The following suggestions on windmill pumping may be found of value. One of the most desirable features in this work is the efficiency of the plant in light winds. A pump used in connection with a windmill should be of smaller size than when operated by hand
When water is pumped by hand, a pump must be used which will perform the greatest amount of work in the shortest time.
The requirements are different in the use of windmills, however, for generally the windmill need not run more than three or four hours of the day to supply the tank with all the water that is necessary. During certain seasons of the year there are many days when the wind is very light, and at such times the windmill should work under as light a load as possible in order that it may be certain of performing some work continuously under such adverse conditions. Therefore a small pump, even though unable to furnish more than half the water that could be pumped by hand during a given time, will prove most satisfactory.
The use of a small pump will allow the windmill to work a greater number of hours during light winds, and will be found to pump more water during the entire twenty-four hours of the day than a larger pump would.
A great mistake is commonly made in building the windmill tower too low. It should be of such height that the wind may reach it freely and without being interrupted in any way. Neighboring buildings, trees, hills, etc., determine the height at which it should be built. If such obstructions are met with, the tower should rise 10 ft. above them.
Another point to be considered is that when such obstructions exist, they are liable during high winds to be the means of producing eddies and counter currents, which result harmfully to the windmill. Moreover, the currents of air at elevations farther away from the ground become more steady and uniform, allowing the windmill to work more efficiently and with less wear and tear. For the reasons above mentioned, windmill towers should ordinarily be constructed not less than 30 ft. in height, and of sufficient strength and firmness to give the windmill as great stability and freedom from vibration as is possible. The following information is necessary in giving intelligent data concerning the selection and installation of a windmill proper for the work required:
The character of the well and its depth should be known - whether it is a driven, drilled, or dug well; if drilled, the inside diameter of the casing must be known; the height and distance through which water is required to be raised, these dimensions being taken from the foot of the pump to the bottom of the storage tank.
The amount of water entering the well during the dry seasons should be known, also the size of tank used, and the amount of water required for an entire day's use, and the height necessary to construct the windmill tower to provide free access of wind to the windmill.