Fig. 2.FIG. 2.
Figure 2 shows the cross section of a country road thirty feet wide, with three lines of tile-drain laid at a depth of about three feet below it. Except in case of necessity, these drains should have an inclination of not less than six inches in one hundred feet. There is no objection to their having more than this wherever the lay of the land permits or requires it. They may often have considerably less in case of need; but, the smaller the rate of inclination, the greater the care needed in securing a true grade. The water of these drains should be collected into a single drain, and led away at intervals of from five hundred to one thousand feet. It may be delivered into a roadside gutter, or into a collecting under-drain, according to the requirements of the situation.
It is now possible to procure drain-tiles at reasonable cost in almost all parts of the country; and these are not only very much better than any form of stone drain, but they are also much cheaper in construction,—the labor of preparing and handling the stone, and of excavating the wider trench that stone requires, amounting to more than the cost of the tile, even with a high charge of transportation added. Incidentally it is proper to say that where tiles cannot be had, a mass of gravel or fine cinders, six inches wide and six inches deep, placed at the bottom of the drain, andcovered with well-packed soil, is preferable even to broken stone or any other form of channel that would permit of the rapid running of water and the washing into the drains of even a slight amount of silt.
The removal of excessive subsoil moisture being secured, attention should next be given to the surface of the road, which should be finished with the firmest material at hand,—with the common earth of the subsoil where nothing better can be afforded,—and which should be brought to a true grade, with avery slightslope from the centre to the edge. For a road thirty feet wide,the elevation of the centre above the level of the edges should not be more than four to six inches, and the grade should be made on a straight line rather than on a curve. If the road is made as flat as the turning-off of surface-water will permit, it will be travelled upon in all its parts; while if it is crowned to a high arch, as is often the case, it will soon be found that the best place to drive is in the middle of the road, and foot-tracks and wheel-tracks will soon form slight channels or ruts which will lead water lengthwise along the road, and which will cause an undue amount of wear and washing. A road may be actually flat to the eye, and equally convenient for travel at every part of its width, and still have enough lateral slope to cause water to run off from it.
It is especially desirable that no surface-water flowing from the roadside (above all, when frost is coming out of the ground in the spring) be permitted to run on to the road. This should be effectively prevented by the formation of sufficient gutters, with such outlets as will prevent ponding at the sides of the road. When it is necessary to carry the water of the gutters from one side of the road to the other, culverts should be provided; and wherever the slope of the road is sufficient to cause water to flow along it lengthwise,—that is, wherever the inclination is more than about one in fifty,—there should be frequent slight depressions from the centre diagonally toward the gutters to carry the flow away before it can accumulate sufficiently to form a washing current.
If it can be done without hauling additional material, it is always well to raise the road-bed somewhat above the level of the adjoining land, and this may usually be accomplished by throwing upon it the subsoil of the gutters. In no case should surface-soil sods or fine road-mud be used for repairs. The most serious objection to the absurd system of road-mending so common in this country lies in the fact that the annual repairing is little more than the ploughing up and throwing back upon the roadway of the soft and unsuitable material which has been washed into the gutters.
What is said above applies especially to country roads; but it is appropriate, so far as it goes, to the better-made and better-kept roads of a village. In the case of these latter, except wherethe soil is naturally dry and firm, some attention should be given to the improvement of the surface; and it is to be considered whether to adopt the expensive process of covering with broken stone road-metal, or to use gravel. One or the other of these is desirable in all cases where there is much tendency to sloppiness in wet weather; but any form of artificial covering is so costly that the early efforts of the improvement association will produce a more telling result if applied in other directions. The necessary cross-walks may be satisfactorily made with coal-ashes.
It is even more easy in a village than in the country, to have the grades of all roadways so regulated as to shed rain-water falling upon them, and to have them so furnished with side gutters so as to prevent water from the roadside from running on to them. The simplest way to effect this, and the neatest way too, is to make gutters outside of the line of the road, say six inches deep and eight feet wide, these being at once sodded or sown with grass and grain to give an early protection against washing; made on such a shallow curve, they will afford no obstruction toany system of mowing that may be adopted, while their great width will give them sufficient capacity to carry away the water of considerable storms.
The work of construction having been duly attended to, it is no less important to provide for regular and constant care. Any rutting that comes of heavy traffic in bad weather should be obliterated either by raking, or, better still, by filling the ruts with gravel or ashes. If such work is attended to immediately on the occasion for it arising, the amount of labor required will be very slight; for it is especially true with reference to roads, that "a stitch in time saves nine." If the filling of ruts and wheel-tracks be done in time, the serious damage that comes from guttering flows of water lengthwise along the road may be almost entirely avoided.
