the citadel, is of uninter- “ rupted extent.” (p. 346.).. From the promontory alfo of I¢- ni-cheyhr, or Sigeum, at its lower extremity, the fame intelligent traveller looked over the plain, the whole feope of which he commanded. “ Its broadeft diameter,” fays he “ may be five “or fix, and its longeft twelve miles to 4tché-keuy. Itis natu- “rally verdant and fertile, and now very generally cultivated, “ excepting near the marfh, which occupies a fifth part.” (p. 347.). This I take to be the marfh at the mouth of the ‘Si- mois, of which afterwards. The * * See their Letters, Appendix, No. V. 40 TABLEAU de la PLAINE de TROVE The Site of Ancient Troy. NEAR the eaftern extremity of the plain, upon a gentle accli- vity, is fituated, as has been faid, the Turkifh village of Bounar- bafbi. While M. Curvarier advanced upwards to this vil- lage, by a pleafant and eafy afcent, rifing gradually from the plain, he paffed through a fpacious cemetery, where each of the tombs is adorned with a fragment of marble or of granite. Pafs- | ing the village he continued to afcend for near a mile, till he arrived at the borders of a precipice of great height. (Ch. IV.). Beneath this precipice a torrent, coming down from the moun- tains above the plain, (but whofe bed in the fummer is com- monly dry), runs in a curve direction toward the north; and, bending its courfe along the northern fide of the plain, flows down through the whole length of it, and difcharges itfelf into the Hellefpont, betwixt the modern Turkith fort called Koum- kaleh on the fouth, and a fort of haven called Karanlik-limani on the north, near Rheeteum. This river is undoubtedly the Si- mois. And upon the rifing ground extending upwards from the village of Bounar-ba/hi to the abrupt precipice encompafled by rocks above and the river below, on every fide, except that which opens upon the village, and where the Scran Gate may be fuppofed to have been, M. Cuevaxier concludes, that the ancient city of Troy was placed. From the fummit of this high ground, where he fuppofes the citadel to have been, and which the Turks now call Ballidahi, mountain of honey, he had a view, as has been faid, of the whole extent of the plain. This being an airy fituation, juftifies, in his opinion, Homer’s epithet of _ ivenoecoe, fo often applied to Troy. (Ch. XVII.). The precipices which fkirt this eminence, and the Simois which runs at the foot of them, render the place impracticable to be aflailed from any other quarter than from the fide towards the village. (did. ). Mr ILLUSTRATED and CONFIRMED. 4s M. CuEvatier further remarked, on this high fituation, four barrows or tumuli, three of which are fimilar to thofe on the fhore of the Hellefpont, (which {hall be afterwards mentioned), and the fourth confifts of an enormous mafs of {tones. This he conjectured to be the monument of Hecror ; and thought it the remains of a demolifhed ftruéture. (Ch. XVII.). Mr Hawkins and Dr SistHorre “ {pent a day in vifiting the “hill fuppofed by M. Cuzvaxier to have been the fite of “ Troy; and the fprings of water, which he confiders as the “ fountains of the Scamander*.” Mr Hawkins thought, that “ the place pitched upon for the fite of the city has much natu- “ ral ftrength to recommend it, particularly the eaftermoft angle “of the hill, which, from its height above the Simois, and its. “ perpendicular form, muft have been confidered as a very “ {trong natural faftnefs in thofe times of warfare, and could “ have been eafily rendered an impregnable citadel; for it is not “ large enough for the fite of the whole city.”——“ Some tumuli,” adds he, “ near the fpot, are certainly ftrong indices.” Dr S1z- THORPE obferved, that “ the fituation, where the citadel is fup- “ pofed to have been, is particularly fteep and rocky:” and that “it 1s covered with prickly anit and a few thorny fhrubs. % the almond tree,” adds he, “ which grows wild, is not with- ‘out its thorns. It -has even more pleating plants, the yellow. phi and the wild olive.” Mr Liston took particular notice of a contiguous place, _where the ftones of what is called the tomb of Hector feemed to have been dug; and he remarked a fort of hollow all around the city, except fome part, which is rocky. Dr Daxiaway, who advanced towards the village from the _ northern fide, thus defcribes his approach: “ As the fetting fun “was more brilliant than for many days paft, the village of Vor. IV. Pe _ Bounar- * See their Letters, Appendix, No. V. 42 TABLEAU de la PLAINE de TROYE * Bounar-ba/hi opened upon us very pleafantly from the ford of “ the Simois, which we pafled within a furlong of the chiftlik “of Hapvci Meumer Agha, the prefent proprietor of a do- “main producing near L. 5000 Sterling fer annum, and inclu- “ ding little lefs fpace, and the identical ground of the kingdom “ of old Priam*. His houfe is mean, but many columns were “ difperfed about it, which had been colleéted from the fites of “ adjacent cities. From the village,’ adds he, “ the hill rifes “ rapidly, and foon becomes an infulated mountain. The lofty “ wall of Troy, and the Sczan Gate, interfeéted the modern “ village of Bounar-bajbi. Afcending the hill, thickly ftrewn “ with loofe ftones for the {pace of a mile, the firft object on the “ brow is a ftony hillock, which CHEvaLizER, with no apparent “ reafon, calls the tomb of Hector. It has been opened and * examined, but we could not learn the refult. There are others “ covered with grafs, appropriated likewife to Trojan heroes.” Dr Dariaway has given a beautiful defign and engraving of the tumulus faid to be Hecror’s. This learned traveller is of opinion, that “ upon the area and the intermediate ground “ from the village of Bounar-bafbi, there is undoubtedly {pace “enough for fuch a city as Troy is defcribed to have been.” (p. 345-). And he obferves, that “ the level falls abruptly on “ the fouth, with a precipitate cliff, into a.deep ravine, forming “a mural rock, now almoft covered at its bafe by the ftream “and fands of the Simois, for the length of forty or fifty yards, “and completing a fortification rendered impregnable by na- ture ; . . . *M. Cuevaier had faid, (Ch. XVII.) that “ near the hill were fituate the “ gardens of Priam, where Lycaon, when cutting wood, was, furprifed by AcuIL- “yes; and on that fpot are ftill fituate the gardens of the Agha of Bounar-bathi, “who, after forty centuries, fucceeds to the king of the Trojans, &c. (Forty, among the Errata, is corrected thirty : which Dr Datraway, not obferving, has fuppofed the author guilty of a miftake), Mr Liston told me that he ate grapes in this very place. ILLUSTRATED and CONFIRMED. 43 “ ture ; and that the face of the ground exhibits nothing worthy “ of remark ; bufhes and huge unhewn {tones only being to be fifteen? : The Sources of the Scamander. But the chief circumftance which afcertains the pofition of the city is the fources of the Scamander. Thefe M. CuEva- LIER was fo fortunate as to difcover, and-defcribes as {till to be feen, a little below the village to the fouth, and as confifting : 1. Of a folitary copious fpring, rifing from the bottom of a ba- fon, bordered with pillars of marble and granite; of which {pring, in the month of September, he felt the water to be tepid; but was affured that it is much warmer about the middle of winter ; 2dly, Several {mall fprings of cold and limpid water gufhing forth from crevices in the rock, at the bottom of the low hills at the head of the plain, and which uniting into one ftream, a little below, receive alfo the firft mentioned fountain, and thus form the Scamander*. (Ch. IV. xix.). “We flept,” fays Dr SistHorrE, “ at Bounar-bajbi, a little be- “ low which rifes the Scamander, fed by numerous {prings of a “ pure cryftalline water. One of thefe is faid to be warm in “ winter ; it communicated to us no fenfation of heat.” This was about the middle of September. Dr Dati away, who was there in November 1795, {peaking of the hot {pring, exprefsly fays: “ It “is at leaft tepid ; and the Agha (in the front of whofe houfe “it is to be feen, at a little diftance) told us, that, in the winter ** months, efpecially during froft, it is hot and {mokes.”—“ Ho- “eR, adds he, “ muft be allowed the privilege of a hot “ fpring, and a river full to the brink, if they happen once with- f2 vocal * Compare Iliad, xxii. 147. 44 TABLEAU de la PLAINE de TROYE “in the year.” (p. 344.). M. Curvarrer found the Turkifh _ women of the village of Bownar-ba/bi wafhing their garments at the fources of the Scamander, as the wives and daughters of the Trojans were wont to do when they enjoyed the {weets of peace, before the arrival of the Greeks *. I repeat this circum- ftance, becaufe Mr Liston affured me that, when he was there, he made the very fame remark. The Courfe of the Scamander. M, CHEVALIER examined the two rivers, the Simois and the Scamander, by tracing them upwards ; the latter, from the place where it now difcharges itfelf into the Archipelago, by a new canal; and the former from its mouth upon the Hellefpont, a little to the north of Koum-kaleb, The new canal of the Sca- mander had been firft obferved by him, on his way from Alex- andria Troas, as he came down from Udjék-Tepé, or monument of AsyEeTEs. About a mile to the northward of this monument, as you pafs the village of Erke/ighi, and near an elegant Kiofk, | or repofing place, conftructed by Hassan, the Turkifh Captain Pafcha, a confiderable {tream flowing down upon the fouth fide of the plain, and then bending towards the Simois, takes a fud- den direétion to the fouth, being plainly diverted into an artifi- cial canal, which carries it a confiderable way, m a floping courfe through a valley, and conveys its waters into 'the Ai- gean Sea. (Ch. III.). This mew canal made a ftrong impreflion on M. CHeEvaLigeR’s mind; and induced him afterwards to ’ fearch for the ancient bed of this beautiful ftream, which he at length found, and traced, as marked on his map. (Ch, IV.). This was a moft important difcovery; and when, in the invefti- . gation, * See Iliad, xxii. 154. ILLUSTRATED and CONFIRMED. 