of the cost of the constant hand-work required in brick

Bewers.

For the first six or seven hundred feet at the head of a sewer, a six inch pipe will remove all of the house and street drainage, even during a heavy rain fall; and if the inclination is rapid, (say 6 inches to 100 feet,) the acceleration of the flow, caused partly by the constant additions to the water, pipes of this size may be used for considerably greater distances. It has been found by actual trial that it is not necessary to increase the size of the pipe sewer in exact proportion to the amount of drainage that it has to convey, as each addition to the flow, where drainage is admitted from street openings or from houses, accelerates the velocity of the current, pipes discharging even eight times as much when received at intervals along the line as they would take from a full head at the upper end of the sewer.

For a district inhabited by 10,000 persons, a 12-inch pipe would afford a sufficient outlet, unless the amount of road drainage were unusually large, and for the largest sewers, pipes of more than 18 inches diameter are rarely used, these doing the work which, under the old system, was alloted to a sewer 6 feet high and 3 feet broad.

Of course, the connections by which the drainage of roads is admitted to these sewers, must be provided with ample silt-basins, which require frequent cleaning out. In the construction of the sewers, man-holes, built to the surface, are placed at sufficient intervals, and at all points where the course of the sewer changes, so that a light placed at one of these may be seen from the next one ;—the con tractor being required to lay the sewer so that the light may be thus seen, a straight line both of inclination and direction is secured.

The rules which regulate the laying of land-drains apply with equal force in the making of sewers, that is no part of the pipe should be less perfect, either in materiai

or construction, than that which lies al ove it; and where the inclination becomes less, in approaching the outlet, siltbasins should be employed, unless the decreased fall is still rapid. The essential point of difference is, that while land drains may be of porous material, and should have open joints for the admission of water, sewer pipes should be of impervious glazed earthen-ware, and their joints should be securely cemented, to prevent the escape of the sewage, which it is their province to remove, not to distribute. Drails from houses, which need not be more than 3 or 4 inches in diameter, should be of the same material, and should discharge with considerable inclination into the pipes, being connected with a curving branch, directing the fluid towards the outlet.

In laying a sewer, it is customary to insert a pipe with a branch opposite each house, or probable site of a house.

It is important that, in towns not supplied with waterworks, measures be taken to prevent the admission of too much solid matter in the drainage of houses. Water being the motive power for the removal of the solid parts of the sewage, unless there be a public supply which can be turned on at pleasure, no house should deliver more solid matter than can be carried away by its refuse waters.

The drainage of houses is one of the chief objects of sewerage.

In addition to the cases cited above of the model lodging houses in Lambeth Square, and of the buildings at Westminster, it may be well to refer to a remarkable epidemic which broke out in the Maplewood Young Ladies' Institute in Pittsfield, Mass., in 1864, which was of so violent and fatal a character as to elicit a special examination by a committee of physicians. The family consisted, (pupils, servants, and all,) of one hundred and twelve persons. Of these, fifty-one were attacked with well-defined typhoid fever during a period of less than three weeks. Of this

number thirteen died. The following is extracted from the report of the committee:

66

"Of the 74 resident pupils heard from, 66 are reported

as having had illness of some kind at the close of the "school or soon after. This is a proportion of or nearly "90 per cent. Of the same 74, fifty-one had typhoid fever, "or a proportion of nearly 69 per cent. If all the people "in the town, say 8000, had been affected in an equal pro"portion, more than 7000 would have been ill during these “few weeks, and about 5500 of them would have had "typhoid fever, and of these over 1375 would have died. "If it would be a more just comparison to take the whole "family at Maplewood into the account, estimating the "number at 112, fifty-six had typhoid fever, or 50 per 'cent., and of these fifty-six, sixteen died, or over 28.5 per "cent. These proportions applied to the whole population “of 8000, would give 4000 of typhoid fever in the same "time; and of these 1140 would have died. According "to the testimony of the practising physicians of Pittsfield, "the number of cases of typhoid fever, during this period, "aside from those affected by the influences at Maplewood, "was small, some physicians not having had any, others "had two or three." These cases amounted to but eight, none of which terminated fatally

66

The whole secret of this case was proven to have been the retention of the ordure and waste matter from the kitchens and dormitories in privies and vaults, underneath or immediately adjoining the buildings, the odor from these having been offensively perceptible, and under certain atmospheric conditions, having pervaded the whole house.

The committee say "it would be impossible to bring "this report within reasonable limits, were we to discuss the "various questions connected with the origin and propaga "tion of typhoid fever, although various theoretical views "are held as to whether the poison prod acing the disease

"is generated in the bodies of the sick, and communicated "from them to the well, or whether it is generated in 66 sources exterior to the bodies of fever patients, yet all 'authorities maintain that a peculiar poison is concerned in its production.

"Those who hold to the doctrine of contagion admit 66 that, to give such contagion efficacy in the production of ས wide spread results, filth or decaying organic matter is "essential; while those who sustain the theory of non"contagion-the production of the poison from sources 66 without the bodies of the sick-contend that it has its "entire origin in such filth-in decomposing matter, espe"cially in fermenting sewage, and decaying human excreta.

"The injurious influence of decomposing azotised matter, "in either predisposing to or exciting severe disease, and "particularly typhoid fever, is universally admitted among "high medical authorities."

The committee were of the opinion "that the disease "at Maplewood essentially originated in the state of the "privies and drainage of the place; the high temperature, "and other peculiar atmospheric conditions developing, in "the organic material thus exposed, a peculiar poison, "which accumulated in sufficient quantity to pervade the whole premises, and operated a sufficient length of "time to produce disease in young and susceptible perTo prevent the poison of "typhoid fever when taken into the system, from producK ing its legitimate effects, except by natural agencies, "would require as positive a miracle as to restore a severed “head, or arrest the course of the heavenly bodies in their "spheres. * * * The lesson for all, for the future, is

66

66

sons.

* * * * *

too obvious to need further pointing out; and the com"mittee cannot doubt that they would hazard little in "predicting that the wisdom obtained by this sad expe "rience, will be of value in the future management of this

"institution, and secure precautions which will forever 66 prevent the recurrence of such a calamity."

The results of all sanitary investigation indicate clearly the vital necessity for the complete and speedy removal from human habitations of all matters which, by their decomposition, may tend to the production of disease. and early measures should be taken by the authorities of all towns, especially those which are at all compactly built, to secure this removal. The means by which this is to be effected are to be found in such a combination of watersupply and sewerage, as will furnish a constant and copious supply of water to dissolve or hold in suspension the whole of the waste matters, and will provide a channel through which they may be carried away from the vicinity of residences. If means for the application of the sewage water to agricultural lands can be provided, a part if not the whole of the cost of the works will be thus returned.

Concerning the details of house drainage, it would be impossible to say much within the limits of this book. The construction of water-closets, soil-pipes, sinks, etc., are too will understood to need a special description here.

The principal point, (aside from the use of pipes instead of brick-sewers and brick house-drains,) is what is called in London the system of Back Drainage, where only principal main lines of sewers are laid under the streets, all collecting sewers passing through the centres of the blocks in the rear of the houses. Pipes for water supply are disposed in the same manner, as it is chiefly at the rears of houses that water is required, and that drainage is most necessary; and this adjustment saves the cost, the annoyance and the loss of fall, which accompany the use of pipes running under the entire length of each house. Much tearing up of pavements, expensive ditching in hard road-ways, and interference with traffic is avoided, while very much less ditching and piping is necessary, and repairs are made with very little annoyance to the occupants of