The mere cleaning work of both the roadway and roadside grass spaces, it will be easy to induce children to perform for slight rewards and encouragement. The daily removal of bits of paper and other rubbish will have an excellent effect on the general appearance of the village. In the autumn the removal of the fallen leaveswill call for something more than children's work; but ordinarily this source of cheap labor will be found sufficient if properly directed.
As a field for encouragement, rather than as an object for the expenditure of the association's funds, the furnishing of an ample supply of water is entitled to very early consideration. Not only is the question of public health very seriously involved in the water problem; but as a mere beautifying element an abundance of water, to be obtained without labor, will have a very telling effect by the facility it gives for preserving the fresh appearance of lawns and shrubbery, and for the cultivation of flowers and vines.
Regarded from the horticulturist's point of view, the climate of pretty nearly the whole of this country is simply detestable. We may arrange to withstand very well the severity of our northern winters; we expect an entire shutting-up of all garden industries, and long cold seasons are an accustomed matter of necessity: but we have never yet learned to accept with patience the almost annual destruction of our lawns and gardens and flower-beds by scathing drought. No public water supply available for an ordinary village would suffice to overcome the effects of a dry season over the whole of even a small homestead; but we may hope to secure enough to keep one or two small sprinklers flowing steadily through the hot months, and so keep a little grass measurably green, and preserve a semblance of life and beauty in flower-beds and delicate shrubbery. It is very rarely that it will be possible to supply water enough in a whole week to equal in its effect a half-hour's rain; but the difference between towns where even the small amount of water is available for the garden and those which are hopelessly given over to drought shows how much may be accomplished in this direction even with limited means.
As in the case of road-making in any thing like a complete and thorough manner, the providing of a water supply must necessarily be directed by professional advice. Although the simpler principles of hydraulics are sufficiently understood, and although it would be quite within the ability of a number of the more intelligent men of any village to secure and distribute a satisfactoryamount of water, the cost of doing such work in an experimental way by persons unaccustomed to its details, as compared with the cost of doing it under the direction of an engineer whose natural judgment and capacity are supplemented by experience and skill, would be without doubt far beyond the fee demanded for his services. In this case, as in many others connected with public and private works, it is always bad economy to save the cost of proper knowledge. Very likely—perhaps indeed very generally—the actual performance of the work, the buying and laying of the pipe, and all that, can be as cheaply done under home direction as under that of a public contractor; but the making of the plans—the deciding upon the source of the supply, upon the means for securing a sufficient head, the sizes of the pipes, the location and construction of fire-plugs, and all the minor details of the work—will be more or less economical, according to the skill, experience, and capacity of the person who directs it.
The sources from which water may be obtained are various. Often enough water of the best quality may be procured by driven, dug, or artesianwells; but, whenever this course is adopted, the wells should be located far enough away from the village, or on land sufficiently high, to make it impossible that there shall be any fouling of the water-bearing strata by the filtration from barn-yards, privy-vaults, or cesspools. Generally, water so secured will have to be raised to an elevated reservoir by some mechanical force. If the demand is to be a large one, and if the community can afford the cost, the most reliable plan will be to use steam-power for pumping; but in smaller places, and where economy is a great object, wind-power may serve an excellent purpose.
If a stream of pure water is available at a sufficient height, it may be led directly to the reservoir, or its current may be used to drive a water-wheel sufficient to do the pumping. In a majority of cases there will be found at no great distance a stream capable of supplying the water needed throughout the dryest season of the year, but not entirely free from organic impurities. In such cases it is often feasible, by excavating a filtering sump or pump-well at a little distance from the side of the stream, and at a sufficient depth below the level of its bed to secure asupply tolerably purified by filtration through the intervening earth. The distance at which this sump should be placed from the bed of the stream will depend on the character of the soil. The more porous this is, the greater should the distance be. This question as to the source from which the water is to be taken is one which, more than any other, calls for experienced judgment.
Frequently the conformation of the surrounding country is such that, even where there is no constant stream, it is possible by the construction of dams to pond an amount of water, to be furnished by surface washing, sufficient to supply the demands of the longest drought. In this case, as in all others where reservoirs are used, it is important to have a good depth of water, and not to allow, even toward the edges, any considerable shallow area. So far as possible, the depth should be everywhere great enough to prevent vegetation, and in all the shallower parts the surface soil should be entirely removed. As a rule, there should be a depth of at least fifteen feet of water, except near the very edges of the pond, and as much more than this as circumstances will allow.
