the edifice, that had been raised by them so slowly, and with so much pains. Still persuaded by the observations made in France, that the length of the terrestrial degree continued diminishing from the equator to the poles, they started doubts respecting the accuracy of the measure taken in the north. They asserted, that it had been executed carelessly, and that the severity of the climate itself might have prevented the employment of all the scrupulous niceness and precision necessary. This accusation was repelled with warmth. The polemical tracts on each side increased; and the love of self was soon more observable in them than the love of truth. A zealous defender of the prolate figure, imagining he had completely refuted the opposite party, would not send his manuscript to the press however, till he had shown it to Fontenelle, whose authority at that time was of great weight. Fontenelle read the work, returned it to the author, and advised him to publish it. The author, a little doubtful of the opinion of the judge, said to him after a moment's silence: 'you give me advice, sir, which you did not follow yourself: a great deal has been written against you, yet you never answered it.' 'O sir,' answered wittily the prudent secretary of the academy, 'I was not so certain of being in the right as you are.'

In this contest the system of the flattening of the poles daily gained ground, from the double advantage it enjoyed of being founded on observations and on the theory of centrifugal forces. Even the Cassinis, the authors of the opposite system, began to waver, and at length acknowledged the necessity of verifying

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verifying the french measures with more accurate instruments, than those which they had employed. In 1739 and 1740, Cassini de Thury, the son of James Cassini, made this verification in concert with the abbé de la Caille; on which occasion the best instruments were employed, and every possible precaution was taken, 'to ensure accuracy. They found, that the degrees for the most part increased from south to north, while a small number only appeared to diminish. The inference from this was in favour of the flattening of the poles, and nothing more was required, but to give it publicity in an authentic form. Cassini de Thury, with his father's consent, had the magnanimity to declare in a public meeting of the academy of sciences, that some errours had crept into the former measures of the degree in France; and to conclude, that the new measures agreed with those of the north in proving the Earth to be an oblate spheroid. He published an account of the business in a book entitled, 'The Meridian of the Royal Observatory verified, &c.' From this time the Earth took, with the common consent of astronomers, and to the great satisfaction of geometricians, the oblate figure which had so long been disputed.

Maupertuis, who was still held out as the author of this revolution, might have enjoyed an unblemished triumph, if his restless and jealous disposition had not continually held before his eyes the speedy arrival of the academicians from Peru, with whom the whole question would require to be discussed anew. Disinterested men of science, without disputing the flatness of the poles, awaited their return, in order to obtain a more perfect knowledge of the form and dimensions of the terrestrial globe. It was well known, that Godin and Bouguer were astronomers of the first rank; that Bouguer was a great geometrician; and that Condamine, though inferiour to his colleagues in science, had surmounted by his zeal and activity a number of obstacles, which opposed the success of their operations. Accordingly there was every reason to presume, that their labours would throw new light on the subject.

The friends of Maupertuis took every means in their power, to destroy or weaken these well founded hopes. They ceased not to repeat, that the problem was already solved, and that the peruvian measures would teach us nothing new, or at most confirm a truth already known. Even the arms of ridicule was employed against them beforehand. Naturally satirical, Maupertuis said in those frivolous companies, where a jest, good or bad, passes for an argument: ' when these peruvians arrive, they will be more perplexed with the figure they will make themselves, than with that of the Earth.'

All this however was to little purpose; in spite of sarcasms and intrigue the measures taken in Peru met with the reception they deserved. Bouguer, in his book On the Figure of the Earth, 1749, related the essential precautions taken by his colleagues and himself, as well for the verification and perfect accuracy of their instruments, as for the most proper selection and use of observations: he discussed several points of astronomy, not before sufficiently elucidated: he made the important remark, that the elliptical. elliptical figure did not exactly agree with every point of the meridians of the Earth: he started other hypotheses, more conformable to the truth in a great number of cases, &c. So many nice researches stamped on the operations in Peru a character of evidence and certainty, which made them be considered as the most perfect in their kind, that had ever yet been executed. Time has confirmed this favourable opinion, while the measures taken in the north are far from being so highly estimated.

Still however the conclusion was, that the Earth becomes flatter toward the poles. The length of a degree at the equator is 56753 toises [120915 yards]: whence it follows, on comparing this with the length of the degree in France, that the axes of the Eartlı are to each other nearly as 178 to 179.

Our unfortunate planet would seem destined to torment man in every view. Scarcely had it regained it's oblate figure, when the regularity of it's composition was disputed, which had never before been called in question; for if the observations in Peru refuted in certain cases the elliptical figure of the meridians, the Earth at least was always considered as a solid of revolution. New observations threw doubts on this opinion, though so natural, and apparently a necessary consequence of the uniform rotation of the Earth round it's axis.

La Caille, in his visit to the Cape of Good Hope in 1750, having measured the length of a degree in the latitude of 33° 18' south, found it to be 57037 toises [121520 yards]; which being greater than that of a degree at the equator, and less than that of a degree

a degree at the polar circle, indicates a flattening of the Earth it is true, but less than would be inferred from the measure of a degree in France, which seems to prove this flattening to be irregular.

The jesuits Boscovich and la Maire established this irregularity, in a manner that would be still more decisive, were it absolutely incontestable. By measures of several degrees of the meridian, taken in Italy in latitudes equal to those taken in France, they found the lengths differ very sensibly from the french measures. Still more: supposing all the meridians of the Earth to be equal and similar, they could not reconcile their own measures either with each other, or with the operations in the north and in Peru. Hence they concluded, that the hypothesis of the similarity of meridians must be given up. Thus several astronomical theories must fall to the ground: the Earth being no longer a solid of revolution, the direction of the plumbline will no longer indicate a perpendicular to the surface of the Earth, or to the plane of the meridian: the observation of the distances of stars from the zenith will not give the true measure of degrees in the heavens, and consequently not of the corresponding degrees on the Earth: &c.

These troublesome consequences did not stop the authors of the new system. Why, said they, is it essential, that the Earth should have a regular figure? If at the beginning it had been a homogeneal fluid mass, the mutual attraction of it's parts, combined with it's rotatory motion round it's axis, would have caused it to assume the figure of an oblate elliptical spheroid: