THE COPPER-PLATE PRINTER.

Ths Copper-Platr Printer is a person who transfers portraits, landscapes, and a variety of other pictures and writing, from engravings on copper to paper, by a very ingenious process, of which we are now to speak.

This art is said to have been as ancient as the year 1450, and to owe its origin to Finguerra, a Florentine goldsmith who accidentally pouring some melted brimstone on an engraved plate, found the exact impression of the engraving left in the cold brimstone, marked with black taken out of the strokes by the liquid sulphur : upon this, he attempted to do the same on silver plates with wet paper, by rolling it smoothly with a roller ; and this succeeded. But this art was not used in England till the reign of King James I. when it was brought from Antwerp by Speed.

The principal things requisite in this business, are the ink, and a press, called a rolling press.

The ink used for Copper-plate printing, is a composition made of stones of peaches and apricots, the bones of sheep, and ivory, all
well burnt ; and, as the best which is used in this business comes from Franfort on the Main, it is known as Frankfort-black. It comes over in cakes, and being mixed with nut oil that has been well boiled, it is ground by the printer on a marble, after the same manner as painters do their colours : a palette: knife is, of course, used in this part of the business.

The rolling press may be distinguished into two parts, the body and the carriage.The body consists of two cheeks or upright posts, joined at the top and bottom by cross pieces, and placed perpendicularly on a wooden stand or foot, which sustains the whole press. From this foot rise four other perpendicular pieces, joined, also, by cross ones : this may be considered as the carriage, because it serves to sustain a smooth even plank, upon which the engraved plate is placed

Into the cheeks are inserted two wooden cylinders, the ends of which being much smaller than the bodies, are called trunnions, and
turn in the cheeks between two pieces of wood, in form of half-moons, lined with polished iron to prevent friction.

The spices left vacant, by the trunnion, are filled with paste-board or paper, that they may be raised or lowered at discretion ; so as
only to leave the space between them necesary for the carriage of the plank, loaded with the plate, paper, and cloths, which consist of swanskin and a piece of broad-cloth.

To one of the trunnions qf the upper roller, is fastened a cross, consisting of two levers, the arms of which give a motion to the upper roller, and that again to the under one, so that the plank is drawn by this means backwards and forwards,

The press and the ink being prepared, the printer takes a small quantity of this ink on a rubber made of linen rags, with which he
smears the whole face of the plate as it lies on a grate over a small fire made of old coal.

The plate being sufficiently inked, the printer takes it to a part of the bench called a jigger, and wipes it first with a rag, then with the hand, over which he has rubbed a piece of whiting. The great art consists in wiping the plate perfectly clean, without taking the ink
out of the engraving. The plate thus prepared, is laid on the plank of the press; over the plate is spread the paper, which has been
previously moistened ; and the arms of the cross are now to be pulled, and by that means the plate, with its furniture, is carried,
between the rollers, over which are the swanskin and broad-cloth : these pinching very strongly, yet equally, in every part, force the
moistened paper into the strokes of the engraving, whence it brings away the ink.

Some works require to be passed through the press twice, and once is sufficient for others, according as the graving is more or
less deep, or as the print is required to be of a lighter or darker shade.

After the prints are taken off, the plate is rubbed over with olive oil to prevent its rusting, and set by against a new impression. If the strokes get filled within, and hardened in the course of working, the plates are boiled in strong ley before the oil is applied.

It is said, that Earl Stanhope has introduced such improvements in the art of engraving, as will enable the artist to take off, from a well engraved plate, at least ten thousand impressions. Thus the paintings of the greatest masters, are multiplied to a boundless extent; and the lovers of the polite arts, iu every part of the, globe, are enabled to enjoy those advantages from which their situations seem to have deprived them.

A journeyman Copper-plate Printer will earn forty shillings a week. And from a strongly engraved plate, three or four thousand good impressions may be taken ; and even then the plate may be repaired and fitted up for other editions.