parts which are to be printed on, from being inked, or, in other words, to keep that part of the sheet which is to form the margin, from getting soiled. After laying on the sheet, and turning the frisket down upon it, the printer doubles the tympan and frisket together, and turns them down upon the types, and then, turning the handle, he rolls the whole carriage, as it is called, under the platen. The bar is then pulled, the screw is thus turned round, and pressing down the platen the printing of the sheet is effected. The bar is then suffered to resume its former place, the screw thereby lifts the platen, the printer rolls out the carriage, unfolds the tympan and frisket, and removes the printed sheet.

The first improvement in the printingpress was made in the year 1620, by Blaen, or Blew, a Dutchman. He had been apprenticed to a joiner, and afterwards rambled into Denmark, where he was entertained by the celebrated astronomer Tycho Brahe. Brahe employed him to make astronomical instruments, and compensated his services by teaching him how to make a globe. On returning home, Blaen became a dealer in books and maps, many of the last of which were engraved by himself. Afterwards, he set up as a printer; and discovering the defects of the printing-press, he made a new one, in which those defects were remedied. He was so pleased with his success, that he made nine of the new presses at one

time, and called them the Nine Muses. This was the press in use until the commencement of the present century, and it is occasionally found standing, and even in use, in printing offices at the present time.

Blaen's press was superseded by the Stanhope press, so called after Lord Stanhope, the inventor of it. His improvement consists in giving to the handle the power of a bent lever. The handle of the press previously used was fixed on the screw by which the pressure was given. Instead of this arrangement, Lord Stanhope succeeded in connecting the top of the screw by a short lever and a link, to the top of a spindle placed parallel to the screw. The handle of the press is attached to the end of this spindle; and when the workman first pulls the handle towards him, owing to the position the levers then occupy, the platen descends very fast, but on reaching the surface of the type, where, of course, the pressure is required, the levers have changed their position in such a manner that the platen moves more slowly but with much greater power.

A is the screw; B the levers connecting the top of the screw with the spindle C, and D is the handle attached to the screw, which being turned, by pulling the handle, forces down the platen.

The advantage arising from this arrangement of levers is, that platens twice as large as those previously used can be worked with

far less strength. The platen of the old press was only half the size of the sheet of paper

on which books are usually printed, as may e seen by comparing the cuts; and in con

Stanhope Press.

sequence it was necessary to roll half the table under the platen, pull the handle, and print half the sheet, then roll the other half of the table under the platen, and pull the handle again before the whole of the sheet was printed. Lord Stanhope's press, however, admits of platens being made sufficiently large to cover the whole of the sheet at one time, while the bent lever handle enables the pull to be effected with great ease. Furthermore, the increased power of the Stanhope press allows of the use of iron, instead of wood, in its construction, and this increases its efficiency, as wood yields to the power of the screw, while iron does not. Lord Stanhope's improvement was afterwards applied to wooden presses, the power of which was greatly increased by it.

The Stanhope press suggested a still greater improvement of the press. The screw which it retained, was superseded entirely by a further use of the lever. Not only is the lever now employed to increase the power of the screw, but also to do the work of the screw. There are now several kinds of presses; but though they differ in the details of their construction, they are exactly alike vi using the lever to produce the impression, instead of the screw. The screw, indeed, is no longer used. The lever is, however, applied in many different ways. In the Albion press, for instance, two wedges or levers are placed within A, and when the press is idle, they lie together

something like the letter; by pulling the bar-handle, they are straightened like the knee on rising from a sitting position, and by their greater length force down the platen upon the type and thus produce the impression.

On the return of the bar-handle to its place of rest, the platen is lifted from the face of the type by means of a spiral spring fixed in the box B, and the two levers fall into the shape of a again. The press, and those succeeding it, are shown with the tables rolled in under the platen.