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amount of sewage ejected in dry weather is found to average no more than 40 gallons per minute, so that a 6-inch pipe would carry away all the sewage produced in the Houses. Fresh air is admitted into the subway and chamber, &c. There is also a 9-inch main branch drain under the basement along the west side of the Houses, which is also ventilated. The total cost of the works, including the four gas engines, the three compressed air receivers, the piping, and the three ejectors, has been a little over 11,5007.

Drains.

1888a. Into the public sewers are carried the drains from the houses. These drains were formerly made of brick, and called "gun-barrel drains" from their circular shape. In course of time they got out of order from decay, rats working their way through, and other causes, so that foul matters soaked through into the soil, which thus became saturated, and foul air ascended into the house. Such drains have been discarded since the introduction, about 1845, of pipes into the sewerage and drainage system. These pipes are made of vitrified stoneware, and are very different to the glazed or unglazed earthenware pipes sometimes substituted for cheapness. The sewage soon corrodes this glazing, which being removed, the half-burnt earthenware sucks in the foul water and decays. Nor is it nearly so strong as the stoneware pipes; these are also supplied with covers for occasional inspection. Pipes are also made specially, feet long and of a thickness equal to one-tenth of the diameter, with Stanford's patent joints, by J. Cliff and Sons, near Leeds. Messrs. Doulton manufacture a patent self-adjusting joint, securing several advantages.

18886. The main drain necessary for the service of the largest house (we suppose the case of one in the country), if the fall be even but moderate, requires no large dimensions. When we see a small river draining considerable tracts of country, often in section only 8, 9, or 10 feet superficial, it may easily be conceived that the surplus water from, and rain falling on, a mansion is a quantity, even in pressing times, that exacts no large area of discharge to free the place from damp. There are few cases in which the greatest mansion would demand more than a 12-inch or 9-inch pipe, with branches of 6-inch and 4-inch pipe; which, with 34-inch lead pipes for soil pipes, if properly connected and laid, will suffice for all purposes.

1888c. One object in draining a house, a mansion, a village, or a town is to make the drains and sewers so that the sewage in them shall never stagnate at any part, but be corstantly flowing with a self-cleansing velocity; and so that the air in them shall never stagnate at any part, but be always flowing, by fresh air passing into their lowest parts, and by foul air discharging from their highest parts into the stratum of the atmosphere above that in which we live and breathe.

1888d. There are several systems of draining a country mansion. Near to the main outlet is fixed a large intercepting trap, to be ventilated. Into this passes, by drains on all sides of it, all the water by the rain-water pipes from the roofs, the soil by those from the water closets, and from the pantry and scullery sinks, as well as any surface water from trapped gratings. The waste pipe from the scullery sink should, previously to passing into the drain, be connected with a grease trap (see PLUMBERY). Some of the rain-water pipes may act as inlets of fresh air and also as ventilators to the drain; but occasionally, and especially near traps, other pipes for inlets of fresh air may be provided to prevent what is called "syphoning." These ventilating pipes are to be of the same diameter as the drain, as required by some authorities, or as the soil pipe as by others, to be carried up to the top of any gable or roof of the house, and to some feet above and clear of the chimney pots, so as to prevent foul air from passing down them by down draughts; the top is sometimes open, but they usually have a cap or exhaust ventilator. 1888e. The rain or surface water from houses in the country, or on open land, should be carried away into the natural streams by glazed stoneware or fireclay pipes, embedded in concrete if the soil require it, and of diameters varying from 3 to 24 inches or more, laid with a proper fall. Where a building has to be erected on soil which holds water, the site should be drained by the use of agricultural pipes, these being discharged into an open gully leading to the main drain, to a stream, or otherwise where convenient.

