Having shown the necessity for discarding brick drains underneath a house, Eassie next considers alternative clay-derived materials, such as pipes formed of baked clay, after the latter has been worked to a consistency which would not naturally allow of an escape of their contents. There are, however, two or three subdivisions of this class. First of all come those kinds whose ends are merely abutted together, and not, as at the present day, socketed at the joints. These are almost equally faulty with brick drains, because when once they are poisoned and become the habitat of life-destroying germs, their normal tone cannot possibly be recovered. The only kind of earthenware drains which ought to be permitted inside a house are glazed socketed pipes, well formed, well kilned, and properly laid down, the whole of the pipes having been set on a concrete bed, and afterwards covered over with properly made concrete, so as to prevent any possibility of sewage reaching the subsoil, and especially water-tanks. It is not every glazed socketed drain-pipe that is fit for laying down, for the most abominably shaped pipes are often met with. There are many makers beyond reproach, and there are scores of pipes showing patent methods of jointing more or less complicated. The majority of the improvements refer to the fast seating of the ends of the pipes in cradles, well covered in cement, and one especially much in use, Stanford’s, provides a ring of material fitting truly upon a ring of similar material in the socket of the pipe, so that when the two ends are put together, with a little grease or resin between them, the pipes fit closely in every direction, and require but little other luting. These pipes are generally adopted for use under a house, and ordinary socketed pipes for outside.
Cast-iron drains are now very often used in place of earthenware pipes, and there is a great deal to be said in their favour, especially since the invention of several processes whereby the interior is prevented from rusting and scaling. Pipes of this material are useful underground in rows of houses, and wherever straight lines of delivery are obtainable, and compared with drain pipes of earthenware, with their necessary surrounding of concrete, they would prove not more expensive. Unfortunately, however, this system cannot always be adopted, unless the house has been planned with a view to this method of drainage; and in most houses it will be observed that the pipes would have to run in front of fireplaces and across doorways if above ground. When iron piping is used, great care should be taken with the jointing, to see that it is properly packed, and with material calculated to last as long as the pipe itself. Iron pipes with merely leaded joints are subject to galvanic action, whereby the iron, sooner or later, thins out by corrosion, the iron perishing by “abnormal local oxidation,” as has been very forcibly stated by B. H. Thwaite. When iron is contiguous with lead, a galvanic action is set up, and, the latter being electro-negative to the iron, the iron suffers. There ought, therefore, always to be an assistant packing in the pipe, and the majority of engineers make use of this. Eassie advises in addition, a luting of Portland cement with the other materials, which may include a previous stuffing of fibrous packing material together with the old-fashioned iron filings and acids.
Given the best kind of drain to lay down, there is still the question as to where to lay it, and here lamentable errors are frequently made. The chief fault perpetrated in this particular is the laying of drains inside a house, when they might just as easily have been laid outside. When a drain is laid down, care is exercised to get the pipes as much as possible in straight lines; and at each departure from a straight line a manhole is formed, enabling any one to inspect the drain at any time, by lifting the manhole cover. If a lighted candle is placed at the bottom of the drain in the manholes, the freedom of the drain from obstructions can be ascertained by looking from manhole to manhole. These inspection chambers should be placed at every departure from a straight line, and where several drains junction together; thus each drain delivery is open to sight, and rods can easily be introduced up the drain pipe should any obstruction occur. These inspection chambers are always best protected by an iron manhole cover, fitting down perfectly into their iron frames, which are sunk into the stone floor.
Most houses in connection with a large brick sewer have a “flap-trap,” just where the house drain enters into the sewer; this flap opens to allow the house sewage to enter the sewer, whereupon it should immediately close again to exclude foul air and rats from invading the house. They sometimes, however, do not shut closely, and in that case their action for good is almost at an end. A householder can have an occasional inspection made of the trap by the sewer men, by paying a small fee to the vestry.
Precautions after Floods.—Dwellings which have been invaded by the waters should receive special care, so that those whom the flood has expelled should not occupy them before they have been made sufficiently healthy for habitation. They should first be cleaned out as quickly and thoroughly as possible, and freed from all dirt and debris deposited in different parts by the water. Continuous aëration and the most active ventilation are the best and most energetic agents. To increase these as much as possible, where it can be done, a large fire should be maintained on the hearth, and the doors and windows opened, so that the light and heat of the sun may contribute their part to purifying the air. At the same time care must be taken to dig a ditch 10-15 in. deep around each house, whose interior is in many cases below the level of the ground. It will also be well, after having torn down all plastering, which will be in a bad condition, to scrape to their bottom all joints in the walls, and to replaster them in the parts of the house most injured, and where bad deposits have principally accumulated. The floors, where such exist, should be carefully attended to, and the soil under them covered with a disinfecting substance, such as pounded charcoal, or sand, or else with an impermeable material, such as flagging, paving blocks, cement, &c. Where the house is several stories high, the top stories should be the first occupied.
Great precautions should also be followed in the treatment of certain articles of furniture, such as beds and mattresses, which must be renovated or replaced, and which should never on any account be used until thoroughly dried. Sanitary treatment, such as adopted for houses, should be applied with no less vigilance to stables and barns. One peculiar feature it is important to note, though it can only be accidentally produced: it is the possible alteration of the water of wells and springs of potable water, in whose neighbourhood matter in a state of decomposition may have been deposited, or piles of excrementitious and organic debris, or sources of water supply which may have been contaminated by the contents of privy vaults. Attention should be directed to this danger. To disinfect cellars into which, by agency of the inundations, the contents of privy vaults may have penetrated, commercial zinc sulphate may be used, either by sprinkling it in powder in the cellar, or by watering the ground when the water has gone down with a concentrated solution of this salt. Concentrated solution of iron sulphate does well, but the disinfection is not so complete as with salts of zinc; it is, however, cheaper.
Ventilation
Ventilation.—The objects of ventilation are twofold—first to get rid of the poisonous gas (carbonic acid) exhaled from our lungs, and second to furnish a supply of life-supporting gas (oxygen, as it exists in fresh air) to our lungs. For healthy living, every adult individual requires at least 1000 cub. ft. of space, or a room 10 ft. square and 10 ft. high; into this room should pass 3000 cub. ft. of air every hour.
In dwelling-rooms, and especially in bedrooms, the fireplace should always be left unclosed, and the flue or damper open for ventilation. The windows should pull down from the top, and a piece of wire gauze should be fixed along the open space at the top; or a pane of glass should be perforated with holes capable of being closed in stormy weather. All rooms, and especially sleeping apartments, should be well aired during the day.