It is now very generally admitted by philofophers, that the noted controversy about the force of moving bodies was at bottom a dif pute of words. The loofe and undefined acceptation of the terms action, effect, performance, &c. in mechanics, proved the fource of endless debate. A question in reality fo nugatory affords not a fingle conclufion applicable to practice. Both parties agreed on the fundamental principle of dynamics: but the followers of Leibnitz were guilty of inconfiftency in fuperadding an arbitrary propofition.

To fhew that the Newtonian doctrine does not answer, so well as the Leibnitzian, the purpose of the practical mechanic, Mr. Anftice defcribes the machine used in founderies for breaking caft-iron, &c.

• It confifts of a ball of iron of one hundred weight, which is raised by manual labour to the height of 64 feet, where it is difengaged and fuffered to fall on a pig or bar of that brittle metal, which by its velocity it is just fufficient to break. Now this ball is raised to the above height by the exact fame mufcular labour and in the fame time, as would be requifite to raise a ball of 4 cwt. 16 feet by ufing any of the mechanic powers. But what will be the efforts in this cafe to break the iron? In the former, the velocity at the moment of percuffion will be as 8, in the latter 4, which, according to the Newtonian doc, trine, will produce a momentum in the one as 8 by 18, in the other as 4 by 4=16, with this advantage attending the latter, that, although it be raised by the fame power in the fame time, it will fall when difengaged in half the time which the former will require. Therefore, by the Newtonian account, there will be great waste of labour, unless the weight of the ball be altered to the greatest, and the height through which it is raised to the leaft, which the given power, as to exertion and time, will admit of."

It is to be observed that neither the Leibnitzian nor the Newtonian doctrine is adequate to the explanation of the fact here mentioned. According to the former, for instance, the effect of the ftroke would be the fame if 64 cwt. fell from the height of one foot :-but Mr. Anftice, and every perfon acquainted with practical mechanics, will readily acknowlege that the fubftitution of this flow ponderous mafs will not produce the end defired. The true explication must be de. rived from the principle which we formerly stated. The rapidity of the defcending body is fuch as to concentrate the whole action of the ftroke on the contiguous portion of the obftacle, without allowing time for the motion to diffuse itself through the mafs. Hence the fracture is commenced, and is continued by the general tremor which ensues. A fimilar confideration will obviate another objection which Mr. Anftice proceeds to make. If a fhip break from her moorings by the action of a current moving with the velocity 1, and it be found that a chain of brittle metal be just sufficient to stop her': if the velocity of the current were 2, it would by the Newtonian doctrine require 2 fuch chains, and by the Leibnitzian 4 such, to stop her motion; and as the effects in both cafes would at last appear to be inftantaneous, it would be in vain to urge that the times of action, during the feparation of the metal in thofe inftances, were different.' The affertion at the clofe of this quotation is very hafty and inac Our fenfes are not fufficiently delicate for philofophical ob

curate.

6

fervation

fervation, Motions, whether extremely rapid or extremely flow, elude their difcrimination. In thefe cafes, it is reafon or the analogy of facts that must direct our decifions. Were ropes fubftituted for the metallic chains, the progreffive ftraining of their fibres, which terminates in rupture, would render the interval of time apparent; yet the only difference in the effects confifts in degree. Inftantaneous in the ftrict acceptation is abfolutely inconceivable; in ordinary language, it denotes a celerity which outftrips the current of our sensations. All motion is performed in time: this axiom, although often neglected, is of most important application in natural philofophy.

We advanced that all the modifications of force may be refolved into preffure. To this doctrine Mr. Antice urges the objection that one bard body may prefs, by its gravity, &c. on or against another, during a hundred days, without producing more effect (as to any mechanical purpose) than in one; although, by the above pofition, the force exerted be a hundred degrees more in one cafe than in the other; therefore, caufes and effects cannot here be equal,' We would only obferve that abfolute hardness is a mere fiction of theory. All fubftances are condenfible, and differ only in the degree of that qua lity. The incumbent body will occafion fuch a compreffion as to form a repulfion equal to the weight; and these two oppofite forces will maintain perpetual balance. If the weight rested on a spring, Mr. Anftice could be at no lofs to conceive our meaning.

