that the 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.
|
| Fig. 14—Inverted Bottle. To illustrate the principle of an automatic supply to a water-closet trap affected by evaporation or other causes. |
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 blowing, will, in such cases, circulate sewer-air freely through the house.
The soil-pipe, if of cast-iron, should be of the greatest thickness 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 foundations to convey sewage. Certain 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 independent 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 ventilated air-space between the two systems of drains, so that there is no opportunity for the foul air from the sewer to enter and circulate 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
