THE METRIC SYSTEM 



LIBRARY 



OF THE 



UNIVERSITY OF CALIFORNIA. 



Class 



Q.nan 



190? 



'if. 



\u) 39.3/04 luctics : 3.2000 ieei ; 1.0930 yarus. 

 Centimeter (cm.)-io millimeters ; 10,000 microns (//) o.oi meter; 0.3937 (f) 



inch. 



Millimeter (mm. )= i, ooo microns (//); o.icm.; o.ooi meter; 0.03937 (^) inch. 

 Micron (//) (Unit of measure in micrometry (i82)=o.ooi millimeter; one 



millionth of a meter ; 0.00003937. (^s^on) inch. 

 Yard;=3 feet ; 36 inches ; 0.91439 meter ; 91.4399 centimeters. 

 Foot=;[2 inches ; 30.4799 centimeters ; 304.799 millimeters. 

 Inch= T V foot ; 3^ yard; 25.3999 millimeters (2.54 centimeters). 

 later (Unit of capacity) 1,000 cubic centimeters (milliliters); ( i quart . ) 

 Cubic centimeter=o.ooi liter (milliliter); (^ cub. inch.) 

 Fluid ounce f 8 fluidrachms) =29.574 cubic centimeters (30 cc. ). 

 Gram (Unit of weight )=i cc. of water; 15.432 grains. 

 Kilogram= i, ooo grams ; 2.2046 (2-i) Ibs. avoirdupois. 

 Ounce avoirdupois=437| grains ; 28.349 grams. 

 Ounce Troy or apothecaries=:48o grains ; 31.103 grams 



TEMPERATURE 



To change Centigrade to Fahrenheit; (C. Xf)+32=F. For example, to 

 find the equivalent of 10 Centigrade, C. = ioXf +32=50 F. 



To change Fahrenheit to Cenrigrade ; (F. 32)Xi~C. For example, to 

 reduce 50 Fahrenheit to Centigrade, (F.=5o, and (50 32)X|=io C. ; or 

 40 Fahrenheit to Centigrade, F.= 40 ( 40 32)= 72, whence 

 72Xf= 40 C. 



30 grams, approx. 



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 foreign opticians see the table of tube-length p. 18. 



The Bausch &. l,omb Optical Co Rochester, New York 



James T. Dougherty 409-411 West sgth St., New York 



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



The Gundlach-Manhattan Optical Company Rochester, N. Y. 



E. Leitz 30 East iSth St., New York 



Edward Pennock 3609 Woodland Ave., Philadelphia, Pa 



A. B. Porter 324 Dearborn St., Chicago 



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



Spencer Lens Company 367-373 Seventh St., Buffalo, N. Y. 



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



Voigtlander und Sohn, A. G 225 Fifth Ave., New York 



Joseph Zentmayer 226-228 South isth St., Philadelphia, Pa. 



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

 scopes and microscope supplies. 