The distribution of water for private use is a simple question of construction; but, as a matter of taste, too vehement a protest cannot be entered against the common misconception as to what is desirable in the way of public fountains. An instance in point is furnished by the public drinking-fountain in Newport. Some years ago there stood at the foot of the Parade a grand old stone bowl, hewn out of a solid block of granite, and filled by a pipe leading from a copious spring. This was a good, sensible, substantial drinking-trough, perfectly adapted to its use, unpretending and handsome. Later, a public-spirited gentleman, desiring to leave a monument of his regard for the city, gave a considerable sum to be used in providing a suitable drinking-fountain at this point. Those who had the control of the fund lacked either the good taste or the courage to refuse to expend it. The result is that this granite horse-basin—one of the best of its sort—has been removed to an obscure position; and there has been erected in its place a wretched cast-iron combination of bad architecture and bad statuary, such as form a conspicuous defacement of the public squares in Philadelphia, wherethey serve the double purpose of furnishing water to the people, and advertising a cheap clothing establishment. The one compensation for the violation of good taste inseparable from these constructions is to be found in the fact that they must, sooner or later, lead the public to realize the absolute unfitness of cast iron for monumental and decorative uses. With the artistic influences which are now so active in the instruction of the American people, it is not perhaps unreasonable to look forward to the day when all of these piles of pot-metal shall be relegated to the scrap-heap, and when less offensive fountains shall take their place. We may even hope to see the iron statue and its stove-like support which supplies water to the horses of Newport condemned to the foundry, and its solid old predecessor restored to the position which it ornamented for so many years.
A wide margin may be allowed for the exercise of taste in the arrangement of village fountains; and where private munificence enables the expenditure of a considerable sum, a good amount of exterior decoration may be admissible: but it should always be borne in mind that so much of the outlay as is needed for the purpose should goto secure a good artistic design. Especially should the use of cast iron be avoided, as being from every point of view, and under all circumstances, whether in the shape of cast-iron dogs or deer, or attempts at the divine human form, absolutely and entirely inadmissible for artistic uses. Better a dug-out log horse-trough, overflowing through a notch in its side, as an ornament to the best-kept village green, than the most elaborate pitcher-spilling nymph that was ever cast in an iron-foundry. So far as the mere construction work of public drinking-fountains and horse-troughs is concerned, not much need be said except in connection with the overflow. In cold climates, there is apt to be from all such structures a spilling of water which covers the ground for some distance with ice. This may be avoided by carrying the overflow by a vertical pipe descending through the body of the water by some well-protected channel directly into a drain in the ground, at a depth beyond the direct action of frosts. If the stream is constant, this depth need be nothing like that to which frost penetrates into the soil,—for the constant movement of the water will prevent its freezing, even if coveredonly a foot deep, though to something more than this depth it will be desirable to have the metal pipe enclosed in a larger pipe of earthenware, giving a space of enclosed air.
Where there is no public supply of water, it is better in most cases (considering the nearness of wells in villages to cesspools and privy-vaults), to depend entirely upon cisterns. In our climate, where rain is abundant during a considerable portion of the year, the water falling upon the roof of any house, if properly collected and stored, is ample for the whole supply of the family which that roof shelters. This water as it falls is ordinarily free from any impurity that can affect its taste, and from every source of serious fouling; though, after a long-continued drought, it is well to divert and discharge upon the surface of the ground the first ten minutes' flow of a shower, so that the impurities of the air and the dust of the roof may first be removed. After this first dash, lead to the cistern all that follows. Even with this precaution, the water will be more agreeable for use if filtered. There are numerous systems for making filters in cisterns, but no otheris so simple nor so durable and satisfactory as the separation of that part of the cistern from which the suction-pipe leads by a wall of brick and cement. It is simply necessary to build a wall of brick set on edge (two and a half inches thick), so as to include about one-quarter of the area of the bottom, sloping it back so as to terminate against the side of the cistern at a height of from four to six feet. This wall should be so well cemented at its joints that water can only pass through the material of brick, and for strength its form should be slightly bulging. A wall of this sort, measuring say six feet at its base, and rising to a height of six feet at its highest point, will transmit an amount of water sufficient to supply the demand of the most constant pumping that any domestic use can require.
As a rule, the open spaces in a country village are subject to no other criticism than that of neglect; but the exceptions are not rare where an attempt at improvement has resulted in a sort of cemetery look that gives any thing but a cheerful, pleasure-ground aspect.
