THERMOMETERS 



527 



WHOLE DAYS AT 



Thermometer Scales 



Fahrenheit. The freezing-point is taken as the thirty-second degree 

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

 point, which therefore becomes 212. The zero of Fahrenheit was sup- 

 posed to represent the absolute zero, or lowest possible temperature. 



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 9 is greater than 5; and a degree of Reaumur is greater, 

 as 9 is greater than 4. 



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. degrees 32) f To reduce Centigrade to Fahr- 

 enheit, multiply the given degree of Centigrade by 9 and divide the 

 product by 5, then to the quotient add 32: (f 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)i 



To reduce Reaumur to Fahrenheit, multiply the given degree of Reau- 

 mur by 9 and divide by 4, then add 32 : (I R + 32). 



To reduce Reaumur to Centigrade, multiply by f . 



