Where the supply fails or the price is exorbitant, one property of water makes it a partial aid.

The rapid evaporation of water will absorb heat so rapidly as to reduce the temperature of adjacent bodies. In the tropics when ice is lacking, water is hung in porous jars in the breeze, and the temperature of the water in the jar is reduced.

To keep milk and butter cool wrap a wet cloth about the containing jar, and set the jar upon the window sill, keeping one end of the towel in a vessel of water; or the cloth may be wrapped directly around the butter. This method is surprisingly effective.