Part 1 of an article from Posselt's Textile Journal (October 1907) on water softening for textile and manufacturing use. It explains hard water (temporary and permanent hardness), the chemistry of removing carbonates, sulphates, chlorides, nitrates and iron with lime and soda-ash, and the Clark and Porter-Clark processes. Most of the text describes the American Water Softener Co. plant, with its motor, chemical tank, oscillating "tipper" and stand-pipe, and gives operating costs and the savings for dyeing, scouring, bleaching and boilers. The article ends with a note on bacterial purification and is to be continued.