204 STUDIES OF NATURE. 



my conception of the way in whi h this motion of 

 the Earth is the effecl of thefe effafions. 



Admitting, with Aftronomers, the laws of At- 

 tradtion among the heavenly bodies, the Earth 

 muft certainly prefent to the Sun, which attr^dts it, 

 the weighticft part of it's Globe. Now, this 

 weightieft part mull be one of it's Poles, when it 

 is furcharged with a cupola of ice, of an extent of 

 two thoufand leagues, and of an elevation fuperior 

 to that of the Continents. But as the ice of this 

 Pole, which it's gravity inclines toward the Sun, 

 melts in proportion to it's vertical approximation 

 to the fource of heat, and as, on the contrary, thç 

 ice, of the oppofite pole, increafes in proportion to 

 it's removal, the necclfary confequence muft be, 

 that the firft Pole becoming lighter, and the fé- 

 cond heavier^ the centre of gravity paffes alter- 

 nately from the one to the other, and from this 

 reciprocal preponderancy muft enfue that motion 

 of the Globe in the Ecliptic, which produces our 

 Summer and Winter. 



From this alternate preponderancy, it muft like- 

 wife happen, that our Hemifphere, containing 

 more land than the fouthern Hemifphere, and be- 

 ing, confequently, heavier, it muil incline toward 

 the Sun for a greater length of time ; and this, 

 too, correfponds to the matter of fad, for oi^r 



Summer 



