the quotient gives the parts of 1:000 the degrees of 

 saturation. 



8.392 gr. at the dew-point 70 



EXAMPLE. = 



1 1.333 gr. at the temp, of the air 80 

 7.40 degrees of humidity, saturation being i.ooo. 



The principles of these calculations will be found 

 in Professor Daniel's Meteorological Essays ; in 

 Mr. Anderson's Essays on Hygrometry ; in the 

 Edinburgh Encyclopedia, Vol. XI, and in the 

 Edinburgh Journal of Science, Vol. VII, page 43, 

 in an excellent article on the Dew-point Hygrom- 

 eter, by Mr. Foggo, from which the table of cor- 

 rections has been partly subtracted. The table of 

 quantity by weight has been taken from Professor 

 Daniel's Work on Meteorology, to which the 

 reader is referred for further particulars. 



126 