There is not much danger that persons who are enthusiastic for the improvement of the town in which they live will err on the side of too great simplicity. The public squares and parks of large and wealthy cities are regulated and maintained at great cost and under skilful and artistic management; and they cannot fail to strike country visitors as being in all ways desirable. So indeed they are. They are a chief element of the city's beauty, and, from an æsthetic point of view, their influence is the best to which its people are subjected. But their beauty and their æsthetic influence are both the result of a well-directed expenditure of large sums of money. It is quite natural that an enriched manufacturer or merchant, proud of his native village, should be ambitious to perpetuate the memory of his benefaction by providing for some corresponding decoration of its public green, and that he should attempt to reproduce there, on the smaller scale proportionate to the circumstances, the sort of magnificence that he has seen in the city park. If left to his own sweet will,—as he often is if he is willing to spend money for the public benefit,—he will, unless a rich man of therarer sort, succeed only in producing a conspicuous imitation.
A park-railing of artistically-worked wrought-iron will be represented by a cast-iron substitute of much more elaborate device; and there will probably be "piled on," here and there, an amount of cheap ornamentation which at the first glance will have a certain imposing effect. In the matter of planting there may be an amount and variety of foreign shrubbery and sub-tropical plants, which, under proper care, would be of great value and beauty, but which, with the neglect to which they are doomed in their village home, are quite certain to abort. In fact, we may expect to see, what indeed we may now see, in painful degree, in many of our smaller towns, a halting attempt at the outside show of the city park, which, in the absence of those elements of artistic selection and appropriateness to the conditions which are to prevail, develop, as time goes on, into an ignominious failure.
The trouble is, that, in all expenditures of this sort, we are apt to begin at the wrong end. In the making of a park, every step that is taken,whether the park be large or small, is a costly one; and, if taken in their reverse order, every step is a wasted one. The chief reason why the final decoration of a city park is so satisfactory is that it is only the crowning work of many processes which have had the best and most careful attention from the outset. The wrought-iron grille, the architectural fountain, the bronze statue, the delicate trees and shrubbery, and the smoothly-finished walks and drives, depend for their success upon a vast amount of costly fundamental work, and a provision for constant skilful care, which have cost a deal of money, and which look to a large permanent outlay. The elaborate fence must stand on no unstable foundation; the fountain must be only the ornamental central point of artistic and well-kept lawns and approaches; the statue must stand amid appropriate surroundings; and all but the simpler native vegetation must have its suitable soil, and be insured its needed protection and care at all seasons. The degree to which these more ornamental features may be given to the village green with any hope of satisfaction will depend almost entirely upon the thoroughnesswith which it has been prepared to receive them. Could the enthusiastic members of the improvement association be brought face to face with the cost that is needed for quite hidden fundamental work in order to prepare their green for the more elaborate artistic decoration, they would be deterred at the outset from attempting any thing so ambitious. Could they know the cost of the mere work of grading and subsoil cultivation, under-draining, manuring, laying the deep foundation for foot-paths, and securing that perfect growth of grass without which all park-like ornament is robbed of half its value, they would set their faces resolutely against all propositions on the part of public-spirited citizens to veneer their unprepared grounds with misplaced exterior adornment.
If money enough can be provided to do the work thoroughly well from its very foundation, then of course nothing more is needed than that its direction be placed in accomplished hands; but unless this is fully assured, if—as is nearly always the case,—economy is the first thing to be considered, then the rule of action is fully stated in two words,simplicityandthoroughness.
Avoid all fantastic ornament, and all decoration of every sort, that would be appropriate only to work of a more complete and substantial character. Let whatever is done be done in the most thorough way. If the ability is only enough to secure good grass, then do every thing that is necessary to furnish the best conditions for the growth of grass, make suitable provision for its care, and attempt nothing further. Good lawn-like grass surfaces, crossed only by foot-worn pathways over the turf, will be more beautiful and more satisfactory than will poor grass and cheaply made and ill-kept walks.
If something more than securing the best grass is possible, then let the next expenditure be in the direction of paths, applying to the construction of these the principles set forth in what has hitherto been said about sidewalks. In the case of level walks, with imperfect means of drainage, it is often desirable to secure the better foundation that is given by filling in to the depth of a foot or more with small stone.
