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

THE FILTER. I5I tube, and will gradually disengage themselves. Or again, if cold water be put into an ordinary glass jug and brought into a warm room bubbles will soon appear on the inside of the glass. This is owing to air being discharged as the temperature rises, until at the boiling point (212°) the water is almost free from air, and consequently boiled water has a different taste. The action of the filter on non-aérated distilled water is imperfect. 5. The action of the charcoal appears to be catalytic— that is, it oxidises the trace of gaseous organic matter or empyreuma passing over with the steam, which thus taints the distilled water. Whatever may be the action of the animal charcoal, it unmistakably converts un- palatable distilled water, into water equal in taste and appearance to water obtained from the best natural sources. When the charcoal is first used a slight trace of am- monia may sometimes be detected, but this will soon pass away on continuing the use of the charcoal. 6. The filter can be made of any shape, provided the water is distributed evenly and does not run in currents. The quantity of charcoal used should not be less than about 4 cubic feet per ton of water filtered per hour. 7. The filter may be made in the form shown in Fig. 19, which represents a cylindrical tank, with a partition (P), so as to cause the unfiltered water entering at (I) to pass evenly down one compartment and up the other to its outlet at (0). Perforated gratings on the top of the char- coal in each compartment keep the charcoal in place, and the proper distribution of the water flows through it. The knobs (K) are to let air escape. 8. The animal charcoal when used for distilled water will retain its effect for a very long time. Care should