This construction keeps the sawdust dry, and the walls are free from dampness. The circulation of air through the outer air spaces carries off the heat imparted to the weather boards by the direct heat of the sun. When the air is humid, or charged with moisture, these air channels are tightly closed. The thickness of the walls may be varied with the capacity of the building. Additional sections of filling and dead air are required for large houses where large quantities of goods are refrigerated. Fig. 67 shows the ground floor. The cold storage house shown in the illustration (Fig. 70) will hold forty tons of ice, and do all the work required for dairy, fruit and domestic service on a large farm with one filling of ice. By regulating the dampers, _D D_, Fig. 68, the circulation can be adjusted to meet all conditions. When these dampers are closed the ice wastes very slowly. The waste water, from meltage, is useful for cooling milk, and the milk room and cooling vats can be placed alongside the storage house or made a part of the same building to advantage. A CREAMERY ICE HOUSE.--A very conveniently arranged and completely appointed creamery is shown in illustrations No. 72 and 73. Fig. 72 is a perspective view, and Fig. 73 the plan of a combined creamery, ice house and water tower. The tank _B_ is placed in the second story of the tower; _C_ is the ice house, _D_ the creamery. At _I I_ are set creamers, which are supplied with water from the tank by pipes passing through the ice house to cool the water. At _G_ is a churn, which may be run by power located in the annex _E_. At _H_ is a butter molder, and _J_ is the veranda. [Illustration: FIG. 72. PERSPECTIVE VIEW OF CREAMERY.] [Illustration: FIG. 73. GROUND PLAN OF CREAMERY.] By raising the ice chamber, a cold store room can be secured below it. If the structure is placed on an elevation, water from the tank can be piped through the dwelling house. COMBINED DAIRY, COLD STORAGE AND ICE HOUSE.--Such an arrangement is shown in illustrations, Figs. 74 and 76. There is no communication between the dairy and storage room. For securing ice for the tank, double doors, made to fit very tight, are set in back of the ice chamber in the loft over the dairy. As leaving this door ajar would rapidly waste the ice, it should be under the care of a competent person and properly secured.