ICE-HOUSES. 329 



wagon loads of sawdust or other non-conductor would be 

 needed for a house of this size. ' 



The best packing is dry hard-wood sawdust. About 

 seven hundred bushels will be required for a house twelve 

 feet square, and ten feet high, to give an ample supply. 

 If sawdust cannot be procured, dry waste tan bark will 

 do very well; dry swamp muck, forest leaves, cut straw 

 chaff, or chaff from the threshing machine, are all very 

 good substitutes ; but an open air space is only about 

 forty per cent as effective as any one of these substances. 

 A house twelve feet square will hold a mass of ice ten 

 feet square, which will give about five thousand pounds 

 for each foot in hight, yielding a supply of one hundred 

 pounds daily, for about two months. One hundred 

 pounds of ice will cool one hundred pounds of water 

 from one hundred and seventy-four degrees down to 

 thirty- two degrees, absorbing one hundred and forty-two 

 deo-rees of heat from the water, in the slow process of 

 liquefaction alone. These figures will enable any person 

 to calculate how much ice may be required for any specified 

 effect. Thus as one hundred pounds of ice absorbs four- 

 teen thousand and two hundred units of heat, and we 

 want to cool seven hundred and ten pounds of milk from 

 sixty-five to forty-five degrees, we shall find that the ice 

 will just do it, because seven hundred and ten pounds 

 cooled twenty degrees equals fourteen thousand and two 

 hundred units. In the use of ice, it is therefore seen to 

 be a great economy to cool the milk down to just as low 

 a point as possible, by means of cold well or spring water, 

 before it is set in the ice-water pool. For a three hun- 

 dred quart dairy, or for twenty-five cows, then, one 

 hundred pounds of ice will be required daily, and for the 

 season of eight months, when ice may be necessary, 

 the ten feet square of ice should be raised eight feet, 

 which will allow for waste, which is usually about forty 

 or fifty per cent on the average of the season. The re- 



