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 oe 9 ba 
To CHANGE DEGREES CENTIGRADE TO EQUIVALENT DEGREES 
FAHRENHEIT. 
Multiply by 9-5 and add 32;-¢. g.. 65° C. X 9-5 = 117 + 32 = 
149° F 
To CHANGE DEGREES FAHRENHEIT TO EQUIVALENT DEGREES 
CENTIGRADE. 
Subtract 32 and multiply by 5-9; ¢. g.. 98° F. — 32 = 66 5-9 
= 37°— C. 
To Finp THE SPECIFIC GRAVITY BY THE “BOARD oF HEALTH” 
LACTOMETER. 
Multiply the reading by .29 and add 1.000; v. g.: Observed reading, 
94 X .29 = 27.26 + 1.000 = 1.027.+ specific gravity. 
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