322 FIGURE OF THE EARIH. 



which, on the The most simple hypothesis, which lirst presented itself ta 

 tlie^oias^heino- '^^''^"" '"^-agination, was that which supposed the earth to be 

 uniformly throughout composed of the same kind of matter, and its sur- 



p^rfe^lv fluid" ^^*'''^ ''^^' °^ ''^^P^^®^°'''^§°"®'"^^^^ ^y ^^^^^""-^^ round its axis, 

 would elevate This hypothesis, adopted by Newton only as an approximation 

 moreS^thl to the truth, is, in fact, perfectly consistent with the equili- 

 polar regions. Hbrium to which particles in a state of paste, or of tardy 

 fiaic'.ity, would arrive in a short time after their present motion 

 was impressed ; and the eccentricity derived from this hypo- 

 thesis is at least not very remote from that which actually ob- 

 tains in the present state of consistence and stability which the 

 earth has since acquired. 



But geological But the homogeneity of the matter, of which the earth con- 

 observations . , . . . . ,, , . 1 , . 1 • T 



show tiiat the ^^^^^> '^ '^^ variance with all geological observations, which 

 (external part prove evidently that at least 5000 toises of the exterior crust 

 is not homo- '^ formed of an immense mass of heterogeneous matters, vary- 

 geneous. ing in density from each other ; and upon the supposition of 



^ a state of fluidity of the whole, it should follow, that the strata 



should successively increase in density from the surface to- 

 wards the centre, that the more dense would accordingly be 

 subjected to less of centrifugal force, and consequently that 

 the spheroidical form resulting from this cause would be less 

 eccentric than would arise from a state of perfect homoge- 

 neity. 

 Sblution of the The most simple, as well as the most effectual means of 

 measur'iiio-'s^. ^'<2!i^}i"g the hypothesis respecting the figure of the earth, is 

 veral arcs of to measure in the two hemispheres several arcs of its meri- 

 the meridians. ^-^^^^ -^^ different latitudes, at some distance from each other. 

 On this subject it must be allowed, that the Academy of 

 Sciences at Paris set the example, in giving the original im- 

 pulse to the undertaking, and not only commenced, but put 

 in execution those parts of the plan which were most difficult 

 and most decisive. 

 The first mea- The results of the first measurements made of different 

 well as the vi- ^^^^ °'^ *^^® meridian of different parts of the world, were 

 braiions of found to be perfectly conformable to the expectations of 

 rhowec"that: Huyghens and of Newton, and also with experiments made 

 the polar re- on the vibration of the pendulum in different latitudes ; and they 



Snei^^^ ^^^' ^^^^ ^^ ^^^'^^ ^^^^ ^^^ ^'^^^'^ ^'^* ^" ^^^'^ flattened at the poles j 



«6ta- 



