Locks and Keys form a curious part of the hardware manufacture. The lock is made of a great many pieces, put together with screws. One part of it is always a moveable latch or bolt, which is capable, by tolerable force, of being thrust partially out through a hole in the side of the lock; and it is this bolt which, catching in a box or cell fixed to the door-post, secures the door to which the lock is attached. The object of the key is to act as a lever which shall move the bolt; and the great point of attention in the matter is, that no key or lever but one of a particular size and shape shall be able to move the bolt; herein is the security which we feel in a good lock. Wolverhampton and its neighbourhood is the great seat of the lock manufacture.
Stoves and Grates.
Stoves and Grates are made in a variety of forms. Their employment is obviously greatly dependent on the kind of fuel employed. In the kitchens of the old baronial residences, large logs of wood were thrown upon an immense stone or brick hearth, and there kindled. But when coals became commonly used in London and other great towns of England, about the year 1400, the use of some kind of stove or grate began to be felt, since the fuel was too valuable to be scattered on a wide-spreading hearth. From that time to the present, one continual series of improvements has taken place, having for their objects, to add to the elegance and neatness of a room, to facilitate culinary occupations, and to derive the greatest possible heat from a given quantity of fuel. It is only within a very few years that the principles regulating the last-mentioned circumstance have been at all well understood. Some parts of the metal for a grate or stove are produced by casting, others by forging, and others by rolling or pressing; and they are put together principally by rivets. For further details on this subject we refer to our seventh chapter.
Bells.
Bells are, generally speaking, made of an alloy of copper and tin, which possesses more resonant qualities than most others. There is also a little ball or clapper suspended in the bell, which, by striking against it, produces the same effect as the hammer which strikes the outside of a church bell. The bell is generally fixed in a different part of the house from the handle with which it is rung, and the connexion between them is made by means of copper wire. As the wire has to turn round many corners and angles, it is fixed, at each corner to a crank, which is a kind of hinge or lever, so contrived as to transfer motion in a new direction at right angles to the former. Considerable care is required on the part of the bell-hanger, to prevent the wire from becoming entangled or interrupted in its free communication from the handle to the bell.
Brass Handles, Ornaments, &c.
Those are produced by turning, by casting, by stamping, or by drawing. In the first mode, the article is placed in a lathe, and turned by tools made of hard steel: in the second mode, melted brass is poured into moulds formed generally of sand, by which any desired form is produced: in the third mode, two stamps, one called a matrass and the other a die, are cut or moulded to similar figures; a piece of sheet brass is laid on the matrass or lower stamp, the die or upper stamp is laid on the brass, and a powerful blow, either from a hammer, or from machinery, forces the brass to assume the form given to the two stamps. By the last mode, a slip of thin brass is forcibly drawn between two rollers, whose surfaces are indented with the requisite device, which device is thereby impressed on the bars. In one or other of these ways, most of the brass-work in our houses is made.
Iron railings and bars of various kinds are made either by forging or casting, and do not call for further notice here.
Preservation of Timber.
In our notices of the timber which enters into the construction of a house, no mention was made of the existing methods of preparing it so as to resist the action of dry rot and other decomposing agencies. Timber so prepared is not in very general use in house-building, and hence the notice of it occupies a more fitting place in the present chapter.