622 
Journal of Agricultural Research voi. xxvn, no. » 
tion is available concerning these relations. In the case of the soils at 
Huntley, the figures reported would indicate that a change in water 
content of 0.6 per cent in the critical zone would change the water level 
1 foot. 
Table III. —Moisture content of soil saturated with underground water, Huntley, 
Mont., May, 1923 
WeU No. 
A 2 .. 
A 4 . 
A6.. 
* 7 -- 
Bi.. 
B2.. 
B3-. 
B 4 .. 
B6.. 
By.. 
B8.. 
C 4 .. 
05 .. 
C 7 .. 
C8.. 
C9.. 
Cio. 
Cn. 
Mean 
Depth. 
m 
Texture 
of soil.® 
Moisture. 
Per cent. 
f I2 - 5 
see 
2 4 . 0 
ssc 
25. 6 
1 14.0 
ssc 
2 4 , 8 
13 - 5 
ssc 
25.3 
11. 0 
ssc 
28.1 
11. 0 
sec 
27.4 
f 11.0 
ssc 
2 5 -1 
l ii- 5 
ssc 
24. 6 
/ io- 5 
ssc 
2 5 - 7 
\ 11.0 
ssc 
26. 0 
11. 0 
ssc 
23-4 
/ II. 0 
see 
2 5. 6 
l II- 5 
see 
26.5 
10. 5 
ss 
29. 6 
9-5 
ssc 
2 5 - 0 
/ 9-5 
ssc 
250 
\ 10.0 
ssc 
24 - 7 
J io- 5 
ss 
22. 2 
\ 11.0 
ss 
22. 7 
r 10.5 
ssc 
26. 4 
V 11.0 
ssc 
24.. 6 
10. 0 
ssc 
2 5-4 
/ 10.5 
ss 
2 3 - 5 
\ II. 6 
ss 
23.0 
/ i°* 5 
ssc 
24. 1 
\ 11.0 
ss 
23. 1 
f 11.0 
ss 
26. 1 
t ii -5 
ss 
2 5. 6 
/ io -5 
SSC ' 
27. 6 
1 ii- 0 
see 
3 °. 8 
25. 4 ±o. 2 
a The letters S and C refer to the proportions of sand and day judged by observation. 
An experiment in lowering the ground-water table by pumping, 
reported from the Salt River Valley, Ariz., (7) 4 , affords a basis for 
estimating the quantity of water involved in a change of level of under¬ 
ground waters. In this experiment a well was put down 285 feet deep 
where the water table was 3 feet below the surface. Water was pumped 
for 630 hours during a period of 34 days, with a total discharge of 77.9 
acre-feet. The maximum draw down at the well was 73 feet. The 
radius of measurable depression of the water table was 2,350 feet, while 
the radius of pronounced depression was 1,150 feet. It was computed 
that for the inner area of 95 acres the water table was lowered 4.4 feet 
and for the outer area of 300 acres it was lowered 0.6 of a foot. The 
removal of 77.9 acre-feet of water cleared 598 acre-feet of subsoil of its 
4 Reference is made by number (italic) to " Literature cited," p. 692-693. 
