30 A YEAR IN SCIENCE 



Value of a centigrade degree in terms of Fahrenheit 

 and vice-versa. Although the freezing point of water 

 on the centigrade thermometer is 0, and on the Fahren- 

 heit 32, and the boiling point of water on the centigrade 

 100, and on the Fahrenheit 212, it must be clear to all 

 that the difference in temperature between the freezing 

 and the boiling points of water is the same, by whatever 

 thermometer measured. 



Since there are 100 C. between boiling and freezing 

 and 180 F. (212 boiling 32 freezing = 180 F.) 

 between the same points 



100C. equal 180F. 



1C. equals 9/5F. 

 Likewise 



180F. equal 100C. 



1F. equals 5/9C. 



Hence to reduce from the centigrade to the Fahren- 

 heit thermometer, multiply the number of centigrade 

 degrees by 9/5. Then, remembering that the centi- 

 grade degrees were measured from the freezing point, 

 start at the same point on the Fahrenheit thermometer. 

 If the temperature is above freezing, add the product 

 to 32. If below freezing, subtract the product 

 from 32. 



To reduce from the Fahrenheit to the centigrade 

 scale, find how many Fahrenheit degrees the given 

 temperature is above or below freezing; and multiply 

 the number of degrees by 5/9. 



