414 
FAIRLEY : BLOWING WELLS. 
December 7th, 5-30 p.m., to 8th, 10-30 a.m. = 18 hours. 
486-6 + 460 
Mean v. = 473-3. 
2 
Total feet passed 473-3 x 1080 = 511,164. 
December 8th, 10-30 a.m. to 4-30 p.m. = 6 hours. Mean 
460 + 398-6 
v. = 429-3. 
2 
Total feet passed 429-3 x 360 = 154,548. 
December 8th, 4-30 p.m., to 9th, 10-30 a.m. = 18 hours. 
398-6 + 0 
Meanv. = 199-3. 
2 
Total feet passed 1080 x 199.3 = 215,244. 
December 9th, 10-30 a.m. to 11-53 p.m., 13 hours 23 minutes. 
232.2 + 0 
Mean v. 116-6. Barometer finally at 30-462. 
2 
Total feet passed 116-6 x 803 = 93,630. 
Therefore, total feet passed from December 5th, at 5-42 p.m. 
(area of tube) 30 . 462 
to December 9th, at 11-53 p.m = 2,724,342 x -085 x 
= 9J millions of cubic feet. '762 
Similar calculations (which can be checked from the table 
already given) referring to the in-current from December 10th, 
1879, to December 13th, the initial barometer being 30-4, and 
30-75 
the final 30-75, give 1,185,153 x -085 x = 11-5 millions 
of cubic feet. °* 35 
The other observations evidently refer to currents which the 
subsequent changes of the barometer did not allow to be completed. 
Assuming that the covering of the shaft of the well was 
air-tight, which was frequently not the case, we have here a 
