[1] At the present day line engravers sometimes work on steel plates, as they are capable of supplying without damage a much greater number of proofs than can be printed from copper plates. It more frequently happens that a copper plate is coated with steel before being submitted to the action of the press, in order to preserve it, and to increase the number of copies without taking off the edge of the workmanship. That is to say, that by means of "electrotyping" a thin coat of metal is superimposed, which, since it considerably increases the power of endurance, increases the productiveness of the plate and the number of proofs that can be taken. [2] Papillon, "Traité de la Gravure en Bois," 1766, vol. i., ch. 1. [3] Pliny, "Hist. Nat.," xxxv., c. 2. [4] "Materiali per servire alla Storia dell' Incisione," &c., p. 83 and following. [5] That is the "Treatises on Latin Syntax" by Ælius Donatus, a grammarian of the fourth century. In the Middle Ages these treatises were much used in schools. [6] Published by John Koelhoff under the name of "Cronica van der hilliger Stat van Coellen," p. 31 and after. [7] "Essai historique et critique sur l'Invention de l'Imprimerie." Lille, 1859. [8] This, at any rate, is what we feel tempted to do as regards the "Biblia Pauperum," a book containing xylographic illustrations, whose date has been variously estimated, and which we are disposed to believe even older than the first edition of the "Speculum." Heinecken, as usual, claims for Germany the production of this precious collection, which Ottley, with more appearance of reason, regards as the work of an artist of the Low Countries, who worked about 1420. In this way Germany would only have the right to claim the plates added in the German editions published forty years later, and which are far less perfect in point of style and arrangement than those of the original edition. [9] The Dutch word _coster_ means churchwarden, or beadle. [10] "Ideé générale d'une Collection d'Estampes, 1771," p. 305. [11] "Discours Historique sur la Gravure." Paris, 1808. [12] See in "L'Artiste," 1839, an article entitled "La plus ancienne Gravure du Cabinet des Estampes de la Bibliothèque royale est-elle ancienne?" [13] "Notice sur deux Estampes de 1406, et sur les Commencements de la Gravure en Criblé." "Gazette des Beaux-arts," t. I^{er}, 2^e période, 1869. [14] "Le Peintre-Graveur," Leipzig, 1860, vol. i., p. 84. [15] "Une Passion de 1446. Suite de Gravures au Burin, les premières avec Date." Montpellier, 1857. [16] "Archiv für die Zeichnenden Künste," 1858.