The seamen of Majorca were as energetic and expert as those of the mainland, and Palma had a great dockyard and arsenal where galleys of thirty benches were built. But the success of the Catalans depended more on their skill and superior knowledge of navigation than on the size and number of their ships. In the middle of the fourteenth century the marine service of Majorca consisted of 30,600 sailors, manning 460 vessels, of which twenty-four were of the largest size, and the others were used for carrying merchandise.[19] Palma could fit out a contingent of large ships as part of the armed fleet of Aragon, and the safety of trade was provided for both by the Government and by private enterprise. Salvador de Sureda was not the only Majorcan notable who fitted out a ship at his own expense to resist the incursions of Barbary pirates. The natives of Majorca were for a long time the leading geographers, inventors of instruments, and constructors of marine charts in Europe. They used the magnetic needle long before its supposed discovery by Gioia of Amalfi, and they could find the polar distance. The rudeness of their instruments increases the merit of the results obtained with them. Their _portolani_, or marine charts, were far more accurate than any of the maps even of a later period. They were in constant use before 1359, when every galley was ordered to carry two charts for navigation.[20] Several Catalan _portolani_ have been preserved. The most interesting, though not the oldest, is now in the possession of the Count of Montenegro at Palma. It was drawn in 1439 by Gabriel de Valseca, who in his own hand wrote the following inscription on it: ‘gabriell de ualsequa la feta en Malorcha an MCCCCXXXVIIII.’ It once belonged to Amerigo Vespucci, as an inscription on the back testifies: ‘questa ampia pelle di geografia fue pagata de Amerigo Vespucio CXX ducati di oro di marco.’ It was bought at Florence in the eighteenth century by Cardinal Despuig, to form part of the library of his nephew, the Count of Montenegro. A facsimile was made for the Spanish Government at the time of the Columbus anniversary, and now hangs in the museum of the Ministry of Marine at Madrid. A curious accident happened to this priceless geographical document in 1839. Georges Sand obtained leave to see it. Up to that time the stiff parchment had been rolled up in a tin case. It was brought out and spread on a table. The famous novelist, to keep it down, took up an inkstand and placed it on the edge of the map. But the parchment, which had been rolled up for centuries, was too strong. It flew back and the ink was upset. Georges Sand, horrified at what she had done, ran straight out of the house. Luckily the injury was not serious, and is confined to the part outside the Mediterranean. The precious map now has a room to itself in the Montenegro palace at Palma. It is framed and glazed on both sides, and kept in a locked case covered with crimson velvet.