114 THE CHEMISTRY OF CREATION. 



that miners working at great depths in the 

 earth, enjoy a kind of perpetual summer, which 

 is almost entirely unaffected by the condition of 

 the surface, even though the earth be clad in 

 the cold but glittering raiment of the sharpest 

 winter. There is a mine in Cornwall, one of 

 the levels of which is so hot, that although a 

 stream of cold water is purposely allowed to 

 flow through it, in order to reduce the temper- 

 ature, the miners are compelled to work nearly 

 naked, and will bathe in water at 80 to cool 

 themselves ! In another mine in the same 

 county, which has been carried to the immense 

 depth of 320 fathoms, the temperature is hotter 

 than on the surface in the warmest summer day ; 

 for while a very hot day in July will raise the 

 thermometer to 82, this instrument in the 

 mine rises to nearly 100. The Artesian wells 

 illustrate the same fact. These wells are formed 

 by boring to the depth of many hundred feet 

 in the earth. It has been found by experience, 

 that the waters of such wells are hotter than 

 ordinary well water, and exhibit a regular 

 increase of heat in proportion to the increased 

 depth of the borings. It has been a speculation 

 whether, in fact, water could not be thus ob- 

 tained sufficiently hot for economical purposes. 

 The celebrated Artesian well at Crenelle, near 

 Paris, has been sunk, after a labour of seven 