What has confused or misled our author, and many others who are not exercised in metaphyfical difcuffion, is the crude doctrine delivered in the common books on Natural Philofophy. The treatises written in the English language are particularly defective. We are forry to confefs that mathematical learning has long been on the decline in Great Britain. The memory of paft glories has nourished our vanity and damped our exertions. Supinely proud of our imagined fuperiority, we have ceafed to cherish the ardent impetuous spirit of

research.

JOINHERIA, and XY Z, muft excufe our non-compliance with their requests. We really have not time to answer all the appli cations for literary advice, &c. which are continually made to us.

6

+++ The letter figned An Old Woman' is received. We do not queflion the Lady's veracity.

ttt W. D.-Clericus of Leicestershire,-J. W. &c. &c. are under confideration.

11 Several small tracts have been tranfmitted to us from certain of the North country Preffes, [Whitehaven, Carlisle, Penrith, &c.] but are unfuitable to our purpose; some are of a date too remote others are not of fufficient confequence.

SIS. The late Mr. STUART'S Antiquities of Athens, Vol. III. will appear in our next Review.

TO THE

SIXTEENTH VOLUME

OF THE

MONTHLY REVIE W

ENLARGED.

FOREIGN LITERATURE,

ART. I. Vogages de M. P. S. PALLAS, &c. i. e. Travels of Profeffor PALLAS in different Provinces of the Empire of Ruffia, and in Northern Alia; tranflated from the German, by M. GAUTHIER DE LA PEYRONIE, Secretary for Foreign Affairs. 4to. 5 Vols. with another of Maps and Plates. Paris. 1789-1793. 71. 178. 6d. De Boffe, London.

THE

THE truly imperial defign fet on foot by the magnificent Catherine, for obtaining an exact account of the inhabitants and the natural and artificial productions of her vaft empire, in which fome of the ableft men in Europe were for many years employed, has already diffufed much copious and ufeful information among the learned in general:-but the works at large of the travellers themselves, having been shut up in the German language, long remained inacceffible to the greater part of readers throughout Europe. The publication before us offers, in the vehicle of a language which may almoft be termed univerfal, the principal of these works,-that of the celebrated Profeffor PALLAS; fo well known for his accurate, various, and extenfive knowlege *.

The tour, of which this is a detail, commencing in the fummer of 1768, did not terminate till July 1774. Its general courfe was fouth-eastward, comprizing the provinces of Kafan and Orenburg, the borders of the Cafpian Sea, the provinces of Onfa and Permia, Tobolfk, the course of the Irtifh, the government of Kolivan, the lake Baikal, and as far * See Review, vols. lxiii. lxix. and lxxi.

APP. REV. VOL. XVI.

LI

eaft

east as the banks of the river Amour. The principal objects of his researches were the manners and cuftoms, religions, languages and antiquities, of the feveral tribes and nations. which he vifited; the natural productions of the countries, efpecially in the vegetable and mineral kingdoms; with the working of mines, and preparation of metals. On all these topics, we find many curious details in his voluminous narration, related with minute exa&nefs, but generally in a manner better fuited to inftruction than entertainment. We shall extract a few of thofe articles which we think will prove most agreeable to our readers; and, as only the last three volumes can now be confidered as a recent publication, we shall confine ourselves to the matter which they afford. They take up the writer at Tcheliabinsk, whence he proceeds eastward to the Altaisk mountains, and the river Irtifh.

