The greatest length of time that I have seen these volatile fish on the fin, has been thirty seconds by the watch, and their longest flight, mentioned by Captain Hall, has been two hundred yards; but he thinks that subsequent observation has extended the space. The most usual height of flight, as seen above the surface of the water, is from two to three feet; but I have known them come on board at a height of fourteen feet and upwards; and they have been well-ascertained to come into the channels of a line of battle ship, which is considered as high as twenty feet and upwards.[13]
But it must not be supposed they have the power of elevating themselves in the air, after having left their native element; for on watching them I have often seen them fall much below the elevation at which they first rose from the water, but never in any one instance could I observe them raise themselves from the height at which they first sprang, for I regard the elevation they take to depend on the power of the first spring or leap they make on leaving their native element.
On the 6th of June, in latitude 1° 50′ north, and longitude 25° 14′ west, a flying-fish was brought me by one of the steerage passengers, which had just “flown” on board over his head, as he was standing near the fore-part of the ship; being still alive when he brought it to me, I hastened to place it in a bucket of water, to ascertain whether it would attempt to spring from it, and “take flight;” however, I found it was too late, for after floating about with its long pectoral fins half expanded, as it remained near the surface of the water, it continued alive for about the space of a minute, and then died. They usually, from the violence with which they come on board, receive some injury against the spars, boats, or chains, sufficient to destroy them; and therefore it will be difficult to observe their true actions as when performed in full vigour in their native element. This specimen measured nine inches in length. What excited my attention in this fish was a species of anatifa attached by its peduncle to the thorax. I regard as a very unusual circumstance, the existence of an anatifa attached to a living animal, particularly one of such rapidity of motion as this fish is usually supposed to be. The height at which this fish came on board could not have been less than fourteen feet from the surface of the water, and on the windward side of the vessel.
The “flight” of these fish has been compared to that of birds, so as to deceive the observer; however, I cannot perceive any comparison, one being an elegant, fearless, and independent motion, whilst that of the fish is hurried, stiff, and awkward, more like a creature requiring support for a short period, and then its repeated flights are merely another term for leaps. The fish make a rustling noise, very audible when they are near the ship, dart forward, or sometimes take a curve to bring themselves before the wind, and when fatigued fall suddenly into the water. It is not uncommon to see them, when pursued, drop exhausted, rise again almost instantly, proceed a little further, again dipping into the ocean, so continuing for some distance until they are out of sight, so that we remain in ignorance whether they have been captured or have eluded pursuit.
The flying-fish swim in shoals, for on one day they are seen rising about, and in the vicinity of the ship, in great numbers; and on the day following, or latter part of the same day, only a few stragglers are seen. When disturbed by the passage of the ship through the shoal, they rise in numbers near the bows of the ship, and the consternation seems to spread among those far distant: the same may be observed when dolphins and albicores are pursuing them. On passing between the islands of Fuego and St. Jago, (Cape Verd group,) in December, 1828, I witnessed a number of bonito in pursuit of flying-fish; the former springing several yards out of the water, in eager chase, whilst large shoals of the latter arose with an audible rustling noise before their pursuers, and the chase continued as far as we could see, a number of victims no doubt being sacrificed to the voracity of their hunters. Besides the finny enemies, they had to encounter, as they rose from the water, boobies, gannets, and tropic birds, which hovered about, and in our view secured very many as they sought refuge in the air. It was a novel sight, and one not often witnessed during repeated voyages, and afforded much amusement and interest to those who beheld it.[14]
Occasionally our attention was excited during the voyage, by the remarkable luminosity assumed by the ocean in every direction, like rolling masses of liquid fire, as the waves broke and exhibited an appearance inconceivably grand and beautiful. The phosphoric light, given out by the ocean, exists to a more extensive and brilliant degree in tropical regions, although in high latitudes it is occasionally visible, more especially during the warm months of the year. The cause of it has excited much speculation among naturalists; and although many of the marine molluscous and crustaceous animals, such as salpa, pyrosoma, cancer, several medusæ have been found to occasion it, yet no doubt debris, from dead animal matter, with which sea water is usually loaded, is also often one of the exciting causes.
As the ship sails with a strong breeze through a luminous sea on a dark night, the effect produced is then seen to the greatest advantage. The wake of the vessel is one broad sheet of phosphoric matter, so brilliant as to cast a dull, pale light over the after-part of the ship; the foaming surges, as they gracefully curl on each side of the vessel’s prow, are similar to rolling masses of liquid phosphorus; whilst in the distance, even to the horizon, it seems an ocean of fire, and the distant waves breaking, give out a light of an inconceivable beauty and brilliancy: in the combination, the effect produces sensations of wonder and awe, and causes a reflection to arise on the reason of its appearance, as to which as yet no correct judgment has been formed, the whole being overwhelmed with mere hypothesis.
Sometimes the luminosity is very visible without any disturbance of the water, its surface remaining smooth, unruffled even by a passing zephyr; whilst on other occasions no light is emitted unless the water is agitated by the winds, or by the passage of some heavy body through it. Perhaps the beauty of this luminous effect is seen to the greatest advantage when the ship, lying in a bay or harbour in tropical climates, the water around has the resemblance of a sea of milk. An opportunity was afforded me when at Cavité, near Manilla, in 1830, of witnessing for the first time this beautiful scene: as far as the eye could reach over the extensive bay of Manilla, the surface of the tranquil water was one sheet of this dull, pale, phosphorescence; and brilliant flashes were emitted instantly on any heavy body being cast into the water, or when fish sprang from it or swam about; the ship seemed, on looking over its side, to be anchored in a sea of liquid phosphorus, whilst in the distance the resemblance was that of an ocean of milk.
The night to which I allude, when this magnificent appearance presented itself to my observation, was exceedingly dark, which, by the contrast, gave an increased sublimity to the scene; the canopy of the heavens was dark and gloomy; not even the glimmering of a star was to be seen; while the sea of liquid fire cast a deadly pale light over every part of the vessel, her masts, yards, and hull; the fish meanwhile sporting about in numbers, varying the scene by the brilliant flashes they occasioned. It would have formed, I thought at the time, a sublime and beautiful subject for an artist, like Martin, to execute with his judgment and pencil, that is, if any artist could give the true effect of such a scene, on which I must express some doubts.
It must not be for a moment conceived that the light described as brilliant, and like to a sea of “liquid fire,” is of the same character as the flashes produced by the volcano, or by lightning, or meteors. No: it is the light of phosphorus, as the matter truly is, pale, dull, approaching to a white or very pale yellow, casting a melancholy light on objects around, only emitting flashes by collision. To read by it is possible, but not agreeable; and, on an attempt being made, it is almost always found that the eyes will not endure the peculiar light for any length of time, as headaches and sickness are often occasioned by it. I have frequently observed at Singapore, that, although the tranquil water exhibits no particular luminosity, yet when disturbed by the passage of a boat, it gives out phosphoric matter, leaving a brilliant line in the boat’s wake, and the blades of the oars when raised from the water seem to be dripping with liquid phosphorus.