3o8 



THE POPULAR SCIENCE MONTHLY. 



that tho various fixtures shall be near one vertical line of soil-pipe 

 extending through the house from basement to roof. This soil- 

 pipe should not be less than four inches in diameter, with an 

 extension above the roof of a size two inches larger, to prevent 

 obstruction by frost. The upper end of this extension should be 

 open, without an attachment of hood, or cowl, or bend, and should 

 not open near a window or ventilator. The soil-pipe should never 

 be connected in any way with a chimney-flue, since downward 

 draughts, when the flue is cold, or when strong winds are blow- 

 ing, will, in such cases, circulate 

 sewer -air freely through the 

 house. 



The soil-pipe, if of cast-iron, 

 should be of the greatest thick- 

 ness made for this purpose, as a 

 safeguard against hidden defects 

 in the iron and the danger of 

 splitting at the joints. Soil-pipes 

 and water-pipes should have in 

 all cases as few joints as possible, 

 and these should be made with 

 the greatest care. The well- 

 known Durham system, which 

 employs screw -joints for the 

 connections of long sections of 

 wrought-iron pipes, undoubtedly 

 gives much greater security 

 against leakage than the more 

 common methods of plumbing, 

 which require all joints to be 

 made by calking with lead. 



No drain-tiles or earthenware 

 pipes of any kind should be used 

 in the house or under the foun- 

 dations to convey sewage. Cer- 

 tain local conditions may sometimes require that drains for 

 subsoil water shall be laid within the cellar-walls, and in such 

 cases it is best to have a separate line of drainage entirely inde- 

 pendent of the sewer, but, if it is necessary to deliver this water 

 into the main house-drain, the connection must be made at some 

 distance from the house, in such a way as to have a freely venti- 

 lated air-space between the two systems of drains, so that there is 

 no opportunity for the foul air from the sewer to enter and circu- 

 late through the open- jointed line of earthen tiles beneath the 

 cellar bottom. Almost equal care is necessary when drains for 

 soil- water are laid just without the cellar- walls, since air from the 



Pig. 14— Inverted Dottle. To illustrate the 

 principle of an automatic supply to a water- 

 closet trap affected by evaporation or otlier 

 causes. 



