FA IK LEY : BLOWING WELLS. 
411 
that of the piping, fittings, and water of the well than upon that 
of the cavity whence it proceeded. 
It was observed that in winter the out-current w r as warmer 
than the temperature of the air. and in warmer weather it was 
frequently colder. 
The vane anemometer obtained from Davis, Optician of Leeds, 
was found on preliminary testing to be tolerably accurate or 
sufficiently so for the purpose. In the first experiments the 
anemometer was allowed to work continuously, and the following 
are the results : — 
The instrument was placed in a horizontal pipe (square at the 
end) connected with the casing of the pump. 
Date. 
Hour. 
Bar. 
Temp. Air. 
Anemt. Readings. 
Direction of 
Current. 
1879. 
July 3 
10-0 p.m. 
29425 
51-5 
M 4 
9-0 a.m. 
•45 
.57 
22,189 
in 
»> 
12-0 a.m. 
•525 
•59 
82,929 
in 
1 * 
6-30 p.m. 
•625 
•56 
274,266 
in 
»> 
10-0 p.m. 
•675 
•53 
411,182 
in 
„ 5 
10-20 a.m. 
•75 
•54 
843,225 
in 
>» 
4-40 p.m. 
•80 
•55 
1,068,290 
in 
M 
10-40 p.m. 
•875 
•51 
1,247,429 
in 
„ 6 
10-40 a.m. 
•925 
•60 
1,645,673 
in 
>» 
4-50 p.m. 
•875 
•61 
1,832,936 
in 
8-20 p.m. 
•825 
•55 
1,857,095 
in, very slow 
Stp'd 3 brs. later 
Here a total rise of the barometer of the 0*4 inches caused 
an in-current of 1,857,095 linear feet, measured by the anemo- 
meter. The sectional area of the pipe where the instrument was 
placed was about -085 square feet. 
Calculated volume of cavity — 
29,825 
1,857,095 x -085 x = 11-76 millions of cubit feet, 
0-4 