45 gation, he came again to the ftream, where it turns into the new canal, and traced it up to its fources already mentioned, near Bounar-ba/bi, no doubt any longer remained on his mind, that this was the true Scamander, which had formerly united its water with the Simois. SuccEEDING travellers have, in the moft liberal and decided manner, confirmed the genuinenefs of thefe inveftigations, and acceded to M. CuEvarier’s conclufions. “ We faw the place,” fays Mr Hawkins, in his firft letter to Mr Liston, ‘‘ where the courfe of this river was diverted by “an artificial canal to the Archipelago.” And he adds, more explicitly in his fecond letter: “ The moft effential point in “ fubftantiating the evidence of CHEVALIER is that of the canal, “‘ made to divert the waters of the Scamander from their origi- “ nal:courfe towards the Simois. This canal we can bear tefti- “mony to. The errors of Woop feem to arife from the over- “ looking this circumftance. As for Srraso, he had never “ wifited the fpot in all probability, and relied onthe authority “of Demerrius of Scepfis*.” Mr Liston himfelf afterwards examined the river with the greateft care, and particularly the: new canal, and the old bed. This laft he crofled on bridges in: different places, and was convinced, that when, occafionally, the ftream of the Scamander is more copious, part of it {till flows into the Simois by this ancient channel. For he differed in opinion from M. CHEVALIER in ‘the idea, that the Scamander is never fubjeét to any increafe or diminution; (Ch. IV. xi.) ; and faw no reafon why it fhould not occafionally {well in the cafe of long continued and heavy rains; though by no means to fuch a degree as the Simois, which is fometimes dried up, and fometimes comes down with the utmoft magnitude and impetuofity.. * See Appendix, No. V. 46 TABLEAU de la PLAINE de TROYE impetuofity *. Moreover, Mr Liston affured me, that from M. Cuevarier’s defcription, the Scamander feems to be a more diminutive water than it really is +. “ For feveral hours,” fays Dr Datuaway, “ we traced, with “ the utmoft attention the courfe of the Scamander from the “ cold or fecond fource, which is a collection of {mall {prings, “ through the morafs, where for fome miles it is pofitively hid, till we reached the new canal, and faw plainly the ancient bed. “ The banks of this river, where expofed, are verdant and beau- “ tiful, and watered to the brink. M. CHEVALIER’s topography “and general idea, after a fair inveftigation, we acknowledged “‘ to be ingenious and plaufible.” (p. 347.). In characterifing the Scamander, M. CHEVALIER mentions particularly “ the tranfparency of the water, which runs upon “a bottom of fand and round pebbles, betwixt two verdant ** banks ”” Dr Datraway fays of the two rivers: “ Simois has broad “¢ fands, with a fudden and rapid current ; Scamander is tran- “ {parent and regularly full, within a narrow channel, and fo e “ they continue to be till their junction, before they reach the ‘Seas th (pi 44.83) M. Cuevaier further defcribes his having paffed the Sca- mander upon an old willow ftretched acrofs, near a mill. Mr Liston alfo mentioned to me this mill, and his having crofled the current in a fimilar manner. The * IF this hypothefis of Mr Liston be well founded, perhaps it may be inferred that the Scamander remains in the fame ftate in which it was in the days of Ho- MER, occafionally flowing into the Simois, but commonly, by what is thought a new canal, into the 7Egean Sea. And if this is admitted, it may affift Mr Heyne in ob- viating a difficulty which occurs to him in his Effay on the Topography of the Iliad. See Appendix, No, III. + Peruaps I may be partly to blame for this, by calling it, in the tranflation, @ rivulet, (p. 13. 15.), and once a ril/, (p.25.). The original is ruzfeau, which might have been rendered a ftream. ns ILLUSTRATED + and CONFIRMED. 47 The Courfe of the Simois. From Yeni-cheyr, which is the Sigean promontory, and which commands;an extenfive view of the plain, M. CHEVALIER particularly obferved the Simois, which interfects the plain along the north fide, “ Its waters were then dried up; but the width “ and irregularity of its. channel, fufficiently demonftrated the “ nature of its devaftations, and its rapidity.” (Ch. IlI.). The Turks call it Menderé. An.extenfive marfh occupies the ground at the place of its difcharge on both fides, and reaches almoft to the fortrefs called Koum-kaleb, This marfh is taken notice of by Straso by the name of Srouwaaiuon, the mouth lake. On his way from this place, M. CHEVALIER paffed the Simois near its mouth, and found it to be more than 300 feet broad. In the marth, on its banks, he obferved certain fmall lakes of frefh and of falt water, and was ftruck with the prodigious quantity of reeds and tamarifks he met with, as he proceeded along the coaft. (Ch. IV.).. He travelled onwards for half an hour, and faw a large barrow, the monument of Ajax, which he examin- ed, as we fhall by and by mention. Having then proceeded as far as It-Guelmes or Erin-keu, he returned, and refolved to af- cend towards the fource of the Simois; and had not proceeded far, when he was fo fortunate as to difcover, to the right, the bed of a {maller river, at that time dry, and covered with plants and turf. This proved, on a nearer inveftigation, to be the old bed of the Scamander. If Mr Woop had adverted to this, in- {tead of ftill fearching higher up for the confluence of the two rivers, he probably would have given a more rational account than he has done of the prefent ftate of the fcene of the Iliad. AFTERWARDS, when M. CHEVALIER had examined the Sca- mander, its fources, and the fituation of ancient Troy, as already mentioned, he refumed the defign of tracing the Simois {till ; higher ; 48 TABLEAU de la PLAINE de TROYE higher ; and went down to its banks, from the village of Aradler, about half a mile to the fouth-eaft of Bounar-bafbi. The tor- rent being then dried up, he refolved to afcend within its chan- nel, {crambling over trunks of trees and rocks borne down by the impetuofity of the current. (Ch. IV.). He walked for five hours between two chains of abrupt rocks, which border the valley, and came into a plain, with a village at its entry, called Iné or Ené. Here he found that a river difcharges itfelf into the Simois, and that it takes its rife near a village called Bahar- lar, to which he proceeded in five hours journey to the fouth-_ ward, through a rugged and mountainous country. This ftream he found to be the fuppofed Scamander of Mr Woop. Returning to Ené he continued to trace the Simois, now the Men- deré, up to the high mountain, whence he was affured it iffued. This proved to be Mount Cotylus, now called Cas-dahi, the moun- tain of the goofe, from which, mifled by Demetrius of Scepfis, Straso makes the Scamander to flow down, confounding it with the Simois. M. CHEVALIER refolved to afcend to the fum- mit of the mountain, which, after being hindered from doing for fome days, in confequence of a great fall of rain, he at laft effe&ted ; of which expedition he gives an interefting defcrip- tion, particularly of the fublime profpeéts he obtained. Ir does not appear that any of the fubfequent travellers I have mentioned, went to the fource of the Simois, or the fum- mit of Mount Cotylus, as M. Cuevarier did: but Dr Sis- — THORPE remarks, that the fituation, where they fuppofed the citadel of Troy to have been, is particularly fteep and rocky, and is girt by the Simois, “ which is now,” fays he, “ entirely “dry: but perhaps the winter torrents may raife it into a con- “ fiderable river. Its banks are fringed with plants, agnus ca- “ ftus, and tamarifk *.’’ Dr * See his Letter, Appendix, No. V. ILLUSTRATED and CONFIRMED. 49 Dr Dattaway crofled the Simois three times: 1. On his way from Udjek-tepé, or the monument of /EsyeTEs; and’ after he had refted during a tempeftuous night at the Chiftliz, built by the famous HassAwn Paha, formerly mentioned, on the sth of November he croffed both the Scamander and the Simois, the latter of which the rains had increafed to a confiderable river ; the bed being from forty to fifty yards wide ; though it is fre- _ quently almott dry, efpecially in the midft of fummer. ‘This was on his way to the village of Thimbrek-keuy, and the temple of A- POLLO Thymbreus ; which he pafled and defcended to the fhore, and proceeded as far as Cape Berbier ; and after exploring the fhores of the Hellefpont, he returned by fea to Koum-kaleb. Here - having landed, he again crofled the Simois over a wooden bridge, near its embouchure 3 (p. 338.); and advancing upwards on the northern fide of that river, he repafled it within a furlong of the Chiftlik of Hapc1 Meumer Agha, at Bounar-ba/bi. (p. 343.). In viewing the fituation of the citadel, where the Simois runs under the rock, he fays, ‘‘ That the divifion of the rifted rock “from the groupe of foreft mountains, does not exceed 150 “yards, and is fearcely farther afunder at the top, finking as * perpendicularly as an artificial channel.” The Monument of AsvEvEs. M. Cuev Atier,as has been faid, began his refearches in Afia at Cape Bada, the ancient promontory of Lectos. From thence he proceeded to the ruins of Alexandria Troas; his account of which has been minutely confirmed by Dr Dattaway. But though the narrative of both travellers be very agreeable and interefting, we did not before, nor do we now, think it necef- fary to detail the particulars. On advancing, his notice was particularly attracted by Udjek-tepé, a barrow of an extraordi- Vou. IV. g nary” 50 TABLEAU de la PLAINE de TROYE nary fize, which already has been mentioned *. He had no no- tion at firft that this was the fame with the monument of Asy- ETES. He contented himfelf with meafuring its dimenfions, and enjoying the magnificent profpect from the top of it. Its height he found to be not lefs than roo feet, and its outline to be 400 paces. He remarked it to be of a conic fhape, and quite regular. After his third journey to the Troad, he had no hefi- tation in concluding it to be the monument of sy¥ETESs. (Ch. TI. XII). . Dr Darraway fays, that “ the tomb of AsyvErEs, according “ to PococKE, or, as it is now called, from the adjacent village, “ Udjek-Tepee, is a barrow of extraordinary height and fmooth “ furface, and was the fituation from whence Potires, the fon of “* Pr1AM, reconnoitred the Grecian camp, and the oppofite ifland “ of Tenedos, with its harbour and promontory +.” Five other Tumuli. Arter M. CuevaLier had examined the new canal of the Scamander, he proceeded, from the place of its difcharge inta the Agean Sea, along the coaft, towards the village of Yeni-cheyr, in order to have a nearer view of feveral high mounds of earth,. which had attracted his attention from the top of Udjek-tepé, or monument of MsyeTEs. The firft he arrived at, called Be- fbik-tepe, is not by any means fo high as that laft mentioned. He next came to that, which, upon the map, he has called 4a- tilocht tumulus, not finding any Turkifh name for it, and which feemed to be of the fame dimenfion with Be/bik-tepé. He then proceeded to the village called /eni-cheyr, ftill inhabited by Greeks, and fituate upon the extremity of the famous Sigean : promontory, * See above. p. 38; + Iliad, II. 792, feq. TLLUSTRATED and CONFIRMED. si promontory, where, juft as he was entering the Church, he faw the Sigean infcription, fo well known to the learned ; and op- pofite to it the bas relief of marble, of the fineft workmanthip, of which Dr CHANDLER has given an exact account ; and there is an elegant engraving of it in Jonian Antiquities. Dr Darxiaway, too, faw this bas relief, as well as the Sigean infcription ; which laft, he obferves, is now placed at the door of a low hut, confecrated as a chapel: and the letters are nearly worn out, the marble having been fo long ufed as a bench to fiton. Mr Liston told me, that the effacing feems to be pre- moted by a drop which falls from the eaves of the chapel. From the top of the promontory M. CHEVALIER had ano- ther extenfive view of the plain of Troy, and faw particularly the mouth of the Simois, as already mentioned ; alfo the Turk- ifh caftle of Koum-kaleb, mentioned by all the fubfequent travel- lers. At the foot of the promontory he remarked two other tu- muli, of which the neareft is underftood to be the monument of ACHILLEs; and the more diftant one M. CHEVALIER fuppofed to be that of Parroctus. Others take it for that of PENELEUS ; the afhes of Parroctus having been depofited in the fame mo- nument with thofe of ACHILLES. “ ADVANCING fome furlongs ever the promontory,” fays Dr Datuaway, “we faw the barrow (be/hik-tepe) called the “tomb of AntiLocuus by Straso. On the other fide of the “ village, under the brow of the hill, crowned by half a dozen “ windmills, near the fea, are two {maller tumuli, generally fup- “ pofed to be thofe, one of which is attributed, by the ancient “ seographers, to the illuftrious friends ACHILLEs and PaTRo-~ “ cius, and the other to PENELEvs the Beeotian.”’ (p. 350.). AFTER remaining fome days near Keum-kaleh, M. CHEVALIER paffed the Simois; and, travelling for half an hour, came to a fifth zwmulus of the fame kind with the reft, having a large aper- ture in its fide, which he entered. The monument being de- £2 molifhed 52 TABLEAU de la PLAINE de TROYE molifhed from top to bottom, its whole interior ftru€ture was to be difcerned. This is fuppofed to be the monument of Ajax, and is called by the Turks In-tepé-Gheuleu, the monument of the mar/b. Yt is fituated at Rheeteum, a promontory or tongue’ of land advancing into the plain oppofite to the Sigean promon- tory. (Ch. IV. XIV.). Dag Dr Datriaway, after crofling the Simois the fecond time, pafied over an extenfive level of ploughed fields, and Gowlu-/ui, a brook, which empties itfelf into the fea near Fn-tepe, or the tomb of AyAx Telamonius. “ This twmulus,”’ fays he, “ is now irre- “‘gularly fhaped. Near the top is a fmall arched way almoft “ choked up with earth, which was the entrance into the vault, “and over it a broken wall, where was once a fmall fepulchral “ fane called Aiantéum.’’ He thinks the whole to be of a much more modern date than the death of Ajax. Dr SrpTHorPE, in his letter to Mr Liston, writes thus: “ I “write to your Excellency in hafte, our veffel tofling about op- “‘pofite the tomb of Ajax, where it has been juft drove by a “ hard gale of wind *.’’ THESE monuments, with the others formerly mentioned up- on the hill of Troy, appear to have made a ftrong impreffion on M, CuervaLier’s mind; and many of the Members of this So- ciety will recolle€@, that, in converfation, he ufed to lay great ftrefs on them. They are objects very confpicuous and ftriking to thofe who fail along the coaft, near the entrance to the Helle- fpont, as Mr Liston particularly informed me. They feem to have made a ftrong impretflion hkewife on Dr DaLLaway, who, on viewing them from Ha/i/eli, near the village of Thimbrek-keuy, (p. 340.), remarks, that the fucceflion of the five ¢wmuli, under the diftant horizon, tend more than any other proof to afcer- tain the Trojan war. He fays afterwards, (p. 349.) : “ Of all the “ proofs advanced by M. CHEvALieEr, the tumuli, fo connected “ with * See Appendix, No. V. ILLUSTRATED and CONFIRMED. 53 * with the Sigean and Rheetean promontories, and the outpofts “ of the Grecian camp, are the moft fatisfactory. The fite is “ likewife confirmed by four others, which, to whatever heroes “they may be conjecturally attributed, with no additional “ weight to the argument, give a certain degree of internal evi- “ dence, and afcertain the fcene of great military tranfadtions, “ or vicinity to a large city.” The Valley of Thymbra. On quitting the monument of Ajax at the Rhcetean promon- tory, and after taking a view of a {mall adjacent harbour called Karanlik-limani, the fbut haven, M. Catv a ier continued his journey to the village of Jt-Guelmes or Erin-keuy, It appeared to be of no confequence to the end in view to proceed in that direGtion any farther, and he returned, in order to trace the cir- cumference of the great plain. On his way back, he foon de- fcended into a delightful valley, called Dhimbrek-deré, the valley of Thimbrek, or Thymbra. On beginning to afcend towards the fource of a rivulet; which runs through it, he was {topped on its left bank, oppofite to the village of Halileli, by a heap of ruins, among which were fome bas reliefs, columns, capitals, entablatures, and infcriptions. He took them for the ruins of the temple of Apotto Thymbrzus, and:copied fome of the in- {criptions, which are now publifhed in the third volume of our Tranfactions. Mr L.aston faw thefe ruins, and told me that they are very confiderable; fome fragments of marble ones’ ftill remaining. Every year the inhabitants carry pieces of thefe to place over the dead in the adjoining cemetery, near the ruins of an old mofque ; fo that foon nothing will remain but the large pieces. M, CHEVALIER, in his map, has, in Mr Liston’s opinion, pla- ced sg TABLEAU dela PLAINE de TROYE ced them too far up. They are at leaft half a mile from the village of Halileli, on the oppofite fide of the rivulet. Dr Dat- Laway has given an elegant engraving of them, and fays, that he “ paffed the village of Lhbimbrek-keuy, and a dilapidated mofque, “ with a cemetery full of parts of fluted columns and cornices, “ fet up as memorials, the probable fite of the temple and city “ facred to APoLLto Thymbreus.” (p. 331.) The Promontories. M. CHEVALIER agrees with all preceding travellers, in holding the promontory of Sigeum to be at the modern village of Yeni- cheyr. That of Rhoeteum he has no doubt in fixing at In-tepe- Gheulew, near the harbour called Karanlik-limani, where the barrow, fuppofed to be the monument of Ajax, is ftill to be feen. He concludes, with the greateft reafon, that M. d’ANVILLE and Mr Woop are miftaken in placing the Rhoetean promontory at Cape Berbier, which, according to the latter, lies about 12 miles from the Cape of Jeni-cheyr or Sigean promontory. (Ch, XIII). He was at the pains to meafure the diftance be- twixt what he thinks the two promontories, and found it to be 3000 fathoms, which agrees with Piiny’s account, who fays it is go ftadia. M. Cuevaier thinks Srrazo miftaken when he reckons it at 60 ftadia. Dr Datiaway obferves, that “ the entrance into the great “plain is formed by the Sigean promontory, and that called “ Rheeteum, about four Englifh miles afunder, through which “ the two rivers Simois and Scamander at length took an united “courfe. Between thefe promontories the Grecian fleet was “ drawn up on dry ground, and probably remained fo during “ the whole war.” (p. 336, note.). ‘ Woop,” adds he, “ mi- “takes Cape Berbier. for the Rhoectean promontory, which “ STRABO ILLUSTRATED and CONFIRMED. 55 “ STRABO makes to be 60 ftadia, Souinus, 26, and PLINY, 30, “ from the Sigean; the latter is the true diftance. (p. 337. note.). “ The city of Sigeum covered the fhore between the twmulus and “a bay, in which IJ anchored for a week, (Nov. 1795), and re- “ furveyed the whole with attention.” Some Miftakes admitted, and corrected. AFTER what has been ftated, and thus confirmed by fuch re- {petable authorities as have been adduced, no reafonable perfon can now doubt that M. CuEvaier has given a true and di- ftinét account of the prefent ftate of the Troad. But as he has had occafion to offer various hypothefes, and to make various obfervations and inferences, during the courfe of his Effay, it is not to be wondered at that a few miftakes fhould have been committed, and fome unneceffary animadverfions introduced. The author was himfelf fenfible of this, as appears from the late letters I received from him*. In the notes, too, which accom- pany the Englifh verfion, I now perceive there are fome errors,. which I wifh to take the firft opportunity of corredting. The Map. M. CHEVALIER, upon information being communicated to him that Mr Liston, as well as Mr Hawkins *, had found. fome inaccuracies in his map, anfwered as follows: “ There is “ nothing I defire fo much as to have any miftakes, that have “ been committed in my map, rectified ; and I moft cordially “ give my aid to every improvement of which that performance oes 1S: * See his firft Letter, Appendix, No. VL ? ‘ 56 TABLEAU de la PLAINE de TROYE “is fufceptible. But I will venture to affure you before hand, “ that the alterations which may be made will not extend to the “monuments eflential to the underftanding of the Iiad; fuch “as the fite of ancient Troy, the fources of the Scamander, “ the tombs of the warriors, the promontories, &c. All thefe “points are fixed relatively to one another, with a degree of “precifion fufficient to prevent any change that may be made “upon them from materially affeting my work. As to mo- “ dern monuments, fuch as Alexandria Troas, &c. I own that I “did not think it neceflary to pay fuch a fcrupulous attention “to them. The line of the coaft was done with the greateft “ exaétnefs, as well as the mouth of the Hellefpont and the “‘ifland of Tenedos ; and therefore I fufpect that upon this the “ new map will make no alteration*.” Dr Dattaway obferves, that M. Curzvarier has defcribed the artifical canal in his map of the Troad as having much too ftraight a direction, — It is conducted round the hill upon which the Chiftlik of Hassan Paha is built. (p. 347.). The Monument of Iwus. AsoutT an hundred paces up the Simois, from the place where it is joined by the old bed of the Scamander, and near the place where the city called New Ilium is fuppofed to have been fitua- ted, M. Cuevatcter had obferved the ruins of a bridge, which - had been built of hewn ftone, and of exquifite workmanthip. Fronting thefe remains, on the right of the river, he faw a fort of rifing ground, which he took to be a demolithed barrow. This he afterwards fancied to be the monument of ILus, and probably the fame with Homer’s Sewopos wedi In thefe con- jectures, * See Appendix, No. VI. ILLUSTRATED and CONFIRMED. 