Part 7

Bore this head full of holes ¼ in. diameter. In the other head bore a hole 1¼ in. diameter, and bolt an iron flange into which the pump pipe is to be screwed. Let the bolts also fasten upon the inside a raised disc of galvanised sheet iron, perforated with a sharp point or chisel. Proceed to charge the filter by turning the top or flanged head down, and placing next the perforated plate a layer of fine gravel 3 in. thick, then a layer of sharp, clean sand 3 in. thick, then a layer of pulverised charcoal free from dust, 3 in. thick, then a layer of sharp clean sand mixed with spongy iron, pulverised magnetic iron ore, or blacksmiths’ scales, followed by a layer of coarse sand, gravel, and broken stone, or hard burnt bricks broken into chips to fill up. Place the perforated bottom in as far as the head was originally; bore and drive a half-dozen oak pegs around the chine to fasten the head. Then turn over the filter, screw the pump pipe into the flange, and let it down into the cistern.

Such a filter requires to be taken out and the filtering renewed in 6 to 12 months, depending upon the cleanliness of the water catch. With the precautions mentioned above in regard to the care of the roof, such a filter should do good work for one year.

=Sanitation.=--This heading is intended to embrace the removal and disposal of the various kinds of refuse and waste produced in the dwelling from day to day. Endless volumes have been written on the subject, but in plain words the whole art resolves itself into sound pipes for the conveyance of the fluid portion and efficient ventilation of the receptacles and conduits.

_House Drains._--It was pointed out by Burton,[1] before the Society of Arts, that where, as in London, the sewerage system is fairly good, dangers to health arise not from the sewers direct, but either from the sewers by means of the house drains, or even more often from the house drains themselves. It is quite agreed by medical authorities that diseases may arise from gases evolved from the drains, or even discharge pipes in a house, entirely apart from any specific infection such as may be conveyed by means of sewers.

This being the case, it will be seen that the thing which most behoves us is to make sure that the house system is efficiently doing its work. It is evident that the objects to be aimed at in constructing a system of house drainage, are as follows:--

First. All matter placed in any of the sanitary appliances in the house must be carried, with the greatest possible expedition, clear of the premises, leaving behind it as little deposit as possible.

Second. All sewer air must be prevented from entering the houses by the channels which serve to carry away the sewage.

Third. Since it is impossible to have house drains absolutely clean, that is, devoid of all decomposing matter, all air from house drains, and even from sink, bath, and other waste pipes must be kept out of the dwelling-rooms.

To which might be added a fourth, that a constant current of fresh air must be established along every pipe in which it is possible that any decomposing matter may remain, so that such matter may be rapidly oxidised, or rendered innocuous.

The number of houses in which sanitary inspectors find the drainage arrangements to be thoroughly good, and to be fulfilling these conditions, is surprisingly small. In fact, in all the houses they are called upon to examine, except those which have been arranged, within the last dozen years or so, by some engineer, builder, or plumber who has made a special study of the matter, are found defects which interfere with the due fulfilment of one or other of these conditions.

Attention is called to Fig. 20, in which the drainage arrangements are shown to be defective. Here Burton has taken such a state of affairs as is by no means uncommon in a London house. Alongside it is a drawing which illustrates a well-drained house (Fig. 21). By their juxtaposition, the defects exhibited will be made more patent.

The first point demanding attention is the condition of the main drain. It will be seen that it is little other than an elongated cesspool. The size is unnecessarily large. As a consequence, even if it were perfect in all other respects, it would not be self-cleansing, inasmuch as there can never pass down the drain which serves for a single house enough water to scour out pipes of the size illustrated, namely, 9 in. diameter.

It will be seen, however, that the state of affairs is far from correct, apart from the size of the pipes. In the first place, the joints are not tight; sewage will soak out into the ground through them. In the second place, although there is ample allowance between the two ends of the drain for a good fall, or incline, this fall has all been confined to a few feet of its length, the part underneath the house being laid almost level. This is done simply to avoid the trouble of excavating the ground to a sufficient depth.

Let us now follow the action of a drain of this kind, and see what it will lead to. Sewage matter finds its way into it. As we all know, this matter depends on water to carry it forward. It is probable that, while the drain is new and the ground comparatively solid around it, sufficient water will remain in it to carry the greater part of the sewage to the sewer. But this state of affairs will not last. Before long, some unusually heavy or obstinate matter will get into the drain. It will be carried only so far, and will then stick. Any water now coming behind it will “back up,” to a certain extent, and will very soon find its way into the soil, from one or more points behind the obstruction--not yet amounting to a stoppage. As a consequence, sewage now passing into the drain, loses its carrying power, and gets no farther than a certain distance. Before long, a complete stoppage takes place, and all the sewage of the house soaks into the ground under the basement. After this, things go from bad to worse. The saturated ground no longer properly supports the pipes, which, as a consequence, will become more and more irregular, and all hope of the drain clearing itself is lost. It is only a question of time, with a drain such as that shown, and the inmates of the house will be living over a cesspool.