Whatever may be the natural character of the soil, unless always well drained by a poroussubsoil, the first step toward establishing a good lawn is to secure perfect underdrainage. Establish a good outlet at the depth of three and a half or four feet below the surface at the lowest point of the area to be drained, and then, selecting the necessary lines for main drains, lay out parallel lines (thirty feet apart at a depth of three and a half feet, or forty feet apart at a depth of four feet) to include the whole area, and on these lines lay well-constructed drains of small open-jointed tiles. Cover these tiles with the most compact earth that has been excavated, and, after filling to a depth of one foot, tramp or ram this earth tightly. Then fill the rest of the trench, heaping over the lines any excess of material that may need the settling effect of heavy rains to work it into place.
The next step is to reverse or thoroughly mix the whole soil to a depth of at least fifteen inches. This work can be completely done only with the aid of hand-shovelling, but the aid of the plough will greatly facilitate it. Its purpose is to secure such an admixture of the organic matter of the surface soil with the more compact material of the subsoil as will make it sufficiently porous andfertile for the easy penetration of roots. It is best that this work should be done in autumn; and, if the land is level, that the freshly raised subsoil should be left exposed in its rough and lumpy condition—without harrowing—to the frosts of winter. If washing is to be apprehended, then sow the ground thickly with rye, harrowing in the seed only roughly. If the seed is sown early enough, the growth will be sufficient to protect the surface from washing. During the winter, let the whole surface be heavily covered with stable-manure,—the more heavily the better, as there is no limit to the amount of coarse manure that may with advantage be used for the establishment of permanent grass. In the spring, as soon as the ground is dry enough to work easily, plough in the manure with as shallow furrows as will suffice to cover the most of it; then harrow repeatedly, bringing the surface to as true a grade as possible, and sow it heavily with a mixture of Rhode Island bent grass, Kentucky blue grass, and white clover. As soon as the seed is well sprouted, showing green over the whole ground, roll the area repeatedly and thoroughly until it is as smooth and hard as it is possible to make it.As soon as the grass has attained the height of three inches, let it be cut with a lawn-mower, and let the cutting be repeated at least weekly throughout the season of rapid growth, and as often as necessary until the end of autumn.
If paths are to be made, it will simplify matters to make them after the grass has become well established, supposing only a good surface footway of ashes or concrete to be needed; for the small amount of excavation necessary under either of these systems may be scattered over the grass spaces without injury. But if the more thorough system is adopted of underlaying the walk with a foot or more of stones, then the work, except the final dressing of gravel or ashes, should be done in the autumn, or, in any case, before the final preparation of the soil for seeding.
Concerning trees and ornamental shrubbery for parks and open spaces, it is not possible to give detailed directions here, beyond recommending, as in the case of roadside plantations, that, unless the work is to remain permanently in the charge of an experienced gardener, withthe necessary appliances for the care and protection of the more delicate specimens, the arrangement and the selection should be confined to the more hardy and vigorous trees and shrubs which experience has shown to be adapted to the climate and soil of the locality.
For roadsides, and largely in parks and village greens, the world offers no tree that can compare in dignity and grace with the broad-spreading American elm; though, for the sake of variety, and for the sake of an earlier effect, many other trees may be added.
It is a recently recognized but an old and universal truth, that human life involves the production of refuse matters, which, unless proper safeguards are taken, are sure to become a source of disease and death. The danger is not confined alone nor chiefly to that element of household waste which is most manifestly offensive, but in almost equal degree to all manner of organic refuse. It is true that fæcal matters are often accompanied by the inciting agent of the propagation of infectious diseases. For convenience, and as indicating the more probable means for disseminating infection, we may call this agent "germs." It has not yet been demonstrated with scientific completeness that a disease is spread by living germs whose growth in a new body produces a corresponding disorder; but all that is knownof the circumstances of infection, and of the means for preventing it, may be fully explained by this theory. Typhoid fever, cholera, epidemic diarrh[oe]a, and some other prevalent diseases, are presumed by the germ theory to be chiefly, if not entirely, propagated by germs thrown off by a diseased body. So far as these ailments are concerned, there is therefore a very serious element of danger added in the case of fæces to the other evil effects which are produced by an improper disposal of any refuse organic matter. That any one or all of these diseases can originate from the decomposition, under certain circumstances of fæcal matters, is not clearly determined. There is, however, good reason for believing that one common effect of the gases arising from improperly treated matters of this kind is to debilitate the human system, and so to create a disposition to receive contagion, or to succumb to minor diseases which are not contagious.
