There is in the Bargello Museum at Florence a beautiful Pax with a nielloed plate attributed to Maso Finiguerra, the date of which is put at 1452. From this plate, before it was nielloed, prints on paper were taken, and one of them is at Paris. But the letterings on this engraving read rightly on the metal, so it was not engraved with the intent that prints should be made from it; indeed, they, as well as the impressions in sulphur, were only made to help in the working. So that it is only safe to say that the possibility of making prints on paper from engraved metal plates was known about the middle of the fifteenth century both in Germany and in Italy. To make a print from an engraved plate requires great pressure, as the paper has to be forced down into every mark, and the resulting mark on the paper is consequently always in relief. The principle of a print made from an engraved wood block is that the projecting parts are covered with a thin film of ink, and when the paper is lightly pressed down upon these lines it picks up the ink from the surface wherever it touches it. In the case of an engraved metal plate, the lines on which are cut in the same way and with a similar graver to that used for white line engraving on wood, the inking and printing is quite different. Now it is the incised lines which print black, and in order to ensure this the whole plate is well rubbed over with ink so as to fill up all the incised lines, and then the unengraved polished surface is carefully wiped clean so as to leave the ink sticking in all the dots, lines and curves. Now damped paper is very strongly pressed upon the inked plate, so as to be squeezed right down into every dot, line and curve. The paper consequently is in relief wherever it has been pressed into a depression, and as there was ink there waiting for it, it will be found to have picked up and absorbed all the ink, so that the print shows black lines in low relief. It will be easily realised that a print from an engraved metal plate cannot be printed with ordinary type at the same operation a wood-block can, so that whenever a book occurs in which such engravings show on the same page with type, there must have been two printings, one strong for the engraving and one light for the type. We find, therefore, that in several instances where engraved illustrations have been used for a book which is for the most part printed from type, that the small piece of text which comes on the same page as the engraving, is also engraved. Not only this, but from time to time entire books have been engraved, illustrations as well as text. The finest English example of such work is to be found in the beautiful edition of the works of Horace, plentifully illustrated and engraved throughout on copper by John Pine. It was published in 1733-7.