island, too, is very old,—as old, doubtless, as the fact of fog-banks and mirage,—and it is well exemplified in those mysterious visions which enticed the sailors of Bristol to many a fruitless quest before the discovery of America, and for centuries tantalized the inhabitants of the Canaries with hope of discovery. The Atlantic islands were not all isles of the blessed; there were many Isles of Demons, such as Ramusio places north of Newfoundland, a name of evil report which afterward attached itself with more reason to Sable Island and even to the Bermudas: “Kept, as suppos’d by Hel’s infernal dogs; Our fleet found there most honest courteous hogs.”[324] Not until the revival of classical learning did the continental system of Ptolemy reach the west; the way, however, had been prepared for it. The measurement of a degree, executed under the Calif Mamun, seemed to the Europeans to confirm the smallest estimate of the size of the earth, which Ptolemy also had adopted,[325] while the travels of Marco Polo, revealing the great island of Japan, exaggerated the popular idea of the extent of the known world, until the 225° of Marinus seemed more probable than the 180° of Ptolemy. If, however, time brought this shrinkage in the breadth of the Atlantic, the temptation to navigators was opposed by the belief in the dangers of the ocean, which shared the persistent life of the dogma of the impassable torrid zone, and was strongly reinforced by Arab lore. Their geographers never tire of dilating on the calms and storms, mudbanks and fogs, and unknown dangers of the “Sea of Darkness.” Nevertheless, as the turmoil of mediæval life made gentler spirits sigh for peace in distant homes, while the wild energy of others found the very dangers of the sea delightful, there was opened a double source of adventures, both real and imaginary. Those pillars cut with inscriptions forbidding further advance westward, which we owe to Moorish fancy, confounding Hercules and Atlas and Alexander, were transformed into a knightly hero pointing oceanwards, or became guide-posts to the earthly paradise. If there be a legendary flavor in the flight of the seven bishops, we must set down the wanderings of the Magrurin[326] among the African islands, the futile but bold attempts of the Visconti to circumnavigate Africa, as real, though without the least footing in a list of claimants for the discovery of America. The voyages of St. Brandan and St. Malo, again, are distinctly fabulous, and but other forms of the ancient myth of the soul-voyages; and the same may be said of the strange tale of Maelduin.[327] But what of those other Irish voyages to Irland-it-mikla and Huitramannaland, of the voyage of Madoc, of the explorations of the Zeni? While these tales merit close investigation, it is certain that whatever liftings of the veil there may have been—that there were any is extremely doubtful—were unheralded at the time and soon forgotten.[328]