If it be intended to have large paper copies of a work, the alteration of margin is made when the number of small paper copies is printed off from each form.
When the sheet is printed, the com positor lays it up, distributes the letter; and proceeds, sheet after sheet, till the body of the work is finished ; then the' title, dedication, preface, introduction, contents, and any other prefatory matter is proceeded with, these being always' printed the last.
The warehouseman then takes the printed sheets away, and hangs them up on poles to dry, varying the number of sheets hung up together from five or six to ten or eleven, according to the state of the weather, the heat of the room, or the pressure of business ; when these sheets are dry they are taken down from the poles, carefully knocked up, and put away in the warehouse in piles ; when the book is nearly finished, from ten to fourteen consecutive sheets are laid upon the gathering table in order, and collect ed sheet by sheet by boys, who deposit each gathering in a heap at the end of the table, which is generally what is styl ed a horse-shoe table, so that when a boy has deposited his gathering he has only to turn himself and begin again. These gatherings are then carefully collated, to ascertain that the different sheets are cor rect and in order, and folded up the mid dle. When the work is finished the gath erings are put together, each of which forms a copy of the work, and pressed ; the work is now completed, and awaits the order of the bookseller, &c., to deliver the copies either to himself, the book binder, or to others, according to circum stances.
The foregoing is the general descrip tion of the manner in which printing is conducted. Each style of work has its
own peculiarities, and each office has de tails appropriate to itself. Philadelphia, Boston, and New-York, are the cities where the great hulk of book printing of this country is performed. Some of the printing offices of these cities are conduct ed on a most extensive scale. In that in which this Cyclopedia is stereotyped and printed (Mr. J. F. Txow's), there are steadily employed, in the various depart ments of proof-reading, composing, and press-work, about 140 persons. In the composing department, where every de scription of book and job printing is ex works in the Oriental and Classical languages—the average amount of daily labor performed is equivalent to a duodecimo volume of 350 pages. In the press-rooms, there are 13 improved Adams' presses, one cylinder, and three hand-presses, throwing off daily about 38,750 impressions—equal to 4,590 duodecimo volumes of 850 pages.
Some of the finest specimens of American typography have issued from this ex tensive establishment--particularly in the Oriental department, in which branch we believe Mr. Trow has no competitor in this country.
In this country, females are employed in some cities as compositors.
The number of people engaged in these employments is perhaps about the same in the United States, as in Great Britain and in France. Germany employs twice as many as either of those countries ; the rest of Europe, collectively, as many as France. In all, at least 150,000 fami lies subsist in the civilized world, by imparting knowledge or creating the faci lities, besides the clergy and the instruc tors in schools, perhaps twice as many more. cSse PRINTING-VRESS.)