A Practical Manual On Sea Water Distillation
With A Description Of The Necessary Machinery For The Process

4 SEA WATER DISTILLATION. (a) Use on Steam Ships. 8. For'^ steam ships generally, there are two purposes for which water distilled from the sea is required. First, Fresh water is obviously required for the drinking pur- poses of the crew and passengers, for although a supply of fresh water may be carried on board, and replenished when calling at different ports, still this is not sufficient to. satisfy requirements. Secondly, And this is hardly a less important requirement for pure water on board ship, is its production to make up for loss of distilled water by waste- in its use for feeding the water-tube boilers on board. Drinking Water—Quantity. 9 The quantity of fresh water considered sufficient for drinking purposes and other usual requirements naturally varies a good deal according to circumstances, and it is difficult to give a rule applicable to all cases. A first- class Battleship in H.M. service, having a crew of, say, 500 men, is allowed about 12 tons of fresh water per twenty-four hours for drinking purposes, &c. For large Ocean Liners, about 3,000 to 5,000 gallons per twenty- four hours is not an uncommon supply of fresh water to be allowed. Loss of Fresh Water on Ships. 10. The exhaust steam from the engines on board is con- densed by surface condensers, and such water is returned to the boiler feed tanks ; but distilling apparatus is re- quired to make up loss by leakage. This loss of fresh water on steam ships has been variously estimated as amounting to something like 8 tons (about 1,800 gallons) per twenty-four hours per 1,000-