APPENDIX 



A. USEFUL RULES AND TESTS 



COMPARISON OF THERMOMETER SCALES 



Centigrade Scale Freezing point of water = 

 Boiling point of water = 100 



^ 



Difference 100 degrees. 



Fahrenheit Scale Freezing point of water = 32 

 Boiling point of water = 212 



Difference 180 degrees 

 100 degrees C. = 180 degrees F. 

 5 = 9 



To CHANGE DEGREES CENTIGRADE TO EQUIVALENT DEGREES 

 FAHRENHEIT 



Multiply by f and add 32; e. g.: 65 C. X I = 117 + 32 = 149 F. 



To CHANGE DEGREES FAHRENHEIT TO EQUIVALENT DEGREES 

 CENTIGRADE 



Subtract 32 and multiply by I; e. g.: 98 F. 32 = 66 X = 37 

 C. 



To FIND THE SPECIFIC GRAVITY BY THE "BOARD OF 

 HEALTH" LACTOMETER 



Multiply the reading by .29, divide by 1,000, and add I.; e. g.: 

 Observed reading, 94 X .29 = 27.26 -*- 1,000 = .02726 + 1. = 1.027 + 

 specific gravity. 



(349) 



