The art of taking copies by impression of type, engraved plates and blocks, or of any design or work whatever, in black-ink or pigments of various colours; but the word printing, standing alone, without any distinctive addition, is usually understood to imply typography, or printing from type, usually called letter-press printing, which we propose to notice in the first place.

It is a remarkable circumstance, that notwithstanding the art of letter-press printing has formed a new era in the history and character of our species, the origin of its invention is involved in mysterious obscurity. The primitive honour of having given birth to this sublime vehicle of knowledge has been claimed by the Italian, the German, the Dutch, and the Swiss nations. The inhabitants of Mentz, Strasbourg, and Haerlem, seem to have the most solid ground for their boastings; but we are bound to state, that the citizens of Venice, Rome, Florence, Basle, Augsburg, and Dordrecht, certify to the contrary thereof. The discussion of this interesting question not according with the nature of our work, we recommend those of our readers who are solicitous for information upon the early history of the art, to the article Printing, in the Oxford Encyclopaedia. We may, however, observe, that it seems to be admitted by all parties that this invention took place about the year 1440, and was brought to England by William Caxton, who set up his first press in Westminster Abbey, and began to print books some time after the year 1471. In the early stages of the art, the impressions were taken off with a list coiled up, such as the card-makers use at this day; but when they came to use single types, they employed stronger paper, with vellum and parchment.

At last the press was introduced, and brought gradually to its present state. The same observation applies to the ink; at first the common writing ink was employed; and the printing ink of lamp-black and size, and lamp-black and oil (that now used) were introduced by degrees. We shall now proceed to explain the printer's art, as it is practised at the present day; premising that it is divided into two branches, composition, or the arrangement of the types, and press-work, or the taking off impressions from types so arranged: the workmen employed are therefore distinguished into two classes,-"compositors" and "pressmen." Each compositor works at a sort of desk, called a frame, and, in most instances, he has a desk or frame to himself. The frames project laterally from the wall. At intervals there are large tables, with stone tops, technically called imposing-stones. Each frame at which a compositor works is constructed to hold two pair of cases; each pair of cases contains all the letters of the alphabet, whether small letters or capitals, as well as points, figures, etc. etc.

One of these pair of cases is occupied by the Roman letters, the other by the Italic. The upper case is divided into ninety-eight partitions, all of equal size; and these partitions contain two sets of capital letters, one denominated "full capitals," the other "small;" one set of figures, the accented vowels, and the marks of reference for notes. The lower case is divided into partitions of four different sizes; some at the top and ends being a little smaller than the divisions of the upper case; others nearer the centre, being equal to two of the small divisions; others equal to four, and one equal to six; in all there are fifty-three divisions in the lower case. The inequality in the size of the cells in the lower case is to provide for the great differences as to the quantity required of each letter. According to the language in which it is used, one letter is much more wanted than another, and the proportions required of each have been pretty accurately settled by long experience. As some of our readers may be curious to know these proportions, as they apply to the English language, we subjoin the type-founders' scale for the small characters of a fount of letter, of a particular size and weight:-

A . . . . . . . . . . .

8,500

b . . . . . . . . . .

1,600

c . . . . . . . . . .

3,000

d . . . . . . . . . .

4,400

e . . . . . . . . . .

12,000

f . . . . . . . . . .

2,500

g . . . . . . . . . .

1,700

h . . . . . . . . . .

6,400

i . . . . . . . . . .

8,000

j . . . . . . . . . .

400

k . . . . . . . . . .

800

1 . . . . . . . . . .

4,000

m . . . . . . . . . .

3,000

n . . . .

8,000

o . . . .

8,000

p . . . .

1,700

q . . . .

500

r . . . .

6,200

s . . . .

8,000

t . . . .

9,000

u . . . .

3,400

v . . . .

1,200

w . . . .

2,000

X . . . .

400

y . . . .

2,000

z . . . .

200

The proportion in which a particular letter is required renders it necessary that the cells of the lower case should be arranged, not as the letters follow each, alphabetically, but that those in most frequent use should be nearest the hand of the compositor. The point to which he brings the letters, after picking them up out of their cells, is not far removed from the centre of the lower case; so that in a range of about six inches on every side he can obtain the c, d, e, i, s, m, n, h, o, p, u. t a. and r. the letters in most frequent use. The spaces, which he wants for the division of every word, lie close at his hand, at the bottom of the central division of the lower case. It must be quite obvious, that the man who contrived this arrangement saved a vast deal of time to the compositor.

The cases, particularly the upper one, are placed in a sloping position, that the compositor may the more readily reach the upper boxes. The instrument in which the letters are set is called a composing-stick, which consists of a long and narrow plate of iron, brass, or other compound metal, on the right side of which arises a ledge, which runs the whole length of the plate, and serves to sustain the letters, the sides of which are to rest against it; along this ledge is a row of holes, which serve for introducing the screw, in order to lengthen or shorten the extent of the line, by moving the sliders farther from, or nearer to, the shorter ledge at the end. Where marginal notes are required in a work, the two sliding pieces are opened to a proper distance from each other, in such a manner as that, while the distance between forms the length of the line in the text, the distance between the two sliding-pieces forms the length of the lines for the notes on the side of the page.

Before the compositor proceeds to compose, he puts a rule or thin slip of brass-plate, cut to the length of the line, and of the same height as the letter, in the composing-stick, against the ledge, for the letter to bear against. Thus prepared, the compositor having the copy before him, and his stick in his left hand, his thumb being over the slider; with the right hand he takes up the letters one by one, and places them against the rule, while he supports them with his left thumb by pressing them to the end of the slider, the other hand being constantly employed in setting in other letters, which is effected by a skilful workman at an average rate of about thirty per minute. A line being thus composed, if it end with a word or syllable, and exactly fill the measure, there needs no further care; otherwise more spaces are to be put in, or else the distances lessened between the several words, in order to make the measure quite full, so that every line may end even. The spaces here used are pieces of metal exactly shaped like the shanks of the letters; they are of various thicknesses, and serve to preserve a proper distance between the words; but not standing so high as the letters, they make no impression when the work is printed.