This peculiarity, coupled with the well known fact that Gutenberg subsequently made at Mentz, three fonts of types on bodies of different size, but closely approximating each other, lead me to the belief that this tool of four pieces should have been some kind of an adjustable type-mould. The only book which can be offered with plausibility as the work of Gutenberg in Strasburg is a _Donatus_, of which four leaves are now preserved in the National Library at Paris. This _Donatus_ is a small quarto, containing twenty-seven lines to the page. The similarity of the types of this book, both in face and body, to those of the _Bible of 42 lines_, suggests the thought that both books were the work of the same printer; but the cut of the letters, the founding of the types and the printing of the book are vastly inferior. It is possible that Gutenberg may have printed some books at Strasburg, but we do not know anything about them. There were many difficulties connected with the proper development of typography, and he may have labored over them many years without any satisfactory result.[247] His earlier experience could not have been materially different from that of other inventors: he may have been kept for years on the threshold of success, vainly trying to remove some obstruction which blocked up his way. If we suppose that Gutenberg [p401] began, as a novice would probably begin, by founding types of soft lead in moulds of sand, the printer will understand why he would condemn the types made by this method. If he afterward made a mould of hard metal, and founded types in matrices of brass, we can understand that, in the beginning, he had abundant reason to reject his first types for inaccuracies of body and irregularities of height and lining. To him as to all true inventors, there could be no patching up of defects in plan or in construction. It was necessary to throw away all the defective work and to begin anew. Experiments like these consume a great deal of time and quite as much of money. The testimony shows that the money contributed by some of the partners in the association had been collected with difficulty. We may suppose that when this had been spent to no purpose, they were unable or unwilling to contribute any more. [Illustration: Fac-simile of the Types of a Donatus attributed to Gutenberg at Strasburg. [From Bernard.]] It may be that the failure of the Strasburg associates was due solely to the audacity of Gutenberg, whose plans were always beyond his pecuniary ability. Even then he may have purposed the printing of the great _Bible of 36 lines_ in three volumes, which he afterward completed in an admirable manner. In trying to accomplish much, he may have failed to do anything of [p402] value. Whatever the reason, it is certain that his partners abandoned Gutenberg and his invention. We read no more of Riffe and Heilmann in connection with typography.