[Copied from How To Do Things, published in 1919 by the Wilmer Atkinson Company, Philadelphia, PA.]
The inexpensive refrigerator, or milk cooler, consists of a wooden frame covered with Canton* flannel. Wicks made of the same material as the covering rest in a pan of water on top of the refrigerator, allowing the water to seep down the sides. When evaporation takes place the heat is taken from inside, consequently lowering the temperature. On dry, hot days a temperature of 50 degrees** can be obtained in this refrigerator. The following description will aid in the construction of this device:
Make a screened case three and a half feet high, with the other dimensions twelve by fifteen inches. Place two movable shelves in the frame, twelve to fifteen inches apart. Use a pan twelve inches square on the top to hold the water, and where the refrigerator is to be used indoors have the whole thing standing in a large pan to catch any drip. The pans and case may be painted white, allowed to dry, and then enameled.
A covering of white Canton* flannel should be made to fit in the frame. Have the smooth side out and fasten the covering on the frame with buttons or hooks, arranged so that the door may be opened without unfastening them. This can be done by putting one row of hooks on the edge of the door, keeping out the warm, outside air and retaining the cooled air. The covering will have to be hooked around the top edge also. Two double strips, one-half the width of each side, should be sewed on the top of each side and allowed to extend over about three inches in the pan of water. The bottom of the covering should extend to the lower edge of the case. Place the refrigerator in a shady place where the air will circulate around it freely. If buttons and buttonholes are used, the cost should not exceed eight-five cents. *Cotton flannel **Fahrenheit