Part 3

This, although an excellent method of curing the trouble, the asphalte cutting off ground air from the house, as well as water, will be expensive, the cost of the asphalte coating being from 20 to 22 cents (10-11_d._) a sq. ft.; and perhaps it may not be necessary to go to so much trouble. It is very unusual to find water making its way through ordinary good concrete, unless high tides or inundations surround the whole cellar with water. If the source of the water seems to be simply the soakage of rain into the loose material filled in about the outside of the new wall, we should advise attacking this point first, and sodding or concreting with coal-tar concrete, a space 3 or 4 ft. wide around the building. This, if the grade is first made to slope sharply away from the house, will throw the rain which drips from the eaves, or runs down the walls, out upon the firm ground, and in the course of two or three seasons the filling will generally have compacted itself to a consistency as hard as or harder than the surrounding soil, so that the tendency of water to accumulate just outside the walls will disappear; while the concrete, as it hardens with age, will present more and more resistance to percolation from below.

For keeping the dampness absorbed by the walls from affecting the air of the house, a Portland cement coating may be perhaps the best means now available. It would have been much better, when the walls were first built, to brush the outside of them with melted coal tar; but that is probably impracticable now. If the earth stands against the walls, however, the cement coating should cover the whole inside of the wall. The situation of the building may perhaps admit of draining away the water which accumulates about it, by means of stone drains or lines of drain tile, laid up to the cellar walls, at a point below the basement floor, and carried to a convenient outfall. This would be the most desirable of all methods for drying the cellar, and should be first tried.

Construction for Earthquake Countries.--The conditions will vary somewhat according to the nature of the climate.

R. H. Brunton, who was for many years resident lighthouse engineer in Japan, follows the principles enunciated by Mallet and Prof. Palmieri, giving the buildings weight and great inertia, coupled with a good bond between their various parts. Prof. Palmieri states that, although solidity and strength in a building do not afford perfect protection, still, so long as fracture does not occur, overthrow is impossible. Dyer states that in his opinion, for dwelling-houses in Japan, the modifications of external design required, as compared with those in Britain, arise not so much on account of the earthquakes as from the heats of summer, the colds of winter, and the typhoons of autumn. Iron roofs are good from a merely structural point of view; but in summer it would be impossible to live in the houses provided with them. If a non-conducting material of the same strength and durability as iron could be found, it might be used. “If the houses are so designed as to be comfortable as regards temperature, and the construction made in good brick, or equally strong stone and mortar, so that the walls are of nearly a uniform strength; if no unnecessary top weights are used, and if the various parts do not vibrate with different periods, they will withstand all ordinary earthquakes, and other precautions will be unnecessary, as these generally produce results more serious than those due to the earthquakes.”

The city of Arequipa, Peru, is particularly liable to earthquakes, owing to its proximity to the great volcano, the Misti, 19,000 ft. in height above sea-level, the city being 7000 ft. above sea-level. The general construction of the houses is peculiar. A light coloured volcanic stone is largely used; this, when quarried, is easily shaped, and it hardens gradually. The roofs are for the most part strong arches, a very good mortar being used. In the earthquake of 1868, it was not so much those arches which failed as the walls, and the spandrels between the arches at front and rear. In some parts of the city, arches extending in one direction stood, while those at right angles to these were thrown down. Since 1868, a good many corrugated iron roofs have been introduced; but they are not suitable to the climate, and are not durable.

Earnshaw, from an experience of 25 years in Manila, where the earthquakes are sometimes very severe, comes to the conclusion to build as strongly as possible, and chiefly in wood, tied and bolted together as in a ship, stone and brickwork only being used in the lower story and in the foundations, and especial attention ought to be paid to the quality of the lime and mortar used in construction. Many materials have been used as roofing, such as the heavy tiles made in the country and others imported there. When, in 1880, fully 60 per cent. of the buildings in Manila had been ruined, an order was issued by the municipal authorities to use corrugated iron or zinc sheeting for that purpose. A diversity of opinion existed as to which was the best and most suitable, for not only had earthquakes to be guarded against, but intense heat and disastrous typhoons. With reference to the latter, in 1881, sheets of iron were flying about in the air like paper. He thinks, therefore, that a light, strong tile roofing is preferable to any other.

