The illustration on page 184, Fig. [460], is a representation of the Corcoran windmill: it contrasts most interestingly with the same apparatus shown in Fig. [459]—a windmill of the early part of the 17th century.
The figure below, [462], exhibits in detail the rear view of the Corcoran mill with the governor. As the speed of the wheel increases it swings the “tail” around, so as to bring the wheel at an angle with the direction of the wind; the latter failing to strike the blades squarely communicates less force, and in consequence the speed is diminished; in case of a very high wind the tail turns so as to present the wheel almost edgewise towards the direction of the blast.
Note.—A windmill of this type was erected at a station on the Long Island R. R. to pump 5,000,000 gallons of water yearly. In order to test the work of the windmill, a water meter was attached to the pump during six months, and it was shown that the average work of the windmill had been 22,425 gallons per day, 4,260,750 gallons during the time stated and an average rate of 8,000,000 gallons per year. The weight of water pumped was 16,168 tons gross and was raised to a height of 66 feet, and the work was done without mishap with little attention given to the pumping machinery.
Fig. 462.
Fig. [461] represents a Corcoran double action suction force pump. The base is hollow and contains the suction and discharge valves; a flange at the left-hand side receives the suction pipe while a corresponding flange on the right-hand side connects with the discharge pipe. An air chamber is attached to the discharge end. The valves may be reached by removing the bonnets on top of the base.
Fig. 463.
Fig. [463] is intended to represent an Ideal steel tank tower; the tank is herein located near the top. A force pump is used where water is delivered into an elevated tank as in this case; a lift pump is employed to discharge water at the spout and not to elevate above it.
The common term “Windmill pump” distinguishes a wind power pump from a hand pump, the difference being in an extension of the piston rod above the upper guide with a hole for connection with the pump rod from the windmill.