THE METRIC SYSTEM 



10 CENTIMETER RULE 



The upper edge is in millimeters, the lower in centimeters, and half centimeters. 



THE METER FOR 

 LENGTH. . . 



UNITS. The most commonly used divisions and multiples. 



(Centimeter (cm.), o.oi Meter; Millimeter (mm.), o.ooi Meter: Micron (u.), 

 •< o.ooi Millimeter ; the Micron is the unit in Micrometry (J 166). 

 {^Kilometer, iooo Meters ; used in measuring roads and other long distances. 

 the gram for \ Milligram (mg.), o.ooi Gram. 



■weight. . . ( Kilogram, iooo Grams, used for ordinary masses, like groceries, etc. 

 the liter for I Cubic Centimeter (cc), o.ooi Liter. This is more common than the correct 

 capacity. . \ form, Milliliter. 

 Divisions of the Units are indicated by the Latin prefixes : deci, o.i ; centi, o.oi ; Milli, 

 o.ooi ; Mia-o, one millionth (o.oooooi) of any unit. 



Multiples are designated by the Greek prefixes : deka, 10 times ; hecto, ioo times ; kilo, iooo 

 timse ; myria. 10.000 times : Meza. one million (1,000,000) times any unit. 



9& 



Meter (U 

 39- 37c 

 Centimete 

 Millimete 

 Micron (. 

 liontl 

 Yard=3 f 

 Foot=i2 

 Inch= T V 

 Liter (Ur 

 Cubic cen 

 Fluid oun 

 Gram (U 

 Kilogram 

 Ounce av 

 Ounce Tr 





» 



& 



& 



» 



« 



«| 



ns { u ) 



1 inch, 

 inch, 

 e mil- 



^(^c^i^c^c^c^^r^cat^c^c^(^c^c^(^cS}c^3cS)(^ic^)c^icSj 



To el to find 



the equiv 



To chaiigc iaicuuv.il. w ^^ij^ig,*^^^ . v » . j- / ,, a _. — x to re- 



duce 50 Farenheit to Centigrade, F.= 5o°, and (50 — 32°)X f = 10 C. ; or — 40 

 Farenheit to Centigrade, F.= — 40 (— 40 — 32°)= — 72 , whence — 72°Xf 

 = — 40 C. 



Address of American Opticians : For the price of microscopes and microscopical supplies the 

 student is advised to obtain a catalog of one or more of the opticians. Nearly all of them import 

 foreign apparatus. For all institutions entitled to duty free importation, American microscopes 

 are sold at duty free rates. For the foreign opticians see the table of tube-length p. 14. 



The Bausch and Lomb Optical Co., New York, Rochester, and Chicago. 



Eimer and Amend, 205-211 3d Ave., New York. 



The Franklin Laboratory Supply Co , Harcourt St., Boston, Mass. 



The Gundlach Optical Company, Rochester, N. Y. 



Win. Krafft (Representative of Leitz in America), 4" West 59th St., New York. 



Edward Pennock 3609 Woodland Ave., Philadelphia, Pa. 



Oueen & Company, 1010 Chestnut St., Philadelphia, Pa. 



Richards & Co., .— 12 East iSth St., New York, and 108 Lake St., Chicago, Ills. 



Spencer Lens Company, 3 6 7~373 Seventh St., Buffalo, N. Y. 



Williams, Brown & Earle, 918 Chestnut St., Philadelphia, Pa. 



G. S. Woolman (Queen & Co. in New York), 116 Fulton St., New York. 



Joseph Zentma5'er, 226-228 South 15th St., Philadelphia, Pa. 



Besides the names here given, nearly every large city has one or more dealers in microscopes 

 and microscope supplies. 



