impulfe; which as yet I do not feel -We own, however, that, in the Author's cafe of the farmer who knows, certainly, that if he does not fow, it is decreed that he shall not reap as well as in his own cafe, above given, the difficulty has appeared to us to be leffened; on our particularly attending to a circumftance or two, on which Dr Priestley has not perhaps fufficiently amplified, to render his doctrine generally intelligible to his readers. Mr. Palmer, at leaft, feems not to have comprehended his former illuftration; by his dwelling fo much on the obfervation, that farmers, in general, do not believe in the doctrine of neceffity-a remark, which appears to us to be of no confequence in the prefent argument. Dr. Prieftley's principal intention, we apprehend, was to fhew, that a belief in the doctrine of neceffity is not incompatible with, or even unfavourable to, the most fpirited exertions; and that a farmer, believing in that doctrine ever fo firmly, will nevertheless, without any dereliction of his principles, exert the fame endeavours as another farmer who is an anti-neceffarian. Thole who have not perfectly underflood Dr. Prieftley's illuftration, may possibly perceive its drift, by feeing it reprefented in a fomewhat new light, or the light in which it ftrikes us.

One of the circumftances to which we have alluded above is, the ignorance of men refpecting the decrees of providence. On this ignorance (and the neceffary influence of motives) we apprehend, that our Neceffarian Farmer founds his plan of conduct; for we will fuppofe Dr. Prieftley's active farmer to be as determined a neceffarian as himfelf; and yet he fhall till and 'fow fields with as much fpirit [Dr. Priestley would fay more] as any of his more orthodox neighbours, who think they have a will of their own. Suppofing one of thefe laft to ridicule our farmer, on account of a conduct feemingly fo inconfiftent with his principles; we can conceive him thus anfwering his opponent:

Will you, Sir, be fo kind as to inform me which of these two decrees has paffed;-whether I fhall fow my fields, and live, or neglect them and ftarve? I firmly believe one of thefe events to be unalterably determined; but I know not which; nor can you inform me. Under this uncertainty (nay, partly because of this uncertainty), but knowing the uniformity of the courfe of nature, and that unless I fow I cannot poffibly reap, and feeling moreover a defire to fow; I fhall fow with as much fpirit as yourfelf; and half a year hence, my barns and ftacks will inform us both what was the decree. Nay, even now, I think I can venture to specify the decree before-hand, and to pronounce, that it is the favourable one; because I find myself determined (by motives that have a certain and neceffary influence) to exert fuch endeavours to fulfil it, as can fcarce fail of producing that effect, according to the usual course of things.

Thus

Thus likewife, in the other inftance, Dr. Priestley might fay; I know not, certainly, whether it is decreed, that I fhall, or fhall not write an answer to Mr. Palmer's book: but, ignorant as I am of that decree, I know my own prefent feelings, and am sensible of a sufficiently strong defire to answer it. I know likewife, that unless I take the pen in my hand, I cannot answer it. Nay, further, though the decree is as yet a fecret to me, it fhall not (in confequence of my endeavours) remain a fecret much longer; for I will fit down, and anfwer it immediately. -And fo, in fact, it has turned out.

In these amplifications of Dr. Priestley's two illuftrations, we know not whether we have caught the whole of his meaning, or only a part of it. If. we have erred, in our attempt to illuftrate it ftill farther, we cannot well incur much difgrace in fuch a dark fubject: and befides, we err in very good company. -As to the main queftion, it is ably difcuffed by both the parties; but the caufe of liberty is more pertinaciously defended by Mr. Palmer, than by Dr. Priestley's former amicable antagonift, Dr. Price. For inftance, the latter owns, that he cannot fee how a contingent event can be the object of fore-knowledge, even to the Deity himself. "It carries," fays he, in his correfpondence with Dr. Prieftley, p. 175. " the appearance, of a contradiction; it is indeed a difficulty, and I do not pretend to be capable of removing it." Mr. Palmer, however, in his zeal for liberty, more boldly gives up, in fact, the divine prefcience; and endeavours to fhew, that the facrifice is not very great for that, by giving up fuch a notion of prefcience, as is directly inconfiftent with the idea of liberty, or agency in man, we only deny that to belong to the fupreme mind, which is in truth no perfection at all:"

