top of frost case (E) is not less than four nor more than eight inches above grade of side-walk.

See that the hydrant is provided with perfect drainage. This may be done, preferable, by connecting the waste (J) by a tile drain with the nearest sewer. In the absence of sewers, lay drain to nearest loose or sandy soil, or dig a hole a short distance from the hydrant, and fill with broken stone, so that the contents of hydrant can waste rapidly after closing main valve. When set in loose, sandy, or gravelly soil the drain-pipe may be dispensed with, as the surrounding earth will readily absorb the waste water. In this case it is necessary to fill around the base of hydrant with stone to prevent the waste-orifice (J) becoming filled up or closed by the earth.

The base (D) should rest firmly upon a solid foundation of stone or masonry, and be well braced against the pressure of water at the bend to obviate any danger of starting the joint.

Using and repairing hydrants.---When a hydrant is first opened, after setting, the water should be allowed to run until it becomes clear, as if closed too soon, the gravel and dirt left in pipe are likely to become imbedded in the valve and cause leakage.