APPENDIX 
A. USEFUL RULES AND TESTS 
CoMPARISON OF THERMOMETER SCALES 
Centigrade Scale—Freezing point of water = 0 
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 “se = 9 “cc 
To Caance Decrees CENTIGRADE TO EQUIVALENT DEGREES 
FAHRENHEIT 
Multiply by 2 and add 32; e. g.: 65°C. X 2 = 117 + 32 =149° F, 
To CHance Decrees FAHRENHEIT TO EQuiIVALENT DEGREES 
CENTIGRADE 
Subtract 32 and multiply by 3; e. g.: 98° F. — 32 = 66 X $ = 37° 
—c,. 
To Finp THE Speciric GRAVITY BY THE “BoaRD OF 
HeattH” LacToMETER 
Multiply the reading by .29, divide by 1,000, and add 1.; e. g.: 
Observed reading, 94 X .29 = 27.26 + 1,000 = .02726 + 1. = 1.027 + | 
specific gravity. 
(349) 