Again, Dr. Price acknowledged it to be abfurd to fuppofe, that men ever act either without, or againft, motives; but he fuppofed the felf determining power to exert itself only when the motives were equal and contrary: - a very rare cafe indeed! - and which reduces,' as Dr. Prieftley obferves, this boasted liberty of man to a very small matter, hardly worth contending for.' Mr. Palmer makes no fuch conceffions; but, in general, fuppofes that the mind may act contrary to any motive whatever.—It is difficult, however, to refift the force of Dr. Priestley's argument, that our volitions, and our actions, depending on them, muft always be the fame, cæteris paribus, i. e. every circumftance being equal; or muft always be definite, in definite cicumftances:-for what, we may afk, is there to produce an alteration, when every affignable circumftance is exactly equal? In phyfics, a propofition of this nature paffes with every one as an axiom;-that fimilar caufes, operating on the fame material fubftance, under fimilar circumftances, muft produce effects pre

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cifely

cifely fimilar.-Why it should be false in pneumatics remains to be explained; even allowing the mind to be immaterial.

man re

That affection of the mind, called remorfe of conscience, feems to prefent a plaufible objection to this propofition. Selfaccufation feemingly implies, that a man would not act the very fame part over again, if he were placed in the fame circumstances. Mr. Palmer accordingly obferves, that when a proaches himself for any thing that he has formerly done, he certainly confiders himself as having had the power of not doing it' and that were he to be placed in the fame fituation again, he would act differently. Dr. Prieftley had before obferved, that, though men may think in this manner, with respect to what is past, they deceive themselves, in fuppofing that they could have acted differently; by their not attending to the change of difpofition, and other circumftances, that have taken place fince the former period. He now adds, that having, fince that time, acquired a different difpofition, and different views of things, they unawares carry them back, and confider how they would have acted with their prefent acquired difpofitions. -Their difpofition being really altered by what has occurred to them fince, they would not now act the fame part over again,'

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On the whole, without difcuffing the merits of the present controverfy, which, from the nature of the fubject, and the improbability of any difcoveries being made in it, may, we apprehend, be carried on to the end of the world, without clearing up the difficulties which attend both fides of the argument:-we fhall only further obferve, that if Dr. Prieftley's antagonists seem to have any advantage over him, it is in thofe particular articles (fuch as refponfibility, merit, and demerit, &c.) where they may allege, with feeming juftice, that a belief in the doctrine of neceffity must have an effect on the bulk of mankind, not fo favourable to morality and religion, as the popular belief on this head though the moral conduct of the neceffarian philofopher, who comprehends the doctrine in all its parts, may, as Dr. Priestley alleges, be improved by his belief in it. For his own part, however, he confiders it as the cleareft of all queftions,' and the truth of it as indubitable as that of any mathematical propofition whatever. I have no feeling,' he adds, either of fear or arrogance, in challenging the whole world in the defence of it. This argument, I compare to fuch ground as one man may defend against an army.

Aware, however, of the unconquerable bias which even philosophical men, of the greateft integrity and abilities, neceffarily acquire towards certain opinions impreffed upon them by the course of their ftudies, habits, fituations, and connections in life; he frankly owns, that he does not expect that any thing he

has

has now advanced, or is capable of advancing, will make the leaft change in Mr. Palmer's view of things. Our present general fyflem of opinions, whether right or wrong, is probably that which we fhall carry to our graves.'-Younger perfons, whose opinions are not yet formed, may nevertheless derive an advantage from thefe publications, that we cannot derive from them ourfelves.

Your fuppofed consciousness of liberty,' Dr. Priestley good humouredly adds, and other popular arguments (though, when analifed they really make against your hypothesis), will always fecure you nine out of ten of the generality of our readers;' who, he elfewhere obferves, will never get beyond the very threshold of the business.'- All that I can do, must be to make the most of my tenth man; and, if I poffibly can, fancy his fuffrage equivalent to that of your nine.'

