_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.