1888f. Town drainage consists of the comparatively clean surface and subsoil water; and of soiled and used water containing organic matters called sewage. The combination of these two waters was established in London towards the end of the last and the commencement of this century, at the time that water supply by pipes to houses became general. This was discharged into the cesspools, and thence by overflow drains into ditches, watercourses, and sewers, open and covered, and thence into natural streams and rivers. The two systems of drainage should, say many persons, be kept separate by the provision of one set of drains for receiving the clean water and discharging it into the natural streams; and of a second set for receiving the dirty water and sewage and conveying it by self-cleansing drains, as fast as it is produced, to prepared agricultural land. This system was recommended by Mr. John Phillips about 1849; but it has not found many advocates, chiefly as it appears to fail from the water in the first portion being

removed from the second portion, and thus there is not sufficient to carry off the sedimentary matter, which would be done when the two systems are combined.

1888g. The position and size of the drains having been settled, the fall has to be arranged. It has been proved beyond a doubt that matters easily carried away by the increased velocity gained by using a small drain, remain as an obstruction in a large drain. A velocity of 2 feet per second is the least which will keep sewers clear of all ordinary obstructions; while house drains and small pipes require a velocity of 3 feet per second to keep them clear (Hurst). A fall of from 2 inches or 3 inches in 10 feet will be found quite sufficient for all practical purposes. A fall of 1 in 30 is considered by many to be a good fall, and not always to be obtained. Pipes half full, with a velocity of 3 feet per second require the following falls:-4 inch pipes, 1 in 100; 6 inch, 1 in 150; 9 inch, 1 in 225; 12 inch, 1 in 300; 15 inch, 1 in 350; 18 inch, 1 in 450; 24 inch, 1 in 600; 30 inch, 1 in 700. With a velocity of 2 feet per second, 4 inch pipes require a fall of 1 in 200; 6 inch, 1 in 300; 9 inch, 1 in 450; 12 inch, 1 in 600; 15 inch, 1 in 700; 18 inch, 1 in 900; 24 inch, 1 in 1200; 30 inch, 1 in 1400 (Sears).

1888h. Hence also the advantage of flushing a drain. One person has urged that his ten-roomed house and outbuildings have not, in the course of many years, ever been inconvenienced by the use of a 3-inch drain, whilst other houses of similar size, having 6-inch and even 9-inch drains, have been seriously affected. Much depends on the fall, and on the careful laying of the pipes, and something on the quantity of water used for household purposes. Where a water closet is placed at or near the head of a drain, a stoppage of its pipe often occurs; while grease from the kitchen sink incrusting in the pipe, for want of occasional flushing with hot water, is another frequent cause. Sewers also occasionally require assistance by flushing them from their head. One of the best arrangements proposed is that of an iron tilting cistern, to hold about 90 gallons, inserted in a brick pit at the head of a pipe sewer. This cistern, with its brass bearings and plates, brickwork, stone cover, and water tap, costs about nine pounds, and if one were placed at the head of each pipe sewer in a town, and all were turned off at the same time, a material assistance in keeping the main line also clear, would be found. The" self-acting syphon flush tank" is now much used for such purposes. Rogers Field's patent consists of two concentric tubes, the outer one being closed at the top and steadied by radial ribs projecting from the inner tube. The annular space between the tubes constitutes the ascending or shorter leg, and the inner tube the descending or longer leg, of the syphon (Builder, 1879, xxxvii. 1,002). There is another arrangement patented by him, combined with a grease intercepter. (See WATER WASTE PREVENTER.) A somewhat similar one is put forward as Adams' patent flushing syphon." Another by

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Banner, as in The Sanitarian's Companion. 1888i. The house drain should be effectually cut off from aërial connection with the common sewer, or any other house drain; also, the house should be cut off from aërial connection with all soil and waste pipes; and all these external pipes and the house drain should be so formed and so connected that they shall at all times be freely flushed with fresh air, and all contribute to their mutual purification. "House drains," writes Mr. Honeyman, "as usually laid at present are not ventilated. A 4-inch drain, as recommended by Sir Robert Rawlinson (Trans. of Sanit. Inst., vol. vi., p. 72) and others, cannot be ventilated by merely leaving openings at each end of it. The friction in such a pipe would neutralise a considerable amount of energy, and there is no energy. The movement of the air is sometimes in one direction, sometimes in the other, and the quantity which gains admission is just about sufficient to promote fermentation and the propagation of organisms, and to allow the escape of abominably polluted air at either end, or into the house if it have the chance. My advice is to increase the size of the drain, to confine the sewage in a narrow channel, and to keep the whole clean. I am not prepared to say that even a well-ventilated house drain would be superior to one absolutely without ventilation, from which atmospheric air is entirely excluded; but it appears to me to be indisputable that there must be either thorough ventilation or none, and that in this case the usual via media is the very worst course that can possibly be adopted."

