Frost and ice accumulate on the surface of these cooling tanks, and their usefulness is thereby impaired. Duplicate tanks should be arranged, so that they may be used in turn, and the ice removed. The ice coat prevents the radiation of the cold into the room, and its force is spent in adding to the ice upon the sides of the tank, a useless waste. In some instances the cold storage houses are divided into two or more rooms, so that various temperatures can be maintained to meet the requirements of a varied stock. [Illustration: FIG. 76. SECTION VIEW OF COLD STORAGE HOUSE AND DAIRY.] [Illustration: FIG. 77. GROUND PLAN OF FREEZING TANK AND BENCH.] [Illustration: FIG. 78. END VIEW OF FREEZING TANK.] A VERY CHEAP ICE HOUSE, but constructed on the same principles as those laid down in Chapter IV for commercial ice houses, may take the form suggested by Figs. 79, 80, 81, or any desired modification thereof. A STILL SIMPLER DEVICE.--Where the expense of an ice house is not warranted by the small use to which it may be put for cold storage, on some farms, a supply of ice sufficient for household purposes can be placed in any convenient corner of a barn or other building. A room partitioned off with rough lumber, and walls, as well as floor, well insulated with non-conducting filling, will answer, and repay its cost many times over during the summer. In Fig. 82 is a view of an ice room built into a corner of a barn in this manner. An above-ground silo, if built of wood, with double walls and air spaces, will make a most excellent ice house, if provided with double doors. The underground, or masonry silo, should be boarded up, with joists between walls, and boards to form an air space, if used for ice. A LITTLE ORGANIZED CO-OPERATION in any farming community where ice-cutting privileges exist, will secure an abundant supply of ice for all purposes for the entire section or neighborhood. It is customary to do the threshing in turn, and all participate in the use of the threshing machine and power, where only very extensive farmers find it profitable to have an outfit for their own exclusive use. [Illustration: FIG. 79.] [Illustration: FIG. 80.] [Illustration: FIG. 81. SUGGESTIONS FOR CHEAP ICE HOUSES.] In a similar manner the benefits of cold storage can be obtained. The houses can be owned by individuals, or by a few families who may be living near enough together to conveniently use one in common. The tools and outfit for cutting and handling the ice can be owned by a few enterprising young men, who can fill a large number of houses yearly by contract; or the appliances can be the joint property of all those having cold storage houses, who may combine to secure them, and also combine their labor in securing the ice crop. This work is done when the ordinary duties of the farm are light, and other interests would not be interfered with. [Illustration: FIG. 82. BARN-CORNER ICE HOUSE.]