As a matter of fact, total obstruction or stoppage has been discovered in 6 per cent. of the houses which have been inspected.

The next point worthy of attention is the soil pipe; this term being at present used to signify the vertical portion of the drain only, although it very often is also used as meaning the almost horizontal drain under the house.

The soil pipe is of lead. This is an excellent material if the pipe be properly arranged, but here it is not. The great fault is that there is no ventilation. As a consequence, the upper part of the pipe will always be filled with sewer gas, which tends to rise in a somewhat concentrated state. Now, sewer gas has a powerful action on lead, and, therefore, a soil pipe arranged without ventilation never stands many years before it becomes “holed,” that is to say, is worn through at its upper part. When this occurs, of course, there is ventilation enough, but it is into the house. The ventilation in this case will, in fact, be most active, because every house, on account of the fires in it, acts, especially in winter, as a chimney, and draws in sewer or other gas from every possible crevice.

At the top of the soil pipe will be found the commonest of all water-closet arrangements, namely, the pan-closet with D trap. This arrangement is exceedingly well known: it is a most skilfully devised piece of apparatus for retaining sewage in the house, and distilling sewer gas from the same, and it is the cause of probably nine out of ten of the actual smells perceived in houses, even if it does not (as some say) give rise to much actual disease.

The soil pipe discharges over a small cesspool at the foot. This is a very common arrangement. The cesspool is usually dignified by the name of a dip trap. The percentage of houses showing leaky soil pipes is 31.

Now, observe that, although our constructor has not ventilated his soil pipe, he has been careful not to leave the system entirely without ventilation. On the contrary, by the simple device of leaving a rain-water pipe untrapped at the foot, he has ventilated the drains, and also the public sewer, into the back bedroom windows! This is a quite common arrangement, and frequently results in typhoid fever.

Next, in order, we may take the case of the discharge pipes from baths, sinks, basins, and all such appliances. It has been laid down as a rule by the best sanitary authorities that these appliances must discharge not into the soil drains, but into the open air over trapped gullies, as it has been found that this is the only way of being absolutely certain that no sewer air shall enter the rooms by the discharge pipes. It is quite true that if a trap be fixed on a discharge pipe of, say, a sink, the greater part of the sewer air may be kept back from the house; but traps, however excellent they may be in _assisting_ to keep out sewer air, are not alone sufficient. There are several reasons for this. In the first place, there is the fact that a certain amount of sewer gas will pass through the water of a trap, or, to speak more strictly, will be absorbed by the water on one side, and afterwards given off on the other side. It is true that in the case of a well-ventilated drain this amount will be infinitesimal, and might even be disregarded, but there are other causes for the uncertainty of a trap. If the appliance, on the discharge pipe of which it is, be disused for a long time, there is the possibility that the water in the trap may dry. In this case, of course, there is no further security. Besides this, however, there is an action known as siphonage, in which the rush of water through a pipe carries with it the water which ought to remain in the trap and form a seal. In Fig. 21 are shown several different ways of connecting sinks, &c., with drains. The discharge pipe often carries an apology for a trap, in the form of a little apparatus called a bell trap. But, as a matter of fact, it is the commonest thing possible to find the bell trap lying on the sink. It has been lifted out of its place to let the water run down the waste pipe more quickly. It is no unusual thing to go into the scullery of a house, and to find the discharge pipe of the sink quite open, and a blast of sewer air issuing from it which will extinguish a candle.

In other cases the sink has an arrangement which is called a grease trap, but is, in reality, nothing more nor less than a particularly foul cesspool. It calls for little remark. The pipe from the sink dips into the foul water to make a trap. In many cases, the pipe does not dip into the water; but there is a bell at the top. Sometimes the drain is at various places made up with bricks. This is a very common thing to find in houses. The bricks are used to save the trouble of getting special junction bends, &c. The other sinks and baths in the house are shown as discharging into the closet traps. This is a very common and objectionable arrangement. Sixty-eight per cent. of houses examined show the defects last mentioned; that is to say, the sinks, baths, or fixed basins are connected with the drain or soil pipe, a trap of some kind generally, but not always, forming a partial security against sewer gas.