57 jectures, however, he was, after a converfation with Profeffor HeEyNeE, convinced he was miftaken; and readily admitted, that his whole XVIth chapter, which is upon this fubje&t, is good for nothing*. After that converfation, alfo, he was difpofed to think that this barrow might probably be that mentioned by Homer, (Iliad, VII. 337.), which was to be deftined as a com- mon one for the warriors who had fallen in battle ; c«gsray év wedi nn. Situation of the Grecian Camp. Carter XIII, where the author treats of the fituation of the Grecian camp, now appears to me to require much amend- ment. That the camp was fituated fomewhere betwixt the Si- gean and Rheetean promontories is generally agreed ; but that it occupied the whole {pace or line of coaft in that interval, as M. Cuevatier has fuppofed, cannot be admitted. This would have made it neceffary for the camp, which confifted of the tents, with the fhips drawn out upon the dry land, as was the ancient cuftom, to occupy the place on both fides of the mouth of the Simois, which M. CHEva.ier, and the other travellers, as well as StRaBo, defcribe as being an extenfive marfh. M. CHEVALIER was evidently aware of this inconvenience; and therefore fuppofes that the Greeks, in the courfe of the war, frequently fhifted their ftation ; and that, at laft, in the tenth year, during the fummer feafon, they encamped, in full force, at the mouth of the Scamander, or Simois, for, at the mouth, they were united. I rEGRET that, in the note, I have endeavoured to fupport this idea, by fuppofing, that “ the Scamander, even in the fum- Vo.. IV. b Somer, * See his Letters, Appendix, No. VI. 58 TABLEAU de la PLAINE de TROYE “ mer, when the Simois was dry, continued to convey its pure “and perennial, though lefs copious, ftream through the midft “ of the camp, in the fame channel through which the Simois, “ after having joined it, difcharged its winter torrents.” (p. 104.). Ever fince I] read Mr Heyne’s Effay, I have given up this hy- pothefis, and willingly accede to his idea, which fuppofes, that the camp only ftretched on both fides towards the promontories Rheeteum and Sigeum ; and that on the north-eaft it extended no farther than the Simois*. In this way the whole is rendered clear, and free from every objection. This, however, makes nothing againft M. Cuevarrer, but that he was not fo fortu- nate in his hypothefis as Mr Heywe, on this occafion, which J am fure he himfelf would have been the firft to admit. Mr Heyne’s notion of the fituation of the camp is confirm- ed by Dr Datiaway ; and the more ftrongly, as the latter does not appear to have feen the former’s Effay on the Topography of the Iliad, or to have known any thing of the coincidence of Mr Heyne’s opinion with his own. In a very diftinét note on this fubjeét, (p. 336.), he obferves, that “ between thefe pro- “montories the Grecian fleet was drawn up on dry ground, “and probably remained fo during the whole war.” And he concludes the note thus: “ The purfuit of the Trojans by “ AcHILLES, fixes the fituation of the Grecian camp between “the confluence of the rivers and Sigeum, for they retreated “‘ over the Scamander to gain Troy, and he kills many of them “in the river.” Of Jome other Miftakes, and erroneous Critici/ms. THE author, in fpeaking of the two tumuli near the Sigean promontory, (Ch. IV. XXI.), fays, that “ he was informed by “a Greek inhabitant of the place, that the name grven to the “ more * See Appendix, No. III. CE Sas a ILLUSTRATED and CONFIRMED. 59 *“ more confiderable of the two was Dios-tapé, which he inter- “ prets the divine Tomb.” Mr Liston obferved, that the inhabi- tants fpoke of both monuments by the appellation of dtheo tepé, which, in their language, has no other meaning than the two tombs. He therefore concluded, that M. CHEVALIER had been deceived by the fimilarity of the found. This is alfo noted in Dr Datiaway’s book, with an aflertion, (but not of Dr Dat- LAwAy himfelf), that the miftake proceeded from M. CuEva- LIER’s ignorance of modern Greek ; which I have the greateft reafon to believe to be without foundation. In examining carefully the furface of the rock of Balli-dahi, M. CHEvatier thought he “ diftinguifhed foundations of an- * cient buildings, the mafonry of which had aflumed the con- “ fiftence of the rock itfelf.””,. Mr Liston, on a narrow infpec- tion, was convinced that nothing could be difcerned but the real fubftance of the rock, which is indeed rough, of a chalky ap- pearance, and, at firft fight, feems as if there was mortar adhe- ring to it. He brought away a fragment of it, which I have here in my cuftody ; and the gentlemen prefent may judge. Ir feems furprifing that there fhould be a total difappearance of every ruin or veftige of a building, to mark the fite of fo fa- mous a city. STRABO, however, gives a good reafon for this, as follows: ‘Ore yao éxmerogSnpiven trav nizrw moAgwy, ov rerews Oz nurcomacwever, ravens Vex Budeuy cdyarerenpmevac, of Altos we&vrEs sis Thy exehvor avdranbi mereveySnour. Agyoucdvenra yor Qauol rov Murv- Anveciov éx ray excidev Aidwv ro Yivyesoy exTely loos. (L: XIII. p. 895.). For when all the cities around were laid wafte, but not entirely de- molifbed ; and while this one was totally overturned, all the ftones were carried off from it to rebuild thofe others. Accordingly, they Jay, that ARcHEAN ax of Mitylené with the frones taken from thence fortified Sigeum. Dr Datitaway, {peaking of the city of Ilium, once fituated near the junction of the Scamander and Simois, and which owed its origin to ALEXANDER and Lysimacuus, fays, b 2 (p. 388.)s 60 TABLEAU dela PLAINE de TROYE (p. 338.), “ It excites no wonder, that, after fo long poffeffion of “it by the Turks, not a {tone fhould remain; yet fome con- * tend againft the exiftence of Troy, becaufe no veftiges were “ difcoverable when ALEXANDER founded the fecond city, “ whilft they admit the latter fact equally unauthorifed by pre- “ fent appearances *.” In a paflage quoted from Heroporus, in which an account is given of the march of XERxEs’s army from Sardes to Aby- dos, the expreflion—z7» Id 0& AaBov & cess eeny Yee, is tranflated advancing towards the left branch of Mount Ida, different from the common way of rendering it, having Ida on the left. As this interpretation is difapproved of both by Mr Heyne and Mr Bryant, I have no inclination to difpute the point with fuch learned antagonifts, provided they can make it appear, that Xerxes could and did proceed, with Ida on his left. ‘‘ Ida,” fays Mr Heyngz, “ has many branches and ridges. The army “ may have gone round one of thefe outfkirts of the mountain ** approaching towards the fea, 1 in fuch a manner as to leave it “ on the left +.” From M. CHEVALIER’ letters, it appears that he was fen- fible that he had at times introduced unneceflary or inaccurate reflections ; of which kind are thofe in Chap. VI. refpecting travellers * Sez, in Mr WaKEFIELD’s letter to Mr Bryant, (p. 11, 12.), a remarkable faé&t refpe€ting the total difappearance of Flaxford Church, about five miles from Nottingham. + I OBSERVE, too, that this notion is fupported in a paper in the fixth volume of Commentt. Soc. Reg. Scient. Gotting. Ann. 1783, 1784; entitled, HeroDoti ac . Tuucypipis Thracia, Jos. CuristorH. GATTERERI: with a map, where XER- XES’s march is traced accordingly. Mr Bryant enters into a long difcuflion upon the fubject, through which I haye no inclination to follow him now, nor ‘hall I afterwards, I fuppofe, when I come to take more particular notice of his Ob/erva- tions; but will freely confefs myfelf refponfible for the whole blame of this miftake, having fuggefted the culpable interpretation to M. CHEvatier, on my firft reading his paper ; and I am anxious that he fhould here be cenfured only for paying fo much deference to my judgment as to introduce an equivalent expreflion into the French original. ee a ILLUSTRATED and CONFIRMED. 61 travellers of high diftinétion, and the priefts in the early ages of Chriftianity : both of which he defires may be ftruck out in a new edition. The former, I obferve, has already been omitted © in the German tranflation ; and the latter, which begins thus : “ But why did not the priefts of the lower empire demolifh “ thofe monuments ?””—has given great offence to, and has been cenfured and reprobated with uncommon afperity by, Mr BRYANT, in his Ob/fervations. (p. 42. 43.). Of the Notice that has been taken of STRABO. In giving a defcription of the Troad, it was neceflary to ad- vert particularly to what a geographer fo refpectable as SrRABO has faid upon that fubjeét. This M. CyEvaxier has done in his VIIth and VIlIth chapters. Srrazo derived the greateft ~ part of his information, relating to the Troad, from DEME- TRIuS of Scepfis, who, though he had his refidence in thofe parts, was evidently deceived refpecting the true fource of the Scamander, and has led Straszo into the fame error. They fuppofe that this river takes its rife in Mount Cotylus, far be- yond the place where ancient Troy was fituated. M. CHEVA- LIER has fhewn this to be a grofs miftake ; and it is evident that it was likewife the chief caufe of Mr Woop’s errors. STRABO faw and frankly admitted the difficulty of reconciling this with HomeEr’s account in the XXIId book of the Iliad, where the. two fources are explicitly mentioned, the one a hot and the other a cold fpring, and both as being in the vicinity of the, Sczan Gate; but Srrazo has not been fuccefsful in his attempt to obviate this difficulty *. ee M. * Mr Heywne, in a note on the German verfion, (p. 85-), as well as in the pre- face to the fame work, (See App. No. I.), thinks it evident that Demetrius fet out on a wrong hypothelis, in confequence of mifunderftanding a paflage of the Mliad,, (XII, 19.). This paffage I had quoted and explained in a note. (p. 59. of the Eng- lith Tranflation.). 62 TABLEAU de la PLAINE de TROYE M. Cuevatier being clearly convinced of this error of De- METRIUS and StRABo, and ftruck with the confufion to which it has given rife, has perhaps fhewn too great a degree of fufpi-- cion of the latter, in refpect to fome other paflages of his ac- count of the Troad ; and may have cenfured him fomewhat too keenly. Wherever this feems to be the cafe, Mr Hryng, in his notes on the German verfion, has taken the part of the ancient geographer, to whom fcholars have been fo long accuftomed to look up with the greateft refpect: and if I were to publifh a fe- cond edition of the Englifh, I fhould certainly, in confequence of carte blanche given by the author *, avail myfelf of Mr Heywne’s affiftance to obviate, as far as poffible, every objection . made to STRABO, except upon the great and fundamental error re{pecting the fource of the Scamander. For this I take to be altogether untenable. “In general,” fays Mr Heyne, in one of his notes, “ nothing can be objected again{t Srraszo, but in “ the fingle cafe where he has allowed himfelf to be feduced by “ DemetTRivs, and changed the fources of the Simois and the “ Scamander.” M. ‘Cueva ier perhaps fhould have been fatis- fied with gaining this point. Bur though it fhould appear, that the author or his editer had, in one or two inftances, mifconceived or mifinterpreted STRABO, where the text is acknowledged to be obfcure, not yet having been properly elucidated by any able editor or commen- tator, this furely would furnifh no argument for fetting afide M. CuHEvaLiEr’s account of the Troad, founded on the author’s actual obfervation, fupported by fo many fubfequent refpectable travellers. In the WIth chapter he has, with due refpect, ta~ ken occafion to quote and comment upon fome paflages of. StrRAsBo ; from which it is clear, that the plain of Troy has not changed its appearance fince the days of that learned writer. : The * See his Letters, Appendix, No. VI. ILLUSTRATED and CONFIRMED. 