1 For particulars of rainfall. see IIL. "Water"Sapply"

The drain from the house should enter above the highest point to which the sewage can rise in the cesspool, and be trapped and ventilated exactly in the same way as if the cesspool was a public sewer (see Fig. 441).

If there is no available land or other safe method for dealing with the liquid overflow from the cesspool, no overflow should be allowed, and the cesspool must be oftener cleansed. If, however, there is sufficient land, the overflow may be directed over alternate filter-beds of either gravel, suitable soil, or coke-breeze, in the manner already described under the head of "Filtration". Where no overflow can be arranged, the cesspool. would be better if constructed in duplicate, as shown in Fig. 44-.

Fig. 441.   Section of Circular cesspool.

Fig. 441. - Section of Circular cesspool.

Fig. 442   Section of Doable CesspooL

Fig. 442 - Section of Doable CesspooL.

The cleansing of cesspools is always a disgusting and troublesome process, and is generally effected at night. It is usually done by hand labour, the contents being shovelled or pumped into carts or wagons, either open or covered, and carried off to be deposited on land or into pits, or otherwise dealt with. This method of emptying cesspits is essentially crude and unscientific. In France and other continental countries, for many years past, they have been emptied by pneumatic force. The vehicle consists of an iron tank on wheels, from which the air is abstracted by a pump; a hose attached to the vehicle is inserted into the cesspool, a stop-cook on the hose is opened, and the tank is filled by the pressure of the atmosphere without causing the slightest nuisance. Messrs. Merryweather, the well-known makers of fire-engines and fire-appliances, have designed and constructed an excellent tank of this description, which is shown in Fig. 448. The apparatus, as will be seen, consists of a tank or receptacle for sewage, a, with dome and connecting-pipe, c, for producing a vacuum in the receptacle. The tank is provided with a man-hole for cleansing purposes, and inlet and outlet sluice-valves. A gauge-glass is also fitted, which gives indication of the quantity of matter in the receptacle. The whole is mounted on strong springs and patent axles provided with four wheels, and a driver's seat and footboard are also fitted. The vacuum pump, to be worked by two men, is of special design, and is mounted on a platform provided with four iron wheels, shown at B. A flexible air-pipe, 0, is supplied for connecting the tank to the air-pump, and a similar pipe, D, for the conveyance of the gases to the stove, E, where they are burnt. Such a method as this is evidently an advance upon the usual methods, and should be adopted by all Local Authorities, who are responsible for the emptying of the cesspools in their districts.

Fig 443   Merryweather's Pneumatic Cesspool emptier.

Fig 443 - Merryweather's Pneumatic Cesspool-emptier.

A better plan than an ordinary cesspit would be, where it can be afforded, the introduction of one of "Cosham's Sewagre-precipitation Tanks", where, with the addition of a small amount of chemicals, the sludge is depoeited at the bottom of the tank, and the effluent may then be passed over land or land-filters, and thus harmlessly soak away or pass into a stream or brook. Drawings of this tank and the adjacent screening and chemical chamber, are given in Fig. 444.

Fig. 444.   Coaham's Patent sewage  precipitation Tank, with screenting and Chamical Chamber

Fig. 444. - Coaham's Patent sewage -precipitation Tank, with screenting and Chamical Chamber.

The above arrangement, or a "Septic" tank and filters, would make a very complete installation for a house of large size, but with respect to cottages and small houses, where there is but little land, the problem of the best method for dealing with the sewage is not easy of solution. Each case must be considered on its merits, and whether a cesspool is used, or earth-closets or privies, they must be of the best construction, and so arranged as to cause no nuisance and to be thoroughly sanitary in every sense of the word.

The Earth-closet is too well known to demand much description. It was the invention of a clergyman, the Rev. J. M. Moule, and has been in operation for a great number of years. It consists of an ordinary closet-seat, under which is a metal container into which is dropped, either automatically or by means of levers, Ac, attached to the seat, or by a scoop, a certain quantity of dry earth, which absorbs the moisture and deodorizes the faecal matter.

The building in which such a closet is fixed should not be inside the house, but should be a separate building, or approached by a short passage with cross ventilation. It must be well lighted and ventilated, with an impervious floor of asphalt, cement, or tiles. The container beneath the seat should be constructed of galvanized iron, and should fit into guides so as to be always directly under the seat. It should be removable either at the back or front, and not contain more than about two and a half cubic feet, so as to ensure constant removal. The contents of the container can be used, with great advantage and perfect safety, in the garden attached to the house, however small. Dr. George Vivian Poore, in an excellent book, Essays on Rural Hygiene, gives some good advice and practical remarks upon this subject. He says: "In order that the dwelling and its surroundings may be wholesome, it is essential that all excremental and putrescible refuse be removed every day. To allow such stuff to accumulate for a week before removal, as is done in some places where what is known as the ' pail-system' is in vogue, is quite indefensible, and I believe that a daily removal would be found easier of accomplishment than a weekly removal." Be considers that the collected material should be at once buried. and as the material when once put under ground is safe, it might be shallowly buried close to the house and the ground cultivated. " If applied with care and knowledge, it can do nothing but good." No antiseptic must be mixed with it, as of course such admixture would kill its fertilizing properties and render the ground sterile, besides killing the microbes which Nature has provided to do the work of purifying.

Earth-closets are now made either to be operated by a handle, as shown in Fig. 445, or to be "self-acting", the motive power in the latter case being furnished by the weight of the person using the closet. A self-acting earth-cloaet of this kind is shown in Fig. 446. A reference to the illustration will explain the nature and working of this closet, a is a magazine for containing the dry earth, or other deodorizing material used. B and b' are the sustaining pieces, which bear up the weight of the material, and also form the regulating orifice, c is a bevelled shelf, which is lined with a metallic plate, and carries in front an iron frame or mouthpiece, through which the perforated shovel or spreader D travels. The action is communicated as follows: - When the closet is being used, the seat is depressed about an inch, forcing down the rods E E on each side of the seat, which raise the long and weighted end of the segmental toothed levers G and g', which in turn throw back the long end of the lever H. This duplex action is coupled by the cross bar J, to which is attached the shovel D.

fig 445  View of Moule's Eartht closet with pail removed.

Fig 445 -View of Moule's Eartht-closet with pail removed.

This is then withdrawn to the back of the bevelled shelf c, and receives the charge of earth, etc.

When the seat is relieved, the weight of the lever brings out the shovel quickly, thus spreading the earth, etc, over the excreta.

This concludes the remarks on Sewage-disposal. - It is a difficult subject, as engineers, chemists, and the legislature differ on so many points connected therewith. No hard-and-fast rules can be laid down, but each case must be taken on its merits, and the choice of any system for the ultimate disposal of sewage must necessarily be left to the judgment of experts.

Fig 446   Sectional View of the British Sanitary Company's Self acting Earth  closet

Fig 446 - Sectional View of the British Sanitary Company's Self-acting Earth -closet.