Daniell on a new liifgrometer. 131 



Evaporation per minute from a surface six inches 



in diameter, 0.18 grs. 



Temperature 40°. 



But it is by comparing together the results of different periods 

 that we shall obtain the information which we require. The 

 whole term of my experiments is as yet but very limited ; but by 

 dividing it, short as it is, we shall obtain some curious points of 

 comparison. 



The means of the first quarter are as follow : 

 Pressure of the atmosphere, . . . ► ^ . . 29.770 ins. 



Do. of the vapour, 0.355 



Weight of vapour in a cubic foot, 3.944 grs. 



Degree of dryness, 4^ 



Evaporation per minute from a surface six inches 



diameter, 0.32 



Temperature, , 48°. 



The means of the second quarter iri 



Pressure of the atmosphere 29.760 ins . 



Ditto of the vapour 0.222 



Weight of vapour in a cubic foot. ■ , 2.543 grs. 



Degree of dryness H 



Evaporation per minute, from a surface six inches 



in diameter 0.05 



Temperature 33 



By subdividing these again into half quarters we obtain, for 

 the first period — 



Pressure of atmosphere 29.88 ins- 

 Ditto of vapour. . , 0.429 



Weight of ditto in a cubic foot 4.697 grs. 



Degree of dryness 6| 



Evaporation 0.50 



Temperature 56° 



For the second period — 



Pressure of atmosphere 29.63 ins. 



Ditto of vapour 0.262 



Weight of ditto in a cubic foot 2.988 grs. 



Degree of dryness 1 J 



K 2 



