16 A YEAR IN SCIENCE 



An exception to the rule. Water shows an exception 

 to the rule that heated bodies expand and cooled bodies 

 contract. We all know that ice floats. In order to 

 float it must, of course, be lighter than water. Ice is 

 frozen water, so evidently in freezing the water has 

 expanded. If two bottles filled with water are very 

 securely sealed, and then one is heated and the other 

 allowed to freeze, both bottles will break. This 

 shows that in each case the water has expanded. It 

 has been found that, if water is heated above 4C. or 

 cooled below that temperature, it expands in both cases. 



A few other substances show a similar disobedience 

 to the general rule for expansion and contraction. 



If water contracted in freezing, ice would be heavier 

 than water and would sink in ponds and lakes as fast 

 as it was formed. As a result, the entire pond or 

 stream would become a solid mass of ice, killing all 

 animal and plant life. It is a well known fact that 

 even in the most severe winter, the deep lakes do not 

 become solid masses of ice, and that fish and some 

 other animals remain alive in the water beneath the 

 ice. 



Freezing water exerts a very great influence on the 

 character of the land around us. Water is everywhere 

 present in the ground, in crevices, and even within 

 many rocks. When winter approaches this water 

 freezes, and then it expands about one-eleventh of its 

 volume. The rock is then broken into countless pieces, 

 for the expansive power of freezing water is almost 



