187. A Cheap Well for Campers. A two-inch galvanized iron pipe with a strong, pointed end containing small perforations is driven into the ground with a sledge hammer. After it has penetrated for a few feet, another length is added and the whole is driven down, and this is repeated until water is reached. A cheap pump is then attached to the upper end of the drill pipe and serves to raise the water. During the drilling, some soil particles get into the pipe through the perforations, and these cloud the water at first; but after the pipe has once been cleaned by the upward-moving water, the supply remains clear. The flow from such a well is naturally small; first, because water is not abundant near the surface of the earth, and second, because cheap pumps are poorly constructed and cannot raise a large amount. But the supply will usually be sufficient for the needs of simple camp life, and many a small farm uses this form of well, not only for household purposes, but for watering the cattle in winter. If the cheapness of such pumps were known, their use would be more general for temporary purposes. The cost of material need not exceed $5 for a 10-foot well, and the driving of the pipe could be made as much a part of the camping as the pitching of the tent itself. If the camping site is abandoned at the close of the vacation, the pump can be removed and kept over winter for use the following summer in another place. In this way the actual cost of the water supply can be reduced to scarcely more than $3, the removable pump being a permanent possession. In rocky or mountain regions the driven well is not practicable, because the driving point is blunted and broken by the rock and cannot pierce the rocky beds of land. [Illustration: FIG. 139--A driven well.] [Illustration: FIG. 140.--Diagram showing how supplying a city with good water lessens sickness and death. The lines _b_ show the relative number of people who died of typhoid fever before the water was filtered; the lines _a_ show the numbers who died after the water was filtered. The figures are the number of typhoid deaths occurring yearly out of 100,000 inhabitants.]