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

158 SEA WATER DISTILLATION. tailed information as to the rules regarding the construc- tion of boilers. 35. The Board of Trade additional rules also provide that the distilling apparatus on board emigrant ships should be taken to pieces every voyage, unless the ship is one holding a passenger certificate, when this opening out of the apparatus is required once every six months at least. The tubes or coils are also to be tested to twice the pressure at which the safety valve is loaded, or twice the highest working pressure of the boiler from which the apparatus can be worked. After putting the apparatus together again, it is to be tested as to its capability of producing its proper quantity. The boiler referred to is (in the absence of an evaporator) a donkey boiler on board the emigrant ship, for the purpose of supplying steam to the distilling condenser. The rules regarding boilers generally apply to these small boilers. 36. The water produced is to be cool, pure, and fit to drink immediately it is drawn from the filter of the appar- atus. The apparatus must include a filter charged with animal charcoal, and the charcoal should be taken out, cleansed, or renewed every voyage, except in cases of ships holding passenger certificates, in which the taking out of the charcoal may be taken out not oftener than once every six months. A capable man is required to be in charge of the apparatus. 37. The steam for working the apparatus must not be taken from the main boiler (this would appear to mean that the main boiler steam must not be condensed for drinking water purposes), and no exhaust steam should go into the condenser if the steam is greasy, and the boiler of the apparatus must not be filled or fed with water from the surface condensers, nor the apparatus be fitted with