THE

MONTHLY REVIEW,

For NOVEMBER, 1772.

ART. I. Tranfactions of the American Philofophical Society, held at Phi ladelphia, for promoting useful Knowledge. Vol. I. From Jan. 1, 1769, to Jan. 1, 1771. 4to. 12 s. Philadelphia printed by Bradford; and fold by Dilly in London.

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O trace the progrefs of fcience through the various nations and ages of the world, to mark the feveral periods of its rife, glory, and decline, to inveftigate the causes of its profperity or decay, and to obferve the complexion of the times, with the political ftate of thofe countries in which science has been either cultivated or neglected, are objects highly worth the attention of the hiftorian and philofopher, and would furnish a great variety of very important, amufing, and useful information.

To execute fuch a task would indeed require a greater compafs of knowledge and difcernment than falls to the share of any fingle perfon, and would be attended with a degree of application and labour, which few would be willing to encounter. The records of the remoter nations and ages are few and imperfect; and the more modern difcoveries and improvements in fcience are so numerous and various, that the neceflary materials for fuch a hiftory could not be collected without an expence which no private fortune could defray, and without fuch a fund of knowledge, and fuch vigour of application, as no fingle perfon, however curious, intelligent, and refolute, can be thought to poffefs. Would princes unite in affording patronage to fuch an undertaking, and employ a fufficient number of the ableft men in every department of science for this truly valuable purpose, it would be productive of confequences much more defirable and beneficial than any which can arife from the more expenfive purfuits of ambition, and the rage of conquefts.

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A defign of this kind, whatever difficulties might attend it, is not altogether impracticable; and the Writer of this article is not without hopes, as well as wishes, that a period will arrive, in which fuch a fcheme, however imaginary it now appears, may be accomplished. The establishment of literary focieties in different parts of the world muft greatly contribute to facilitate fuch an undertaking. Their tranfactions, carefully preferved and publifhed, ferve as a repofitory of ufeful mate rials for thofe who, in any future time, may have inclination and encouragement to attempt a tafk, fo laudable and fo important. Thefe may be confidered as fo many treasuries, into which every one throws his mite, in order to augment the general flock and they are fice of access to all who wish to enrich themselves by the contributions of others.

In this view only fuch establishments are very important and ufeful and the feveral members and patrons of them may be respected as the directors and guardians of fcience, ever disposed to encourage and affift the ftudious and inquifitive.

But this is not the only advantage accruing from fuch literary establishments. Every friend of fcience has an intereft in this common fteck, and is defirous of repaying into it, with improvement, the contributions he has received. There is a degree of reputation and honour in being connected with the friends of science, to which no liberal and ingenuous mind can be infenfible. It ferves to excite a laudable ambition; and, we may add, that united views and labours promife a much fpeedier and higher advancement in ufeful knowledge, than the feparate efforts of individuals. If we appeal to fact, we shall find that the progrefs of science, of mathematical and philofophical science especially, has been furprisingly accelerated fince the establishment of literary affociations in the various nations of Europe and it is certain, however other caufes may have confpired, that fuch affociations have not a little contributed to this end. What may we not expect from the fpreading of fimilar inftitutions, formed on the most liberal and laudable principles, in other parts of the globe? In this view the Ameri can Philofophical Society, inftituted for promoting ufeful knowledge in general, and thofe branches thereof in particular as may be more immediately ferviceable to the British colonies, claims peculiar notice.

As to the origin of this Society, we are informed, in the introduction to the volume before us, that, two Societies having formerly fubfifted in Philadelphia, whofe views and ends were the fame; viz. the advancement of useful knowledge, it was judged that their union would be of public advantage; and they were accordingly united January 2, 1769, by a certain fundamental agreement; the chief articles of which are-1ft. That the name

of the united fociety fhall be The American Philofophical Society, held at Philadelphia, for promoting useful Knowledge. 2dly. That there fhall be the following officers of the Society; viz. one Patron, one Prefident, three Vice-Presidents, one Treasurer, four Secretaries, and three Curators. 3dly. That all the above officers fhall be chosen annually by ballot, at the first meeting of the Society in January, excepting only that inftead of electing a Patron, the Governor of the province be requefted to be Patron?

We have likewife a brief account of the laws and regula tions of the Society. It appears from the lift for the years 1770 and 1771, that Dr. Franklin, a gentleman univerfally known and esteemed in the literary world, was elected their firft Prefident, and that the number of members is near 300.

Useful knowledge is the leading object of this inftitution; and therefore the members propofe to confine their difquifiiens principally to fuch fubjects as tend to the improvement of their country, and advancement of its intereft and profperity.'

The publishers of this volume have prefixed to it a fhort account of the ancient and prefent ftate of that part of America now poffeffed by the English, and of the province of Philadelphia in particular. They have traced a very striking refemblance between this country and that part of China, which lies in the fame latitude; or that tract of land which forms the eastern fide of Afid, in refpect of foil, climate, temperature of the air, winds, weather, and many natural productions: and they observe, that the fame resemblance is remarkable between the western fide of the old world and the western fide of our continent; whereas the eastern and western fides of the fame continent differ greatly.'

