Precaution against Snakes entering Dwellings.—There is no regular system adopted to prevent snakes entering dwelling-houses in Ceylon, as it is of rare occurrence to find any but rat snakes in European dwellings, and these are not venomous; but it is usual to clear away a portion of space about each bungalow and put on sharp gravel, and also to have coir matting laid down upon the verandahs, as snakes dislike crossing over rough surfaces such as gravel and coir. Trees should be at such a distance from the house (or bungalow) as to prevent the possibility of snakes dropping from the branches on to the roof.
Reducing Echoes and Reverberations.—The report of a committee of a Würtemberg association of architects upon the deadening of ceilings, walls, &c., to sound, gave rise to considerable debate, after which the following conclusions were reached. The propagation of sound through the ceiling may be most effectually prevented by insulating the floor from the beams by means of some porous light substance, as a layer of felt, a filling of sand, or of stone coal dust, the latter being particularly effective. It is difficult to prevent the propagation of sound through thin partitions, but double unconnected walls filled in with some porous material have been found to answer the purpose best. Covering the walls and doors with hangings, as of jute, is also quite serviceable.
To those who carry on any operations requiring much hammering or pounding, a simple means of deadening the noise of their work is a great relief. Several methods have been suggested, but the best are probably these:
1. Rubber cushions under the legs of the work-bench. Chambers’s Journal describes a factory where the hammering of fifty coppersmiths was scarcely audible in the room below, their benches having under each leg a rubber cushion.
2. Kegs of sand or sawdust applied in the same way. A few inches of sand or sawdust is first poured into each keg; on this is laid a board or block upon which the leg rests, and round the leg and block is poured fine dry sand or sawdust. Not only all noise, but all vibration and shock, is prevented; and an ordinary anvil, so mounted, may be used in a dwelling-house without annoying the inhabitants. To amateurs, whose workshops are almost always located in dwelling-houses, this device affords a cheap and simple relief from a very great annoyance.
Echoes are broken up by stretching wires across the room at about 4-5 ft. above the heads of the audience. Often there is strong echo from the windows, which is lessened by the use of curtains, but with some sacrifice of light. Very thin semi-transparent blinds would check echo a good deal, but architects should not have large windows in the same plane; large unbroken surfaces of any kind are very apt to reflect echoes, yet we constantly see rooms intended for public meetings so built as to be spoiled by the confusing echoes.
Waterproofing Walls.—In many badly constructed houses with thin walls there is a tendency for damp to make its way into the interior. Several remedies for this inconvenience have been published at various times. The following procedure is described by a German paper as a reliable means of drying damp walls. The wall, or that part of it which is damp, is freed from its plaster until the bricks or stones are laid bare, next further cleaned off with a stiff broom, and then covered with the mass prepared as below, and dry river-sand thrown on as a covering. Heat 1 cwt. of tar to boiling-point in a pot, best in the open air; keep boiling gently, and mix gradually 3½ lb. of lard with it. After some more stirring, 8 lb. of fine brickdust are successively put into the liquid, and moved about until thoroughly disintegrated, which has been effected when, on dipping in and withdrawing a stick, no lumps adhere to it. The fire under the pot is then reduced, merely keeping the mass hot, which in that state is applied to the wall. This part of the work, as well as the throwing on of the river-sand against the tarred surface, must be done with the trowel quickly and with sufficient force. It must be continued until the whole wall is covered both with the tar mixture and the sand. The tar must not be allowed to get cold, nor must the smallest possible spot be left uncovered, as otherwise damp would show itself again in such places, and where no sand has been thrown the following coat of plaster would not stick. When the tar covering has become cold and hard, the usual or gypsum coating may be applied. It is asserted that, if this covering has been properly dried, even in underground rooms, not a sign of dampness will be perceived. About 300 sq. ft. may be covered with the quantities above stated.
An excellent asphalte or mortar for waterproofing damp walls or other surfaces is the following patented composition:—Coal tar is the basis, to which clay, asphalte, rosin, litharge, and sand are added. It is applied cold, and is extremely tenacious and weather-resisting. The area to be covered is first dried and cleaned, then primed with hot roofing varnish—chiefly tar. The mortar is then laid on cold with trowels, leaving a coat ⅜ in. thick. A large area is then coated with varnish and sprinkled over with rough sand. To frost or rain this mortar is impervious. The cost is 5d. per sq. ft., and for large quantities 4d. In the case of stone walls the following ingredients, melted and mixed together, and applied hot to the surface of stone, will prevent all damp from entering, and vegetable substance from growing upon it. 1½ lb. rosin, 1 lb. Russian tallow, 1 qt. linseed-oil. This simple remedy has been proved upon a piece of very porous stone made into the form of a basin; two coats of this liquid, on being applied, caused it to hold water as well as any earthenware vessel.
For brickwork, the Builder gives the following remedy:—¾ lb. of mottled soap to 1 gal. of water. This composition to be laid over the brickwork steadily and carefully with a large flat brush, so as not to form a froth or lather on the surface. The wash to remain 24 hours to become dry. Mix ½ lb. of alum with 4 gal. of water; leave it to stand for 24 hours, and then apply it in the same manner over the coating of soap. Let this be done in dry weather.
Another authority says, coat with venetian red and coal tar, used hot. This makes a rich brown colour. It can be thinned with boiled oil.