4 USEFUL TABLES 



The U. S. gallon contains 231 cu. in. = .134 cu. ft., nearly; 

 or 1 cu. ft. contains 7.481 gal. The following cylinders con- 

 tain the given measures very closely: 



Diam. Height 



Gill If in. 3 in. 



Pint 3in. 3 in. 



Quart 3iin. Gin. 



Diam. Height 



Gallon.... 7 in. 6 in. 



8 gallons 14 in. 12 in. 



10 gallons 14 in. 15 in. 



When water is at its maximum density, 1 cu. ft. weighs 

 62.425 Ib. and 1 gal. weighs 8.345 Ib. 



For approximations, 1 cu. ft. of water is considered equal 

 to 1\ gal., and 1 gal. as weighing 8J Ib. 



The British imperial gallon, both liquid and dry, con- 

 tains 277.274 cu. in. = .16046 cu. ft., and is equivalent to the 

 volume of 10 Ib. of pure water at 62 F. To reduce British to 

 U. S. liquid gallons, multiply by 1.2. Conversely, to convert 

 U. S. into British liquid gallons, divide by 1.2; or, increase 

 the number of gallons one-fifth. 



THE METRIC SYSTEM 



The metric system is based on the meter, which, according 

 to the United States Coast and Geodetic Survey Report of 

 1884, is equal to 39.370432 in. The value commonly used 

 is 39.37 in., and is authorized by the United States govern- 

 ment. The meter was originally intended to be one ten- 

 millionth of the distance from the pole to the equator, 

 measured on a meridian passing near Paris. This distance 

 was carefully calculated, and a standard meter bar made 

 and deposited among the archives of France, at Paris. It 

 has since been discovered that the original calculations were 

 at fault and the standard meter is somewhat short of one 

 ten-millionth of the earth's quadrant. Nevertheless, the 

 error is so small that it was not considered necessary to 

 change the standard to make it correct, and the original 

 meter length is still preserved. 



There are three principal units the meter, the liter (pro- 

 nounced "lee-ter"). and the gram, the units of length, 

 capacity, and weiglit, respectively. Multiples of these units 



