Although the composition of type-metal varies greatly in different countries, and eveu in the practice of different British founders, lead almost invariably forms the principal ingredient. Some of the earliest fouuders are supposed used iron to harden it ; but in modern times regulus of antimony is commonly employed for the purpose. Different founders use different alloys, and in different proportions, and this frequently forms a trade secret. The size of the type also occasions a difference, as a small type requires to be harder than a large type.
• An invention has also been introduced'by which a coating of copper is given to the face of the typo by an electro-galvanic process, render ing it much more durable at a moderate expense.
Some letters, from their peculiar form, require more care than others, owing to the projection of certain prominent points beyond the shank or body of the type. Such are called kerned letters ; and, from their greater liability to injury, rather more than a due propor tion of them is cast with a fount. In the common Romau alphabet, f and j are the only kerned letters ; but in an italic fount, d, g, j, 1, and y are kernel on one aide, and f on both sides, and some of the capitals also. As the kerned f cannot bo pladed close to another f, an i, or au I, it becomes necessary to east what are called logotypes, or types containing two or more letters cast on one body. Those in common use are ff, fl, fi, ffi, and ffi. An attempt was made on a very extensive scale in the last century to introduce the use of types bear ing whole words or syllables, under the name of logography, or logo graphic printing, but although an edition of ' History of Commerce,' in four quarto volumes, 1787-9, and some other works, were printed in this way, the scheme was eventually abandoned.
Aa the several letters of the alphabet are, in common printing, required in very different proportions, the number east of each letter in a fount needs to be carefully regulated. The proportions vary in different languages, and in different kinds of work; but for ordinary English book-work they arc about as follows:— To the above are added accented and dotted letters, in numbers ranging from 100 to 250 ; numerals 1 to 9, and 0, from 1000 to 1300 each ; and notes or marks of reference, parentheses, brackets, &c., in
number varying from GO to 300. The number of CAPITALS sup plied with such a fount ranges from the lowest number, 80 (Z), to the highest, 800 (1), with 40 of lE and 30 of (E. Of [matt CAPITALS, the number required in ordinary cases is about one-half that of large capitals; and Italics aro also supplied in small numbers. Spaces, Which are pieces of metal resembling the shanks or bodies of letters, and nand to separate worths, are east of various thicknesses, to enable the conspleitor to jrstsfy his work, or to fill. up each line to the Name degree of tightness, by varying the spaces between the words. Of the smallest kind, which are called, from their extreme thinness, hair spates, 3000 are supplied with a fount of the above extent. Of the three next sizes, called Mix, middle, and Mick spares, the numbers are and 18,000 respectively. The next in order are n.quadrats, or spaces equal in body to the letter n, of which 5000 are required ; and m-cetadrats, double in thickness to the last, and similar in bode to the letter m, which is exactly square, or as wide as it is deep, of which the number is '2500. In addition to these are larger quadrats, equal in body to two, three, or four in'a, which aroused for filling up lines at the end of a paragraph, or in poetry, and for setting up blank lined in order to separate two paragraphs. These are supplied by weight, according to the kind of work for which the fount is reqitire Although all British founders employ the same names for types of similar size, it is to be regretted that perfect uniformity in the sizes is not sufficiently attended to to allow the types of different foundries to be used together without inconvenience. The subjoined specimens show the various sizes employed in England for book-work, beginning with the largest, and descending to the most minute: 1. Great Primer is the largest type ever used for printing books. It is seldom employed for any thing excepting large folio and on this account is sometimes called Bible Test The French call this typo Gros Remain, and the Germans, from its having been the third of seven sizes formerly used, name it Tread. About 511 m's in width, or the same number of lines in depth, occupy a foot.