REFRIGERATION. 345 



those countries in which the temperature of the 

 climate is generally very high.* 



Although the temperature of the air varies in 

 different countries, as well as in the same coun- 

 try at different seasons, it may, nevertheless, be 

 considered a general truth, that when the tem- 

 perature is increased on the plain surface, the 

 minimum of low temperature prevails at the 

 polar regions, and progressively becomes higher 

 towards the line of the equator, when it may 

 be said to have attained its maximum. The 

 temperature of Siberia and of Africa are as 

 different as they are distant from each other; 

 in the one, it is found, according to the present 

 scale, as low as 5 of Fahr. t in the other, as 

 high as 114 degrees: although this great differ- 

 ence of temperature exists on the plain surface, 

 a greater uniformity prevails, in the upper parts 

 of the firmament, insomuch that in ascending 

 the highest mountains of the world, at whose 



* At Benares, in the East Indies, the manufacture of ice is 

 carried on to a very large scale; a piece of ground is divided 

 into plots four or live feet wide, the borders of which are 

 raised four inches above the central surface: dry straw is 

 placed on this part, and a number of earthen pans, of a very 

 porous quality, smeared over with butter on the inside, are 

 placed on it. In the evening, water is poured into these pans, 

 and ice from one to two inches in thickness, is found in them, 

 the ensuing morning." 



