REGNAULT’S HYGROMETRICAL RESEARCHES. 657 
TaBLe II].—Evperiments made in an enclosed room in the 
College de France (August, 1843). 
t. tu. t—t!. ho. D. £. = 
21-44 17°44 4-00 760°13 0-605 0:5649 0°6644 
21-65 17-73 3°92 757-03 0624 05743 0°6745 
22-06 18-08 398 756°75 0-644 05775 0°6716 
22-47 18:41 4:06 756:27 0-659 05769 0-6689 
22°39 |. 1848 3-91 758-50 0-661 05816 06831 
23°52 19-32 420 758-49 0°686 05652 0:6663 
23°38 18-02 5°36 75861 0-594 04930 0:5814 
23°73 18-44 5-29 757-40 0598 04889 05902 
25°75 19°81 5°94 755'33 0-652 0°4731 05656 
23°44 18-97 4°47 758-28 0:669 0°5530 0-6457 
TABLE 1V.—Exzperiments made in the Class-room of Physics. 
=: 
0°8187 
0°7709 
0°7582 
0°652 
0-645 
0649 
0-715 
0-706 
The fractions of saturation, calculated with the formula, are 
here much stronger than those deduced from direct weighing of 
the water contained in the air; in other words, the temperature 
t', indicated by the moist thermometer, is not lowered enough 
by the evaporation of the water which occurs at its surface to 
give in the formula the true elastic force x of the vapour. This 
circumstance is evidently dependent on the air being much less 
agitated than the external. 
The experiments inserted in Table V., compared with those 
of Table IV., prove it in a perfectly evident manner. The psy- 
chrometer being placed in the class-room of physics, exactly as 
in the experiments in Table IV., two large windows on the op- 
posite sides were opened. The thermometers, being placed be- 
tween the two windows, were exposed to a pretty strong current 
of air. The indications of the apparatus immediately approached 
those which it would have given in the open air. 
