Democratic Sentinel, Volume 18, Number 9, Rensselaer, Jasper County, 16 March 1894 — How Ice Forms. [ARTICLE]

How Ice Forms.

On the surface of a river or water exposed to the air ice is made by the coldness of the air against the top of the water. When water is cooled thus it at first shrinks in size, and, therefore, sinks below the less cold water next to it. This in turn gets cooler, shrinks and Sinks, and so on, till the water from the top to bottom is lowered to four degrees above centrigrade zero. As soon as the water gets colder than this it begins to swell, and, therefore, no longer sinks as before, but stays on the top, and, if the cooling still goes on till zero centigrade is reached, it begins to turn into iqe. When, by the colder air a-top of it, as much heat is taken away from this water at zero as would have raised a pound of water at zero to a pound of water at seven-ty-nine degrees centigrade, a, pound of ice is formed; when twice as much, two pounds, and so on, till, if the air above the water keeps cold enough, the whole of the water will in time be marie into ice. Perhaps the most satisfactory way of all for producing ice in large quantities is that of compressing dried air by means of a force-pump into strong wrought iron cylinders. As the air is forced into the cylinders it gives out the heat it contains to surrounding objects colder than itself. When again allowed to expand the air requires this heat once more and takes it from anything it touches. If, therefore, a vessel of water is held in the stream of air issuing from such a wrought-iron cylinder, the water loses its heat to the expanding air and gets frozen. This process is in use on vessels bringing the carcasses of sheep and bullocks from Australia and America.—[Atlanta Constitution.