Staying Cool

Since most of us don't have an ice-house handy at summer events, here's documentation for evaporative cooling as a period technique for cold beverages:

TO MAKE WATER COLD IN SUMMER--The following is a simple mode of rendering water almost as cold as ice:--Let the jar, pitcher, or vessel used for water, be surrounded with one or more folds of coarse cotton, to be constantly wet. The evaporation of the water will carry off the heat from the inside, and reduce it to a freezing point. In India and other tropical regions, where ice cannot be procured, this is common. 

--The Golden Receipt Book (London, 1848)