What most tempts man? The difficult, the useless, the impossible. Of all maritime enterprises, that to which the most persistent energy has been given, is the north western passage, the direct line from Europe to Asia. And yet, the plainest common-sense might anticipatively have told us that, given, the existence of such a passage, in a latitude so cold, so blocked up by ice, it would, practically, be useless; few would, none could, make any regular use of it. _Open this year, it is quite sure to be closed up next year._ Remember that that region has not the flatness of Siberia; it is a mountain of a thousand leagues, horribly broken, with deep chasms, with seas, that, thawed one hour, are frozen up the next, passages between icebergs, which shift their position from time to time, open to invite you, and close to crush you. At length, in 1853, that passage was found, by a man who had got so far in, that it was safer to go ahead, than to recede, and who, therefore, went daringly and desperately forward, till he found that which he sought. Now we know what that passage is; men's minds are calmed down; we know that there is such a passage, and we have not even the smallest desire to make use of it. When I spoke of that passage, as being _useless_, I spoke of it as a commercial highway. But in following this commercially useless enterprise, we have made many very useful discoveries for Geography, Meteorology, and the magnetism of the Earth; just as silly Alchemy, has done so much for wise, and admirably useful Chemistry.