Having thus far treated of methods of dealing with "water-carried" sewage, it will be necessary to turn to the question of what is known as "Interception", or the intercepting of the faecal matter and waste products of our dwellings, etc, without allowing them to enter the sewers. It must not, however, be lost sight of that, in every large community, sewers will still be a necessity, even if an "interception ten is introduced, for, as the Rivers Pollution Commission of 1868 reported (First Report, vol. i. 1870, page 30), "the retention of the solid excrements in middens is not . . . attended with any considerable diminution in the strength of the sewage, although the volume, even in manufacturing towns, is somewhat reduced". In other words, an interception system will not do away with the necessity for sewers to carry off the slop water, the washings of yards, and also of the public streets, percolations of filth from cesspools, dung-pits, and the like, and also manufacturers' wastes, public urinals, etc. The crowding of our populations into cities, and the altered conditions of our lives, have made it absolutely necessary that the cleanly and convenient method of carrying away our sewage-matters by water should take the place of the filthy method of storing such matters in or near our habitations. The difficulty of removing and ultimately disposing of this filth is a serious objection against all the so-called "interception" systems. These systems may be summarized as follows: -

(1) Various forms of middens.

(2) Box, tub, or pail closets.

(3) Dry-earth, ash, or charcoal closets.

The primitive "fosse", ditch, or simple hole dug into the ground to receive the human faeces, gradually evolved into the privy, no doubt first by the introduction of some kind of rough scat, and then it was built round and roofed for privacy (hence "privy") and for shelter. Before this advance was made, it is probable that the fosse or hole was lined, or "steined" as it is technically tailed, with a rough lining of stones or bricks. Then a more modern seat was added, and the privy or midden was complete.

Fortunately the old-fashioned midden-closet is now almost a thing of the past in most of the larger towns in this country, though it is still to be found in rural districts and attached to isolated houses. Mr. Redgrave, in a paper which he read before the Institution of Civil Engineers in 1876,1 says:

"It can only be spoken of in the language of Mr. Radcliffe (vide Rivers Pollution Commission, 1868, First Report, vol. i. 1870, page 30) as the standard of all that is utterly wrong, constructed as it is of porous materials, and permitting free soakage of filth into the surrounding soil, capable of containing the entire dejections from a house, or from a block of houses, for months and even years; uncovered and open to the rain, the wind and the sun, difficult of access for cleansing purposes, and unventilated and undrained." And again, in the First Report of the Rivers Pollution Commission, speaking of Manchester at pages 23 and 24, the commissioners say: - "In spite of district inspection under an energetic and experienced chief, in spite of police assistance, and notwithstanding that the penny post enables every householder so easily to give notice to the scavenger, privies and ashpits are continually to be seen full to overflowing and as filthy as can be. . . . These middens are-cleaned out whenever notice is given that they need it, probably once half-yearly on an average, by a staff of night-men with their attendant carts. Occasionally twenty or thirty middens are thus cleaned out in succession, the contents being wheeled along the whole length of the row, making the air offensive for several nights together,and creating a naieance none the less injurious because, the work being done when the people are asleep, the filthy smell is not perceived."

1 Vide Minutes of Proceedings of the Institution of Civil Engineers. Vol xlv. page 180.

Later sanitation insists that where these abominations exist, the pit shall be lined imperviously - to prevent soakage into the surrounding soil - with hard bricks or stones, set in cement mortar, and rendered or covered with cement mortar or other hard impervious material. Sanitation also insists that the midden shall be so covered and ventilated that the effluvium may pass away harmlessly into the air, and not solely through the seat into the privy building. The pit should also if possible he drained, so as to carry off the moisture, and the shape of the pit should be so arranged that its contents can he easily removed, and with as little nuisance as possible. A still more modern improvement is the provision of some simple arrangement whereby the contents of the pit may be deodorized by the addition of dry earth, ashes, or some such cheap absorbent and deodorant It is almost unnecessary to state that a privy of this description (see Fig. 430) is thoroughly insanitary, when it is situated near any dwelling-bouse.

It will be seen on reference to the foregoing figure how difficult it would be to cleanse such a privy or midden, but the following illustration shows an example of an Improved midden-privy as constructed at Nottingham. The bottom of the receptacle is concave, in order that everything may gravitate towards the centre of the pit. and the brickwork is well rendered in cement on the inside to make the pit impervious. There is also a special opening through which ashes or other deodorant may be thrown on to the contents of the pit, and a ventilating shaft is also shown to be carried up, so as to give thorough and safe ventilation. The riser of the seat is constructed in brickwork, and the floor is paved.

Fig ,430  Section of insanitary Privy and CesspooL

Fig ,430 -Section of insanitary Privy and CesspooL.

The Nottingham type of midden is, of course, free from many of the objections raised against the old-fashioned midden-privy; but a better example is that of the Burnley midden-closet (Fig. 432), the receptacle of which has the floor constructed of glazed stoneware, with an overflow-pipe connected with the sewer, and is of such small dimensions that its contents can be easily and readily removed.

Fig. 431.   Plan and Section of Mldden closet In use at Nottingham.

Fig. 431. - Plan and Section of Mldden-closet In use at Nottingham.