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"In the manufacture of artificial ice, ammonia is liquefied by being compressed by powerful pumps; then the liquid ammonia is cooled by passing cold water over the pipes containing it. the liquid ammonia is distributed through pipes, where it evaporates rapidly. The gas is drawn back by the pump, condensed to a liquid, and used again. The pipes in which the evaporation takes place are immersed in a strong salt solution, which, by furnishing heat for evaporation, is cooled to a point below the freezing-point of water." -Brownlee 1907

Refrigerating Plant

"In the manufacture of artificial ice, ammonia is liquefied by being compressed by powerful pumps; then…