METRIC SYSTEM 



3758 



METRIC SYSTEM 



most of the republics of South America use the 

 metric system, and it has also been legally 

 recognized in Japan and China. England and 

 its possessions and the United States are the 

 only civilized countries that have not adopted 

 it for common use, although these legally recog- 

 nize it. For scientific work and measurements 

 the metric system is used all over the world. 



In 1866 Congress passed the law making the 

 use of the metric system legal in the United 

 States for those who wish to use it, and since 

 that time it has been adopted for many pur- 

 poses. It is used in all the base measurements 

 and the computations of the Coast and Geo- 

 detic Survey, in weights at the mint for coining 

 money, in weighing all foreign mail matter, and 

 in all the government departments dealing 

 with the operations of the tariff laws, as well 



1 CUBIC 

 DECIMETER 



(1000 CUBIC CENTIMETERS) 

 EQUALS 



1 LITER- 



(UNIT OF CAPACITY) 

 1 WTER. OF WATERWEIGHS 



1 KJLOGRAM 



(UNIT OF WEIGHT) 



UNITS FOR COMPARISON 



as in the United States Bureau of Standards at 

 Washington. Since 1894 the legal units of elec- 

 trical measures in the United States are based 

 on the metric system. The metric system is 

 the legal system of weights and measures in 

 Cuba, Porto Rico and the Philippines. 



A knowledge of the metric system is there- 

 fore very useful and in some cases absolutely 

 necessary. Anyone who intends to engage in 

 business, and especially in foreign trade, or 

 who wishes to enter the civil service, or intends 

 to become an engineer, or who is planning to 

 study any branch of pure or applied science, 

 must have a good knowledge of the metric 

 system a system quite easily learned on ac- 

 count of its simplicity. 



How It Is Organized. The metric system 

 presents many advantages. The principal unit 

 of the system js the meter, which is the unit of 



length, in the same sense that the yard is our 

 common unit of length. All the other units of 

 surface, volume, capacity and weight are di- 

 rectly derived from it. Furthermore, the inter- 

 relation between them is a very simple one, 

 as a definite volume of water is taken as the 

 unit of capacity and mass. Thus one liter 

 contains one cubic decimeter of water and 

 weighs one kilogram. Then the whole system 

 has a uniform scale of relation between its 

 units, which is a decimal one, that is, the scale 

 selected for the multiples and subdivisions of 

 the various units is ten. This is shown in the 

 following table: 



ten millimeters =one centimeter 

 ten centimeters =one decimeter 

 ten decimeters =one METER 

 ten METERS =one dekameter 

 ten dekameters =one hektometer 

 ten hektometers^rone kilometer 

 ten kilometers =one myriameter 



The same is true for the other units, the liter 

 and the gram. Thus ten liters are equal to one 

 dekaliter, or ten decigrams are equal to one 

 gram. 



Another advantage of the metric system is 

 its uniform system of names, which are formed 

 by adding to the chief units the same prefixes, 

 as given in the table below. Each unit is 

 divided into tenths, hundredths, thousandths 

 and so on, for subdivisions, and multiplied by 

 ten, hundred, thousand, and so on, for units of 

 higher denominations. 



The names of the higher denominations are 

 formed by the use of Greek prefixes and the 

 names of the subdivisions by the use of Latin 

 prefixes : 



f myria means 10,000 



r . I kilo means 1,000 



1 hekto means 100 

 [deka means 10 



The units are the meter, liter, gram. 



fdeci means one tenth (.1) 



Latin J centi means one hundredth (.01) 



(^milli means one thousandth (.001) 



Metric numbers are written decimally, with the 

 decimal point placed immediately after the 

 unit. For example, 156.735 m. reads 156 meters 

 and 735 millimeters; or 156.735 g. reads 156 

 grams and 735 milligrams. Calculations with 

 the metric system are easy and are made ac- 

 cording to decimal rules. Any denominations 

 may be reduced to the next higher by moving 

 the decimal point to the left, or to the next 

 lower by moving the decimal point to the right. 

 The Unit of Length. The unit of length is 

 the meter, which is described at length in these 





