s water into the basin over the
top of its southern rim, the water, as it leaves the pipe, flowing over
a standard weir, without end contractions, into a stone gutter. A
by-pass pipe, with suitable valves, passes around the western side of
the basin and connects to the outlet pipe.

This comparatively small amount of work equipped a very good natural
reservoir with a capacity of 422,000,000 gal., which can be increased to
1,000,000,000 gal. by embankments across low places in the rim.

_Service Reservoirs_.--At Coyote, an artificial service reservoir, 100
by 200 ft. on the bottom, with slopes of 1-1/2 on 1 and a total depth of
15 ft., serves as an equalizer of the flow to and away from the pumps
at that point. The pump-house is built alongside this reservoir. The
delivery pipe from the Nogal Reservoir runs directly to the pumps, but
has a tee-branch, 50 ft. long, into the Coyote Reservoir. This branch
passes through a valve chamber between the pump-house and the reservoir.
In this chamber there are controlling valves and an automatic overflow.
This overflow is provided against the contingency of a full reservoir
and idle pumps. If the pipe line is delivering water faster than the
pumps discharge it, the surplus goes into the reservoir. This
arrangement is self-acting and controlling. There is a similar
arrangement at the Luna pumping plant, also at the Carrizozo service
reservoir, and at the regulating reservoir on the Corona summit.

Each of the four service reservoirs is of the same size, and lined with
4 in. of 1:2:4 concrete. At Luna and Corona the concrete is reinforced
with 3/8-in. round rods spaced 12 in. from center to center, both ways.
This reinforcement should have been used in all the work.

_Pumping Plants_.--The pumps at Coyote and Luna are Nordberg duplex,
cross-compound, condensing, crank-and-fly-wheel machines, with 6-in.
plungers, traveling 600 ft. per min. at full normal speed, and designed
to work against 300 lb. per sq. in. They have a guaranteed efficiency of
135,000,000 ft-lb. per 1000 lb. of steam at 150 lb. and superheated 75
degrees.

The boilers are 125-h.p., Sterling, water-tube, with Foster
superheaters, and 33-in. stacks, 100 ft. high.

Each plant is in complete duplicate pump and boiler units, only one set
working at a time.

The pump building is a substantial concrete, brick, and steel structure,
50 by 80 ft. in plan, with a fire-wall, with two steel doors dividing
the floor space