On the Powers of Steam, &c. 115 



which comes over the sands lying between the Bala- 

 gate-Mountains and the sea-coast ; the effect of damp 

 clothes on the human body : for without having re- 

 course to this method of reasoning, it is difficult to 

 conceive why a damped shirt should have. more per- 

 nicious effects, than immersing the body into a water 

 bath, of the same temperature. 



It would be needless to enumerate all the particu- 

 lar phenomena which are to be explained on these 

 principles ; but I cannot help taking notice of one, 

 as it is of a very singular nature, and as it is a strong 

 illustration of this system. By a letter from Sir Ro- 

 bert Barker, published in the Philosophical Transac- 

 tions for 1775, it appears, that ice is made, in consi- 

 derable quantity, at Allahabad, Calcutta, and other 

 parts of the East-Indies, where natural ice was never 

 seen, and where the thermometer was never known 

 to sink so low as the freezing point. 



He informs us, that, upon a large open plain, three 

 or four excavations are made in the earth, each about 

 thirty feet square, and two feet deep, the bottoms of 

 which are strewed with a pretty thick layer of sugar- 

 canes, or of the dried stalks of Indian-corn. Upon 

 this bed is placed a number of shallow earthen pans, 

 filled with water, which has been previously boiled. 

 These pans are unglazed, scarce a quarter of an inch 

 thick, about an inch and a quarter in depth, and made 

 of an earth so porous, that it is visible from the ex- 

 terior part of the pans, that the water has penetrated 

 the whole substance. 



