314 



Daniell on a new Ht/groMeter. 



Table II. — continued. 



The first column contains the degrees of temperature ; the 

 second the corresponding force of vapour ; the third the amount 

 of evaporation per minute, from a vessel of six inches diameter, 

 in calm weather ; the fourth the amount in a moderate breeze ; 

 and the fifth in a high wind. 



The use of this table as applied to the hygrometer is this : let 

 it be required to know the force of evaporation at the existing 

 state of the atmosphere. Find the point of condensation by the 

 instrument as before directed. Subtract the grains opposite 

 that temperature, either in the third, fourth, or fifth columns, 

 according to the state of the wind, from the grains opposite to 

 the temperature of the air in the same column, and the re- 

 mainder will be the quantity evaporated in a minute, from a 

 vessel of six inches diamteer, under the given circumstances. 

 For example ; — let the point of condensation be 52°, the tem- 



