APPENDIX. 



METRIC AND IMPERIAL SYSTEMS OF WEIGHTS AND 

 MEASURES. 



The initial unit of the metric system is the Metre (m.) 

 or unit of length, representing one-fourth-millionth 

 part of the circumference of the earth round the poles. 



The unit of mass is the Gramme (g.), and repre- 

 sents the weight of one cubic centimetre of water at 

 its maximum density (viz. 4 C. and 760 mm. mercury 

 pressure) . 



The unit of the measure of capacity is the Litre (/.) , 

 and represents the volume of a kilogramme of distilled 

 water at its maximum density. 



The decimal subdivisions of each of the units are 

 designated by the Latin prefixes niilli = ^-^\ centi= 

 J-O-Q-; deci -^\ the multiples of each unit by the 

 Greek prefixes deka= 10; hecto= 100; kilo= 1000; myria 

 = 10,000. 



For a comparison of the values of some of the more 

 frequently employed expressions of the Metric System 

 and the Imperial System, the following may be found 

 convenient for reference : 



Length : 



i millimetre ( = i mm.) = -fa of an inch. 



* centimetre (= i cm.) = f of an inch. 



L inch (i") =25 millimetres or 2j centimetres. 



Mass: 



i milligramme ( = i mg.) = 0.01543 grain (or approximately 

 & grain) . 



i gramme (= i g.) = 15.4323 grains. 



i "kilo" or kilogramme (=i kgm.) = 2 pounds, 3^ ounces 

 avoirdupois. 



i pound avoirdupois ( = i ^0=453.592 grammes. 



i ounce avoirdupois ( = i oz.) =28.35 grammes. 



i grain = 0.0648 gramme or 64.8 milligrammes. 



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