The same debilitating effect and the same injurious influences often result from the neglect of other organic wastes. The refuse of the kitchen sink is free from fæcal matter; but it contains, in a greater or less degree, precisely the kind oforganic material which has gone to make up the more offensive substance. If its final disposition is such as to contaminate the water that we drink or the air that we breathe with the products of their decay, the danger to life is hardly less than that from the decomposition of fæcal accumulations.
It is proposed now to set forth, in the simplest way and without much discussion of principles (which may be studied elsewhere), the methods and processes by which village households and communities may be protected against the influences that come from an excess of soil-moisture, from damp walls, and from imperfect removal or improper disposal of organic filth.
We will assume that a village has a water supply sufficient to admit of the use of water-closets in all houses, and to furnish a good flushing for kitchen sinks, &c. A necessary complement of this work—indeed, it should properly precede it—is the establishment of a system of sewers by which all of this liquid outflow may be carried safely away. It would be out of the question in a small or scattered community, especially where roadways are unpaved, to establish any systemwhich should include in its working the removal of surface water. The moment we undertake to make sewers of sufficient capacity to carry away the storm water of large districts, then we enormously increase the scale and cost of the work.
So far as the removal of house sewage alone is concerned, the work need by no means be very costly. If a tolerable inclination can be given to the line of sewers,—say a fall of one in two hundred,—a six-inch pipe will have a capacity quite up to the requirements of a village of two thousand inhabitants using one hundred gallons of water per day per head. It will, however, be safe to use a pipe of this size only when it is true in form and carefully laid, so that there shall be no retarding of the flow at the joints from the intrusion of mortar, or any other form of irregularity. Unless the joints are wiped quite smooth, the roughness remaining will serve as a nucleus for the accumulation of hair, shreds of cloth, and other matters which will hold silt and grease, and form in time a serious obstruction. Nothing smaller than six-inch pipe should be adopted for a street sewer. Unless the work is to be most carefully done, for all but the branch lines,for a population of five thousand, or less according to the fall of the sewer, it will be safer to use eight-inch pipes. These pipes must be laid with great accuracy as to grade and direction. All corners should be turned with curves of large radius and regular sweep, and with an additional fall to compensate for the increased resistance of curves. The weight of the pipe should not be supported upon the sockets (see Figure 3), partly as a question of strength, and partly because any irregularity of form or thickness of the socket would change the inclination of the sewer. The bottom of the trench being brought exactly to the required grade, let there be dug out a depression greater than the projection of the socket, the pipe resting upon its finished bottom for its wholelength. (See Figure 4.) Too much care cannot be given to the thorough filling with cement of the space between the socket and the pipe inserted into it; the whole circle being well flushed and wiped, so that there may be no possibility of leakage.
FIG. 3 PIPES RESTING ON THEIR SHOULDERS.FIG. 3 PIPES RESTING ON THEIR SHOULDERS.
FIG. 4. PIPES RESTING ON THEIR FULL LENGTH.FIG. 4. PIPES RESTING ON THEIR FULL LENGTH.
The objection to leakage is twofold: sewage matters escaping into the soil might contaminate wells and springs; and it would also rob the flow through the pipes of water needed to carry forward the more solid contents. The continued efficiency of these small drains for carrying away the solid or semi-solid outflow of the house is dependent very largely upon the presence of sufficient water to create a scouring current. While eight-inch pipes are admissible as a safeguard against imperfect laying, they are liable to the grave objection, that, where the service to be performed is greatly less than their capacity, the stream flowing through them will not be sufficiently concentrated to carry forward the more solid parts of the sewage. Up to the limit of their capacity, six-inch pipes properly laid are greatly to be preferred, as insuring a deeper stream which will more generally attain thevelocity of three feet per second, needed to move the heavier constituents of the sewage. The difference in cost between six-inch and eight-inch pipes will be sufficient to cover any extra cost of the most careful workmanship. However much attention may be given to the cementing of the joints, it will be impossible to prevent the running into the pipes of a certain amount of mortar; and the workman should have a swab or a disk of India rubber of the exact size of the bore of the pipe, with a short handle attached to its middle, to draw forward as each joint is finished, and so scrape away any excess of mortar before it hardens.
Wherever it is, or may probably become, necessary to attach a house-drain or land-drain, there should be used a length of pipe having a side branch, oblique to the direction of the flow, to receive such connection. The location of these branches should be accurately indicated on the plan; and they should be closed with a flat stone or a bit of slate, well cemented in place.