63 The opening of ACHILLES’s Monument, Tue XXIft chapter contains a number of pleafing remarks on the fubjeét of the tumuli to be feen on the fhores of the Hel- lefpont ; and any perfon of fenfibility muft, on the perufal, feel his mind affected with a foothing, though folemn, fenfation; and be ready to confefs, that M. Curvazier has there exprefled himfelf in a moft elegant and interefting manner, Inaccuracies, however, and redundancies, may now and then be perceived, fome of which were pointed out to me by Mr Liston, and they ought to be corrected in-a new edition. t Ir appears, in particular, that M. CHevaxieEr had not recei- ved very accurate information re{pecting what was found in the tomb of AcHILLEs, in confequence of the operation of digging into it, which had been performed after his departure from Con- ftantinople, by the direction of Count DE CuorszuL GourriEr, the French Ambaffador. He had been told, that towards the centre of the pile were found “ two large ftones leaning at an “ angle the one againft the other, and forming a fort of tent,. * under which was difcovered a fmall ftatue of MINERVA, feat- “ed in a chariot with four horfes ; and an urn of metal filled “ with afhes, charcoal, and human bones ; which urn was encir- “ cled in feulpture, with a vine branch, from which were fuf- “ pended bunches of grapes done with exquifite art.” ‘Ture does not appear to-have been any foundation for the figure of a chariot. There were however fome curious reliques found there. Mr Liston faw at Conftantinople the very per- fon who had been employed to conduct the operation of dig- ging ; and who had retained fome of the fragments in his own. cuftody, which he offered to difpofe of. It appears from a let- ter, publifhed in a note by Dr Datiaway, and giving a very particular account of this affair, that this perfon was the Signior SOLOMON 64 TABLEAU de la PLAINE de TROYE Sotomon GuorMEZANO, fon of the late French Conful. After immenfe labour, he at laft difcovered the place where the re- liques were depofited. When collected, they filled a large cheft. He delivered them to his employer M. Cuorstu1, who repaid his trouble with thanks only: but he referved feveral {peci- mens, which he afterwards fhewed and explained, when the Count was no longer formidable. Of thefe a lift is given in the letter ; fuch as, pieces of burnt bones; pieces of a metal vafe ; charcoal of vine branches ; a piece of mortar and ftone ; a piece of metal of a triangular fhape; pieces of very fine pottery, well painted with wreaths of flowers of a dark olive colour, &c. An account is then given of the ftrata of earth dug through. Dr DaLiaway, in the text, fays, that “ extreme age, and the “ preffure of the ground, had crumbled into atoms of ruft all “the metallic fubftances. The wn or vafe, M. FauvAt, an “ ingenious artift, now refiding at Athens, received from M. “ CHOIsEUL in its decayed form, and made a model from it, “ which has been exhibited to feveral conoiffeurs, as much to “ their furprife as fatisfaction.” Dr DaLtLaway adds: “ And “ the godde/s, with her chariot and four horfes, feems to prove that *“‘ the Troad continues to be the land of invention.” Yet it is very remarkable that Mr Hawkins, who faw M. Fauvat at Athens, exprefsly fays, that this laft mentioned gentleman de- nied the exiftence of an urn, but fpoke of a {mall bronze image of MinErvA, of which he fhewed them a caft. “ At Athens,” fays Mr Hawks in his fecond letter to Mr Liston, “ we fell “in with M. FauvatL, a very ingenious artift, long in the fer- “ vice of M. pE CuorsEuL, who affured us, that M. CHEva- ** LIER’s account of the goblet, difcovered in the tomb of AcuIL- *« LES, 1s perfectly fabulous. It originated, it feems, from the “ fragment of a {mall bronze figure, which, when he had clean- “ fed, and put together, proved to be a very curious image of “ MINERVA. He fhewed us a caft which he had made of it in * plafter, — ILLUSTRATED and CONFIRMED. 65 “ plafter of Paris *.” According to M. CuEVALirR, then, there were both an urn and a figure of Minerva ; according to Dr Da.uaway an urn, but no figure or ftatue ; and according to Mr Hawkins a {mall ftatue, but no goblet or urn. It fhould feem, therefore, that this affair ftill ftands in need of further elucidation f. Bur whatever may be thought of thefe barrows; “ fuppo- “fing,” fays Mr Heyne, “ that M. CHEVALIER was miftaken, “ and that the eminences were not at all tombs, the main point “remains what it was. The fources of the Scamander are near “ Bounar-ba/bi, and in that neighbourhood is the fite of Troy t.” Of the Objections made by Mr BRYANT. Mr Bryant, whofe name has been long fo well known in the learned world, has, in the warfare he has thought fit to wage with M. Cuevaigr, been, no doubt, pretty fuccefsful in feve-« ral affaults, where the latter has laid himfelf fomewhat open ; (as we have admitted to be fometimes the cafe) ; but he has to- tally failed in obtaining any thing like a decifive victory. Tuts learned gentleman having, thirty years ago, embraced an opinion, not a new one indeed, but, I believe, almoft general- ly efteemed very extravagant and paradoxical, that no Trojan war, fuch as forms the foundation of the poems of Homer, was Vor. IV. io ever * Appendix, No, V. + In the above-mentioned letter, quoted by Dr Datiaway, an inftance of a — - very ftrange pitch of arrogance is recorded. It is there faid, that “ when the bar- “ rows were clofed up, Count Cuorsgut canfed a fheet of lead to be placed on the “ bottom, infcribed, Ouvrage fait par le Comte De CuorsEvt GourFirr, /’an 1787. $ Concxusion of his preface to the German verfion. See Appendix, No. I, 66 TABLEAU de la PLAINE de TROYE ever carried on*, and that even no fuch city as Troy ever exifted, had employed himfelf occafionally, during that long period, in an attempt to eftablifh the truth of this odd opinion. The fub- je&t had grown a favourite one ; and the author feemed to him- felf to be upon the point of achieving his great undertaking ; when M. Cuevaier’s performance appeared. This obliged him to ftop fhort for a little, and to paufe. He took his refolu- tion. Encouraged, by obferving fome flips committed by an author, as yet raw in the art of fyftematizing, it feemed more eligible to him to endeavour to reduce the obftructing fabric toa heap of ruins, than to demolifh and fupprefs his own occafional labour of thirty years. ‘The avowed object, then, of Mr Bry- ANT’s pamphlet, is to fet afide M. CHEvauier’s De/cription, as unfound and fanciful. I once indeed heard, that, after the Od- Jervations had come out, the author met with fome travellers, who affured him, that M. CHEVALIER’s account of the prefent ftate of the Troad was a fair and true one; in confequence of which, it was reported, that he had renounced his heretical opi- nion upon the fubject, and was to fupprefs his Differtation. This IL was very glad to hear, as I thought the fo doing would have redounded very much to Mr Bryant’s honour. But I was foon convinced that this information was premature, by my re- ceiving a printed copy of the Di/értation, in a prefent, from the learned author himfelf; in the perufal of which, one, every now and then, regrets (at leaft this was the cafe with me) that Mr BryAnT had ever undertaken fuch a toilfome inveftigation, em- ployed fo much learning, and wafted fo much ingenuity, which the appearance of M. CHEvA.teEr’s work, thirty years fooner, might have prevented ; and perhaps ‘might have engaged thofe very talents to affift in fupporting and illuminating a fyftem, which * See Mr Macravrin’s Differtation, to prove that Troy was not taken by the Greeks. Vol. I. p. 43, &c. Lit. Cl, of Tranfactions ‘of this Society. (ILLUSTRATED and CONFIRMED. 67 which they have now been employed to puzzle, perplex, and obfcure. After all, if the learned veteran had feen Mr Heynn’s -Effay on the Topography of the Iliad*, and Dr Datzaway’s late publication, in both of which M. Cuevatier is fo ably fupported, I imagine he would have been deterred from publifh- ing his grand {ceptical work, notwithi{tanding the great labour it: had coft him, Mr Bryant,in the introduction to his Ob/ervations, charges the author and his editor with indulging in fevere critical cen- fure againft Dr Pococxr, Mr Woop, Dr Cuanpter, and Stra- Bo, But I can’t help thinking that the accufation is too ftrong- ly ftated. I hope it was not with an intention to create an early prejudice in the mind of the reader againft the perfons animad- verted upon, and in favour of what was to follow. Wiru refpeét to the firft of the above-mentioned authors, M. - Cuevatrrer had faid, that “ his account of Troas, though full “ of errors, and in every refpect obf{cure, yet proved to him a “very ufeful guide in his refearches,”’ (Ch, VI.). He, no doubt, found confiderable obfcurity, and a number of errors, in Dr PococKke’s account ; and where was the harm in faying fo? But Mr Bryant, in his complaint that Dr Pococxe has been un- juftly accufed, does not fubjoin the qualifying clanfe of the fen- tence, viz. that “‘ notwithftanding thefe defects, the work pro- “veda very ufeful guide ;” but he referves this latter part of the expreffion, till he find an opportunity of introducing it with more effect, and more fitly for his own purpofe afterwards. I am not fure if this way of difmembering expreffions, and expo- fing them in disjointed morfels, fhould be confidered as a very ' fair'mode of attack. If'M. Cazvatrer was convinced that Dr Pocock was mifled by Srrazo, and regrets that he did not vather truft to his own obfervation, which probably would £2 ) | * have * See Appendix, No. III. 6§ TABLEAU de la PLAINE de TROYE *“‘ have brought him to agree with Homer,” I cannot perceive any very fevere cenfure in this: On the contrary, M. CHEva-- LrER finds out, and adds a very good excufe for PococKE, which is, that he could not, at that time, have the afliftance of a geo- metrical apparatus in his obfervations, as it was then hazardous to produce any fuch to the view of the Turks. On other occa- fions, M. CHEVALIER pays compliments to Dr Pocock, calling him, in one place, “ that excellent traveller,” infomuch, that he appeared to me to have even over-rated his merit. In a note, therefore, (p. 100.), I have ventured to fay as much, in as far as related to the art of compofition. For, on reading Po- cocke’s travels, I certainly thought him very deficient in point of arrangement, and very confufed in the communication of his ideas. This, however, was expreffed with all due defe-. rence to his veracity, which I believed to be quite unim- peachable. But, if it will give any fatisfaction to Mr Bry- ANT, I am ready to admit, that I may have been miftaken in thinking Dr Pococke a confufed and inelegant writer. And yet the late Mr Gipson, whofe acutenefs nobody will deny, when he pays a compliment to Dr Pococke’s plan of the feven hills of Conftantinople, adds, ‘‘ that this traveller is feldom fo fatisfactory.” As to the manner in which Mr Woop is treated, it will no doubt feem very difrefpectful in the eyes of thofe who are dif- pofed to believe in his doftrine concerning the fource of the Scamander; but to M. Cuevatrer this appeared fo palpably untenable and abfurd, and he was fo confcious of his victory, that he has, no doubt, purfued his triumph with a great deal of vivacity and pleafantry. Where Mr Woop appeared to have merit, it has been allowed him; but becaufe he viewed the Troad erroneoufly, Mr Bryant thinks it inconfiftent to admit that his defcription of the coaft is exact; and fmartly fays, (with what ILLUSTRATED and CONFIRMED. 