On opening the pan, nothing is seen but a solid lump of metal, which, when carefully broke round the mould, a thin plate is obtained from the mass, exhibiting a perfect appearance of the page from which the mould was taken.--This is called a stereotype plate, which in general is not above the eighth of an inch thick, and is printed from in the same manner as a page of types. Such is the process of stereotyping, which has become pretty general throughout the trade, but is not much known to the public. ENGRAVING. ON WOOD. As we have shown in our article on Printing, Wood-engraving was in fashion prior to the invention of printing. We are informed by Albert Durer that Engraving on Wood was invented about the year 1520; he may be a good authority in some matters, but in this he has committed a mistake of nearly one hundred years; seeing that there is at least an impression of one engraving on wood, the representation of the Creation, which was in existence prior to 1430. It was undoubtedly a piece of rough workmanship; but what could be expected at that early period of the art? It has been, however, gradually improving ever since, and it has now attained a point of excellence equal to any of the fine arts, and calls forth the admiration of every lover of the beautiful. It would be invidious to select any of the numerous artists now flourishing--perhaps it would be difficult to make a selection where so many are upon an equality; and we are of opinion they themselves are more willing to accept the public approbation as their reward, than any praise our pen could bestow. All we can do is to recommend our readers to examine for themselves; they have abundant opportunities in the numerous illustrated publications that are daily issued from the press, and bestow that meed of praise upon the respective artists they may deem proper. The process of engraving on _wood_ is diametrically distinct and opposite to that of engraving on _copper_ or _steel_; as in the former, the shades are produced by the parts of the work which are made most prominent, and obtrude upon the surface of the substance; whence its chief merit has been regarded in leaving broad and well-proportioned lights. The parts to produce this effect being of necessity excavated, great art and a masterly judgment are necessary to effect this, and at the same time not to weaken the substance, lest it should be injured in the pressure necessary to produce an impression.