COMPUTATION TABLES. 153 



VIII. THERMOMETER SCALES. 



Fahrenheit. The freezing-point is taken as the 32d degree 

 of the scale, and 180 degrees are made between that and the 

 boiling-point, which therefore becomes 212. 



Centigrade or Celsius. The freezing-point of water is 

 taken as zero, and boiling-point as 100. 



Reaumur. The freezing-point of water is taken as zero, 

 the boiling-point as 80. 



A degree Centigrade is therefore greater than a degree of 

 Fahrenheit as nine is greater than five ; and a degree of Reau- 

 mur is greater, as nine is greater than four. 



To reduce Fahrenheit degrees to Centigrade, subtract 32 from 

 the given degree of Fahrenheit and multiply the remainder by 

 5 and divide it by 9 : (F. - 32) f. 



To reduce Centigrade to Fahrenheit, multiply the given 

 degree of Centigrade by 9 and divide the product by 5, then to 

 the quotient add 32 : (|C. + 32). 



To reduce Fahrenheit to Reaumur, subtract 32 from the 

 given degree of Fahrenheit and multiply the remainder by 4 

 and divide by 9 : (F. - 32) f. 



To reduce Reaumur to Fahrenheit, multiply the given degree 

 of Reaumur by 9 and divide by 4, then add 32 : (|R. + 32). 



