EVERYTHING HAS WEIGHT 155 



earth, and unless an object rests 

 upon something it will fall in that 

 direction. If we wish to balance 

 anything so that it will stand erect 

 we must have either a large place 

 upon which the object rests or we 

 must have most of its weight be- 

 low the place upon which it rests. 



The illustration shows you how you 



can balance a pencil upon its point 

 by means of a knife. Explain the 

 reason for this. 



Since everything has weight, people have used 

 weight as a method of measuring material, for a long 

 time. Just as there are standards for length, area, and 

 volume, so there are standards for weight. The com- 

 mon English standards are the pound and ton, and they 

 have no special meaning. The French units are the 

 gram and kilogram (100 grams) and mean something. 

 The gram is the weight of one cubic centimeter of 

 water at 4C. and the kilogram is the weight of 1000 cubic 

 centimeters of water at 4C. This gives two ways of 

 measuring water. It may be measured in a graduate or 

 it may be weighed. The number of cubic centimeters 

 and the number of grams will be the same. In the Eng- 

 lish system the weight of a cubic foot of water is 62.4 

 pounds at 4C. There is no connection between any 

 two parts of the English system and many different num- 

 bers must be remembered in order to change from one 

 unit to another. The French system of weights is also 

 decimal and there is nothing to remember. The weights 

 are always expressed in parts of a kilogram or parts of a 

 gram. 



