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ASTRONOMICAL PAPERS. 



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earth we tread, the water we drink, and the very ah- lu 

 which we breathe, fwarm with living creatures, all fitted to 

 their feveral habitations. Are we to fuppofe that this little 

 globe is the only animated part of the creation, while the 

 comets, many of which are larger worlds, and run a nobler 

 courfe, are an idle chaos, formed for the fole purpofe of 

 being frozen and burnt in turns. We cannot admit the 

 thought; the comets are doubtlefs inhabited. The great 

 viciflitudes of cllaiate, is the only plaufible objedion that 

 has been made to this opinion. The comet of i68o came 

 within one hundred thouilmd miles of the Sun, but the 

 Sun's whole diameter Is more than feveil hundred thoufand 

 miles. The comet's heat was then fuppofed to have beea 

 two thoufand limes hotter than red hot iron; but the fame 

 comet was about twelve thoufand millions of miles from 

 the Sun, at his greateft diftance, when it is fuppofed, that 

 he perceived ten thoufand times lefs heat than we ufually 

 enjoy. Hence it is fuppofed, that fuch a planet could never 

 afford a comfortable refidence for rational creatures. 



But here philofophers have taken for granted that the 

 heat of every body is inverfely as the fquare of its diftance 

 from the Sun, a proportion which I greatly fufped; for I 

 apprehend that it is contrary to experiment. 



Were heat a certain body proceeding immediately from 

 the Sun, the quantityof heat in any fpace would doubt- 

 lefs be Inverfely as the fquare of its diftance from the Sun. 

 But I fee no reafon to believe that heat comes from 

 the Sun, while there is much reafon to think that It does 

 not. We perceive that light comes from the Sun. We 

 alfo perceive that heat is produced In the bodies on which 

 the rays of light fall, hence we are apt to confound light 

 and heat together, though it be demonftrable that light is 



not heat and that heat is not light. So contracted 

 knowledge of tlie primary conftituent parts of bodies, that 

 we cannot readily determine why any particular 

 fliould not excite heat with equal facility in all bodies. 

 But we are taught by experience that difTcrent quantities 





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