462 Transactions. — Miscellaneous. 



float upwards into the house and become a source of clanger to 

 health. If it becomes at the same time a cause of offence to 

 the nostrils, we may congratulate ourselves, because we shall 

 be warned of what has taken place. Another danger is that 

 mere evaporation from the trap of some discharge-pipe which 

 is seldom used may leave an unobstructed passage for foul 

 air to enter the house. 



When this fuller knowledge of the conditions of the pro- 

 blem was properly realised it was soon seen that the air- 

 tight system must be given up. This abandonment must not, 

 however, be understood to indicate an indifference to the pre- 

 sence of leakage in the pipes or drains. So far from this, 

 freedom from leakage is now more carefully guarded against 

 than formerly, and, in order to secure it, better materials and 

 more perfect jointing are demanded. In considering how to 

 provide a vent for the air displaced by every discharge of 

 water into the pipes, it became necessary to guard against the 

 possibility of its entering the house. It was seen that the 

 vent for it must be carried above the highest window, above 

 the eaves, and even above the joints of the slates. A simple 

 method of doing this was to carry the soil-pipe, or a smaller 

 continuation of it, upwards to the ridge of the roof, or to a 

 stack of chimneys, instead of stopping it at the highest water- 

 closet. Another step in advance was to form a free inlet for 

 air at the bottom of the soil-pipe. By these two improve- 

 ments a current of fresh air was made to pass constantly 

 through the whole length of the pipe when not being used, 

 and this would render any accumulation of injurious air im- 

 possible. When a soil-pipe so fitted came to be used, the 

 discharged water would encounter nothing to retard its 

 exit. The air below the descending water would be forced 

 forward through the lower opening, and that above it would 

 freely yield to the downward suction. This would prevent 

 the risk of the demand for air causing the water to be sucked 

 out of the traps. It will be seen also that each of these open- 

 ings acts as an inlet or an outlet, as occasion demands. Plate 

 XLIX., fig. 1, shows a soil-pipe ventilated in the way de- 

 scribed. 



The next step in the direction of improvement is to dis- 

 connect all water- wastes from the soil-pipe. It must be obvious 

 that the connection of these with a soil-pipe connected with a 

 drain will bring many further dangers of contamination to the 

 air of the house, because it means that openings are provided 

 into other rooms than the water-closet — into rooms, indeed, 

 where bathing, washing-up, and cooking are being done. Such 

 connections, therefore, not only bring additional dangers, but 

 greater ones, because of the longer time during which the air 

 of these rooms is breathed by the occupants of the house. The 



