The westerly drifting of the Jeannette.
The westerly drifting north of Alaska observed by Mikkelsen and Leffingwell.
The existence of Crocker Land.
The shoaling indicated by a sounding of 310 fathoms taken in Lat. 85° 23´ N.
The eastward progression of the tide wave along the northern coast of Grant Land as shown by observations at Point Aldrich, Cape Sheridan, and Cape Bryant.
The great age of the ice found in Beaufort Sea.
Items of some importance in this connection, but which cannot be regarded as established facts are:
The probable westerly courses taken by casks set adrift off Point Barrow and off Cape Bathurst, the one recovered on the northeastern coast of Iceland, the other on the northern coast of Norway;
The question suggested by Harrison whether or not enough ice escapes from the Arctic to account for the quantity which must be formed there if one were to adopt the assumption of an unobstructed polar basin.
Taking various facts into consideration, it would seem that an obstruction (land, islands, or shoals) containing nearly half a million square statute miles probably exists. That one corner lies north of Bennett Island; another, north of Point Barrow; another, near Banks Land and Prince Patrick Island; and another, at or near Crocker Land.