Storing Well-water.

The reservoirs for storing well-water should be covered with brick arches, as the water is generally found to become rapidly impure on being exposed to the sunlight, principally owing to the rapid growth of vegetation. Various methods have been tried, such as keeping up a constant current of fresh water through them, and a liberal use of caustic lime; but so rapid is the growth of the vegetation, as well as the change in the colour of the water, that a few hours of bright sunlight may suffice to spoil several million gallons. These bad results are completely prevented by covering the reservoirs.