Shipbuilding from the earliest days of the Republic formed an important industry. The timber was obtained from the forests of Monte Sergio, now, alas, disappeared, and from those of Lagosta and Meleda, of which traces still remain, as well as from Bosnia. The iron came from the interior, and was manufactured at Venice or locally, the canvas from Ancona and the Marche, pitch from Dalmatia, cordage from Ragusa itself. So jealous was the Republic of the shipbuilding industry, that no native builder (_calafato_ or _marangone_) might lend his services to foreigners, under which heading the Slaves were included. In later times an exception was made in favour of the Turks. The harbour of Ragusa, which is too small for large modern steamers—these always land passengers and goods at Gravosa—in the Middle Ages was ever busy with arriving and departing ships, and the arsenal hands were always engaged in building or repairing craft of all kinds. Other shipping yards existed at the Isola di Mezzo, at Malfi, on Giuppana, and later at Stagno, Slano, and Ragusavecchia. The Ragusan vessels were famed throughout Illyria, and the Republic was frequently requested to lend some to this or that Slave potentate, to the Hungarians, and sometimes to the Venetians themselves. [Illustration: COURTYARD OF THE SPONZA (CUSTOM-HOUSE)] The dangers of navigation, even in the Adriatic, were by no means trifling. The storms of that narrow sea, the sudden gusts of _bora_ or scirocco which sweep down among the countless islands, channels, and promontories of the east coast with terrific violence, are considered dangerous for small ships even to-day. In the Middle Ages the light sailing-craft ran much greater risks. But piracy was then the chief source of anxiety. We have already spoken of the Narentan corsairs in a previous chapter, but even after Venice had broken their power, piratical communities still survived. Almissa, between Stagno and the Narenta, was their chief centre, and its inhabitants were almost exclusively devoted to piracy. The Ragusan statutes contain numerous provisions forbidding all intercourse with them. A Ragusan who sold a ship to the Almissans was fined 100 _ipperperi_ besides the price of the vessel itself; nor could he buy one from them, as it was presumed to be stolen property.[210] Occasionally some arrangement was made with this community of freebooters, and in 1235 a treaty of perpetual peace was signed with Koloman, Count of Almissa.[211] But it proved to be of little avail, and the Ragusan annals are full of entries concerning the depredations of the pirates. The Almissans were not finally subdued by the Venetians until after they regained Dalmatia in 1409. Other piratical communities were found in Northern Dalmatia and Croatia—the district formerly known as the Kraina[212]—and from the ports of Apulia,[213] Sicily, and even from Cattaro pirate vessels often issued forth to ravage the Dalmatian coast or prey upon the Adriatic trade.