MATTER AND ITS PROPERTIES 



51 



FIG. 16. MEASURES OF 

 VOLUME 



thousand meters) is the unit used in measuring distances. 

 A meter is about 3J feet; a kilometer is about f of a mile. 

 Instead of describing a river as 1 dekameter deep, 3 hec- 

 tometers wide, and 125 kilometers long, we should say it was 

 10 meters deep, 300 meters wide, 

 and 125 kilometers long. 



48. Weight. When we have 

 found out the volume of a body, 

 we still do not know how much 

 matter there is in it. The way to 

 find out is to weigh it, and the 

 amount of matter is called weight. 

 Two bodies of the same volume 

 may differ greatly in weight; as, 



a Cubic foot of lead and a cubic I. How many cm. in 1 dm.? 



foot Of COrk, a quart of kerosene 2 - ?ow many sq. cm. in a surface 



1 dm. on each edge? 3. How 



and a quart of mercury, a cubic ma ny cu. cm. in a block 10 cm. 

 centimeter of ice and a cubic ? n each edge? u 4 - What name 



is given to such a volume: 



centimeter of stone. 



49. Measurement of Weight. The gram (about -fa of 

 an ounce or fifteen grains) is the metric unit for small weights; 

 it is used by druggists, chemists, and dealers in gems and 

 precious metals, and in all scientific work. The table of 

 weights is similar to that of length, except that the unit is 

 the gram. A kilogram (one thousand grams) is equivalent 

 to about 2j pounds; it is the unit used in measuring large 

 masses. 



The weight of one cubic centimeter of pure water at the 

 temperature of 39 Fahrenheit is accepted as the unit of 

 weight, one gram (g.) ; and it is nearly correct to assume that 

 one cubic centimeter of clean, cold water weighs a gram. 

 Therefore one thousand cubic centimeters of water weigh 

 one thousand grams or a kilogram (kg.). It is a simple 

 matter to determine the weight of water in a tank or reservoir 

 by measuring the capacity of the tank in cubic centimeters. 



