M. Madden, in his _Lettres d’un Bibliographe_, has argued that a very early school of typography existed at Cologne, in the Monastery of Weidenbach. Though his researches have thrown a great deal of light on various points connected with early printing, and are in some ways of real value, much that he has theorised about Weidenbach requires confirmation. We can hardly be expected to believe, as he would try to persuade us, that Caxton, and Zel, and Jenson, and many other printers whose types belong to different families, could all learn printing at this one place. It would be impossible for men who had learnt to print in the same school to produce such radically different kinds of type, and work in such different methods. The early tentative essays of Zel’s press can be clearly identified, and their order more or less accurately determined, from their typographical characteristics. His earliest books were quartos; and of these the first few have four point holes to the page. These point holes are small holes about an inch from the top and bottom lines, and nearly parallel with the sides of the type, made by the four pins which went through the paper when one side of the page was printed, and served as a guide to place the paper straight when the other side was printed.[13] [13] The use of four points to obtain a correct register is generally a sure sign of the infancy of a press. Blades says they are to be found in all the books printed in Caxton’s Type 1. Then, before he settled down to printing his quartos with twenty-seven lines to the page, he experimented with various numbers of lines. We can safely start with the following books in the following order:— _A._ Cicero, _De officiis_, 34 lines to the page. Chrysostom, _Super psalmo quinquagesimo_, 1466, 33 lines to the page. Gerson, _Super materia celebrationis missæ_, 31 lines to the page. Gerson, _Alphabetum divini amoris_, 31 lines to the page. These form an early group by themselves, and commence on the first leaf; the second group begins with _B._ Augustinus, _De vita christiana_ and _De singularitate clericorum_, 1467, 28 and 27 lines to the page. Then follows a number of tracts by Gerson and Chrysostom, all having four point holes, and all probably printed before 1470. Zel continued to print throughout the whole of the fifteenth century.