Fig. 126.—Concrete cover for a spring.
Fig. 127.—Concrete cistern top.
In the use of driven wells, the water-bearing soil must be sufficiently open to allow the water to flow into the pipe as fast as the pump takes it away.
Bored Wells.
—In many localities the water-bearing stratum is of such nature as to give a ready flow of water but yet not sufficient to permit of the use of a sand-strainer; if, however, the opening is somewhat enlarged, the water will enter with sufficient rapidity to supply a pump. In such cases bored wells are quite generally used. They are made by boring a hole of the required size with an earth auger. These wells are made of any size up to 2 feet in diameter. They are often called tubular wells because they are lined with iron tubing or tile, to prevent the earth from refilling the hole.
Fig. 128.—Driven well with a sand-point strainer.