English: From book "The Ontario high school physics"

Year: 1917 (1910s) Authors: Merchant, F. W. (Francis Walter), 1855-1937 Chant, Clarence Augustus, 1865-1956 Subjects: Physics Physics Publisher: Toronto : Copp Clark Contributing Library: The University of Western Ontario, Western Archives Digitizing Sponsor: Ontario Council of University Libraries and Member Libraries

Caption: "Regelation of Ice"

"If a substance expands on melting, its melting point will be raised by pressure, while if it contracts its melting point will be lowered. We would expect this. Since extra pressure applied to a body which takes a larger volume on melting would tend to prevent it from expanding, it would be reasonable to suppose that a higher temperature would be necessary to bring about the change; on the other hand, if the body contracts on melting,increased pressure would tend to assist the process of change,and a lower temperature should suffice.

An interesting experiment shows the effect of pressure on the melting point of ice. Take a block of ice and rest it on two supports, and encircle it with a fine wire from which hangs a heavyweight (Fig. 276). In a few hours the wire will cut its way through the ice, but the block will still be intact. Under the pressure of the wire the ice melts, but the water thus formed is below the normal freezing point. Hence it flows above the wire and freezes again as the pressure there is normal. The process of melting and freezing again under these conditions is called regelation."