656 REGNAULT’S HYGROMETRICAL RESEARCHES. 
was composed of two thermometers with a spherical bulb of 10 
millimetres in diameter. The same apparatus was employed in 
the second series of the preceding table. 
TABLE II. 
Thermometer. Weight Been eee 
of water 
found. Found. Calculated. 
Dry. | Moist Ze a 
wv. tt ho P- P 3 
a 
5:80 | 5:41 | 0°39 | 768-22 | 03525 | 08314 0-943 
8:56 | 7:73 | 0:83 | 770-13 | 0-4345 | 0-8533 0-891 
The fractions of saturation calculated are all, with one excep- 
tion, one-tenth higher than those given by direct experiments, 
and often in a very marked manner ; it is true, that in low tem- 
peratures, and for large degrees of humidity, the indications of 
the psychrometer offer little precision on account of the slight 
difference of the temperatures indicated by the dry and moist 
thermometers. 
Two other series of experiments were made in enclosed spaces : 
their object was to demonstrate that the same formula cannot be 
applied in this case. The first series, Table III., was made in a 
room 100 cubic metres in size, which the operator, who observed 
the thermometers from an adjoining room with a telescope, did 
not enter. The second series, Table IV., was made in the class- 
room of Anatomy in the Collége de France. 
