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information was prodigious, his activity was indefatigable, and every region of knowledge which he traversed received marks of his original and inventive genius. But he was far inferior to Newton, both as a philosopher and as a man. None of his productions will bear a comparison with the Principia, or the Optics, of Sir Isaac Newton; nor do we think any of his mathematical writings equal to the Universal Arithmetic, or the Fluctions of Newton. We cannot conclude this account better than by giving the comparison between the two men, drawn up by Newton himself, on occasion of this very controversy.

"It must be allowed that these two gentlemen differ very much in philosophy. The one proceeds on the evidence arising from experiments and phenomena, and stops where such evidence is wanting; the other is taken up with hypotheses, and propounds them, not to be examined by experiments, but to be believed without examination. The one, for want of experiments to decide the question, does not affirm whether the cause of gravity be mechanical or not mechanical: the other, that it is a perpetual miracle, if it be not mechanical. The one, by way of inquiry, attributes it to the power of the Creator, that the least particles of matter are hard; the other, attributes the hardness of matter to conspiring notions, and calls it a perpetual miracle, if the cause of this hardness be other than mechanical. The one does not affirm that animal motion in man is purely mechanical the other teaches that it is purely mechanical, the soul or mind (according to the hypothesis of a harmonia præstabilita) never acting on the body so as to alter or influence its motions. The one teaches that God (the God in whom we live, and move, and have our being,) is omnipresent; but not a soul of the world: the other, that he is not the soul of the world, but intelligentia supra mundana, an intelligence above the bounds of the world; whence it seems to follow, that he cannot do any thing within the bounds of the world, unless by an incredible miracle. The one teaches, that philosophers are to argue from phenomena and experiments to the causes thereof, and thence to the causes of those causes, and so on till we come to the first cause the other, that all the actions of the first cause are miracles, and all the laws impressed on nature by the will of God are perpetual miracles and occult qualities, and, therefore, not to be considered in philosophy. But, must the constant and universal laws of Nature, if derived from the power of God, or the action of a cause not yet known to us, be called miracles and occult qualities, that is to say, wonders and absurdities? Must all the arguments for a God, taken from the phenomena of nature, he exploded by new hard names? And must experimental philosophy be exploded as miraculous and absurd, because

408

Graphical Representation of the daily Rate of the [DEç.

it asserts nothing more than can be proved by experiments, and we cannot yet prove by experiments, that all the phenomena in nature can be solved by mere mechanical causes? Certainly these things deserve to be better considered." *

ARTICLE II.

A Graphical Representation of the daily Rate of the Barometer during a Year in London, Paris, and Geneva. By J. P. Pictet, Assistant Professor of Natural Philosophy in Geneva.†

THE representation in Plate XIV. was made out by the author upon a very small scale from a great collection of observations of the rate of the barometer at London, Paris, Geneva, and Madrid, laid before the Natural History Society of Geneva. It contains a complete year of observations, made in the three first named cities. The upper half of the copper-plate reaches from the autumnal equinox of 1806 to the vernal equinox of 1807, the lower half extends from this equinox to the autumnal equinox of the same year. "We see here very evidently," says M. Pictet," how much more the barometer rises and falls in winter than in summer. The complete harmony which exists between the three barometrical curves, and the very regular parallelism of their inflections is surprising, when we consider the great distance of the three places from each other.‡

In January and February we find the greatest, in July and August the smallest, alterations in the height of the barometer. Very high and very low positions correspond in all the three places within a day. The figures upon the plate mark the day of the month on which these maxima and minima were observed. An exception is observable in October, 1806, The barometer was highest in London on the 24th, at P on the 25th, and at Geneva on the 26th. Likewise in January, 1807, it was highest at London on the 5th, in Paris on the 6th, and at

Phil, Trans, 1714, vol, xxix. p. 173.

+ This curious paper was published in the Bibliotheque Britannique for Jan. 1811. I have translated it from Gilbert's Annalen for May, 1812. It is evident that the German editor has made considerable alterations in the ori ginal.-T.

The same thing holds good in another set of barometrical curves con structed by M. Pictet upon a much larger scale, embracing a longer period of time, and including likewise a curve for Madrid.

When these curves are compared, it appears that all the principal inflexions agree very nearly with each other in time and amount: only, the farther north a place lies, the sooner does the change begin at it.

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22 Sept 1807

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Rate of the Barometer at London, Paris & Geneva, for a year.

Engraved by J.Shury for D.Thompson's Annals. Published by R.Baldwin Paternoster Ron, Dec. 1.1813.

Geneva on the 7th. In November the barometer stood lowest in London on the 3d, in Paris and Geneva on the 4th. As these alterations in the weight of the atmosphere begin usually at London, they seem to proceed chiefly in a direction from west to east ; but this commencement in London is not without exception. In May, 1807, the barometer was lowest at Paris on the 29th, at London and Geneva on the 30th.

Though the curves have a great resemblance to one another upon the whole, yet there are some particulars in which they differ: for example, in London the barometer sunk without interruption from the 13th to the 21st of January, 1807; while in Paris and Geneva it made several oscillations during the same time, which agree with each other in these two cities. On the 13th of January, 1807, the barometer sank slowly in Paris and Geneva; but in London it descended with such velocity that in 48 hours it had sunk 0.71 inch. The cause of this change in the barometer must be very powerful, yet completely local, and of very short duration, since the rate of the barometer agrees within a day in London, Paris, and Geneva. It were to be wished that we knew the state of the atmosphere at London on the day of this rapid descent of the barometer. This knowledge would probably throw some light on so sudden a fall.*

I consider the present attempt to be sufficient to show how important it would be to keep daily tables of meteorological observations on different parts of the meridian and parallel of Paris, and to exhibit these observations every year in the state of curves. By this method more knowledge of the modifications which take place in the atmosphere would be gained by a single glance of the eye than by a painful comparison of voluminous observations. To save trouble, tables might be published so contrived that the observer would have no more to do than to denote the daily observation by a point upon the table. At the end of every half year the curve may be directly drawn. A copy of such a graphic delineation might be sent to the central board, which already exists under the name of Board of Longitude, and holds its meetings at the observatory of Paris. Here a complete table of all the observations would be constructed, and a copy of it sent to every observer; from which he would see the fruit of his labour, and be induced to continue his observations. The choice of the places of observation, accurate directions for the benefit of the observers, the precision of the instruments, and

In Great Britain it holds, without exception, as far as my observations have gone, that when the barometer falls suddenly a violent wind soon follows, not always at the very place of the fall, but within no very great distance. I have no doubt that the fall alluded to by M. Pictet was followed by a violent south-wester.-T.

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