It will at times be necessary to use larger conduits than even an eight-inch pipe. Up to a diameter of fifteen inches, it is cheapest to usepipes, but for eighteen inches or more, brick-work is cheaper; and at that size—a considerable regular flow of water being insured—the slight roughness of brick-work offers no serious objection. The use of oval or egg-shaped sewers will rarely be necessary under the circumstances that we are considering; but there may be exceptional conditions where the covering-in of a brook, or storm-water course, cannot be avoided; and in such cases the volume of water may vary so greatly that there will at times be a mere thread of a stream, and at times a torrent. Here the oval form is the best, as concentrating a small flow within a narrow and deep channel, and still giving the capacity needed for exceptionally large volumes. All bricks used for sewers, man-holes, &c., should be of the very hardest quality, and true in form. The general rule is to be kept in mind, that the thickness of the wall of a brick sewer should not be less than one-ninth of the inner diameter; that is to say, that up to a diameter of three feet the thickness of the wall should equal the width of a brick,—four inches. This applies to circular sewers only: the oval form, being less strong, calls for a wall of athickness equal to one-eighth of the largest diameter.
Connecting drains leading from houses to the sewer are to be made at private cost; but they should be made in accordance with plans furnished by the public authority, and by a workman acceptable to that authority.
The householder might be permitted to take the responsibility of the finishing of his drain, but for the fact that the working of the public sewer calls for the largest amount of water in proportion to the amount of solid matters that it is possible to secure, and thus makes it imperative that this drain should be absolutely tight, so that the liquid parts of the house outflow shall not trickle away through its joints, leaving only the more solid parts to flow into the public sewer.
Properly graded and smoothly jointed, a four-inch pipe will carry more water than even the largest boarding-house or country hotel is likely to discharge. There is, however, a tendency in all house-drains to become filled in the early part of their course by the accumulation of grease and solid matters caught in the grease. Where no form of grease-trap is used, there is a certainargument in favor of the use of six-inch pipes for the upper part of house-drains. The use of a grease-trap, however, should always be insisted upon; and with its aid these obstructing matters will be retained, and the outflow may be perfectly carried by a four-inch pipe.
So far as the public sewer is concerned, it makes little difference what is the size of the house connection drain through the greater part of its course; but the junction with the sewer should, under no circumstances, where six-inch sewer-pipes are adopted, be more than four inches. I should even insist on four-inch connections with an eight-inch sewer. Through neglect, or by reason of improper management, many kinds of rubbish find their way into house-drains; and a four-inch opening will admit as many of these into the sewer as it will be able to carry away. If, by reason of bad construction or neglect, an obstruction is to be caused at any point, it should be in the drain, which the person responsible for it must cleanse or repair.
The grease-trap referred to above may be any form of reservoir which will retain the flow from the kitchen sink until it has time to cool, whenits grease will be solidified, and will float at the surface. The outlet from this trap should be at such a distance below the surface of the water, that there will be no danger of its floating matter passing in with the discharge. A very simple device for this purpose is shown in Figure 5. From a trap of this sort the flow is constant whenever additions are made to its contents.
FIG. 5.—GREASE-TRAP. I, Inlet; V, ventilator; O, outlet.FIG. 5.—GREASE-TRAP. I, Inlet; V, ventilator; O, outlet.
Figure 6 shows the invention of an English engineer, Mr. Rogers Field, which has the effect of retaining all of the outflow from the kitchen sink until it is entirely filled,—say thirty gallons. When filled, any sudden addition of a few quarts of water, as from the emptying of a dish-pan, brings into action a siphon whose entrance is near the bottom of the tank; and this siphon rapidly discharges all of the contents above itsmouth in a flow having sufficient force to carry forward not only any solid matters which it may contain, but also any ordinary obstructing accumulations in the drain below. The soil-pipe, carrying the discharge of water-closets, should not be delivered into the flush-tank, but at a point farther down the drain, so that any solid matter it may deposit shall be swept forward by the next action of the flush-tank. The more often the flush-tank is filled, and the greater the proportionof its water to its impurities, the more efficient will be its action. Therefore the slop closet waste leading from the upper story, and even the outlet pipes of bathing-tubs, may with advantage be delivered into it.
FIG. 6.—FIELD'S FLUSH-TANK. A, Receiver; B, grating; C, ventilator; D, siphon; F, entrance to drain; I, delivery from sink.FIG. 6.—FIELD'S FLUSH-TANK. A, Receiver; B, grating; C, ventilator; D, siphon; F, entrance to drain; I, delivery from sink.
