In another moment his boat was lifting on the swell towards the rocks.  He pulled quickly, occasionally turning to note that the strange figure, whose movements were quite discernible to the naked eye, was still there, but gazing more earnestly towards the nearest shore for any sign of life or occupation.  In ten minutes he had reached the curve where the trend opened northward, and the long line of shore stretched before him.  He swept it eagerly with a single searching glance.  Sea and shore were empty.  He turned quickly to the rock, scarcely a hundred yards on his beam.  It was empty too!  Forgetting his previous scruples, he pulled directly for it until his keel grated on its submerged base.  There was nothing there but the rock, slippery with the yellow-green slime of seaweed and kelp—­neither trace nor sign of the figure that had occupied it a moment ago.  He pulled around it; there was no cleft or hiding-place.  For an instant his heart leaped at the sight of something white, caught in a jagged tooth of the outlying reef, but it was only the bleached fragment of a bamboo orange-crate, cast from the deck of some South Sea trader, such as often strewed the beach.  He lay off the rock, keeping way in the swell, and scrutinizing the glittering sea.  At last he pulled back to the lighthouse, perplexed and discomfited.

Was it simply a sporting seal, transformed by some trick of his vision?  But he had seen it through his glass, and now remembered such details as the face and features framed in their contour of golden hair, and believed he could even have identified them.  He examined the rock again with his glass, and was surprised to see how clearly it was outlined now in its barren loneliness.  Yet he must have been mistaken.  His scientific and accurate mind allowed of no errant fancy, and he had always sneered at the marvelous as the result of hasty or superficial observation.  He was a little worried at this lapse of his healthy accuracy,—­fearing that it might be the result of his seclusion and loneliness,—­akin to the visions of the recluse and solitary.  It was strange, too, that it should take the shape of a woman; for Edgar Pomfrey had a story—­the usual old and foolish one.

Then his thoughts took a lighter phase, and he turned to the memory of his books, and finally to the books themselves.  From a shelf he picked out a volume of old voyages, and turned to a remembered passage:  “In other seas doe abound marvells soche as Sea Spyders of the bigness of a pinnace, the wich they have been known to attack and destroy; Sea Vypers which reach to the top of a goodly maste, whereby they are able to draw marinners from the rigging by the suction of their breathes; and Devill Fyshe, which vomit fire by night which makyth the sea to shine prodigiously, and mermaydes.  They are half fyshe and half mayde of grate Beauty, and have been seen of divers godly and creditable witnesses swymming beside rocks, hidden to their waist in the sea, combing of their hayres, to the help of whych they carry a small mirrore of the bigness of their fingers.”  Pomfrey laid the book aside with a faint smile.  To even this credulity he might come!