1888k. A system has lately (1887) been patented by Mr. H. R. Newton, architect, whereby he shows the absolute necessity for the total enclosure of sewage from air in all ways, to prevent exhalations arising, and to absolutely control the method for their suppression. He points out the injurious influence of forcing air into fouled water in any way, or of allowing fouled water to have any contact with air; drains and sewers, he maintains, should be always full, instead of empty.

18887. Various arrangements are advertised for obtaining access to drains for inspection without the necessity for breaking into them, or for clearing stoppages. At the end of the drain next the sewer (and perhaps at other places) should be formed a manhole or "inspection" chamber, having a syphon trap in it, or between it and the sewer. It may be formed of bricks in cement, sometimes set on a concrete bed, and is usually 3 feet 6 inches by 2 feet 6 inches in the clear, and finished with an air-tight cover, as by a

Yorkshire stone set in cement. The depth of the drain determines the depth of the chamber, which must be larger if very deep. At the bottom of it is an open channel

about 9 inches deep, so that it glance whether the sewage is In the end next the sewer an at the drain between the trap ing, if necessary. The cap to times be securely fixed and

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FIG. 615k.

A, Inspection chamber at the back of the house. B, Ditto, or manhole, in the front of the house. C, C, C, the drain running from the sewer at the end H, through B, wherein is shown a syphon trap, with a pipe D through which the drain can be cleansed, if necessary. This chamber B is ventilated by a pipe No. I. to let foul air out or fresh air in. The pipe No. II. is a ventilation pipe to the house drain, and also to a soil pipe, No. III. E and F are trapped gullies or gratings in the yards or gardens. Into A would also be carried the drain from the grease trap. This figure is obtained from Catherine M. Buckton's Our Dwellings, Healthy and Unhealthy, 8vo., Longmans, 1885, p. 65.

III

II

IV

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I

1888m. Fig. 6157. is a plan and section of the interior of an ordinary town house, showing the position of each sanitary apparatus, as urged by officials and by others. The figure is from Buckton's Our Dwellings, 1885, p. 62. Plan: E, back kitchen; F, front kitchen; G, front yard or area; H, yard or garden; D, steps down to the basement; a, the drain, taking the trapped gully in garden, passing through the inspection ehamber b, which takes the drain from the water closet soil pipe, and from a, the grease trap, with its vent pipe No. IV. from e, the sink in the scullery. No. II. is the vent pipe to the house drain, and No. III. the vent pipe to the soil pipe. In the front area, G, is the inspection chamber r, through which passes the drain x,

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having s, the trap to sepa- PLAN AT B
rate it from the sewer, and
into this chamber runs the

trapped gully; No. I. is the vent pipe from it. Section: A and в are two water closets, the plans are given at the side; and as a sanitary arrangement there should be a lobby, lighted and ventilated, between the water closet and the staircase, somewhat as shown on plan B; y, slop sink,

with syphon trap passing on to the head of a pipe into

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FIG. 6152.

the drain. The other letters apply to the above description also.

Iron Drains.

