34 EXPERIMENTAL GENERAL SCIENCE 



37. The Advantage of the Metric System. The great 

 advantage of the metric system is that it is a decimal system, 

 in which ten of one denomination makes one of the next 

 higher, exactly as in our coinage. This renders it easy to 

 make calculations of various kinds, since one denomination 

 may be changed into terms of another by multiplying or divid- 

 ing by tens, hundreds or thousands. Moreover, in the English 

 system, we cannot conveniently express low denominations 

 as fractions of higher ones. In the metric system, however, we 

 have but to set the quantities down in their order and insert a 

 decimal point at the proper place. In this system, all the 

 tables one will ever need in measuring lengths, 

 surfaces, weights, and volumes may be learned 

 in a single morning instead of requiring months 

 for the study of the tables as in the English 

 system. 



38. The Meter. The meter from which the 

 metric system takes its name is the standard of 

 length. At the time it was established, it was 

 Fio 5 _ The intended to be one ten-millionth of the distance 

 standard meter, from the equator to the pole, or the forty- 



millionth part of a great circle or meridian. It 

 is, therefore, a little more than three feet in 

 length (39.37 inches). For practical purposes, it is defined as 

 the distance, at the temperature of melting ice, between two 

 lines ruled on a certain bar of platinum and iridium which is 

 kept at the International Bureau of Weights and Measures 

 near Paris. Accurate copies of this bar are preserved at 

 Washington and at the capitals of many other countries and 

 serve as standards with which other measuring instruments 

 may be compared. Owing to the difficulty of exactly repro- 

 ducing these standard meters by ordinary measurements, if 

 lost or destroyed, it is now proposed to designate a certain 

 number of light waves as the length of a meter. These light 



