Pytheas had opened up the road to the north to the Scandinavians by discovering Iceland (the famous Thule) and the _Cronian_ Ocean, of which the mud, the shallow-water, and the ice render the navigation dangerous, and where the nights are as light as twilight. The traditions of the voyages undertaken by the ancients to the Orkneys, the Faroe Islands, and even to Iceland, were treasured up among the Irish monks, who were learned men, and themselves bold mariners, as their successive establishments in these archipelagos clearly prove. They were also the pilots of the Northmen, a name given generally to the Scandinavian pirates, both Danish and Norwegian, who rendered themselves so formidable to the whole of Europe during the Middle Ages. But if all the information that we owe to the ancients, both Greeks and Romans, with regard to these hyperborean countries be extremely vague and so to speak fabulous, it is not so with that which concerns the adventurous enterprises of the "Men of the North." The Sagas, as the Icelandic and Danish songs are called, are extremely precise, and the numerous data which we owe to them are daily confirmed by the archaeological discoveries made in America, Greenland, Iceland, Norway, and Denmark. This is a source of valuable information which was long unknown and unexplored, and of which we owe the revelation to the learned Dane, C. C. Rafn, who has furnished us with authentic facts of the greatest interest bearing on the pre-Columbian discovery of America.