The extent and scope of Hayes's discoveries, as set forth in his account of the expedition in "The Open Polar Sea," gave rise to persistent and adverse criticism both as to the soundness of his judgment and also as to the accuracy of his observations. Three expeditions, by their later surveys, have demonstrated that the astronomical position assigned by Hayes to his "farthest" on the east coast of Grinnell Land is impossible. There is unmistakably an error either of latitude or of longitude. Cape Joseph Goode, it is to be remarked, is in the longitude assigned by Hayes, while Cape Lieber is no less than six and a half degrees to the eastward; reversely, Lieber corresponds nearly to Hayes's latitude, while Cape Joseph Goode is a degree and a half to the south. Grave and undisputable errors in other latitudes, all being too far to the north, indicate that the mistake in this instance is also of latitude. In justice to Hayes it should be said that the latitude of his "farthest" depended solely on a single observation with a small field sextant of the meridian altitude of the sun. While this is the common method on shipboard it is exceedingly objectionable in Arctic land determinations. It depends not only on the honesty of the observer, but on the condition of the sextant and also on the manner in which it is handled; either of these three qualities being faulty the observation is incorrect. The tendency of the sextant to "slip," as it is turned over for reading, and the almost invariably benumbed condition of the hands of the traveller, indicate the extreme difficulty of making any single reading with accuracy. Again, with haste demanded so often by adverse circumstances, the index of a very small sextant may be misread a whole degree. It is unquestioned that one or the other of these accidents happened to Hayes, for the independent investigations of Bessels, Schott, and others lead to the inevitable conclusion, which any scientist may verify by examination of Hayes's widely separated data, that his "farthest" is placed too far north. The consensus of opinion in the Lady Franklin expedition pointed to Cape Joseph Goode, 80° 14´ N., as Hayes's "farthest," as it agreed better with Hayes's description than any other point; it may be added that from this cape Hayes could not see the Greenland coast above Cape Constitution, which he leaves blank on his chart, and again, here the unusually heavy spring tides, of nearly twenty-five-foot range, break up the southern half of the floes of Kennedy Channel, thus forming early in the year large water-spaces--the Open Polar Sea of Hayes and Morton.