69 what reafon I leave others to judge), “ a mah fo erroneous, and “* fo exact, was never before feen.” Dr CuanDienr, in one paflage, is blamed for giving his rea- ders too much credit ; but a good reafon for this is afligned in. the note. In another place, he is noted as having once inadver- tently fpoken of the rivers, repugnantly to his own right notion of them. I have not had time to examine what foundation M. CHEVALIER had for this remark. Perhaps it might as well have been fpared. I find it is omitted in the German edition: very probably at the author’s own defire. Of Dr Cuanpter, M. CHEVALIER {peaks elfewhere with the greateft deference and re- {pect ; and I queftion, if Dr Coanpier will thank Mr Bryant for coming forward as his champion, where he had not himfelf obferved any antagonift on the field. Ir is furprifing that Mr Bryant, in his zeal for the reputa- tion of STRazo, did not perceive that he himfelf is as guilty of rejecting the teftimony of that admired geographer as M. CuE- VALIER, when it happens to difagree with his own ideas. An inftance of which we find in his Differtation. (p. 44.). “ Of “Troy,” fays he, “ there is no fign: no remainder: nor was “ there ever any upon record.”—“ Str Bo endeavours to give a “ reafon for this: but I believe that it will not be deemed fatis- “ factory.” And fo he produces the paflage which we had occa- fion to quote above. (p. 59.). Mr Bryant employs the firft three pages immediately fuc- ceeding his introduction, in endeavouring to prove that the city of Troy, as defcribed by Homer, mutt have been much nearer the fea than the fituation affigned to'it by M. CHEVALIER, which is afferted to be contrary to the very evidence of the poet him- felf. I am glad I have it in my power to give a very fhort, and, I think, a very fatisfaftory anfwer to this objeétion ; and I feel the more fo, becaufe Mr Bryant’s arguments have, in this par- ticular, 70 TABLEAU de la PLAINE de TROYE ticular, brought over to his fide a very learned and intelligent Reviewer in the Briti/b Critic, (May and June 1797); infomuch that, after combating Mr Bryant fuccefsfully in the other — parts of the Ob/ervations, he at laft feels himfelf under the ne- ceflity of feeking for the fite of Troy farther down the plain, in which I am forry I cannot go along with him. The anfwer al- luded to is furnifhed in a few -words by Dr DaLLaway; and coming from one who has been upon the ground, muft have more weight than any thing which could be faid on the fubje& by a perfon who has not had that advantage. ‘‘ The diftance “ from the Grecian camp to the fite of Troy,” fays this accurate obferver, “‘ has fupplied thofe who contend againft its exiftence “with many plaufible objections. It is, however, certain, that “the prefent village of Koum-kaleh is fituate on a fand-bank “ more than a mile in extent, which will reduce the diftance, “ fuppofing it to be an accretion from the Hellefpont, to lefs “ than eight Englifh miles from, Bounar-ba/hi, where the Scean “ Gate once ftood. The advanced works, both of the Greeks “ and Trojans, leffened the intermediate fpace.. The diftance of “ the moft advanced.rank of fhips from the fea is not mention- “ ed; perhaps we might not be far from the truth in fuppofing “it half a mile, and a/quarterof a mile farther from thence to “the fea. Allowing the firft circumftance of the accretion at “ Koum-kaleb, and the Grecian camp having been advanced in- “to the plain, the diftance of Troy,|is. perfe@tly reconcileable “with every: incident mentioned | by Homenr., It is likewife evi- “ dent.from the cireumftances of, the wat.'.Had the city, been “ very near, the firft work of; the. Grecians. muft have been a “ ftrong fortification to prevent. fudden, attacks, without it, “ their deftru@tion mutt be inevitable. Befides, there had not “been a, theatre, large’ enough for. the, jactions! ofthe war.” (p. 336, .337-)s Mr | x ILLUSTRATED and CONFIRMED. 71 Mr BrvyanT afterwards, (p. 14.), argues from a paflage of Ho- MER, (Iliad, XX. 216.),—éae} &rw lasoe ion Ev wedin reroasso,—that Troy muft have been fituated in the plain, much nearer the fhips than M. CHEVALIER imagines. To this Dr DaLLaway alfo gives the following fatisfactory anfwer: “ The moft eleva~ “ted ground on the edge of a precipice was the Acropolis, other- “‘ wife called Pergamus, (Iliad, IV. 507. V. 460. and XXIV. “ yo00.). Ilion was lofty enough to be called windy, (paffim ), yet “ it was lower than Pergamus, (XXIV. 700.) ; fo that it is once * faid to be in the plain, é redia, (XX. 216.), as ftanding at the “ head of the plain on an eafier acclivity, and being lower than “ the mountains of Ida. It is, notwith{tanding, incontrovertible, “ that Troy ftood on the afcent, (VI. 74. XXIV. 390.); and the “ éewede, which was without the town, has the fame epithet zwzn- “ dy, (XXII. 145.), from its unfheltered fituation. The wall ex- “ tended only in the front of the plain, the natural fortification “ of cliffs above the Simois rendering its continuance unnecef- “ fary. Mr Bryant lays much ftrefs on the expreflion & z2diw, “ which might have been ufed comparatively, and in contradi- “ ftin@ion to higher acclivities, and not pofitively.’’ (p. 349-)- Wuart Mr Bryant fays of the diftance between the promon- tories, the fituation of the Grecian camp, and of the Sgwouos re Now; (p. 4. to p. 13.); alfo his criticifms relating to SrraBo, and upon a paflage of Heroporus, (p.-15.—28.), do not here require a particular anfwer or difcuflion, after the conceflions already made, and the amendments which have been propofed. In the cafe of a new edition of M. CHEvaiEr’s Treatife, it is admitted that feveral of Mr Bryant’s remarks might furnith afliftance in the correction of fome errors and inaccuracies, and would merit a tribute of praife to the learned author’s acute- nefs ; but they can have no effect in fubverting the great and effential articles of M. CHEVALIER’S inveftigations and difcove- ries, Nor 72 TABLEAU de la PLAINE de TROYE Nor will I enter any further into what is objected to the ac- count of the Scamander, taken from the diminutive fize of the river; enough having been already faid upon that fubjeé& to convince any unprejudiced perfon that the ftream, which has its fources at Bounar-ba/bi, and which has been explored and defcribed by other refpectable travellers, as well as M. CHEva- LIER, anfwers perfeétly to all the defcriptions and hints to be found in the Iliad ; allowance being always to be made for the poetic way of reprefenting fuch things*. Enough too has been already faid concerning the tombs. THE paffage in the defcription, where M. CHEVALIER has expofed himfelf moft to the power of Mr Bryant, is contain- ed in two paragraphs in the VIth chapter, where CLEMENS Alexandrinus is referred to, and where the priefts of the low- er empire are mentioned. The obfervations there made are evi- dently ill digefted, and rafhly thrown out. This the author has frankly admitted, by direting them to be totally rejected in the cafe of his book’s being reprinted}. But ftill this does not in the leaft affect the material parts of the Treati/e; and fuch diminutive or partial victories as this will fearcely entitle Mr Bryant to the honour of an ovation, far lefs to the glory of a triumph. : Mr Bryant, I find, willingly allows the author and the edi- tor fome praife for exploding the idle notion of HecTor’s flight three times round the city of Troy ; and fupports them in their endeavour to fhow the abfurdity of fuch a fuppofition. At firft I was afraid there might be fome fort of decoy in this, fome contrivance, like that of the wooden horfe, for deftroying us ; efpecially as this was a quarter (—évSe podisw AuBuros ss rors, xui exidgomov txrero resvyos—) where I never had felt very bold, having ftill had my doubts about the poet’s acceptation of zsgi. But * See Mr Heyne’s Preface, Appendix, No. I, + See Appendix, No. VI. ILLUSTRATED and CONFIRMED. 73 But I was foon convinced that Mr Bryant had no treacherous defign in making this conceflion; and the hypothefis having al- fo the ftrong fupport of Mr Heyne*, there is now good reafon to be confident that it is well founded. M. CuEvALier, in the beginning of his XIIth chapter, had remarked, that Mr BryAnT has endeavoured to prove “ that “ the Greeks were miftaken in fuppofing thofe to be the tombs “ of heroes, which were in reality confecrated mounds.” This obfervation, it feems, was of too general a nature. Mr Bryant meant what he faid to be taken in a limited, not a general, -fenfe ; and thinks himfelf much injured by this mifreprefenta- tion, He wifhes, therefore, that M.CurvaLier had pafled him by unregarded ; and in this. wifh I heartily concur: for I am fure M. Cueva ier will fincerely regret that he fhould have written any thing that could be conftrued into a defign to in- jure Mr Bryawnv’s reputation; which I am as much convinced he never intended, as I am confcious that I never meant, by the long unfortunate note fubjoined on the fubject of barrows, to fupport him in any fuch defign. Bor in following Mr Bryant any further, I am afraid I fhould trefpafs on the indulgence of the Society. I did former- ly, and do now, entertain a high refpeét for that gentleman’s talents, learning, and character: at the fame time, I cannot help lamenting, that he fhould ever have mifemployed thofe talents, and that learning, in a laborious attempt which can never en- lighten the mind with any cheerful rays of conviction; nor - ever reach beyond a dreary and difguftful ftate of obfcurity and doubt, tending to blunt or extinguifh thofe pleafing fenfations which the poems of Homer excite in every breaft qualified to © feel their genuine fpirit; and for a diminution of which, the efforts of a frigid and phlegmatic erudition, even if fuccefsful in proving them to have been derived entirely from fiction, would {carcely be able to compenfate. But that “ the war on which Vou. IV. k “ HomER * See his Note, Appendix, No. II. 74 TABLEAU de la PLAINE de TROYE. “ Homer founded his famous poems was never carried on, and. “ that, if the city called Troy ever exifted, it muft have been in “ Egypt, and not in Phrygia ;—nay, that Homer himfelf, un- “ der the name of UtyssEs, was the hero of his own Odyfley,” are paradoxes, I fhould think, too whimfical, too violent, and too repugnant to the beft authorities of antiquity, ever to admit of any thing like a proof. On the other hand, that the fcene of the iad has, derived great light from the laudable refearches and fortunate difco- veries of M. CHevarier mutt be allowed; and therefore he de- ferves the thanks of every admirer of the works of the great poet. This is the decided opinion of many ; and particularly of one, whom the world allows to be qualified in an eminent degree to judge of this fubject, the learned and fagacious Pro- feffor Hryne ; to whofe Effay on the Topography of the Iliad, which is annexed in the Appendix*,I beg leave to direct your attention. f APPEN- # No. IT. ‘ - ‘ APPENDIX, containing Papers and Letters referred to in the foregoing Detail. No. I. (p. 31.) From Profejor HEyneE’s Preface to the German Ti ranflation of. M. CHEYALIER’s Treatife *, O penetrate, at leaft with the mind’s eye, beyond