As mentioned before, the only ventilation in this case is such as will permit the issuing sewer gas to find its way into the house. It is by no means unusual to find no provision at all for ventilation, or to find the ventilating pipes so small that they are totally useless. In more cases than one, Burton found the soil pipe carried up as a rain-water pipe into the attics, where it received rain-water from two gutters, one from each side of the roof, and discharged all the sewer gas which escaped by it. Generally, the drinking-water cisterns are situated in such attics.

It may be noted, in the other drawing (Fig. 21), that a trap is fixed on the main drain, which will keep back almost all sewer gas, and that ventilating pipes are so arranged that a constant circulation of fresh air exists through the whole drainage system, and will carry away with it any little sewer gas which passes through the trapping water.

The most perfect water-supply arrangement does not necessitate the existence of cisterns in the house at all. This is beside the mark, for the reason that in London, to which Burton confines his remarks, the supply of water to the greater portion of the town is intermittent, so that cisterns are a necessity.

Water, even in London, is almost always delivered in a sufficiently pure state to be drunk, but it is a very common thing for it to be contaminated in the cisterns. Even if there be no actual disease germs carried into the water, there is liability of deterioration from the mere fact of a large quantity of water being stored for a long time before use. If the cisterns are of so great size as to hold as much water as is used in, say, three or four days, it follows that all water drawn has remained in these cisterns for an average time of several days. This is by no means likely to improve its quality, but, on the contrary, if it does nothing else, it renders it flat. There are far more dangerous causes of contamination than this, however. The commonest of these is to be found in direct communication between the drains and the cisterns through the overflow pipes of the latter. This is shown in Fig. 20. It will be seen that there is a trap on the pipe by way of protection against the sewer gas. This is a by no means uncommon arrangement; but, as will be readily understood, such a trap is absolutely of no good. An overflow pipe to a cistern is merely an appliance to be put in use in case of an emergency; that is, in case of derangement of the ball valve through which the water enters. As a matter of fact, an overflow may not occur from year’s end to year’s end--probably does not--and, as a consequence, the trap soon becomes dry, and the temporary security afforded by it is lost. In 37 per cent. of houses inspected, Burton found direct communication between the drain or soil pipes and the drinking-water cisterns.

Another means by which the water of cisterns is contaminated is by their being placed in improper positions. Quite frequently, a cistern in which drinking-water is stored, is situated in, or even under the floor of a w.c. Burton has known more than one case in which the drip tray under a closet actually discharged into a cistern.

It is even possible for contamination of water to occur through the mere fact that a water-closet is supplied from a certain cistern. With a water-closet supplied by the modern regulator-valve apparatus, this is most unlikely; but it will be readily seen how it may occur with such an arrangement as that shown in Fig. 20, which is common. Here it will be seen that for each water-closet there is a plug in the cistern. This plug is so arranged that when it is raised by the wire which connects it with the water-closet branch, it suddenly fills what is called a service box, this being a subsidiary cistern fixed under the body of the main cistern, and in direct communication with the water-closet. After the water has run out of the service box, this is free to fill itself with foul gas from the water-closet by the service pipe, and the next time the plug is lifted this same foul gas passes into the water, which absorbs a part of it.

There are many other points in the drainage arrangements of a house which may possibly become causes of danger, such as surface traps in areas, &c. In speaking of the drain of a house, it has been considered as a single length of pipe; but it must be remembered that in any drainage system, except the most simple, there are branch drains, often many of them, and that these are liable to the same evils as the main drains, and require the same attention. In fact, seeing that less water is likely to pour down them, they require more attention.

Burton concludes his paper with a brief description of the methods in use for discovering defects in house sanitation.

One thing that is absolutely necessary for such inspection, and without which it would be quite incomplete, is to open down to the drain. This should be done at the nearest point to that at which it leaves the premises. There is no absolute guide to tell where this point is, but after some experience it is generally possible to hit upon the spot with very little searching. In the house illustrated in Figs. 20, 21, it would be under the front area or cellar. The ground should be entirely removed from the drain for at least two lengths of pipe. It is also very desirable that a portion of the ground over the top of the drain should be removed.

We may next take the point of trapping of the main drain and ventilation of the system. It will be seen that, in the case of the drawing of the imperfect arrangements, the drain is shown to be in direct communication with the sewer. The consequence is that any leakage which may exist in the house drain permits gas not only from the drain itself, but from the sewer also, to find its way into the house.

