V 



\ 



EARTH AND 



L 



A ^' 



T 



D S. 



iphere heated, probably the beams being there refle6:ed from the 

 unequal furface of the earth, and crolTing one another in various 

 diredlions caufe greater warmth; and moreover the atmofphere be- 

 ing denfer and more filled with vapours near the common level of 

 the earth, when once warmed to a certain degree, preferves the heat 

 for a longer time *, The contrary mufl take place in a fituation 



> 



more remote from the common level of the earth, where the atmo- 

 fphere is thinner and lefs capable of retaining the warmth. Thefe 

 two principles will contribute to explain the phaenomenon. Under 



r 



the tropicks, the atm.ofphere and furface of the earth is more heated 

 than towards the poles, becaufe the fun operates at the firfl place 

 .more vertically, and at the other more obliquely, and therefore lefs 

 cfFedually : the hills being under the line in a more heated atmo- 

 ifphere,"the line of eternal fnow, is there naturally more removed 



4 

 I . 



t * 



from the common level of the earth, than towards the poles, where 

 the air is neither fo intenfely nor fo conflantly heated, which con- 

 fequently brings the line of eternal fnow much lower. 



The atmofphere being a fluid environing our globe, mufl con- 

 fequently be fubjecfl to all the laws of nature to which the whole 



F 2 



globe 



■- 



I— 



.* Infcnora qwoque tepcnt, prlmum terrarnm halitu^ qui multum facum calldi affert, 

 Jcinde quia radii foils replicantur & quoufque redire potuerunt, repllcato calore benignius 

 fovent, . Seneca Naf, Slnaji. U z.c. X-* 



35 



the nearer to the general, level of the earth, the more is the atmo- moun- 



.TAINS, 