Although the flush-tank may receive no fæcal matter, and even though the housemaid's sink may not deliver into it, it will contain in the discharge from the kitchen alone an amount of organic matter which will produce offensive and dangerous gases by its decomposition. To provide for the safe removal of these gases, a ventilating pipe should be carried up to some point not near to any window or chimney-top.
From the time the sewers are ready for service no accumulation of fæcal matter or other organic household waste should be allowed to remain in the village. All old vaults and cesspools should be filled with earth, and disinfected by the admixture of lime with the upper layers of the filling. The use of water-closets in all houses should be made imperative; and the construction and arrangement of soil-pipes and of all outlets should be regulated by the health authorities.
It is not worth while here to discuss the detailsof the construction of water-closets and other interior plumbing work, except with reference to soil-pipes and such drains as may deliver the outflow of soil-pipes to the public sewer. The soil-pipe should be of cast iron, carefully jointed with lead, not less than four inches in diameter, and carried by the straightest course possible up through the roof and generally higher than the ridge-pole. Its open top must not be near any window, and if within ten feet of a chimney it should be at least one foot below the level of the top of that chimney. There should be no trap in the soil-pipe, and no trap in a private drain between the outlet of the soil-pipe and the sewer. The reasons for this rule are twofold:—
1. No matter what amount of water may be used for flushing out the soil-pipe, its sides will always be more or less coated with organic filth; and, however slight this coating, there will be a certain amount of decomposition. The decomposition of all such matters must be rapid and complete, not slow and partial. A necessary condition of complete destructive decomposition is an abundance of atmospheric air to supply the oxygen which complete decomposition demands.If the soil-pipe is closed at its top, or if it is obstructed by a trap in the lower part of its course, there can be no such circulation of air as safety requires.
If there is an opportunity for the free admission of air from the well-ventilated sewer to feed the upward current almost constantly prevailing in a soil-pipe open at both ends, the gases resulting from the decomposition will be of a different and less injurious character than where the air is confined,—and by the mere volume of air passing through the pipe they will be so diluted that even were they originally poisonous their power for harm will be lessened.
The gases formed by the decomposition of organic matter in the sewer itself, or in the soil-pipe, have a certain expansive force which is greatly increased by the elevation of temperature, caused, for example, by the discharge of hot water into the pipe or sewer. If the soil-pipe is open at its upper end this expansion will be at once relieved; but if the top of the pipe be closed there will always be danger of the forcing of the feeble barrier offered by the ordinary water-seal trap of a branch pipe leadingfrom a wash-basin or sink. Then, too, the sealing-water of the trap readily absorbs any foul gases presented at its outer end, toward the soil-pipe, and gives it off in an unchanged condition at the inner or house end. Such traps retard, but do not prevent, the entrance of sewer gases into the house. Water-seal traps which are unused for any considerable time are emptied by evaporation, and thus open a channel through which the air of the soil-pipe may find its way into the house.
It is usual in modern plumbing to relieve the pressure of gas in the soil-pipe by what is called a "stench-pipe." This is a pipe from one to two inches in diameter, leading from the highest point of the soil-pipe to the outside of the roof, where it is bent over to prevent the entrance of foreign matter, or is closed at the top and perforated with holes to allow the gas to escape. This small stench-pipe is inadequate for the necessary work. It is very important that there be the freest possible channel for the movement of air; and nothing will suffice for this save the continuing of the pipe, at its full size, to its very outlet. Indeed, angles and bends in a pipe by increasing friction form a serious obstruction.
The arrangement of the soil-pipe here indicated, although excellent and efficient, is susceptible of further improvement by the use of a ventilating cowl or hood at its top. There are many forms of such cowls in use which are effective whenever there is a sufficient current of wind; but most of them require a certain force to bring them into action, and when this force is absent they usually retard the flow they are intended to increase. This is true of a recent invention known as "Banner's ventilating cowl," which so long as the wind blows is a most effective device. When the air is perfectly still, however, it offers by its curved air-way a certain resistance to the current, and in the case of baffling winds and flaws the air may blow directly into its opening.
Among the various inventions of this sort nothing seems so free from objection as the old arrangement known as the "Emerson" ventilator, shown in Figure 7. This gives a straight outlet, protected by a disk far enough above it not to prevent its delivery of air; and it becomes an effective suction cowl, with the least movement of the wind from any side or from above or below. No eddy caused by the angles of gable roofs can give it a backward draught; and if a pipe armed with it be held toward the strongest gale a puff of smoke blown into its other end will be instantly drawn through. As the patent for this invention has run out, it is competent for any tinsmith to make it, and it is a common article of manufacture.