Prof. C. Clericetti, of Milan, and W. H. Thelwall relate that after the earthquake in the island of Ischia in 1883, which was of a most destructive character, and caused an enormous amount of damage in the island, 2000 persons having lost their lives, and many more being injured, a commission was appointed by the Italian Government to obtain information, and to frame rules for the rebuilding of the structures. It was ascertained that, speaking generally, buildings founded on hard, solid lava had withstood the shock successfully, whilst those founded upon looser or lighter materials, such as tufa or clay, had suffered very much, and therefore in regard to the re-erection of buildings it was pointed out that the first thing to do was to select eligible sites, and to build, wherever possible, upon lava; and, where that was not possible, to dig down to comparatively solid ground, and then fill in a heavy platform of masonry or concrete, 3 ft. or 4 ft. thick, extending over the whole area of the building, and projecting 3 ft. or 4 ft. beyond. The building of any kind of vaulting above ground was forbidden. Light arches were only to be allowed over window’s and openings of that kind. The heavy flat roofs formerly used to a large extent were condemned. The commission recommended that buildings should be chiefly constructed with an iron or wooden framework, carefully put together, joined by diagonal ties, horizontally and vertically, with spaces between the framework filled in with masonry of a light character. The joists and the roof trusses were to be firmly connected together. In plan, buildings should be square, and where the direction of the last shock could be traced, one diagonal should be placed in this direction. Not more than two stories above ground were to be allowed, and there might be one under ground, but it must be of very moderate height. In no case was the height from the lowest point of the ground to the top of the walls to exceed 31 ft. Openings for doors and windows were to be vertically over each other, the jambs being not less than 5 ft. from the corner of the building. No openings for flues were allowed in the thickness of the walls, and no projections from the face of a building, except light balconies of wood or iron. If solidly built structures, and particularly if there was only one story above ground, the roofs might be covered with tiles; but these must be light, and fastened with nails or hooks, so as not to be displaced even by violent shocks.

=Water Supply and Purification.=--The supply of water to both town and country houses has been dealt with at length by Eassie and Rogers Field in essays written for the Health Exhibition Handbooks, and the following information is mainly condensed and adapted from their papers.

The conditions of supply in the two cases differ in being from a general and public source in the one and from a special and private source in the other. In each case, the consumer has to control the purity and application of the supply after its delivery into the dwelling; and in the second case he is further responsible for the character and quantity of the supply before delivery. The second case, therefore, in a great measure covers the first, and demands extended treatment.

_Amount required._--The first consideration is the quantity of water required. The supply to towns from waterworks is usually expressed in “gallons per head of population per diem,” and varies exceedingly, much of the variation being due to waste. This is especially the case in towns where the supply is intermittent. In several towns having a constant supply, steps have been taken systematically to measure the water supplied to different streets and districts, and it has been found that, without restricting the supply in any way, the consumption of water has been immensely reduced, simply by sending inspectors to make a house-to-house visitation and search out and repair leaky pipes and defective taps and ball-cocks. It is by no means an unusual thing for the consumption to be reduced one-half by inspections of this kind, showing that at least one-half of the water which was previously supplied to the houses was simply wasted through leaky fittings.

Many people are inclined to think that waste of this kind is not a bad thing, as it must help to keep the drains flushed. Field points out that this is quite a mistake. A small dribble of water from a leaky pipe or a leaky tap, though it will waste a great deal of water in the course of 24 hours, is perfectly useless for flushing the drains. What is wanted for this is the sudden discharge of a large quantity of water. The dribble of water from leaky pipes and taps does no good in any way, but simply wastes what might be usefully employed, and in many cases causes a supply to run short which would otherwise be ample for all legitimate uses. Another point that it is difficult to realise is the large quantity of water which will run to waste through what is apparently a very small leak. The quantity leaking looks so small in comparison with the quantity running when a tap is open, that one is inclined to think it perfectly insignificant, forgetting that the leakage goes on continuously night and day, whereas the tap is only open for a few minutes. In country houses, where it is often difficult to obtain a sufficient supply of water, it is particularly important to bear in mind the serious influence that leaky pipes and taps have on the consumption, and never to allow such leakage to go on for any length of time.

