A gradual refrigeration proceeded through the Pliocene period.
To produce refrigeration the operation is reversed.
It extended the meaning of the term " railroad " to include switches, spurs and terminal facilities, and the term " transportation " to include private cars, and all collateral services, such as refrigeration, elevation and storage.
The city has a monument (1900) to John Gorrie (1803-1855), a physician who discovered the cold-air process of refrigeration in 1849 (and patented an ice-machine in 1850), as the result of experiments to lower the temperatures of fever patients.
In the first refrigeration is produced by the expansion of atmospheric air, and in the second by the evaporation of a more or less volatile liquid.
In 1870 the subject of refrigeration was investigated by Professor Carl Linde of Munich, who was the first to consider the question from a thermodynamic point of view.
In some cases, instead of the entrance being at the sides or ends, it is at the top, all goods being raised to the top floor in lifts and lowered by lifts into the rooms. With good machinery the cost of raising is not great, and is probably equalled by the saving in refrigeration, since the rooms hold the heavy cold air as a glass holds water.
Of Mechanical Refrigeration (Chicago); Redwood, Theoretical and Practical Ammonia Refrigeration (New York); Stephansky, Practical Running of an Ice and Refrigerating Plant (Boston); Ledoux, Ice-Making Machines (New York); Wallis-Taylor, Refrigerating and Ice-Making Machines (London) Ritchie Leask, Refrigerating Machinery (London); De Volson Wood, Thermodynamics, Heat Motors and Refrigerating Machinery (New York); Linde, Kdlteerzeugungsmaschine Lexikon der gesamten Technik; Behrend, Eis and KdlteerzeugungsMaschinen (Halle); De Marchena, Kompressions Kdltemaschinen (Halle); Theodore Koller, Die Kdlteindustrie (Vienna); Voorhees, Indicating the Refrigerating Machine (Chicago); Norman Selfe, Machinery for Refrigeration (Chicago); Hans Lorenz, Modern Refrigerating Machinery (London); Lehnert, Moderne Kdltetechnik (Leipzig); L.