The engineer will now be able to tell much of the state of affairs. He will see of what size the drain is; he will be able to tell of what material the joints are made, taking those exposed as samples; he will, in all probability, find the ground under the pipes soaked with sewage, and be able at once to say that the drain is in a leaky and bad condition; he will find whether it is properly supported on concrete, or has been “tumbled” into the soil; he will be able readily to discover what is the total fall in the drain from back to front. At this stage of the proceedings, the drain itself should not be opened; but, on the contrary, if the taking up of the ground should have exposed any joints which are evidently leaking, these should be made temporarily good with clay. The reason is, that it is desirable, before anything has been disturbed, to test the system for the purpose of discovering what amount of leakage there is into the house.

There are various ways of doing this, but the two commonest, which Burton describes and illustrates, are those known as the “peppermint test,” and the “smoke test.”

The smell of peppermint is well known, possibly to some of us unpleasantly well known, but probably its excessive pungency when in the form of the oil, and when brought into contact with hot water, is not generally understood. It will readily be believed that if such an excessively pungent mixture as this be introduced into the drainage system of a house, even the smallest leakage will become evident. Suppose the least possible defect to exist in any joint of any of the pipes, a strong smell of peppermint will be evident near the defect. The only difficulty is in finding a place to introduce the peppermint. It will be quite evident that it is no use to pour it into any of the appliances in the house, as, were such done, this smell would so rapidly permeate the whole of the premises, by way of the staircase, passages, &c., that time would not be allowed to detect the leakages. Some means must be discovered of getting the peppermint in from the outside. This is not always possible, but generally it is. In the case illustrated, there would be no difficulty. The rain-water pipe at the back admirably suits the purpose. One person gets out on the flat roof, near the top of the pipe, and provides himself with peppermint, and 4 or 5 gallons of water, as nearly boiling as possible. Meantime, all doors and windows are closely shut, and persons are stationed about the house to observe if the smell expected becomes evident, and to locate, as far as possible, the point from which it issues. The man on the roof pours about ½ oz. of the oil down the pipe, and follows it with the hot water. He need then retreat from the place a little, for the peppermint-laden steam which will come from the pipe is blinding in its pungency. As soon as possible, he plugs up the top of the pipe with a towel, or some such thing, to prevent the occurrence of the vacuum which would otherwise be in the pipes, and which would tend to draw air from the house into the pipes instead of from the pipes into the house at any leakage. It would probably not be a minute before the people in the house would perceive the smell at various places. The manipulator of the peppermint must remain perched on the roof until those inside have had time to make their observations, otherwise he will infallibly bring the smell with him.

The test described is an excellent one. It is searching, and is simple in application, but it has one drawback. It is impossible by means of it exactly to localise a leakage. This drawback does not apply to the smoke test. A smoke machine is nothing more nor less than a centrifugal pump attached to a vessel for generating smoke. The pump pumps smoke out by a pipe, which may be inserted in any pipe in direct communication with the drain or in an aperture made for the purpose. The test is, in all respects, similar to the peppermint one, except that the leakage is not smelt but seen.

After the test has been performed the drain may be opened. This may be done by breaking into a pipe in front, by breaking off a collar, or by punching a round hole in the pipe. In any case it will be possible to judge much of the condition of the drain by the manner in which water runs through the pipes. If we have discovered that there is sufficient total fall, we can now see whether or not it is uniform. We shall, as remarked before, find in six cases out of every hundred examined that there is total stoppage, that no sewage whatever leaves the premises, and that consequently it must all be depositing under the basement.

If the drain, after all tests so far applied, and from what can be seen of it, appear to be in good condition, it may be further tested by filling, or attempting to fill it with water. There is probably not an average of one drain in a thousand in London which would remain full of water for an hour. For the rest it is necessary to examine all appliances, to trace the pipes from them, and sometimes to test these pipes.

The engineer has now completed his inspection, and has but to consider how he will make the best of a bad job, and put things to rights. At the beginning of his paper Burton expressed his intention of confining himself to a description of defects, and said he should not describe what he considered a perfect system; he, however, points out one or two of the chief features of the arrangements in the house which he calls well drained.

Most notable, probably, is the small size and sharp fall of the drain pipes. Further than this, it will be seen that the drain is disconnected from the sewer by a trap, and that it is accessible for inspection throughout, simply by lifting certain iron covers (Fig. 22). A close examination would show that every foot of drain pipe and discharge pipe is so ventilated, that there will be a current of air through it; that no appliance discharges into the drain direct, but that there is an atmospheric disconnection in every case; that air from discharge pipes of sinks, &c., is all trapped from the house; that there is separate water supply for closets, and for other purposes; and that no cistern has any connection with the drains. Further will be noticed, the difference in construction of the closets, &c.