It is sometimes possible to economize by building a large tank containing about 36,000 gallons and using only a small pipe to fill, but always keeping the tank full. Such a tank would contain 4800 cubic feet or would be twenty-two feet square and ten feet deep, or it may be twenty-five feet in diameter and ten feet deep. This tank would have to be erected in the air, higher up than the top of the buildings, and would require heavy supports and a great expenditure. Unless, therefore, a convenient knoll or sidehill is available on which to build a concrete tank, the large pipe direct from the water-supply must be provided for fire protection. Whether it is worth while depends on the cost of insurance and whether it is considered cheaper to pay high rates for insurance or to spend the large sum for protection. A third choice is also open, namely, to carry no insurance and to install no fire hydrants and to run the inevitable risk of losing the house by fire. Perhaps the decision is a mark of the type of man whose property is concerned. _Rain water-supply._ It will often happen that no pond or brook is available for a water-supply, and if water is obtained, it must come directly from the rain. Apparently, this is quite feasible, since an ordinary house has about 1000 square feet area on which rain water might be caught and carried to a tank. In the eastern part of the United States, the annual rainfall is, on the average, 3-3/4 vertical inches per month, or the volume of water from the roof will be 310 cubic feet. This is nearly 80 gallons a day, or enough for three or four people. The rain from the house and barns might be combined, making perhaps 5000 square feet, and giving an ample volume of water for the needs of a dozen people.