It has also been supposed, that since the right whale does not cross the torrid zone, which to him is as a belt of liquid fire through which he cannot pass, therefore "the right whale of the northern hemisphere is a different animal from that of the southern." It is, however, a well-established fact, "that the same kind of whale which is found off the shores of Greenland, in Baffin's Bay, etc., is also found in the North Pacific, and about Behring Straits; the inference therefore is, that there must be an opening for the passage of whales from one part of the Arctic Ocean to the other." The following facts are taken from Maury's recent work on "The Physical Geography of the Sea," and cannot fail of being interesting to whalemen, and indeed to all classes of readers:-- "It is the custom among whalers to have their harpoons marked with date and name of the ship; and Dr. Scoresby, in his work on 'Arctic Voyages,' mentions several instances of whales that have been taken near Behring's Straits side with harpoons in them bearing the stamps of ships that were known to cruise on the Baffin's Bay side of the American continent; and as, in one or two instances, a very short time had elapsed between the date of capture in the Pacific and the date when the fish must have been struck on the Atlantic side, it was argued, therefore, that there was a _north-west_ passage by which the whales passed from one side to the other, since the stricken animal could not have had the harpoon in him long enough to admit of a passage around either Cape Horn or the Cape of Good Hope. "Thus the fact was approximately established that the harpooned whales did not pass around Cape Horn or the Cape of Good Hope, for they were of the class that could not cross the equator. In this way we are furnished with circumstantial proof affording the most irrefragable evidence that there is, at times at least, open water communication through the Arctic Sea from one side of the continent to the other; for it is known that the whales cannot travel under the ice for such a great distance as is that from one side of the continent to the other. "But this did not prove the existence of an _open_ sea there; it only established the existence--the occasional existence, if you please-- of a channel through which whales had passed. Therefore we felt bound to introduce other evidence before we could expect the reader to admit our proof, and to believe with us in the existence of an open sea in the Arctic Ocean.