Stable as the vessel may have been, however, a matter which must be taken intoconsideration is the possibility of a sideslip - the slipping of a vessel down a swellor sea, which gives her a list at a dangerous angle. It must be remembered thatwhen the Waratah was last spoken, thesea was "coming down like a wall." Captain E. W. Owens, an authority on the stability of ships, quotes the case of the sailing ship Ellerbank, lost off Cape Horn in1890. Enormous rollers had set in fromthe west and south, and a south-westerlygale arose. The ship heeled over, andwithout warning, fell broadside into atrough that looked as deep as a chasm,and in the descent "turned turtle." Captain Owens points out that a wave maytake a contour varying from the arc of animmense circle to an absolutely perpendicular wall of water. It may take an incurving shape like a giant note of interrogation. Such seas as these occur where there are strong currents, the Cape of Good Hope and its vicinity being especially favorable to such formations. If the roll of a vessel in a great beam sea shouldsynchronise with her descending positionon the sloping "shoulder" of an exceptionally formed wave, the crest of whichis parallel to the line of her keel, conditions exist which would tend to capsizeeven a moderately stable vessel. There is always this possibility overriding all other theories.