THE METRIC SYSTEM. 



io-centimeter rule. The upper edge is in millimeters, the lowei in centimeters and half 

 centimeters. 



UNITS. 



THE METER, for 

 LENGTH . . . 



THE MOST COMMONLY USED DIVISIONS AND MULTIPLES. 



Centimeter (cm), i/ioo meter; Millimeter (mm), 

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

 micron is the unit in micrometry. 



Kilometer, 1000 meters; used in measuring roads and other 

 long distances. 



THE GRA 

 WEIGHT 



. ( Milligram (mg), i/iooo gram. 

 M ' for \ KiL 



Kilogram, 1000 grams, used for ordinary masses, like 

 ( groceries, etc. 



THE LITER, for ( Cubic Centimeter (cc), i/iooo liter. This is more 

 CAPACITY . . . . ( 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, 10 times; hecto, 100 

 times; kilo, 1000 times; myria, 10,000 times. 



TABLE OF METRIC AND ENGLISH MEASURES. 



METER = 100 centimeters, 1000 millimeters, 1,000,000 microns, 39.3704 

 inches. 



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

 approximately. 



MICRON (/u) (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) = i/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 (437^ grains) = 28.349 grams [(3 g rams > 



Ounce Troy or Apotheca"ries' (480 grains) = 3 1.103 grams j 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 = 50 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 f = - 4- C. 



From ''The Microscope" (by S. H. Gage) by permission. 