Whether this fpirited letter of Dr. Prieftley's is the termination of the prefent controverfy, is yet in the womb of fate. At the close of it, he thus expreffes himself, like a true Neceffarian, on the subject. Now, that I have advanced, I verily believe, all that I can, in fupport of my opinion, I ought to acquiefce in the success of my labours, be it more or lefs.-I do not, however, make any fixed refolutions. If you make a rejoinder, as I think you ought, and will be advised to do, I, true to my principles as a Neceffarian, shall act as circumstances shall determine me.'

ART. VI. PHILOSOPHICAL TRANSACTIONS of the Royal Society of London. Vol. LXVIII. Part 2. For the Year 1778. [Con cluded from laft Month's Review.]

METEOROLOGICA. L. Article 32. Comparison between Sir George Shuckburgh and Colonel Roy's Rules for the Measurement of Heights with the Barometer. In a Letter to Colonel Roy, F. R. S. from Sir George Shuckburgh, Bart. F. R. S.

S

IR George Shuckburgh, in his curious paper, entitled, "Obfervations made in Savoy, in order to afcertain the Height of Mountains by Means of the Barometer," and printed in the Philofophical Transactions for 1777, had investigated rules for correcting certain irregularities of the barometer, arifing from the different degrees of heat and cold in the atmosphere, and the expanfion of the different materials of which the inftruments are made, as alfo fome others of lefs moment. About the fame time, and from fimilar experiments, made in different parts of Great Britain, Col. Roy had deduced rules for correcting the fame things. To investigate the differences between the

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Colonel's

Colonel's rules and his own, though thefe differences are very fmall, is the defign of this paper; in the courfe of which it appears that the two principal caufes of difference arife from the expanfion of quickfilver and the expanfion of air. The difference arifing from the former Sir George fhews can feldom amount to more than about 5 feet in a height of 11,000. In their equations for the expanfion of air, the difference is indeed greater, and may be 4 feet in 1000, if the mean height of the two barometers be 27 inches, and the thermometer ftand at 52°. The error increases as the difference between the heights of the two barometers and the height of the thermometer increases. Sir George fubjoins fome reafons for fufpecting the accuracy of thofe obfervations, which feem to require an equation that depends on the latitude of the place.

MATHEMATICAL. Article 33 An Account of the Calculations made from the Survey and Measures taken at Schehallien, in order to afcertain the mean Denfity of the Earth. By Charles Hutton, Efq; F. R. S.

The Newtonian philofophy supposes that attraction is exerted not only between the great bodies which compose the universe, but also between the most minute particles of matter which those bodies confift of: hence it is evident, fuppofing this doctrine to be true, that the plumb-line of a quadrant, or any other aftronomical inftrument, fituated on the fide of a very high hill, or in its neighbourhood, must be attracted from its proper perpendicular direction by the matter in fuch hill; and of confequence, the meridian altitude of any ftar, observed with that inftrument, will be different from what it ought otherwife to be and, moreover, if the meridian altitude of the fame ftar be obferved both on the north and fouth fides of the hill, the attractions in thefe two cafes being different ways, the difference of the two meridian altitudes, when corrected for the difference of the two geographical fituations of the instrument, will be proportional to the fum of the two attractions.

It was on this principle that Dr. Maskelyne, Aftronomer Royal, about the year 1770 or 1771, proposed to the Royal Society, to determine, by experiment, the truth or falfehood of the Newtonian fystem of gravitation. The thought was not new, as the Doctor himself remarks, in his proposals, but was attempted once before by the mathematicians who went from France, about the year 1736, to meafure a degree of the meridian, on or very near to the equator: the manner, however, in which the experiment was then conducted, was by no means fuch as to give fatisfaction to philofophers in general; and if it had, the importance and delicacy of the experiment is fo great as ftill to merit many repeated trials; for as the Author of the paper

now