218 THE FARMER AT HOME. 



enables these animals to ascend with more facility than to descend, 

 and hence, when pursued, they always attempt to gain the summits 

 of the mountains. They inhabit the chain of mountains extending 

 from Mount Taurus, between Eastern Tartary and Siberia. In Eu- 

 rope, they are found on the Carpathian and Pyrenean chains, and in 

 the Grisons and other parts of the Alps. 



ICE. A brittle transparent body, formed of some fluid, frozen or 

 fixed by cold. The specific gravity of ice to water is as eight to nine ; 

 or the specific gravity of water being one, that of ice is ninety-three ; 

 hence, being lighter than water, it floats upon it. The specific gravity 

 of ice was tried by Dr. Irving,, in Phipps' voyage to the north pole ; 

 who found that when a piece of the most dense ice which he could 

 meet with was immersed in snow-water, the thermometer thirty-four 

 degrees, fourteen-fifteenth parts sunk under the surface of the water ; 

 in brandy just proof, it barely floated; in rectified spirits of wine, it 

 fell to the bottom at once, and dissolved immediately. This rarefac- 

 tion of ice has been supposed to be owing to the air bubbles produced 

 in ice while freezing ; these, being considerably large in proportion 

 to the water frozen, render the ice so much specifically lighter. 



Accordingly, it is said that a considerable quantity of air is lodged 

 in the interstices of water, though it has not there any elastic property, 

 on account of the disunion of its particles ; but these particles coming 

 closer together, and uniting as the water freezes, light, expansive, and 

 elastic air bubbles are thus generated, and increase in bulk as the 

 cold grows stronger ; whence of course the ice grows lighter, and 

 these air bubbles acquiring an elastic force, burst to pieces any vessel 

 in which the water is closely contained. But snow-water, or any 

 water being boiled over the fire, affords an ice more solid than ordi- 

 nary, and with fewer bubbles. Pure water, long kept in vacuo, and 

 frozen afterwards there, freezes much sooner, on being exposed to the 

 same degree of cold, than water unpurged of its air and set in the 

 open atmosphere. And the ice made of water thus divested of its air, 

 will expand in freezing ; though it is much harder, more solid and 

 transparent, and more ponderous, than common ice. 



ICE-HOUSE. An ice-house may be simply a large cellar with 

 hollow walls, containing fixed air ; or, which is better, with walls 

 filled in with sawdust or tanning, which is a non-conductor of heat, 

 and furnished with roof and door, made in the same manner, and 

 also with a drain to allow the escape of water produced by a partial 

 thaw. The drain is as important as the non-conducting walls and 

 roof; for standing water, on the floor or bottom of the vault contain- 

 ing the ice, is as prejudicial to the preservation of the article as heat 

 itself. Latterly it has been judged preferable to erect an ice-house 

 above ground, to having it under ground, or in a cellar. In both 

 cases, the construction is similar ; the walls, roof, arid door being 

 double, say with an intervening space of twelve inches, well filled and 



