WARMING AND VENTILATION. 



313 



ascend in these pipes arise from their internal surface or at the bottom 

 of the pipes, and will not be very abundant, (Fig. 30.) 



To prevent the gases from spreading to 

 the interior of the rooms, water-closets 

 called English closets are usually employed 

 within dwellings. In less particular houses 

 and in public establishments, there is 

 simply i)laced under the opening a basin 

 called EogerMothe's apparatus, which tips 

 and empties itself by the weight of the con- 

 teuts aloue, aud then returns and closes the 

 - opening. 



_. These convenient means are not always 



sufficient to prevent the introduction of bad 



smells on account of small cracks in the 



joints of the apparatus. 



In all cases it is better to keep the seat li or 2 inches above the upper 



edge of the bowl, letting the front and the two sides reach to the seat 



aud to connect this space with a ventilating-pipe extending above the 



roof. 



If this pipe can be placed near a source of regular heat, such as the 

 kitchen-flue, or if hot-water pipes can be carried into it, as in the case 

 of mansions heated by hot water, it would be easy to obtain a sufficiently 

 powerful draught in this pipe. 



But if this method is not available, as often is the case in small dwell- 

 ings, the same effect may be secured by placing in the pipe a small gas- 

 burner, burning at most 1 or 1^ cubic feet an hour, and which, by the 

 aid of a transom, will illuminate the closet at the same time that it puri- 

 fies it. A common lamp might even be made use of, burning ^ or f 

 ounce of oil an hour, (about 3L to Jj of a pint.) 



The ventilating-pipe should be about from 4G to G2 square inches in 

 area, and the small burner, burning li cubic feet an hour, would, in 

 most cases, secure the renewal of 1,000 cubic feet of air an hour, which 

 would suffice not only to expel all the gases coming from the seat and 

 its descending-pipe, but even to renew the air of the room several times 

 an hour by drawing in that of the surrounding corridors and also pre- 

 vent the infection of the interior of the house. 



110. Example. — Office of the Northern Railroad Company, (Fig. 31.) — If, 

 instead of English water-closets, only open seats are used, or even those 

 called Turkish seats, similar arrangements would produce the same 

 results. 



Fig. 31 shows the plan adopted with success in the office of the 

 Northern Railway Company, where there are in the five stories twenty- 

 seven water-closets. The down-pipes serve for all the pairs of seats in 

 each story, and are only three in number. They are 9 inches in diame- 



