No. (21), of 1447, inscribed, "... Vera cosmographorum cum marino accordata terra, quorundam frivolis narrationibus rejectis MCCCCXLVII," denotes, as Nordenskjöld points out, not any connection with Marinus of Tyre (by means of a since lost MS., or otherwise), but merely the author's purpose, viz., "to present here a picture of the world, according to the conception of learned cosmographers, adapted to or grouped round a skipper-chart or portolan of the Inner Sea." West Africa, in this chart, does not present anything specially noteworthy. No. (22). Similar in purpose to No. (8) are both the Leardo Maps of 1448 and 1452, which in detail are somewhat similar to the Bianco of 1436. The West African coast of these Designs does not call for special notice. No. (23), of 1455, signed "Presbiter Bartolomeus de Pareto civis Janue ... composuit ... MCCCCLV. in Janua," is not of high value for its date, and shows no evidence of correspondence with Prince Henry's work. The West Africa of this design need not be specially noticed here. No. (24), the most famous of the whole series, is more fully noticed on pp. cxl-cxliv. Fra Mauro was, perhaps, helped by Cadamosto among others. It is noteworthy that the Doge Foscarini, in the letter quoted below, pp. cxl-cxli, couples the success of Cadamosto and the work of Fra Mauro, as two things which should induce Prince Henry to persevere.[268] [Footnote 268: See Major, _Henry Navigator_, p. 312.] A new mappemonde,[269] discovered by Kretschmer in the Vatican Library, and noticed in his monograph of 1891, is of 1448; while under date of 1444, Santarem refers to a "Portolan portugais inédit," which is not further known. [Footnote 269: The "Walsperger," _Eine neue mittelälterliche Weltkarte_.] These were the works[270] which in cartography bore most closely upon the Infant's explorations; and we may here summarise the evidence of the same as to the advance of knowledge along the West African coast and among the Atlantic Islands.