to it an uncertain, though bright and dazzling
aspect: but this appearance was confined to the lower part of the land;
the bold shores and high groves were clearly defined.

"I trust we are not the subjects of some fearful illusion," said Browne,
breaking a long silence, during which all eyes had been rivetted upon
the island; "but there is something very strange about all this--it has
an unearthly look."

As he spoke, the bright haze which floated over the sea near the
surface, began to extend itself upward, and to grow denser and more
impervious to the sight: the wooded shores became indistinct and dim,
and seemed gradually receding in the distance, until the whole island,
with its bold heights and waving groves, dissolved and melted away like
a beautiful vision.

"What is this?" exclaimed Browne, in a voice of horror. "I should
think, if I believed such things permitted, that evil spirits had power
here on the lonely sea, and were sporting with our misery."

"It is a mirage," said Arthur quietly, "as I suspected from the first.
But courage! though what we have seen was an optical illusion, there
must be a real island in the distance beyond, of which this was the
elevated and refracted image. It cannot, I think, be more than thirty
or forty miles off, and the current is sweeping us steadily towards it."

"I suppose then," said Morton, "that we can do nothing better, than to
trust ourselves entirely to this current which must in fact be a pretty
powerful one--at least as rapid as the Gulf Stream."

"We can do nothing better until the wind changes," replied Arthur,
cheerfully; "at present I am disposed to think we are doing very well,
and fast approaching land."

But there was no change of the wind, and we continued hour after hour,
apparently making no progress, but in reality, as we believed, drifting
steadily westward. All through the day we maintained a vigilant watch,
lest by any possibility we should miss sight of the island which Arthur
was so confident we were approaching. Late in the afternoon we saw a
flock of gannets, and some sooty tern; the gannets passing so near that
we could hear the motion of their long twisted wings. Later still, a
number of small reef-birds passed over head; all were flying westward.
This confirmed Arthur in his belief of the proximity of land. "See,"
said he, "these little reef-birds are bound in the same direction with
the others, and with ourselves; you may depend upon