1888n. The "Newman" complete system of Cast Iron Drainage, of which the first introducers and sole manufacturers are the North British Plumbing Company. A paper is published by them, On the use of Cast Iron for House Drains, by W. D. Scott Moncrieff, C.E., read at the National Health Society's Exhibition, 1883. The advantages of cast iron are put thus: 1, its superior strength and capacity to resist fracture; 2, the greater lengths in which it can be manufactured, and the corresponding reduction in the number of joints; 3, the greater facilities for making the joints secure by means of lead run in, sulphur, oxidised iron filings, red lead and yarn, &c. The points to be considered in adopting cast iron are: 1, the available means for preserving it; 2, the determination of the capacity and weight of the pipes; 3, the character of the connections best suited to the material; 4, the nature of the joints; 5, the comparative cost. The preserving methods besides paint are: 1, the coating with a preparation of tar, known as Dr. Angus Smith's composition; and 2, the Bower-Barff process, consisting of coating the surfaces of the iron with magnetic oxide after a very careful cleansing, and then painting to protect the surface from being injured too deeply at any time, for if scratched, oxidation quickly follows. They can also be glazed inside. At each end of the drain a manhole can be formed, so that the drain could be swept clean from end to end by a sweep's machine. Some objections have been raised to iron drains, more especially that of the iron cracking, as it is well known iron rain-water pipes will crack, even when protected from the atmosphere.

18880. The pipes in 6 to 9 feet lengths, with inspection covers, curved junctions, are to be laid on concrete, or on a dwarf wall, or on iron bearers, and in a trench or subway under the passage, so that the whole length can be open to inspection at any time. Five-inch pipes are usually adopted, 3ths of an inch thick, giving about 120 lbs. as the weight of a 6 feet length. When the soil pipe is connected to the iron soil drain, a copper ferrule should be wiped on to the end of the soil pipe, the latter being threaded and caulked as for the ordinary iron joint. The joints may also be screw joints. The company also furnish the necessary house drain terminal, manhole covers, flush tank with annular syphon, rain-water flushing head, grease trap, water-waste preventer cistern, mica nonreturn valve, soil-pipe cowl, improved valve closets, air ventilator and tubes, Winser's channel pipes and bends, straight and taper, in best enamelled stoneware; white enamelled sinks for kitchen and scullery; caulking sleeve of brass, for securing lead pipes in iron sockets, with oakum and lead; and many others of similar modern appliances.

Testing a Drain.

1888p. There are several methods of ascertaining if the pipes are properly laid, as well as for finding the place of an escape of smell into the house. 1. By the peppermint test, relying upon smell. This is applied by pouring down the ventilating or other accessible pipe outside the house, about two ounces of strong (essence o) peppermint, quickly followed by about two quarts of hot water, the orifice of the pipe being instantly plugged up to prevent the escape into the atmosphere of the scent. If perceived in any room, or closet, or sink, there exists the evil. 2. By the smoke test, relying upon sight chiefly, the invention (1883) of Mr. C. Innes, C.E. Straw may be placed in the drain, say at the inspection shaft (if there be one), then saturated with petroleum, and lighted, with care on account of the flare. Then the drain must be covered over so that the smoke shall ascend the drain, escaping at the ventilating pipe, if there be no crack or defect by which also to escape. A pinhole in an iron pipe has thus been detected when the previous test failed to point out the exact spot. Pain's "smoke rockets" burn from ten to fifteen minutes, and emit a dense volume of smoke. "The Banner patent drain grenade" or "drain ferret" is made of thin glass, and charged with powerful pungent and volatile chemicals. When the grenade is dropped down any pipe it breaks, and the effect produced by its contents is distributed only as intended. When drains to be tested by the smell or smoke test pass through a house, care must be taken to close all openings; and when applied outside, the openings should be closed, to prevent any smell entering from the outside.

1888q. În places where the drain is deep and has been laid in clay with rubbish over, and perhaps finished by concrete with a coat of cement over, or tile, or other paving, if the ground be probed with an iron or steel rod to the bottom of the trench, it has been found that smoke was ac ually issuing from the drain; and it also showed the state of the ground, the point of the probe indicating the nature of the soil at the bottom of the trench. A third test is the water test to the main drain of a house. The pipes have to be stopped up at both ends in order to be filled with water, and some upright part formed, or selected, for the purpose of observing if the drain hold the water, or the reverse. The ends of the branches into it having been also stopped up, the water may then be turned on, and the pipes filled to a part marked on the upright pipe. It is then to be carefully watched to ascertain if the water falls

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below the mark; should it do so, it at once proves that there is a leak somewhere (James Stewart, senr.)

