8 MATTER AND ITS MEASUREMENT 



meter. The name of the smallest money unit, the mill, 

 is derived from the Latin mille, meaning 1000. Cent is 

 from centunij or 100, and dime is from decem, meaning 10. 

 A mill is i^o of a dollar; a cent is m', a dime, ^. In 

 the same way i^o of a meter is called a millimeter ; ife, 

 a centimeter ; and nj, a decimeter. 



9. The Standard Meter. Men intended that the meter 

 should be 40.000.000 ' of the earth's circumference, but 

 we now define it as the distance between two fine lines 

 __ ====================== _ ruled on a metal bar 



(Fig. 6). The bar is 

 made of an alloy (mix- 

 united Statefp^totype Meter. tllTc) Of the metals plati- 



num and iridium. While 



the distance between the lines is being measured, the 

 bar is kept at the temperature of melting ice; that is, 

 at Centigrade (cf. 63 and 69). Thirty-one inter- 

 national standard meters were made at Paris and dis- 



tributed among the principal governments of the world. 

 Two of them were brought to the United States and are 

 kept at Washington. 



The length of the meter is 39.37 inches, or 3.28 feet. The exact 

 measurement of the meter is very difficult, because the metal bar 

 changes its length slightly, but in recent years the meter has been made 



