his Analyfis; accufes him of ignorance of logic, and of lan 'guage; and compares his Perfian ftories to Mother Goofe's Tales. Indeed he indulges throughout his whole Apology a vein of pleafantry at Mr. Richardfon's expence, which one would not have expected from a man of fuch profound erudition. However, as Mr. Richardfon obferves, he is fometimes a little fad fomething like an April day; now raining, now fhining; laughing with one eye and crying with the other.' Mr. Bryant afferts, that although his etymological fyftem might be found contrary to truth, the history would fpeak for itself; and without thefe helps be authenticated;" and he challenges his adverfary to a fuller examination of his performance. The latter accepts the challenge; and obferves that upon re-examining his Syftem at large, with more attention, what before feemed merely improbable, he now conceives, upon Mr. Bryant's own grounds, to be irreconcileable with the facred writings; to be unfupported by reafon ; to be inconfiftent with itself. In a word, to be impoffible.

In order to fupport thefe pofitions, Mr. Richardson, who wishes to address himself to the common fenfe of general readers, whofe line of ftudy may not have led them to oriental pursuits, arranges his obfervations under different heads. The etymological difquifitions, which fome part of the. fubject requires, are thus feparated from the reft, which depends onobfervations and arguments altogether foreign from eaftern tongues. He begins, in fection z, by confidering the inconfiftencies in the chronology of the Analyfis. Chronological accuracy ought to form the groundwork of every rational historical deduction; and ought to have been an object of peculiar attention to Mr. Bryant, whofe fyftem was to reform all former fyftems; to render fuperfluous every future fyftem ;. and to clear up the perplexing difficulties which had fo long embarraffed our greateft chronologers.' Mr. Bryant likewife tells us,

that his book was to be the bafis of hiftory, the standard of criticism, and the guide to the ftudies of youth.' Yet Mr.. Richardson obferves, that this learned gentleman has adhered to no regular ftandard of chronology. He has taken the range of many volumes; and his extracts are copious. But their jarring chronologies he feems to have followed without reflection; and to have involved himself in a labyrinth of perplexity, which makes him at variance with the Bible, with its verfions, and with himself That the reader may judge how far he has proved thefe points, we. fhall infert the paffage. at large.

By the Hebrew Bible, the Deluge happened in the year of the Creation 1656: by the Septuagint, in 2262; and both agree in fixing the divifion of the earth to the days of Peleg.

The migration of the pofterity of Noah to the different regions affigned to them by divine appointment, the learned gentleman labours to prove, as the leading point of his fyftem, to have been an event prior to the Babel difperfion. And this migration, on the authority of Eufebius, he has placed in the year of the world 2672, when Noah was 930 years old. But in another place, tranfcribing from Epiphanius, he supposes Noah to have refided with his pofterity, before the migration 659 years, in the neighbourhood of Mount Ararat, where the ark is faid to have refted after the Deluge. These facts and dates he confiders as undifputed; he realons from them, and makes them the groundwork of his fubfequent pofitions.

Now let us try their validity. And first, by the chronology of the Hebrew Bible. The Flood, as before obferved, happened in the year 1656: Noah, being then 600 years of age. He lived afterwards 350 years, and died in the year 2006. Peleg, in whole days the earth is declared by Mofes to have been divided, was born in the year 1757; and died in 1996. But, according to the calculations adopted by the learned gentleman, the divifion, instead of being in the life-time of those two patriarchs, could not take place till 666 years after the death of Noah ; and 676 after the death of Peleg. Whilft, in the other paffage, as quoted from Epiphanius, a ftill greater impoffibility is fuppofed for Noah is there faid to have been alive 659 years after the deluge; which would not only poftpone the migration 249 years later than 2672, which he had already determined upon, but extend Noah's life to 1259 years; although every concurring authority makes the fum of his age to have been only 950.

Let us now confider these pofitions by the Septuagint chronology. Noah, at the era of the flood, which is fixed by the chief copies of that verfion to the year 2262, was, as above noticed, 60 years old: to which, if we add the 350 years he lived after it, he must have died in the year 2612, fixty years before the migration, inftead of being alive twenty years afterwards. Whilft Peleg, not having been born, agreeable to the Septuagint, till the year 2794, the migration, according to the date the learned gentleman has followed, muft have taken place 122 years before his existence.

Rut, however inconfiftent he might have been with all the chronologies of the facred writings; a conformity with himself might perhaps have been expected. But even this we do not find. I have neither time, inclination, nor room, to dwell upon many points. 1 fhall only mention one. In his inveftigation of the Egyptian dynafties, he places the Exodus of the children of Ifrael, in the year before Chrift 1494; (which is within about two years of our Bible chronology): their refidence

n Egypt he computes at 215 years: the shepherd kings, whom he fuppofes to be Cuthites, ruled over Egypt 259 years; and were expelled 37 years before the fettlement of Jacob and his fons. Now if thefe fums are added together, the Cuthite invafion must have been 2005 years before Chrift: or (as he here goes by the Hebrew chronology) in the year of the world 1999; which is no fewer than 673 years before he, in another place, makes them, or any of the fons of Noah, to have moved from the spot where the ark rested after the flood, So that the three great objects of this elaborate work; the deluge, the migration, and the expeditions of the fons of Chus, are left, in a point of fuch importance as time, fo wholly unfettled, as to vary in every circumftance and to differ, in fome, near 800 years.'

On a future occafion we fhall give an account of our author's ingenious obfervations concerning Mr. Bryant's theory of the difperfion : his examination of the Cuthite system; and his remarks upon Sanconiathon, Manetho, Berofus, and other writers cited by Mr. Bryant in defence of his opinions.

