THE METRIC SYSTEM. 



lo-centimeter rule. The upper edge is in millimeters, the lower in centimeters and half- 

 centimeters. 



The Meter, for 

 LENGTH 



The Gram, for 

 WEIGHT 



The Liter, for 

 CAPACITY .... 



Units. The most commtinly l'.sf-d DnisioNS a.-:d i\i lm.tipi.es. 



Cailinieter (cm), l/loo meter; Millimelf?- (mm), 

 l/iooo meter; Micron (</), i/iooo millimeter. The 

 micron is tlie unit in micrometry. 

 Kilometer, looo meters; used in measuring roads and other 



long distances. 

 Milligram (mg), i/iooo gram. 

 Kilogram, lOOO grams, used fr>r ordinary masses, like 



groceries, etc. 

 Cubic Centimeter (cc), l/iooo liter. This is more 

 common than the correct form. Milliliter. 

 Divisions of the units are indicated by Latin prefixes: deci, i/io; centi, 

 i/ioo; milli, i/iooo. 



Multiples are designated by Greek prefixes: deka, lo times; hecto, loo 

 times; kilo, lOOo times; myria, 10,000 times. 



TABLE OF METRIC AND ENGLISH MEASURES. 



Meter = 100 centimeters, jooo millimeters, 1,000,000 microns, 39.3704 



inches. 



Millimeter (mm) = 1000 microns, i/io millimeter, i/iooo meter, 1/25 mch, 



approximately. 



Micron [iX) (unit of measure in micrometry) = 1/1000 mm, i/ioooooo me- 

 ter (0.000039 inch), 1/25000 inch, approximately. 



Inch (in.) = 25.399772 mm (25.4 mm, approx.). 



Liter = 1000 milliliters or 1000 cubic centimeters, i quart (approx.). 



Cubic centimeter (cc or cctm) = l/iooo liter. 



Fluid ounce (8 fluidrachms) = 29.578 cc (30 cc, approx.). 



Gram -— 15.432 grains. 



Kilogram (kilo) = 2.204 avoirdupois pounds (2|- pounds, approx.). 



Ounce Avoirdupois (437i grains) = 28.349 grams [(30 grams. 



Ounce Troy or Apothecaries' (480 grains) = 31.103 grams) approx.). 



TEMPERATURE. 



To change Centigrade to Fahrenheit: (C. X |) +32 = F. For example, to 

 find the equivalent of 10° Centigrade, C. = 10°, (10° x |) + 32 = 5°° F. 



To change Fahrenheit to Centigrade: (F.- 32°) X f = C. For example, to 

 reduce 50 Fahrenheit to Centigrade, F. = 50°, and (50°- 32°) X f = 10° C. ; 

 or - 40° Fahrenheit to Centigrade, F. = -40°, (- 40°-, 32°) = - 72°. 

 whence — 72° X » = - 4°° C. .. „ „ ^ 



— From "The Microscope {by S. ff- Gage) by permission. 



