This law has been known only of late years. Even so ingenious an inquirer as Captain Cook notices the mildness of the climate, without attempting to account for it. He records, that, in his opinion, “cattle might subsist in Oonalaska all the year round without being housed”;[85] and this was in latitude 53° 52´, on the same parallel with Labrador, and several degrees north of Quebec; but he stops with a simple statement of the suggestive fact. This, however, was inconsistent with the received idea at the time. A geographer, who wrote a few years before Cook sailed, has a chapter in which, assuming that the climate of Quebec continues across the continent, he argues that America is colder than Asia. I refer to the “Mémoires Géographiques” of Engel.[86] He would have been astonished, had he seen the revelations of an isothermal map, showing precisely the reverse: that the climate of Quebec does not continue across the continent; that the Pacific coast of our continent is warmer than the corresponding Atlantic coast; and that America is warmer than Asia, so far at least as can be determined by the two opposite coasts. Such is the truth, of which there are plentiful signs. The Flora on the American side, even in Behring Strait, is more vigorous than that on the Asiatic side, and the American mountains have less snow in summer than their Asiatic neighbors. Among many illustrations of the temperature, I know none more direct than that furnished by the late Hon. William Sturgis, of Boston,--who was familiar with the Northwest Coast at the beginning of the century,--in a lecture on the Oregon question in 1845. After remarking that the climate there is “altogether milder and the winter less severe than in corresponding latitudes on this side the continent,” he proceeds to testify, that, as a proof of its mildness, he had “passed seven winters between the latitudes of 51° and 57°, frequently lying so near the shore as to have a small cable fast to the trees upon it, and only once was his ship surrounded by ice sufficiently firm to bear the weight of a man.”[87] But this intelligent navigator assigns no reason. To the common observer it seemed as if the temperature grew milder, travelling with the sun until it dipped in the ocean.