the nar- row circle to which life is bounded, and to ftudy na- ture on a large feale, is a propenfity in the conftitution of man. From this principle arifes the pleafure which we receive from the defcription of foreign lands, and in the reprefentation of na- tural fcenes and profpects. In the cafe of celebrated places, this pleafure is enhanced, when, in countries well known to fame, the remembrance of illuftrious ations is before us. ‘The inte- reft rifes ftill higher, if the {pot be what is termed claffic ground, the mention of which in ancient authors is connected with im- portant events; or where the topography is doubtful, and has become a fubjeé& of controverfy. Tuts is the cafe with the Troad. Homer furnifhes us with fo much accurate obfervation, that we are ready to imagine our- hile felves * I am indebted for the tranflation of the following Extratts, from the German of Mr Heyne’s Preface and Notes, and of the Effay on the Topography of the Iliad, to a very ingenious young gentleman, now the Reverend ALEXANDER Brunton, minifter of Bolton in Eaft Lothian ; formerly educated at this Univerfity, and who refided fome time at Berlin, as private fecretary to the late JosrrH Ewart, Efqj Britifh minifter at that court. My learned friend, Mr James Bonar of the Excife, took the trouble of revifing and preparing it for the prefs. D. 76 TABLEAU de la PLAINE de TROYE felves able to make a vifible reprefentation of the country. But if we try to complete the picture in all its parts, we fhall meet with gaps and with places which do not coincide with the reft of the defign. Accurate defcriptions of this diftri€@t have not been obtained. Strazo is the only author who has furnifhed us with a mi- nute account of the Troad, compofed not from the perfonal ob- fervations of this great geographer, but borrowed from DEME- TRIus of Scepfis.s DEmErTRiIvs feems indeed to have a juft title to belief and refpeét, as he was born in the neighbourhood of the Troad, and had in all probability furveyed it himfelf. Our good opinion of him is confirmed by the accuracy with which particular places are laid down, and by their coincidence with the defcriptions of the ancient poets. Tuts author, however, gives rife to a ftill greater embarraff- ment, not fo much refpecting the fituation of Troy, for it is af- figned to what, in all probability, is its exact place, as in regard to the river Scamander and its fources, which are thrown far back in the mountainous region behind Troy. SuccEEDING travellers have thrown little light on the Troad. Woop, alone, made it a ferious object to explore this claffic ground, and to form an accurate idea of it. He was prepared for the inveftigation by claflical erudition. He travelled, he fays, with his Homer in his hand, but he feems to have had STRAEO alone in his eye. Without attending to fo many other circumftances, which might have directed his view, the fources of the Scamander were his only point, from which he furveyed every thing elfe; and as he was miftaken in the fituation of thefe, every thing elfe muft have received from him a falfe po- fition and appearance *. To * An ingenious criticifm on Woop's Effay on Homer, which appears in the ori- ginal of this preface, is here omitted, as not immediately connected with the prefent fubje&t. D. YH PR EN 'D DX Non ls 79 To the edition in.1775 of Woop’s Effay on the Original Genius and Writings of Homer, was added his Comparative View of the ancient and prefent State of the Troad. Some years afterwards, I read in the Society a paper attempting to explain the military tranfactions in the Iliad, according to the topography of the country *.. Had,I kept. by Homer I fhould have fallen into fewer miftakes: but, unfortunately, from confidence in fuch a man as Woop, who had vifited the country with his Homer, in his hand, I took him and his chart of the Troad for my guides, and thus allowed myfelf to be entangled in fuch a labyrinth of errors, that I {trove in vain to extricate myfelf. THE main blunder in Woon is the alteration of the fources of the Scamander, and the confequent placing of ancient Troy deep in the mountainous region of Ida. Every thing elfe was now confounded. Woop did not perceive that Demetrius of Scepfis, whom Srraso- follows, builds, in. this inftance, on a mere hypothefis. Demetrius, I imagine, founded it on an er- roneous interpretation of Iliad, XII. 18, &c..¢, which he under- - ftood geographically, without confidering that he had before him a poet, not'a geographer. Woop, indeed, traced the courfe of a ftream, till at laft he found another that flowed into it: he then fought the fources of this new ftream, and difcovered them. Thus far, all is accurately obferved, and coincides with DEMETRIUs’s affertion. But was this ftream of courfe the Scamander ? ‘and, was. Troy to be immediately transferred to that fpot? Had not Srrazo preceded him with a multitude of doubts? Woop helped himfelf out with changes of nature, which muft have taken place here, and have altered of confe- quence the face of the country. But fuch changes hiftory knows of only upon the coaft, or when occafioned by the overflow of rivers : * Tuts paper is publifhed in Compentat. Soc. Reg. Scienttarum Gottingenjis, tom. VI. under the title of De acie Homerica, et de oppugnatione caftrorum a Tra- jants fata. + See above, p. 61. 78 TABLEAU de la PLAINE de TROYE. rivers: and fuch Homer himfelf defcribes, Iliad, VII. 459, &c. XIL. 13—33. THE transference of Rhoeteum to Cape Berbier is an error not peculiar to Woop: but the Grecian camp derives from thence an extent which again does not accord with HomeEr’s defcrip- — tion. ‘The poet is not indeed to be a geographer; but he muft not feign any thing which contradiéts the firft glance at nature, or clafhes with the known accounts of the topography of the country. The epic poet muft reprefent nature as certain leading circumftances require. ‘The main circumftance here is the ge- neral chart of the face of the country, and an eftablifhment of certain principal fpots. As to the reft of the fcene, fancy muft have full play in fuggefting its greatnefs and extent. The epic poet’s chief engine is the marvellous. By an accurate determina- tion of every particular, the illufion would quickly vanifh. Much mutt appear only in great mafles: Some things muft be and muft remain in obfcurity, that the fancy of the hearers or readers may have room to work, to form to itfelf an idea of greatnefs and power. Homer therefore does not give an accurate determination of the Grecian camp, or of the field of battle. Here the fancy of the reader has room to operate, as that of the poet himfelf has been engaged in working up every thing into the great and wonder- ful. Every thing appears to him many degrees higher than it is in real nature. Muft he not raife the reader to the fame pitch? “ T fee gods arifing” is the language of the poet; and when'he is read as a poet ought to be, it will be the language of the reader alfo. Jf we are at any time to figure to ourfelves the Scamander as a tremendous torrent, which, as a god, fights with AcwiLLeEs, and threatens to bury him in its waves, Ho- MER muft not inform us how diminutive its real fize is. He muit leave us, by affociation with the greatnefs of the effect, to give it all the bulk our fancy can grafp. He in no place gives the exact dimenfions of the town and fortrefs of Troy. This is quite APPENDIX, Nol 79 quite natural; for fuch accuracy could in no refpect have had an advantageous effect. The combat of AcurLLEs and HEcToR is filled with the wonderful. The race of both heroes is traced by means of points, which the fancy of the reader may extend as far as it can; the walls, the wild fig tree, the watch-tower, the fources of the Scamander. But it may be premifed, that to a perfon who knew the topography of the country in the days of Homer, nothing would be reprefented, which he would have recognifed and declared to be falfe and erroneous, elfe the effect of the poem would have been loft. “WHEN we fpeak of the Troad, it may be viewed in various lights. What is the prefent appearance of that country ? What was it formerly, at different times, particularly in the days of Homer? and how can its prefent appearance be reconciled with the defcriptions of that poet? Or, again; in Homer there is a certain appearance of the country defcribed. How far does this _ actually accord with nature? Each of thefe views and queftions it is rather the province of the geographer and hiftorical critic to anfwer. There is ftill another view of the fubje&, As the post cannot be read with pleafure, without a fenfible reprefenta- tion, what is the reprefentation he gives of the face of the coun- try? To what extent does he give it? and how much of this kind of knowledge muft accompany or precede the reading of the Iliad? , ; _. Tue explainer of Homer is properly bound to difcharge on- ly the laft taf. With this view I had entirely new modelled the above mentioned. Memoir, according to Homer, and had taken no further affitance from Srraso than coincided with and illuftrated Homer’s, account. So much the more lively was my pleafure, when I perceived, in the paper of M.Cugva- LIER, a greater coincidence with my ideas than I had found,in Woop, or in any other work. This induced me to annex ta this 80 TABLEAU dela PLAINE de TROYLE. this publication my Memoir in a new drefs, in order, at leaft, to remedy the errors it may have formerly occafioned. b¥i Tuart the fources of the Scamander are ftill found near Bou- nar-ba/bi ;—that of its junction with the Simois the ancient channel ftill remains, as the ftream is now diverted into a canal, which falls into the fea below Sigeum ;—that the ftream which comes down from the hills is the Simois, and not the Scaman- der ;—and, alfo, that the other ftream, which the former re- ceives, is no Scamander ;—that Bounar-ba/hi exhibits the fite and veftiges of ancient Troy ;—that even the citadel is ftill diftin- guifhed by its abrupt precipice :—all thefe are leading remarks and obfervations which we owe to M. CHEVALIER. The coatt,. the promontories, the tombs, the temple of APoLLo at Thymbra, Callicoloné, and other places, receive from him all the diftinat- nefs that readers of Homer can with. M. Cuevarter vifited the country about the year 1787. He was at that time attached to the embafly of M. DE CHorIsEUL — Gourrier at Conftantinople. The occafion both of his draw- ing up the paper, of its being read before the Royal Society of Edinburgh, and afterwards publifhed by Mr Dauzet, are de- tailed in the preface of this laft gentleman *. I Hap the pleafure of M. CHEVALIER’s acquaintance during his fhort refidence at Gottingen. The perufal of parts of his tra- velling journals made me defirous to communicate to my coun- trymen the whole work. ‘This propofal, however, was attended with feveral difficulties, particularly, that the paper was the pro- perty of the Royal Society of Edinburgh, and that it was aflign- ed to a place in the third Volume of their Zran/aétions, which © was not to be publifhed for a twelvemonth. In the mean time, upon fignifying my wifhes, I