They fhew in what refpects the country is ftill capable of improvement, and they lead the way to difcoveries that may not only be beneficial to the Americans themfelves, but may render them more useful to their mother country. They inform us, that' though it will be a principal part of their business to inquire, and try to find out what their own country is capable of produ cing; what improvements may be made in agriculture, farming, gardening, &c. yet it is not propofed to confine the views of the Society, wholly, to thefe things, fo as to exclude other ufeful fubjects, either in phyfics, mechanics, aftronomy, mathematics, &c. The chief merit (thus they conclude their preface) the Society mean to claim to themfelves, is only that of encouraging and directing inquiries and experiments; of receiving, collecting, and digefting difcoveries, inventions, and improvements; of communicating them to the public, and diftinguishing the Authors; and of thus uniting the labours of many,

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to attain one end, namely, the advancement of useful know ledge and improvement of our country."

In the profecution of this very liberal and afeful plan, we are perfuaded they will have the best wishes and affiftance of all the friends of fcience and humanity. The fpecimen they have already given does honour to their ingenuity and industry, and promifes great advantage to every branch of ornamental and ufeful knowledge, from their future difquifitions and labours.

This volume is divided into four fections, each of which contains a variety of articles on fimilar subjects. If these articles had been numbered, they might more eafily have been referred to; and this, though a trifling circumstance, is not altogether unworthy their attention, in their future publications.

In giving an account of this volume, we fhall clafs its feveral articles under the heads of Aftronomy, Mechanics, &c. as we have done in reviewing the Tranfactions of the Royal Society: and we fhall begin with that which occupies the principal place in this collection, viz.

ASTRONOMY.

The first article under this head is A Defcription of a new ORRERY, planned, and now nearly finished, by ĎAVID RITTENHOUSE, A. M. of NORRITON, in the County of PHILADELPHIA,

This machine is to have three faces, perpendicular to the horizon. From the center of that in the front, which is to be four feet fquare, arifes an axis, to fupport a ball, representing the fun. Other balls, to reprefent the planets, are contrived to move in elliptical orbits, having the central ball in one focus, and to defcribe, as nearly as poffible, equal areas in equal times. The orbits of the planets are to be properly inclined to each other; their aphelia and nodes are to be justly placed; and their velocities fo ordered, as to differ infenfibly from the tables of aftronomy in fome thousands of years. This machine is furnifhed with three indexes, which point out the hour of the day, the day of the month, and year, anfwering to the fituation of the heavenly bodies, then reprefented; they will ferve this purpofe for a period of 5000 years, either forward or backward, There are other contrivances for determining the fituation of a planet, as it may be obferved, either from the earth or fun. One of the fmaller faces exhibits all the appearances of Jupitèr and Saturn, and of their fatellites: and the other reprefents all the phænomena of the moon, and the whole process of folar and lunar eclipfes in refpect of time, quantity, and duration; together with the fun's declination, equation of time, &c. The whole of this machine may be adjusted by a pendulum clock, and the clock part of it may be contrived to play a great variety of mufic.

There.

There is a great number of articles in this collection, relating to the tranfit of Venus in 1769. It would much exceed our limits to give a particular account of each of these. In some we have a defcription of the places of obfervation, and of the inftruments made ufe of on this occafion; together with preliminary experiments and obfervations, towards afcertaining the motion of their clocks, and the longitude of their feveral ftations. In others, we have the obfervations themfelves, with all the circumftances attending this rare and interefting phænomenon, minutely and accurately reported. Others exhibit a comparative view of the obfervations of aftronomers in different parts of the world, together with the longitudes and latitudes of the places of obfervation; the method of calculating the parallax from thefe data, and the parallax itself. We shall only obferve in general, that the aftronomers in America have been no Jefs skilful and diligent in improving and applying this curious phænomenon to ufeful purposes than their affociates in other quarters of the globe. They have fpared neither expence nor labour in procuring all neceffary affiftance and information; they have been fupplied and encouraged by the generosity of their friends; and, whilst others were difappointed by intervening clouds, the heavens were peculiarly propitious to their wishes and expectations.

In the appendix to the aftronomical papers, we have two or three articles which deferve particular notice. The first is a letter from the Rev. Mr. Ewing to the Society, communicating an improvement in the construction of Godfrey's (commonly called) Hadley's quadrant, not long fince difcovered. The greatest inconveniences arifing from the former conftruction of this inftrument are owing to the badnefs of the glaffes, the planes not being ground parallel to each other, and to its ftanding in need of a new and careful adjustment almoft every time it is ufed. These imperfections, it is apprehended, are removed by the new construction: and this inftrument will be peculiarly ferviceable for finding the longitude at fea, by the obferved diftance of the moon from the fun, or from a known ftar near her path, as angles may be measured by it with much greater precifion than with the common quadrant. For these purpofes it is propofed, that the arch should contain 120 whole degrees, and be numbered from the middle to 120 both ways, and that instead of one central fpeculum, two fhould be fixed to the index, inclining to each other in an angle of 60 degrees. When thus adjufted, they are to be fcrewed faft by the maker. The chief advantage attending this new construction is this, that the inftrument becomes hereby capable of affording a number of obfervations, fo that by taking the mean of feveral, the

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