UNDERGROUND WATER. 
243 
level 7 broke into a cavity, already described, from which a large flow of water 
immediately rushed and, pouring down the shaft, drowned the pumps at level 8. 
In a comparatively short time the water rose to a point about 45 feet above level 7. 
Early in July, 1901, these levels were recovered by pumping and by bulkheading 
the south drift on level 7, whence most of the water issued. Drifting was resumed 
on level 8 near the end of 1901, and the water steadily increased until in July, 1902, 
the pumps were raising from 2,500 to 2,800 gallons per minute. Early in August 
the attempt at further development below the water level was temporarily aban¬ 
doned, pumping was stopped, and the water rose to a point 2.5 feet below level 7. 
During the next thirteen months—that is, until the opening of the El Paso drainage 
tunnel—the water fell about a foot per month, the lowering of the water being 
probably due mainly to the pumping in the El Paso mine. September 6, 1903, the 
tunnel was completed to the El Paso mine and the restraining bulkheads blown out. 
September 7 the water in the Elkton stood at the shaft 29.5 feet below the floor 
of level 7, or 9,015.4 feet above sea level. The first rush of accumulated water 
from the tunnel soon subsided to the normal flow. The following table exhibits 
the subsequent relation of the Elkton water level to the tunnel drainage: 
Relation of water level in Elkton mine to drainage through El Paso tunnel, September 13, 1903, to May 15, 1901,\. 
Date. 
Eleva¬ 
tion 
above sea 
level of 
water in 
Elkton 
mine. 
Flow 
from El 
Paso tun¬ 
nel. 
Weekly 
decrease 
in eleva¬ 
tion of 
Elkton 
water. 
Weekly 
varia¬ 
tions in 
tunnel 
flow. 
Date. 
Eleva¬ 
tion 
above sea 
level of 
water in 
Elkton 
mine. 
Flow 
from El 
Paso tun¬ 
nel. 
Weekly 
decrease 
in eleva¬ 
tion of 
Elkton 
water. 
Weekly 
varia¬ 
tions in 
tunnel 
flow. 
September 13,1903 .. 
Feet. 
9,013.5 
Gallons 
per 
minute. 
2,084 
Feet. 
Gallons 
per 
minute. 
January 17, 1904.... 
Feet. 
8,988.3 
Gallons 
per 
minute. 
6,186 
Feet. 
2.4 
Gallons 
per 
minute. 
+934 
September 20,1903 .. 
9,012.4 
1,780 
1.1 
- 
304 
January 24, 1904... 
8,985. 4 
6,494 
2.9 
■ +308 
September 27, 1903 .. 
9,011.6 
1,840 
.8 
+ 
60 
January 31, 1904... 
8,983.2 
6,211 
2.2 
-283 
October 4, 1903. 
9,010.9 
1,808 
. 7 
- 
32 
February 7, 1904... 
8,981.0 
6,464 
2.2 
+253 
October 11, 1903. 
9,010.3 
1,846 
.6 
+ 
38 
February 14, 1904... 
8,978.7 
6,383 
2.3 
- 81 
October 18, 1903. 
9,009.6 
1,819 
.7 
- 
27 
February 21,1904.. 
8,976.8 
6,525 
1.9 
+ 142 
October 25,1903. 
9,008.8 
1,925 
.8 
+ 
106 
February 28, 1904... 
8,974 8 
6,398 
2.0 
-127 
November 1,1903 ... 
9,008.0 
2,004 
.8 
+ 
79 
March 6, 1904. 
8,972.9 
6,350 
1.9 
- 48 
November 8, 1903 ... 
9,007.5 
1,920 
. 5 
- 
84 
March 13, 1904. 
8,971.0 
6,660 
1.9 
+310 
November 15, 1903 .. 
9,006.8 
1,947 
.7 
+ 
27 
March 20, 1904. 
8,969.0 
6,476 
2.0 
-184 
November 22, 1903 .. 
9,005.9 
2,685 
.9 
+ 
738 
March 27, 1904. 
8,907.3 
6,758 
1.7 
+282 
November 29, 1903 .. 
9,003.7 
4,259 
2.2 
+ 1 
574 
April 3, 1904. 
8,964.3 
6,855 
3.0 
+ 97 
December 6, 1903.... 
9,000.4 
4,835 
3.3 
+ 
576 
April 10, 1904. 
8,962.2 
6,838 
2.1 
- 17 
December 13, 1903... 
8,997.9 
5,130 
2.5 
+ 
295 
April 17, 1904. 
8,959.8 
6,805 
2.4 
- 33 
December 20, 1903... 
8,995.8 
5,085 
2.1 
- 
45 
April 24, 1904. 
8,957.8 
6,843 
2.0 
+ 38 
December 27, 1903... 
8,993.7 
5,174 
2.1 
+ 
89 
May 1, 1904. 
8,955.8 
6,848 
2.0 
+ 5 
January 3, 1904. 
8,992.5 
4,452 
1.2 
- 
722 
May 8, 1904. 
8,954 4 
6,533 
1.4 
-315 
January 10,1904.... 
8,990.7 
5,252 
1.8 
+ 
800 
May 15, 1904. 
8,952.9 
6,700 
1.5 
+ 167 
The data in the foregoing table are graphically shown in fig. 22 (p. 236). It 
there appears that a few days after the El Paso tunnel cut into the great watercourse 
that raised the flow from 2,000 to over 5,000 gallons the water in the Elkton began 
to fall with comparative rapidity. The line in the diagram representing this fall 
is nearly straight and strikingly independent of the subsequent fluctuations in the 
flow from the tunnel, indicating that the rate of fall of the Elkton water is practi¬ 
cally limited by the flowage capacity of the natural fissure which afforded the first 
