Note 222 — Chapter XI · THE JOURNAL OF GALLEGO—PREFATORY REMARKS.

To find in a dark night and in thick weather an opening in a line of coral-reef on an unknown coast, is an undertaking fraught with the greatest hazard, even for a ship possessing steam power. The only available guide is that which was followed by this clear-headed navigator; but it is one which, as it depends on the luminosity of the sea, can only be of occasional service. When the sea has been unusually phosphorescent, each roller, as it breaks on the weather-edge of the reef, is marked by a disconnected line of light, reminding one of the straggling fire of a line of musketry. I once saw this phenomenon splendidly exhibited on the coast of Japan, the sea-surface being crowded with myriads of “Noctilucæ.”