Another remarkable feature of the North Atlantic is the series of submerged cones or oceanic shoals made known off the northwest coast of Africa between the Canary Islands and the Spanish peninsula, of which we may mention: the “Coral Patch” in lat. 34° 57′ N., long. 11° 57′ W., covered by 302 fathoms; the “Dacia Bank” in lat. 31° 9′ N., long. 13° 34′ W., covered by 47 fathoms; the “Seine Bank” in lat. 33° 47′ N., long. 14° 1′ W., covered by 81 fathoms; the “Concepcion Bank” in lat. 30° N. and long. 13° W., covered by 88 fathoms; the “Josephine Bank” in lat. 37° N., long. 14° W., covered by 82 fathoms; the “Gettysburg Bank” in lat. 36° N., long. 12 W., covered by 34 fathoms.[29]

All of these subaqueous mountain-top lands or hidden elevated plateaus are conspicuously nearer the ocean surface than the real depths of the sea—so much nearer that they inevitably raise the suspicion of having been above that surface within the knowledge and memory of man. It is notorious that coasts rise and fall all over the world in what may be called the normal non-spasmodic action of the strata, and sometimes the movement in one direction—upward or downward—seems to have persisted through many centuries. If we assume that Gettysburg Bank has been continuously descending at the not extravagant rate of two feet in a century, then it was a considerable island above water about the period dealt with by the priests of Sais. Apparently the rising of Labrador and Newfoundland since the last recession and dispersion of the great ice sheet has been even more. Here the elements of exact comparison in time and conditions are lacking; nevertheless, the reported uplift of more than 500 feet in one quarter and nearly 700 in another is impressive as showing what the old earth may do in steady endeavor. It must be borne in mind, too, that a sudden acceleration of the descent of Gettysburg Bank and its consorts may well have occurred at any stage in so feverishly seismic an area. All considered, it seems far from impossible that some of these banks may have been visible and even habitable at some time when men had attained a moderate degree of civilization. But they would not be of any vast extent.

Facts and Legends As to Submergences in Historic Times

Westropp has made an interesting and important disclosure of the legends of submerged lands with villages, churches, etc., all around the coasts of Ireland. In some instances they are believed to be magically visible again above the surface in certain conditions; in others the spires and walls of a fine city may at times, it is thought, be still seen through clear water. Nearly, if not quite, every one of them coincides with a shoal or bank of no great depth, the upjutting teeth of rocks, or a barren fragmentary islet—vestiges perhaps of something more conspicuous, extended, and alluring. Westropp says: “When we examine the sea bed, we see that it is not impossible (save Brasil and the land between Teelin and the Stags of Broadhaven) that islands may have existed within traditional memory at all the alleged sites.”[30] In some cases considerable inroads of the ocean are perfectly well known to have occurred within relatively recent historic centuries. The same on a large scale is certainly true of Holland—witness Haarlem Lake and the Zuyder Zee. Other countries, perhaps most countries, might be called as witnesses.

In these considerations of known facts and legends still repeated we are dealing mostly with events of periods not excessively remote, but the same laws must have been at work and the same phenomena occurring in earlier millenniums.

If there were men to observe, the legend would follow the subsidence; and Phoenician or other voyagers would naturally bear it back to the Eastern Mediterranean, to Plato or the sources from which Plato derived it.

In any such case the submergence would most likely be exaggerated and made a great catastrophe, but there were special reasons why the exaggeration should be enormous in this particular story. It is the office of a myth or legend to explain. We see that in Plato’s time the Atlantic Ocean was believed, in part at least, to be no longer navigable, and with some modifications this idea persisted far down into the Middle Ages, involving at least a conviction of abnormal obstacles hardly to be overcome. The account of Critias is: “Since that time the sea in those quarters has become unnavigable; vessels cannot pass there because of the sands which extend over the site of the buried isle.” This item differs from the other features of the narration put into his mouth by Plato, in that it related to a present and continuing condition and in a way challenged investigation—which would have to be at a distant and ill-known region but was not really impracticable. It must be evident that Plato would not have written thus unless he relied on the established general repute of that part of the ocean for difficulty of navigation.

Reports of Obstruction to Navigation in Early Times

We get further light on this matter of obstruction from the Periplus of Scylax of Caryanda, the greater part of which must have been written before the time of Alexander the Great. Probably we may put down the passage as approximately of Plato’s own period. He begins on the European coast at the Strait of Gibraltar, makes the circuit of the Mediterranean, and ends at Cerne, an island of the African Atlantic coast, “which island, it is stated, is twelve days’ coasting beyond the Pillars of Hercules, where the parts are no longer navigable because of shoals, of mud, and of seaweed.”[31] “The seaweed has the width of a palm and is sharp towards the points, so as to prick.”[32]

Similarly, when Himilco, parting from Hanno, sailed northward on the Atlantic about 500 B. C., he found weeds, shallows, calms, and dangers, according to the poet Avienus, who professes to repeat his account long afterward and is quoted by Nansen, with doubts inclining to acceptance. It reads: