The uncertainty attending the visual organ during the continuance of the aurora and of the twilight, must have been noticed by all those person’s who have frequented the ocean.  Most sailors have the power of eye-sight strengthened from constant practice, and from having an unobstructed view so generally before them; yet I have known an officer, who was famous for his quickness of sight, declare that in the evening and morning he found it difficult to retain sight for more than a second or two at a time, of a strange sail; at night, even with an inverting glass, his practised eye could retain the object more steadily.

The public were amused for some time, a few years ago, by the tales of brother Jonathan respecting the huge sea-serpent.  Without at all disputing the existence of creatures of that nature in the ocean, I have little doubt that a sight I witnessed in a voyage to the West Indies, was precisely such as some of the Americans had construed into a “sea-serpent a mile in length,” agreeing, as it did, with one or two of the accounts given.  This was nothing more than a tribe of black porpoises in one line, extending fully a quarter of a mile, fast asleep!  The appearance certainly was a little singular, not unlike a raft of puncheons, or a ridge of rocks; but the moment it was seen, some one exclaimed, (I believe the captain)—­“here is a solution of Jonathan’s enigma”—­and the resemblance to his “sea-serpent” was at once striking.

Ice, sometimes, when a-wash with the surface of the sea may be mistaken for breakers; and that which is called “black ice” has, both by Capt.  Parry and Mr. Weddell, been taken for rocks until a close approach convinced them of the contrary; and, I dare say, others have been in like manner deceived, especially near Newfoundland.

A scole of or indeed, a single, devil fish (Lophius) when deep in the water, may appear like a shoal; and I think, that of all the various appearances of strange things seen at sea, this monstrous animal is more likely to deceive the judgment into a belief of a submarine danger being where none actually exists, than any other.  I have watched one of these extraordinary creatures, as it passed slowly along, occupying a space two-thirds of the length of the ship (a 32-gun frigate;) its shape was nearly circular, of a dark green colour, spotted with white and light green shades, like the ray, and some other flat-fish.

Mr. Kriukof gave a curious description to Capt.  Kotzebue of a marine serpent which pursued him off Behring’s island:  it was red and enormously long, the head resembling that of the sea-lion, at the same time two disproportionately large eyes gave it a frightful appearance.  Mr. Kriukof’s situation seems to have been almost as perilous above the surface of the sea, as Lieutenant Hardy’s Spanish diver’s was, with the tinterero underneath!

In the History of Greenland, (which, by the by, may with propriety be called Parrynese,) I think there is a well authenticated account of a large sea-serpent seen upon the coast of that vast insular land in Hudson’s sea.