Modern plumbing as a trade is the arranging and running of pipes to supply pure water to buildings, the erecting of fixtures for the use of this supply, and the installing of other pipes for the resulting waste water. The work of the trade divides itself therefore into two parts: first the providing an adequate supply of water; and second, the disposing of this water after use. The first division offers few problems to the plumber, little variety in the layout being possible, and the resul...