While useless waste should be prevented, it is most important that the legitimate use of water should be encouraged in every way. As Dr. Richardson has well pointed out, absolute cleanliness, properly understood, is the beginning and the end of sanitary design, and thorough cleanliness, of course, can never be obtained without an ample water supply. Not only should there be sufficient water for baths, lavatories, and washing of all kinds, but there should be a liberal allowance for flushing water-closets and all other sanitary appliances. Taking these sanitary considerations into account, as well as giving due weight to the observations which have been made by engineers and others on the quantity of water actually used in houses under different circumstances, it may be assumed that, if waste is efficiently prevented, a supply of 20-25 gallons per head per diem is sufficient in ordinary cases for houses with baths and water-closets. If horses are kept, a separate allowance should be made for them, and for stable purposes (a useful approximate rule being to reckon a horse as a man); and if water is used for watering gardens or ornamental purposes, this must also be reckoned separately. If earth-closets are adopted instead of water-closets, less water will be required, and 15-20 gallons per head per diem will be sufficient. In cottages with earth or other dry closets, the quantity of water required will be still less: 10 gallons per head will be an ample supply, and even 5-6 gallons may do in cases where it is absolutely necessary to limit the quantity used.

_Sources of Supply._--Water for country houses is, in the vast majority of cases, derived from springs or wells. Rain-water collected from roofs is very frequently used as an auxiliary, and occasionally as the main supply. There are instances in which the supply is taken from streams or rivers, and even some in which water running off the surface of the ground is collected in “impounding reservoirs” (a mode often adopted for the water supply of towns); but these cases are exceptional, and attention will here be confined to springs, wells, and roof-water.

The real source of all fresh water supply is rain. Springs and wells form no exception to this rule, though in their case the connection with the rainfall is not so clear at first sight as it is in the case of streams and open watercourses, because the passages by which the rain reaches springs or wells are not visible, and heavy rainfalls often have no apparent effect on their yield. In various parts of the country occur curious intermittent springs (locally called “bournes”), which burst out in some years and not in others, and the connection between which and the rainfall is still more obscure. Rain-water, before it issues from the ground as springs, accumulates in the porous strata beneath, and forms, as it were, large underground reservoirs; it is from these reservoirs that wells, sunk into the porous strata, derive their supply.

The amount of rain varies enormously in different parts of the world, some districts being either absolutely rainless, or having only a very few inches of rain in the year, whereas others have some hundreds of inches in the year. Even in England itself there is considerable variation. The average rainfall for the whole country is about 30 inches a year, but the amount in different parts of the country varies from about 20 inches to nearly 200 inches a year. The eastern side of England, as Field remarks, has much less rain than the western side, and, roughly speaking, if a line be drawn from Portsmouth to Newcastle-on-Tyne, it will divide the country into a dry portion and a wet portion. The portion of the country on the east of this imaginary line will (with the exception of the south coast, which is wetter) have only 25 inches of rain or less, and the portion on the west of the line will have from 30 to 50 inches, with much larger amount in the Cumberland and Welsh mountains, and at Dartmoor.

The rainfall of the wettest year is about double that of the driest year. This gives a very useful rule for roughly ascertaining the extreme rainfalls, which are really more useful for the purpose of water supply than the rainfall for an average year. The fall in the driest year may be assumed to be one-third less than the average, and for the wettest one-third more. Thus, with an average rainfall of 30 inches, the fall of the driest year would be 20 inches, and that of the wettest year 40 inches.

A portion only of the total rain which falls is available for water supply, as there is always more or less loss. In the case of rain falling on roofs, the loss is comparatively small, but in the case of rain falling on the surface of the earth the loss is considerable. The latter is disposed of in three different ways: part of it runs directly into open watercourses and streams, part is taken up by vegetation or lost by evaporation, and part percolates through the surface ground and accumulates in the water-bearing strata which feed the springs and wells.

From observations made on the amount of percolation in different cases, it has been found that the amount of percolation does not depend so much on the amount of rain as on the conditions under which it falls. By far the greater portion of the percolation takes place in winter and comparatively little in summer, the reason being that in winter the ground is wet, evaporation is small, and vegetation is inactive, so that a large proportion of the rain sinks into the ground; whereas in summer the reverse is the case, so that most of the rain is taken up before it can percolate. So great is the difference between summer and winter as regards percolation, that one may generally leave the summer rainfall altogether out of consideration, and assume that, in this country, it depends on the amount of rain which falls during the six months from October to March, whether the underground store of water will be fully replenished or not.

The height of the accumulated underground water is indicated by the level at which water stands in wells: and it is found that this height varies considerably, the variations usually following a regular course: the water is generally lowest in October and November, it then rises till it reaches its highest point in February or March, and after this it falls slowly till the following autumn.

A condition to be studied in selecting a spring as a source of water supply is its “seasonal” variation. As Field points out, a spring which will give an ample quantity of water in the winter may give an insufficient quantity in the autumn, so that the measurement of a spring in winter should never be depended on for determining whether it will do as a source of water supply. The only safe way is to wait till the autumn yield has been ascertained; even then an allowance must be made for the previous winter, if it has been a very wet one, the yield of the spring becoming abnormally high.

