In the same way, from Rome to Barcelona was usually made a sea-trip, although the sailors coasted instead of going direct. All voyages in fact were coasting voyages whenever possible; no landsman was more scared of the open sea than the average sailor during this period, the greatest for the exploration of oceans that the world has ever seen, except, perhaps, that unknown age when the islands of the Pacific were colonised. The fear was based on an accurate knowledge of their own incapacity, revealed to us by one or two travellers who were interested in the science of navigation. A certain Frenchman embarked at Vannes for Portugal; no bearings were taken, and the pilot had no chart; trusted to his eye for his knowledge; which resulted in his coasting along Galicia under the impression it was Asturias. So with the master of the Venetian ship that Lithgow sailed in; he had no compass, cast anchor at night and guessed his whereabouts in daytime by the hills he recognised; on his way back from Alexandria a storm drove them out of their course and he describes, in his doggrel verse, the sailors spending hours identifying headlands, only to find themselves mistaken. Indeed, there was no satisfactory method of ascertaining longitude at sea; although European rulers were offering rewards to the inventor of a method, no one was successful in trying to solve the problem, not even Galileo.[30] So habitual a practice was coasting that if a ship was intent on avoiding a pirate the surest plan was to keep to the open sea. [Illustration: SHIP FOR A LONG-DISTANCE VOYAGE] But for the most part they seem to have trusted to luck with regard to piracy, knowing pirates to be as likely to be met with as storms. The two chief centres were Dunkirk and Algiers, and as the Dunkirkers and Algerines met in the Atlantic, the Baltic was the only European sea free from them, during the latter half of this period at least. In the earlier, war was so continual as to provide employment, or pretext, for the bulk of the scoundrels and unfortunates of the continent whom the comparative peace that succeeded turned loose on commerce, and consequently on tourists.