We cannot here detail all the work of explorers who, in the sixteenth century and after, extended discovery in one or another of these directions; nor, indeed, in the case of some of the earlier journeys, do the records admit of doing so. It is thus probable that in the second half of the sixteenth century Portuguese sailors had anticipated Henry Hudson in acquiring considerable knowledge of Hudson Bay, but it is not possible to say how far they had penetrated it. In 1558 Nicolo Zeno of Venice put forth a forged narrative of a fictitious journey which he attributed to an ancestor of his own. He attached a map to it, and showed thereon an imaginary land named Frisland to the south of Greenland, and other equally false details which set many later travellers and geographers astray. Sir Martin Frobisher, holding that the discovery of the North-West passage was the crowning piece of exploratory work remaining to reward the adventurer, secured Queen Elizabeth’s and other powerful interests, and led an expedition to the north-west in 1576. Zeno’s map put him wrong when he discovered Eastern Greenland and thought it to be Frisland, and he subsequently reached the southern part of Baffin Land; but this was supposed to be Greenland. He made a second voyage in 1578. Frobisher’s successor, John Davis, another explorer of high scientific standing, misinterpreted some of Frobisher’s results, as other geographers did, thus placing Frobisher Strait not in Baffin Land but in Greenland, where it long appeared in maps. Davis made voyages in 1585, 1586, and 1587. He passed along Davis Strait, and explored both its eastern and its western shores, extending the knowledge of the west coast of Greenland on his third voyage as far north as 72° 41´. Henry Hudson, in his two earlier voyages in 1607 and 1608, was concerned with the seas of the north-east, and we shall consider them later. But in 1610 he sailed west and entered Hudson Bay, where, after many sufferings, he was set adrift by a mutinous crew and was lost. Following him Sir Thomas Button, in 1612, became acquainted with the west coast of the bay, and maintained the belief, which was upheld for more than a generation following, that the North-West passage to the Indies would be found to open from this coast. In 1615 and 1616 William Baffin made a voyage which brought within men’s knowledge the channels which ramify northward and westward from the head of Baffin Bay; but this knowledge was not appraised at its true value; indeed, even the authenticity of his work came to be doubted, notable though the voyage was for many important discoveries, including, among others, remarkable magnetic observations, for in Smith’s Sound Baffin discovered the greatest known variation of the compass. His explorations carried him more than three hundred miles beyond Davis’s northern limit. In spite of these discoveries, which gave no impulse towards theoretical