In the neighbourhood of this river, M. PALLAS procured a remarkable bird, the white crane, called Sterk by the Ruffians ; which he thus defcribes:

Thefe cranes are more crafty than the common fpecies. As foon as they perceive a man, even at the greatest diftance, they immediately rife into the air and give the alarm: their cry resembles that of the fwan. They are nearly five feet in height when they ftretch themfelves out, fo that they fee a great way. The leaft noise in the rufhes fcares them, and the fowlers are obliged to take the opportunity of approaching while they are bufy in watching for the little fifh on which they feed. They fear dogs lefs than men; infomuch that when they fee dogs on the banks, they run on them, and attack them with fury; forgetting that at the fame time they expose themfelves to the fowler. They attack men with equal rage while they have young, if any one approaches their nefts. In that cafe, they do not rife into the air, but defend their retreat with obstinacy; and their bulk, and very fharp cutting beak, render them dangerous. They make their nefts on little eminences covered with reeds in the midst of the rushy marshes, and weave them with small rushes. The male and female fit and take care of their young alternately. They never lay more than two eggs; which are of the fize of that of a goofe, and are of a greenith yellow, fpotted with brown. The young arrive nearly at their bulk in the first year, during which their feathers are of an ochre yellow, fomewhat white beneath; the head a little black near the bill. In the fecond year, they become white, having only the quill-feathers black. The head is red where divested of feathers, that is, as far as beneath the eyes; and it has little hairs of the fame colour. The fkin, bill, and feet become red; the neck alone preserving somewhat of a fiery yellow. This fhade is loft as they grow old, when they acquire all over the dazzling whitenefs of the iwan. Thefe birds are found from the Uralfs mountains to the Obi, but most frequently near the extenfive lakes and folitary noraffes of the heaths of Ifchimi and Barabini. They refort to the fouthern diftricts every spring; at which period they have also been

feen

teen to cross the Cafpian Sea, but in fmall numbers; and it is to be prefumed that they país one by one, and rise very high in the air, fince they are scarcely perceived. They are no where feen in flocks fo numerous as thofe of the common crane. It appears that the former travellers through Siberia have taken this bird for the white ftork, on account of the affinity of the Ruffian name, fterk: but it has been through the want of examining them with attention. The white

ftork is not found in Siberia, but in Bukaria, where they build on roofs and chimnies as in Europe. Young ferks may be reared with common cranes, and live well with them; yet, though tame, they are apt to be mischievous, and readily attack children, to whom they are dangerous.'

The veftiges of the works of that antient and unknown people, the Thudes, at the rich mineral mountain of Schlangenberg, in the hilly country between the Obi and Irtish, form a curious object of fpeculation. They are thus defcribed:

The antient labours of this nation in the Altaisk mountains prove what an induftrious race they were. It appears that the Tfhudes knew how to make a distinction between the upper and the lower ores of the Schlangenberg. They have wrought the rich and tender ores of ochre, and the clays of the furface of the foil, by deep rakes, and pits which they have carried more than five fathoms in depth. They were deftitute of means and tools to penetrate into the folid minerals. In the ftill exifting upper works, an excavation is found which has been filled up; a proof that they made an attempt to pierce into the hard fpar, and fucceeded fo far as to make a tunnel-fhaped cavity. This fact may be certified, fince their tools have been found buried in the minerals of the new works. All their mining inftruments are of copper. Last year, one of their pick axes of the fame metal was found at the depth of ten fathoms. As a proof that they were ignorant of iron, all the knives, poniards, points of arrows, and inftruments, buried in the antient fepulchres of the Tfhudes, exifting near the chain of mountains and in the heath washed by the Irtish, are of copper. Instead of a hatchet, they made ufe of very hard ftones of an oval figure, round which they hollowed a groove, which doubtless ferved for fixing a thong, in order to use them more easily. Several of these ftone hatchets have been dug up. Some years ago, the entire skeleton of an old miner, half mineralized, was found among the ores. He had, without doubt, been buried by the falling in of the earth. A leathern fack filled with very rich ochre was found near the skeleton. All the marks that have been discovered prove that thefe antient miners dug the ochres only in order to procure the gold which they contain. Between the mouth of the fhaft of Nadefda and the ftamping-mill near Zmiiefka, the ruins of their works have been found, extending more than 100 fathoms along the ftream. This proves that they here washed the fhlick of gold which they got from the pounded ochres and tender ores. Thefe ruins have been found ftill to contain metal enough to deferve being again ftamped and fubmitted to washing.

All these labours throw no light on the origin of the Thudes, called Tbudaki by the Siberian Ruffians. They would feem to have de