Underground Water Cisterns
Picture 55 shows an underground water storage cistern circular in plan, bottle-shaped in section, and built of brickwork with puddled clay backing and covered with a stone top. It is also fitted with a pump, the suction pipe of which should be kept up at least six inches from the bottom of the cistern, so as to prevent sediment being drawn up the pipe. This should be of iron, as a lead pipe is liable to be dissolved, by the action of the water. Potable water stored in these cisterns is found to be colder in summer and warmer in winter than that supplied through ordinary town mains. They should be cleaned at least once a year, access being obtained by means of a ladder from the top.
Picture 55. Underground Cistern.
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