Ice 



worn-out cloth ? Moreover, this fracture, 

 caused by the water freezing, is effected 

 as quietly as possible. There is no ex- 

 plosion such as you might imagine, no 

 fragments thrown out. Without any dis- 

 turbance the metal is rent, and that is all. 

 If you were astride on the gun you would 

 have nothing to fear at the time of the 

 rupture. 



It is probable that you will not have the 

 opportunity of seeing the bursting of a 

 cannon by ice, but I can suggest another 

 experiment. Take a bottle, fill it quite full 

 of water, then cork it with a strong cork 

 fastened by a string. Expose your bottle 

 in the open air during a sharp frost. Sooner 

 or later you will find it in pieces, broken by 

 the pressure of the ice. Here again there is 

 no danger. The fragments of the bottle 

 are not thrown off. They adhere together, 

 joined by the ice, or else they fall quietly to 

 the ground. 



In the new pump which has replaced the 

 old one damaged by the cold, there is a tap 

 quite at the bottom of the cylinder, and 

 when a hard frost is expected the tap is 

 turned to let the water escape. This is to 

 prevent the ice from forming in the cylinder. 



