By the year 1655, the publishing undertakings of the Amsterdam House exceeded in importance those issued from Leyden. It is with this date that the presses of Amsterdam begin to produce the series of Latin authors in the twelvemo form of which Leyden heretofore held the monopoly. It is also with this date that the Amsterdam imprint finds place upon the works of Balzac, Barclay, Charron, Du Refuye, etc. The most considerable of the undertakings of Louis of Amsterdam, in respect at least to the risk incurred and the investment required, was the French Bible of Desmarets, a work that had been begun in 1664 and that was completed, in two folio volumes, in 1669. This work was the culmination of the publishing career of Louis, whose death occurred in the year following its completion. His successor in the management of the Amsterdam House, his cousin Daniel, gave to the business a large measure of skill, experience, judgment, and activity, which appears to have been without break. Daniel’s first experience as sole partner came in a time of difficulty. The disastrous war with England during the years 1665-1667 interfered very seriously with the general prosperity of the State, and caused special embarrassments to the book-trade and publishing interests. This was the war which resulted in the transfer to the English flag of the colony of New Amsterdam, thereafter to be known as New York. Daniel succeeded in weathering the storm, and by the time of the Peace of Breda, he had been able, with the aid of his editorial adviser Wetterus and of the skilled typographer Wetstein, to place the business on what seemed to be an assured foundation. One of his correspondents of the time was the ingenious Nicholas Thoynard, author of the _Harmony of the Gospels_. Thoynard gave special study to the possibility of improving the methods of printing, and, as early as 1680, put before Elzevir a scheme for placing on the presses _formes solides_, apparently the first suggestion of the modern stereotype plates. Daniel dismissed the scheme as impracticable. “To print two forms at one time,” he said, “is something absolutely impossible to carry out, and it would in any case be of no service.” Nicholas Heinsius (the son of Daniel Heinsius), who had first been associated with Daniel in Leyden, had, when the latter migrated to Amsterdam, transferred his own literary interests and editorial service to the Amsterdam House. The intimacy of the two men continued through their lives, and they died within a few months of each other.