Wells may be either shallow or deep. The latter are always preferable, but sometimes the former must be relied on. The great and serious danger in connection with shallow wells is their liability to pollution from cesspools and drains, whose liquid contents (fully as poisonous as the solid) filter through the surrounding soil and go to swell the volume of water in the well, especially if, as nearly always happens, the cesspool is much shallower than the well.

In country villages, frequently the cesspools and wells are so intermixed that the entire bed of water is polluted, and hence all the wells are unsafe. But in isolated houses, if the well and cesspool are some distance apart, pollution of the well will depend chiefly on the direction of the movement of the underground water. If this movement is from the cesspool towards the well, the polluted water will flow towards the well; if the movement is in the contrary direction, the polluted water will flow away from the well. Hence Field’s caution, that before sinking a shallow well where sources of contamination are in the neighbourhood, the direction of the flow of the underground water must first be carefully ascertained, bearing in mind that it is not safe to assume that this flow is in the direction of the fall of the land, though it very frequently is so: if there is the slightest doubt, levels must be taken of the underground water in different places, and the source of contamination be accurately localised. Contamination from surface soakage can frequently be prevented by raising the top of the well above the adjoining ground, and paving the surface round the well with a slope so that the rain-water runs away from it. Norton Tube wells, which consist of an iron tube driven into the ground and surmounted by a pump, are useful for excluding surface pollution. If the pollution is sufficient to contaminate the subsoil and reach the underground water, no precautions that can be taken in constructing the well will keep the pollution out.

Generally, deep wells are safer from contamination than shallow wells, but may still, under certain circumstances, be polluted.

On the question whether a well which has been-polluted by a cesspool will become fit for use after the cesspool has been removed, no rule can be laid down. If the removal of the sources of pollution has been thorough, the well will frequently recover its purity; but under other circumstances the well may remain impure. As to the least distance between wells and cesspools compatible with safety, while the Local Government Board of London is content with 20-30 yards, Dr. Frankland insists on at least 200 yards. It would be more rational to forbid cesspools of all kinds; at the same time, possible leakages from drains, through injury or otherwise, must not be omitted from the estimate of risk of pollution. Again, the effect of increased demand upon the contents of the well at once extends the danger, because as the water in the well is lowered so is the area from which the well draws its supply increased, the ratio varying from 20 to 100 times the depression. Where a whole day’s supply is pumped at once into an elevated tank, the maximum figure will be reached.

Those who intend sinking wells are advised first to read a little book by Ernest Spon, on the ‘Present Practice of Sinking and Boring Wells,’ 2nd edition, 1885.

Rain-water collected from roofs forms a valuable auxiliary supply too often disregarded. In towns it is rarely pure enough for domestic use, but in country districts it is generally wholesome.

A country resident thus describes the manner in which he utilises rain-water, falling upon an ordinary tin roof, covered with some sort of metallic paint, said to contain no lead, and flowing into a large cemented brick cistern, whence it is pumped into the kitchen. The cistern differs from the usual construction in this manner: across the bottom, about 3 ft. nearer one side than the other, is excavated a trough or ditch about 2 ft. wide and 2 ft. deep; along the centre of this depression is built a brick wall from the bottom up to the top of the cistern, and having a few openings left through it at the very bottom. The whole cistern, bottom, sides, and canal included, is cemented as usual, excepting the division wall. Upon each side of the wall, at its base, 6-12 in. of charcoal is laid, and covered with well-washed stones to a further height of 6 in., merely to keep the charcoal from floating. The rain-water running from the roof into the larger division of the cistern, passes through the stone covering, the charcoal, the wall, the charcoal upon the other side, lastly, the stones, and is now ready for the pump placed in this smaller part. It is much better that the water at first pass into the larger division, as the filtration will be slower, and the cistern not so likely to overflow under a very heavy rainfall. He has used this cistern for many years, and was troubled only once, when some toads made their entrance at the top, which was just at the surface of the ground, soon making their presence known by a decided change in the flavour of the water.

If the house chances to be in a dusty situation, several plans will suggest themselves whereby a few gallons at the first of each rain may be prevented from entering the cistern. Should the house be small, and therefore the supply of water from its roof be limited, do not lessen the size of the cistern, but rather increase it, for with one of less capacity some of the supply must occasionally be allowed to go to waste during a wet time, and you will suffer in a drought, whereas a cistern that never overflows is the more to be relied upon in a long season without rain.