468 Life of Count Rumford. 



climates of the world Let us with becoming diffidence 



and awe endeavour to see what the means are which have been 

 employed by an almighty and benevolent God to protect his fair 

 creation." 



It was absolutely necessary that a great quantity of 

 living water should be preserved in a fluid state in 

 winter as well as in summer. Water must therefore 

 be prevented from parting with its heat in a cold at- 

 mosphere. Liquids part with their heat only in conse- 

 quence of their internal motions, and proportionately to 

 the rapidity of those motions, which are produced by 

 changes in the specific gravity of a liquid, induced by 

 a change of temperature. Now it has been proved that 

 the peculiarity of water is that the change in its specific 

 gravity induced by any given change in temperature is 

 very small ; and, when water is cooled to within seven 

 or eight degrees of the freezing point, it not only ceases 

 to be further condensed, but actually begins to expand, 

 and continues increasingly to do so as long as it can 

 be kept fluid. And when water is changed to ice it 

 expands even still more, and the ice floats on the surface 

 of the uncongealed part of the fluid. The consequence 

 is that the tendency of water to cooling by mere con- 

 duction when exposed to a cold atmosphere is thus 

 retarded. The Count then proceeds to trace the opera- 

 tion of the principle which he has thus described, in 

 effecting, as a result, that when the upper surface of a 

 lake, for instance, is covered with ice and snow, the 

 mass of water below loses no part of its heat, but 

 rather increases it. He then passes to a very lucid 

 and eloquent exposition of the beneficent agency of 

 the oceans of salt water under the operation of the laws 

 he has investigated. It is but just that the "devout 



