1 30 Inquiry concerning the Nature of Heat. 



acknowledged, even by the most determined sceptic, 

 that these animals have been exceedingly fortunate in 

 obtaining clothing so well adapted to their local circum- 

 stances. 



The excessive cold which is known to reign, in all 

 seasons, on the tops of very high mountains and in the 

 higher regions of the atmosphere, and the frosts at night 

 which so frequently take place on the surface of the 

 plains below in very clear and still weather in spring 

 and autumn, seem to indicate that frigorific rays arrive 

 continually at the surface of the earth from every part 

 of the heavens. 



May it not be by the action of these rays that our 

 planet is cooled continually, and enabled to preserve the 

 same mean temperature for ages, notwithstanding the 

 immense quantities of heat that are generated at its sur- 

 face, by the continual action of the solar rays ? 



If this conjecture should be well founded, we should 

 be led to conclude that the inhabitants of certain hot 

 countries who sleep at night on the tops of their houses, 

 in order to be more cool and comfortable, do wisely in 

 choosing that situation to pass their hours of rest. 



[This paper is printed from the Philosophical Transactions of the 

 Royal Society, XCIV. (1804), pp. 77 - 182.] 



