In the consideration of the three-pipe system, under Plate 56, a method was described for overcoming the incrustation of water fronts and range connections, incident to the use of hard water, by means of a separate storage of soft water, which would generally be rain water collected in cisterns.

For various reasons, such as an insufficient supply of rain water, this method may not always be satisfactory, and we believe that the following method will often be found preferable. We allude to the use of a water-softening device, several of which have been introduced, designed for use in connection with domestic water supplies.

Plate LVII. The Softening Of Hard Water For