experienced a complaifance and readinefs to oblige, which calls for the warmeft * See the Preface to the Englith Tranflation. APBRENDIX,-No.1. ata warmeft and moft grateful acknowledgment on my part. Not only M. CHEVALIER gave me every afliftance, but, on the part of the Royal Society of Edinburgh, I was anticipated with affu- rances which fhew the liberal fentiments of thofe Literati, who are far fuperior to any little felfifh vanity. I had even imme- diate’ accefS to a tranflation of the Paper’ before it had ap- peared in the Society’s Tranfactions. A copy of this tranflation was fent to me before its publication, and the earlieft impref- fions of the ‘maps were communicated to me. If ever the o¢cu- pations of learned men merited the title of the ftudies of huma- nity, it was m the prefent'inftance. To the exertions of Pro- feffor Datzex;"1 am particularly indebted.» He preferved, on this occafion, his character, already high in my eftimation, by fhewing himfelf:in no ways actuated by envy, omby any little jealoufy, towards ‘a profeffor in‘his own line.» © > - lcommitrep the German tranflation to ‘a young paoailitee {cholar, Mr Coarnues FreDERIC DoRNEDDEN. According to the permiffion which I received from Edinburgh, and from the au- thor, I have added fome remarks, which are chiefly critical, or) relate to the interpretation, particularly of Srraxo, or refer to a comparifon of \paflages in Homer. On different points I have received from the author written explanations, and have, by his _ permiffion, made fome changes and additions. The particular ftate of literature in Germany would perhaps have required. other changes, omiffions, and abbreviations ; ; but a work v was not my property. Tue author fets out always from tombs, and feems to lay the greateft ftrefs on the obfervations he has made refpecting thefe. There may have been particular reafons for this. For us they! decide little. Suppofing’ that M. Cueva Lier was miftaken, and that the eminences ‘were not at all tombs, the main point re-- mains what it was; the fources of the Scamander are near Bou- nar-bafhi ; and in that neighbourhood is the fite of 'Troy. Vor. IV. L No. II. . * 82 TABLEAU de la PLAINE de TROYE. No. IE. (p. 73.) Mr Heywe’s Note, additional to Mr Dauzex’s, on ACHILLES’S Purfuit of Hector. (iad, XXII. 165.). LONG as this note has been*, I find it neceflary ftill to fub- join another. We ought, | think, to take-up the fubje& in this way. Here, as frequently happens in regard to Homer, two diftingt queftions occur: 1. How the Ancients underftood Ho- MER? 2. How he may and /hould be underftood ? UNQUESTIONABLY the ancients often underftood their Ho- mer furprifingly ill; and in the inftance before us it may very well have happened that they miftook his meaning. His com- mentators haye conftantly been deficient in pomt of acquaint- ance with the topography of the Troad. Seldom was this rug- ged coaft vifited by travellers, as no great road either led to or run through it. Over the precipices of Mount Ida it was hardly poflible that there fhould lie- any much frequented path. To the prefent hour this coaft continues to be but rarely vifited. Thofe tracts only are known to us through which caravans tra- vel. Even where an accurate acquaintance with the topography of the country might have been moft confidently looked: for, in StrAszo for inftance, we find nothing more than an abridg~ ment of the accounts of DemETRivs of Scepfis ; amd that this laft mentioned author, in his examination of the ground, car- ried throughout in his mind a preconceived hypethefis, is, evi- dent in what relates to the fountains of the Simois and Scaman~ der. This may perhaps have’ been the cafe too, whem he affert- ed * See the Englifli Tranflation of M. Cuevavier’s Effay, p. 135, Sc-; and the Getman; p. 206, &c. D. APPENDIX, No U. 83 ed, as follows, of the place which he had rightly marked out as the fite of ancient Troy, “ Hecror could not poflibly have “ been purfued round about New Ilium, but he might very “well haye been fo round ancient Troy,”’—4 de curs dyer regidgouy. (STRABO, p. 895. A.). . In Quintus of Smyrna, who, as well as DEMETRIUS, refided juft upon the weftern coaft of Afia, we find a fimilar deficiency in point of local knowledge. No wonder, then, that even he makes Hecror be dragged around the walls, wei xérxna. (I. 111. XIV. 132.) VIRGIL’s imitation of this incident, in the combat between #inEas and Turnus before Laurentum, (quoted and referred to in the Effay), can prove nothing more than that Vircit ei- ther adopted in his narrative a different plan from Homer, or endeavoured to give fomewhat more probability to his ftory; juft as in another paflage we find him fubftituting, for the tri- ple chace of the combatants, the more probable incident of dragging the dead body of Hecror round the city ; Ter circum Iliacos raptaverat Hecrora muros. He obferved, in this, the fame rule by which he conduéted him- felf on other occafions, not always to be anxious to tread in the very fteps of Homer, but, where a different delineation fhould of- fer more poetical beauties, to carry his imitation at large through the whole circle of poets, epic or dramatic. In this particular, of the dragging of Hecror’s body, he followed fome other poet, probably Eurrripes. (See Excurf. XVIII. ad £n. I). IF it is to be maintained, that the paflage in Homer, refpect- ing this purfuit of the combatants, cannot mean that it was ac- tually round about the city, and that fuch a purfuit could not poflibly have taken place, the main proof muft be drawn from the topographical fituation of the country. Ancient Troy was acceflible only on the fide next the fea. On the quarter of the I2 Acropolis, 84 TABLEAU dela PLAINE de TROYE. Acropolis it was furrounded by abrupt precipices, and deep ra- vines ; and at the bottom lay the rocky bed of the Simois, as M. GuEvA.ier, an eye witnefs, affures us. His teftimony, by the by, affords a folution why the Greeks, numerous as they were, never completely invefted the city, though this would have been a natural and effe€tual plan of operation. It explains, too, why they did not cut off all approach to the place; for we find freth fupplies and provifions received without interruption from Phrygia; allies and auxiliaries arriving conftantly at Troy. On the fide next the mountains there muft therefore have been a free accefs to the town. Hence, too, it is no lefs evident, that Homer, intimately acquainted as he was with the ground, ne- ver could have faid what has been afcribed to him, that AcuiL- Les chafed Hector thrice round the walls. Still lefs can this be fuppofed, when what the poet is thus made to fay is palpa- bly abfurd in itfelf, that two combatants fhould run three ‘times round the walls of a city) For either, if we fhould’ reckon the thing poflible, our idea of the city muft be diminutive and con- temptible ; or, fhould we fuppofe the city to be large, the im- probability becomes obvious, and we are ftruck with the abfur- dity of the army’s ftanding idle, waiting for the re-appear ance of the runners from the oppofite fide of the walls. Add to this, that fuch an abfurdity is by no means neceflarily implied in the words ; nor would it at all occur, were the paflage read without pigamnee: and with proper attention to its meaning. All the combats take place before the Scaan Gate. Thus far had Pa- Trocius, the preceding day, driven back the flying Trojans. (XVIII. 453. XVI. 712.). No battle, no tranfacion, is men- tioned, as happening in any other quarter, or on the oppofite fide of the town. It is on the Scean Gate that Priam and his Trojans ftand, to be fpectators of the fight. (Iliad, II. 145—154. XXIL 25. 462.). Even during the flight of HecTor, we do not find Priam running from one gate to another, from one fide APPENDIX, No. Ul. gs. fide of the walls to the other; he continues ftanding on the Scaan Gate.—The whole narrative of the tranfaction in queftion is as follows :— Hecror at firft takes his {tation before the Scan Gate, waiting on foot the approach of AcuIties, (XXII. 96.); but as ACHILLES draws near, he is feized with a panic. To efcape from him, he takes his flight along the foot of the wall, (r qurseuosl 3h SONA RHE Te antl aitinte sh, sur inter ast ésitvor. 1e0q ysrorttisrorts anh. TiodpelLs sty Pe =A onesies plait soApaINO Gry mhagab gr 3), ovine, IF Lp s0rilens..¢: noqPag, our;s9}-485 agop als abies it dais : shuts voc nicer Ais aise iodo bo Bigirt, : : 1 Yaute fees reyodtee SNS RSs Ly Ve 14 72 MSD LAN eT) 24 . ra - : fal , > - + - y 4 . gor ¢ y * it 7 . ; ‘ ‘i a ee. | _ > ae } kas i ; y ‘ ey ie 4 <3 4) é ee : i 2 i > * d vy FHSS, TORY a s * > 4 ereks r ‘ ae oy “ CyeR arias vitor Ut, Xe Cem Bas i: Vie co 4 A nets beter. } Sans Ie AVEAS' TR PYIAE 4 49 ges. byyepreiemse . ‘ Le \, A tute ei cesar be bie ce We EERO at iM MA reat 4G h YAK: ak pe sie et NPAC + 3 e : : ; by SPP, ee ead, ae Va et wy SOR f-ebaases Br VIB or ¢ . . P ~ ’ a Ar Sees pe AD Se hehe f aer RATT RN Et > * ae 0 ” if vw Rie wire veella 2e broke * - » he ae ay CTA > S54 at 2 Smt . % Ape =" rite % 4 e ra - eat ‘ hy ‘ ” ed iy war i oa Ps j TT “é d ~t ‘i ow tor 4 ‘ et > UES. Sree, - 2 2hOE- Swi Led hEvbR ; : y . == ei * 2 r ist z . vi ? : or ’ ere ONES eC AR ee BAS AES CORRS. MORRO, COMA, .€ Pitas ‘s - i ? 4 t ’ 4 be - - ; ; * *, oh > a , ot = i , geht Sos CHEE a . A > * ss y. : 4 if - ' ‘ r E.R RA TA HISTORY. Page 14, line 12, for flots, read floats. 30 line Jaft, for laft Article, Part II. read laft Art. Phyf. Cl, Part IL. PART Il. PHYS, PAPERS, Page 111. /ine 4. from the bottom, for M, read N- 12. from the bottom, for Join AH, read Join EH. 1I9Q. 4. from the bottom, for ArroLLonius read APOLLONIUS. 120, 11. from the bottom, for hence the quadrilateral, read hence, if AG, GK be joined, the quadrilateral, &c- 132. 6. from the top, for fig. 20. Pl. IV. read fig. 13. Pl. II. N. B. In Pl. IV. fig. 18. the points B and K muft be joined by a ftraight line. 335. This Paper is by miftake numbered V. inftead of VI. and the fame error is continued in numbering the remaining Papers of the Phyf. Cl. 138. line laft. for the latitude here given, viz. 57°. 9’. 1/’, read 57°. 8’ 59%”, the Z fun’s femidiameter, ufed in the reduction of the obfervations, _ having been 14’ too great. 2 2 178. 6. inftead of the term =: e, read > é. 193- 4- from the bottom, for quilt-like read quill-like PART III. LIT. PAPERS. Page 86, line 21. for ACHILLEs, read PATROCLUS, 10r. . 5. from the bottom; Notes, for tomb read trench > DIRECTIONS FOR THE BINDER. Tue Binder is defired to obferve, that this VoL. confifts of Four Sets of Pages, to be arranged, after the Tante or Contents, in the following Order, viz.: Part I. containing the History oF TRE SocieETy, with the Pages regularly numbered as far as 40; and afterwards going on with-the numbers included between parenthefis, thus (1), &c. to the end of PartI. Then follows Part II. confifting, 1ft, Of Parers OF THE Puysicat Crass, with the Pages numbered in one Series; and, 2dly, PAPERS OF THE LiteRary Cxass, with the Pages numbered in another Series. 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