[To be continued. ]

Sonorum Doctrina rationalis et experimentalis, ex Newtoni, optimorumque Phyficorum Scriptis, Methado Elementaria congefta. Cui præmittitur Difquifitio de Aere et Modificationibus Atmosphæra. Au&tore Guilielmo Hales, A. M. 410. 6s, boards. Wallis.

AS

S a proper introduction to the doctrine of founds, Mr. Hales firft treats of the nature of air. After defining it, from its phenomena, to be an elaftic and compreffible fluid, and therefore capable of occupying a greater or lefs fpace than it naturally poffeffes, he enumerates the various ways in which its expansive property has been accounted for. Richard and others think it is caufed by a spiral or twisted form in the particles of the air; Pafcal, &c. imagine it arifes from an expantion of its parts after the manner of wool; while Euler, Bernouilli, and others, after Des Cartes, account for it by the centrifugal force of the fubtle manner within bubbles of air, by the circular gyration of which a continual endeavour of expanfion arifes. But Newton thinks that the extremely great expansion of the air cannot be accounted for by these hypothefes, and fufpe&ts that the air confifts of very fubtle particles mutually flying from one another by forces reciprocally pro portional to the diftances of their centers; for it is demonftrable that a fluid compofed of fuch particles will have its denfity and elaflicity proportional to its compreffion, and its volume in the fame proportion reciprocally; which property

is fhewn by experiments to belong to the air, either accurately or very nearly, as was first discovered by Boyle and his difciple Townly, and confirmed by all obfervations and ex periments to the prefent time. It must be confeffed, however, that all the experiments have been made with air not varying greatly in denfity; and whether the property obtains when the density differs by many hundreds or thousands of times, is perhaps to be doubted, at least it has never been Thewn by experiments. He then remarks fome other properties of air, and thews that it may be compreffed into a very fmall volume; for that it has been compreffed into a face 13 times less than its natural bulk by Boyle, 60 times lefs by Halley, 300 times lefs by Richmann, and into 1551 times lefs by Hales; in which last case it would be of almoft double the gravity of water, which is something more than 800 times the denfity of common air. But as to its expanfion, it feems to be beyond all limits. That befides real air, the terrestrial atmosphere contains vapours, exhalations, and other heteroge neous particles of bodies.-That all bodies expand with heat and contract with cold, but air in a greater degree than any other. Various degrees of expansion and elasticity with heat. -That the mean denfity of the air, at the furface of the earth, is to that of water, as 1 to 870 nearly. And that the whole preffure of the atmosphere is equal to a column of about 5 miles high, of this mean denfity; but that the exact height cannot be computed becaufe of the heterogeneous particles in the atmosphere.-He then afferts Halley's rule for computing the denfity of the air at any affigned altitude, viz. that while the altitudes increase in arithmetical progreffion, the denfities decrease in geometrical progreffion; but feveral objections are brought to this rule, because it fuppofes the elafticity to be accurately as the compreffion, and that the degree of heat is every where the fame. This part of the work is then closed with fome account of the method of estimating 'terreftrial altitudes and depreffions by the height of the mercury in the barometer tube, which meafures the preffure of the air. An ingenious method, and which may fometimes be ufeful.

The fecond part of the work treats of this very difficult sub! jea, the pulfes of the air caufed by the tremulous motion of fonorous bodies. Having defcribed the terms relating to, and the properties of thefe pulfes, he explains Newton's folution of this problem: Given the denfity of the air and the elaftic force, to find the velocity of a pulfe.' The folution of this problem from theory, determines the velocity of found to be about 1020 feet per fecond of time. But on account of the

Ff4

vapours

vapours contained in the air, the number ought perhaps to be increased nearly to 1142, what it has been found to be by experiments.

The third part treats exprefsly on the doctrine of founds, He defines found to be pulfes of air propagated by the vibrations of tremulous bodies, and thence conveyed to the tym, panum of the ear. From experiments with pneumatical machines, and from thunder or the firing of guns at the tops and bottoms of mountains, he fhews that air is neceffary to found; that founds are not heard from a vacuum; and that they are more or lefs intenfe according to the denfity of the air. He then explains the effect of found in mufical chords, And fhews that found is not produced by a loco-motion in the air like to wind, as it does not affect the flame of a candle, &c. placed near the fonorous body.

Mr. Hales afligns the fourth part to what he calls the phenomena of founds. He here fhews, that found diffufes itfelf equally in all directions:-That the force or intenfity of found decreases in the duplicate ratio as the diftances increase.That found is audible at various diftances according to its own intenfity, and other concomitant circumftances, which being various and numerous, the utmoft limits are not known, but that the firing of cannon has been heard to the distance of 200 miles.-That the velocity of found is about 1142 feet in a fecond, varying a very little from this number, either more or lefs, according to winds, heat and cold, &c.-That the mean velocity of the wind, as from 10 to 15 miles an hour, and that the greateft velocity hardly exceeds 60. While that of found is near 800 miles in the fame time. the two motions!-He then again treats of the determination of diftances by the velocity of found.-Of vibrating chords, and mufical founds in general. Shewing that tones are more grave or more acute, as the vibrations of the fonorous bodies are flower or quicker. Of wind inftruments, pipes, trumpets (for the mouth and ear), whifpering domes.-From Newton's Arithmetica Univerfalis, prob. 50, is delivered the folution of this problem; To find the depth of a well, from the return of the found of a ftone let fall and ftriking the bottom of it.-Finally it is fhewn that found is tranfmitted from one medium into another.

So different are

The next part treats of reflex founds or echos. Of thefe Mr. Hales defcribes the properties, and relates accounts of fome of the most remarkable ones in different parts of the world. As reflex founds fly with the fame velocity as the di rect or primitive ones, he remarks an eafy method of determining the diftance of an object from the time in which it

returns