A windmill of the best design is made entirely of steel with small angle irons for posts for the tower, and with the mill itself made of galvanized iron. It requires a good foundation and must be well anchored to the masonry piers by strong bolts set well down into the masonry. If the mill is set directly over the well and the storage tank supported on the tower, a very compact arrangement is accomplished and the danger from frost is the only difficulty to be apprehended. However, the tank is often placed in the attic, some distance from the well, to which it is connected by suitable piping. The location of the windmill requires careful consideration in order that it may receive the prevailing winds in their full force and at the same time be properly located with reference to the well. It must be remembered that the surface of the wheel is exposed to the full fury of a storm, and both the wheel and the tower must be strong enough to withstand such storms. Figure 43 shows windmill and water tank in the vicinity of Ithaca, New York. _Hydraulic rams._ A hydraulic ram is the cheapest method of pumping water, provided that the necessary flow with a sufficient head to do the work is available. It requires about seven times as much water to flow through the ram and be wasted as is pumped, so that if it is desired to pump five hundred gallons a day, the stream must flow at the rate of about thirty-five hundred gallons per day to lift the necessary water. The two disadvantages of a ram are, first, that a fall of water is not always obtainable or that the stream flow is not always sufficient, and second, that the action of the ram is subject to interruptions on account of the accumulation of air in summer and on account of the formation of ice in winter. In fact, in winter it is necessary to keep a small fire going in the house where the ram is at work in order that this interruption may not take place. Its great advantage is that it requires no attendance, no expense for maintenance, and practically nothing for repairs. It operates continuously when once started, and, except for the occasional interruption on account of air-lock, is always on duty. [Illustration: FIG. 44.--Installation of ram.] Usually the water is led from above the dam or waterfall in a pipe to the ram and flows away after passing through the ram, back into the stream. The water pumped is generally taken from the same stream and is a part of the water used to operate the ram. This is not necessary, however, and double-acting rams are manufactured which will pump a supply of water from a source entirely different from that which operates the ram. The following table from the Rife Hydraulic Engine Manufacturing Co. gives the dimensions and approximate costs of rams suitable for pumping against a head not greater than about thirty feet for each foot of fall available in the drive pipe:-- TABLE XI