FILE.
RASP.
For softer substances, such as wood, a kind of file is often used called a “rasp,” which, instead of having furrows cut on it, is struck into little dints by means of a three-cornered piece of hard steel, which, as it enters the file, throws up a projection also.
For filing bone and ivory, a kind of file is used with very large notches, not crossed by others, the edge of each of which acts like a plane-iron or chisel, and takes off shavings from the bone.
TYPE.
TYPE CASTING.
The casting of types for printing is for the most part done by hand, and singly, and it is one of those arts in which extreme dexterity (only to be acquired by incessant practice) enables the founder to accomplish an amount of labour which would seem to any one not witnessing the process impossible. To cast each piece of type it is necessary to dip a little ladle into a pot of melted metal, to fill the mould, give it a sudden jerk with the left hand so as to make the melted metal go well into the little mould, open the mould and take the type out, shut up the mould and fasten it, and yet a skilful workman can perform these operations five hundred times in an hour—that is to say, rather more than eight times in a minute—producing a type each time; this has afterwards to be finished off by others. The metal of which type is made consists of lead and antimony—the antimony hardens it and makes it take a sharper impression. The letters are first cut in steel, and from these “dies” the moulds are made in brass, by stamping, and in these the types are cast.