Use of Leveling Triangle. 179 
of the levelling apparatus above this peg by exactly that amount 
which the line rises per each instrument-length (B C), and swing 
the other end around into the direction from which the ditch is 
to come, until, when level, it is just six inches above the ground. 
Drive a peg here, which will, like the first, be six inches high, 
and proceed as before. Care should be taken to give the top of 
each peg exactly the correct elevation. The level must be hori- 
zontal when resting on any peg, and raised exactly that amount 
which the line rises per level-length, above the preceding peg. 
It will be found convenient to use a carcfully-prepared block 
to hold on the top of each stake at the rear end of the level in- 
stead of trusting to measurement each time.* 
Locating Contour Lines for Checks or for Distributing Ditches. 
—This work can be done with the aid of the level above de- 
scribed. For instance, to locate a contour (a line of equal ele- 
vation), as required in the construction of a check levee, drive 
a peg until its top has a convenient elevation from the ground, 
say one foot. Rest one end of the triangle on this peg and 
swing the other around until when B C is horizontal this other 
end has exactly the same elevation from the ground as the top 
of the peg. At this point drive a second peg and proceed as 
before. If the tops of the pegs be chosen as the height of the 
levee, they may be retained as grade stakes as well as line stakes 
for the embankment. 
Storing Water from Small Sources—For individual uses 
quite a respectable water supply can sometimes be developed 
from apparently mean sources. This can be done by clearing 
out and opening up hillside springs, and often by tunneling into 
the hillside to intercept subterranean water-flows, or by pumping 
from a well. Even a small spring, yielding but two quarts per 
second, is equivalent to a three-inch stream, and would be suf- 
ficient for several acres in fruit trees. To derive the greatest 
benefit from small springs, however, a reservoir is necessary, 
in which the flow of twelve to twenty-four hours, or even a 
longer period, can be accumulated, and then discharged as re- 
quired. It is by using water in driblets that many springs are 
wasted. A spring supplying even one and a half inches of water 
would be wholly swallowed up by a thirsty soil within two hun- 
dred feet of its source, when, by arresting the flow and accumu- 
lating it in a reservoir and discharging at intervals in a 
volume four times as large, it would more than cover eight 
times the surface. A spring flowing two quarts per second will 
discharge forty-three thousand two hundred gallons in twenty- 
four hours. This would require a reservoir‘forty by twenty 
*C.E. Grunsky, C. E., in acific Rural Press. 