1888r. Among other general and special recommendations (Woodward, in R.I.B.A. Transactions, with additions), are the following:

1. Constant supervision during the laying of drains, to secure good workmanship both in the laying and jointing.

2. Drains are best laid when the carcase is completed and the roof put on. They are not required sooner, and they are then less likely to be disturbed. If left for a later time they may probably be hurried over.

3. Wherever possible, drains should be laid outside the house. When inside, their direction should be indicated on the floor by a sufficient width of the floor material being laid so as to be easily taken up at any time to obtain complete access to the drains.

4. All old drains and cesspools, and all soil which has been in contact with or saturated by any of them, should be entirely removed from the premises.

5. Junctions should always be made by a gentle curve or bend with the length of the pipe, and never at a right angle.

€. A regular and uniform fall should be secured; a too great fall may rapidly carry away the liquid while the soil remains.

7. The pipes should, if the soil 'be soft, be laid in a bed of concrete or on well-tempered clay puddle, and formed to suit the curve of the pipe.

8. The joints of all pipes should be well socketed, and the pipes should have a full bearing on the bed, not being allowed to bear only on the joint, so that channels should be formed in the bed, or be cut out for the sockets to rest in.

9. The joints should be carefully cemented or clayed in all round; not the least particle of cement or clay should remain on the inside of the pipes, as on hardening it forms an obstruction and the nucleus for stopping the drain.

10. All traps should be earthenware syphon traps, with inlets and covers, with ready access for cleaning out. Grease traps for scullery sinks should be ready of access for periodically removing the grease, which otherwise passes into the drain and assists in forming an obstruction. These traps should be ventilated.

11. As flushing plays an important part in all systems of drainage, the waste water from sinks, baths, rain-water pipes, &c., should pass down the house drain. Lately, in some systems, these have been kept distinct from the soil drains; but as very little water accompanies the one emptying of a water closet apparatus, there is much danger of soil remaining, an evil which is avoided by the flushing obtained from the other sources.

12. At the junction of pipes a shaft or inspection chamber should be formed, with a proper cover, to allow of access to the pipes, and by which rods may be passed up and down the drain in case of a stoppage.

13. Before the drain enters the sewer, and outside the house, a similar shaft should be built, with a stone or iron cover well cemented down, and a syphon trap fixed on the sewer side of the shaft, with a ventilating pipe carried up well above the roof of the house. 14. All overflows, wastes, and rain-water pipes should discharge over an open gully trap, and not be connected direct into the drain. Where practicable, gully traps should be fixed outside a building.

15. Air inlets should be fixed as far as possible from windows and doors.

16. If the drain has but a slight fall the use of a flushing tank is indispensable. 1888s. The importance of sanitary inspections may be shown in the necessity of some modifications to the existing drainage of a house. The following remarks and suggestions will be useful to the investigator:-"It cannot be too strongly impressed on the public mind, that to make a house fairly safe from dangerous inroads of sewer gas (or smell), as it is termed, is not by any means a gigantic undertaking. In the case of a new house, an architect of ordinary professional capacity is quite alive to the modern ideas of sanitation, and he will no doubt see that, so far as his client permits him, all that is proper to be done is thoroughly carried out. The difficulties become apparent when he has to deal with an old house, the drains of which he knows nothing about; but even here the task of securing safety from poison from the sewer is not such a very hard one. Take, for example, an ordinary street house. The water closet apparatus is of the old kind, perhaps set in an apartment in the centre of the house, without any communication with the open air. The sink waste is directly connected with the drain, supposed to be protected by an old bell-trap, which is of little use. The cistern has the old standing waste pipe, also directly connected with the drain, and serves the sink as well as the water closets. The rain-water pipes are also directly connected with the drains, which run under the kitchen floor or basement passage, and uninterruptedly onwards to the old iron flap trap (at the sewer), which, if it exists, or is in right action, is the only opposing force to direct contact with the main sewer in front.

1888t. "Now this is, apparently, a very alarming state of things, to be remedied only (some would say) by the removal of pipes, cisterns, and apparatus throughout the house, involving perhaps the dislocation of everything in it, and the substitution of the net

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