Page:Popular Science Monthly Volume 39.djvu/38

28 was of an inch and a quarter internal diameter, and the lengths were placed five inches apart. Through this coil the ammonia circulated, the absorption system being used to effect the congelation.

The machines with which ice is made have also another and up to the present time a larger application. This is the production of cold in breweries, abattoirs, markets, and cold storage



houses. The fermentation of beer must take place at quite a low temperature, which must be steadily maintained; hence energetic and continuous cooling of the wort has to be provided for. The brewers were formerly among the largest customers of the ice companies, but now nearly every brewery has a refrigerating machine of its own, and more machines are used by them than by all other users put together. No ice is made with these machines, except for packing beer for shipment, as the cooling required can be accomplished more conveniently by circulating cold brine or cold fresh water in pipes where it is needed.

The system of cold storage which has sprung up within the past few years has been made possible by this same process. Immense quantities of meat and other perishable provisions are now kept in great warehouses until wanted, thus insuring a steady