SEWAGE 



343 



receiver, a portion of the noisome gas escapes at 

 once into the atmosphere of the apartment in which 

 the closet is located, and very often pervades the 



air of the habitation. 

 This is a form of 

 water-closet that 

 never should, under 

 any circumstances, 

 be used, and, as it 

 is expensive both in 

 first cost and in 

 maintenance, it is 

 difficult to under- 

 stand how it is that 

 it still finds a place 

 in the houses of the 

 people. The D-trap 



i which is used in 



connection with this 

 pan closet should 

 also be prohibited. 



The valve water- 

 closet is also largely 

 used. It has a valve 

 at the bottom of the 

 basin, and it differs 

 but slightly in prin- 

 ciple from the pan 

 closet. In this form 

 of closet there is not 

 so much space be- 

 tween the valve and 

 the trap as in the 

 pan closet. It is, 

 however, difficult to 

 p. . maintain the valves 



water-tight, and, on 

 the other hand, it is 



an expensive article, and nothing like so perfect a 

 sanitary appliance as gome cheaper forms of closet. 

 The ordinary hopper closet is one of the simplest, 

 cheapest, ana most sanitary devices, and when 

 furnished with an adequate flushing-cistern is one 

 of the best and sweetest appliances which can be 

 used in houses. This is shown in fig. 4. The 

 flush-out closet (fig. 5) is a closet which has been 

 largely used in recent years. It has some objec- 

 tions in consequence of the faecal matters being 

 spread out over a large area and 

 but imperfectly coveredwith water, 

 and the tendency of the flush water 

 to break up the faecal matters de- 

 posited in the basin, which gives 

 rise to effluvia when the closet is 

 used. 



Trough closets are largely used 

 where numbers of people con- 

 gregate together, as in clusters of 

 cottages, workhouses, mills, and 

 barracks. An ordinary form of 

 closet or latrine is shown in fig. 

 6. This is cleansed by a flushing- 

 tank which fills up slowly with 

 water, and discharges rapidly by 

 siphon action. The provision of 

 urinals, lavatories, and water-closets 

 for public use is a matter of neces- 

 sity in most towns, and lately in 

 large towns these conveniences 

 have been constructed in chambers 

 below the street level, which are 



approached by a flight of steps. 



In the case of detached nouses 

 and cottages where there are no 

 sewers it is often a difficult 

 matter to know how to deal with the liquid refuse 

 produced, including the chamber slops and waste 

 water. Probably, in the majority of cases, the best 



mode of dealing with these matters is by appli- 

 cation to the garden by throwing them on the 

 surface, or into an open trench freshly cut for the 

 purpose, and as far from the habitation as possible. 

 Means have also been provided in some rural 

 districts to distribute these waters by a series of 

 underground agricultural drain-pipes laid about 1 

 foot belowthe surface,and intermittently charged by 

 a gulley having an intermittent discharge by means 

 of a siphon connection with the drain. Where 

 waters are distributed in this way in retentive soils 

 a lower set of agricultural drains laid at a depth of 



Fig. 5. 



about 4 feet should be provided for collecting the 

 drainage after purification in passing through the 

 land. The success of this mode of disposal, how- 

 ever, largely depends upon the nature of the 

 ground. 



Cesspools. Wherever it is necessary to construct 

 a cesspool for the retention of sewage, it should be 

 in such a position with reference to the water- 

 supply as not to foul (in case the cesspool leaks) 

 any well used as a source of water supply. As all 

 underground waters move in particular directions, 

 the cesspool should invariably be on the lower side 

 of the source of water-supply. It is absolutely 

 necessary that cesspools should be built of good 

 materials, and made perfectly water-tight with 

 Portland cement, otherwise pollution of the ground 

 and ground water is sure to arise, the evil conse- 



Fig. 6. 



quences of which may spread for unlimited di- 

 tances in the direction of the moving ground water. 

 Cesspools also require to be properly ventilated, 



