Not only Mediterranean seaports, but the lakes of North Italy and central Europe, and the Hanseatic ports, are enumerated as nurseries of crusading mariners and marine skill. Finally, after the conquest of Egypt, Marino designs the establishment of a Christian fleet in the Indian Ocean to dominate and subjugate its coasts and islands. He also gives a sketch of the trade-routes crossing Persia and Egypt, as well as of the course of Indian trade from Coromandel and Gujarat to Hormuz and the Persian Gulf, and to Aden and the Nile. The maps and plans which illustrate the Secreta are probably (in the main, at least) the work of the great portolan chart draughtsman Pietro Vesconte: practically the whole of this map-work corresponds with what Vesconte has left under his own name; much of it is indistinguishable. Among the plans that of Acre is of peculiar interest, being the most complete representation known of the great crusading fortress on the eve of its destruction, with the quarters of all its contingents of defenders (Templars, etc.) indicated. The chart of the Mediterranean and Euxine and of the Atlantic coasts of Europe is composed of five map-sheets, which together form a good example of the earliest scientific design or portolano; in the world-map a portolano of the Mediterranean world Is combined with work of pre-portolan type in remoter regions. Here the shore-lines of the countries well known to Italian mariners, from Flanders to Azov, are well laid down; the Caspian and the north German and Scandinavian coasts appear with an evident, though far slighter, relation to practical knowledge; and some idea is shown of the great continental rivers of the north, such as the Don, Volga, Vistula, Oxus and Syr Daria. Africa, away from the Mediterranean, is conventional, with its south-east projected, after the manner of Idrisi, so as to face Indian Asia, and with a western Nile traversing the continent to the Atlantic. Chinese and Indian Asia show little trace of the new knowledge which had been imparted by European pioneers from the Polos' time, and which appears so strikingly in the Catalan Atlas of 1375. Sanuto's Palestine map is remarkable for its space-defining network of lines, which roughly answer to a kind of scheme of latitude and longitude, though properly speaking they are not scientific at all.