The sun had set early and the moon did not rise till late; but, as soon as the orb of day had disappeared below water, the horizon all round became nearly as black as ink, without any after-glow, as had invariably been noticed at previous sunsets. The whole sky was dark and pitchy like; only a few stars showing themselves momentarily for a while high up towards the zenith, although they were soon hidden by the mantle of sombre cloud that enveloped the heavens everywhere.
Meanwhile, the entire surface of the sea, in every direction as far as their eyes could reach, seemed as if covered with a coating of frosted silver; and, all around the ship, at the water-line, there appeared a brilliant illumination, as if from a row of gas jets or like the footlights in front of the stage of a theatre. Where the sea, too, was broken into foam by the slight motion of the ship, it also gave out the same appearance; and the faint wake astern was as bright as the track usually lit up by the moon or rising sun across the ocean, resembling a pathway of light yellow gold.
When Fritz first saw the reflection, on looking over the side of the ship, he thought that something had happened down below, and that the appearance he noticed was caused by different lights, streaming through the portholes and scuttles.
“What are they doing with all those lanterns in the hold?” he asked Eric in surprise.
The sailor lad laughed.
“No ship lanterns,” said he, “are at work here. They say that this queer look of the sea is occasioned by thousands of little insects that float on the surface and which are like the fireflies of the tropics. Don’t you recollect reading about them?”
“But then, this light is so continuous,” replied Fritz. “It is bright as far away as we can see.”
“Yes, I suppose the shoal of insects stretches onward for miles; still, it is only when it is dark like this, with the sky overcast, that you can see them. At least, that is what I’ve been told, for I never saw such a display before.”
“You’re ’bout right, my lad,” observed Captain Brown, who had come over to leeward, where the brothers were. “I forgit what they call the durned things; but, they’re as thick as muskitters on the Florida coast. You’ll see ’em all clear away as soon as the moon shows a streak, though. They can’t stand her candlelight, you bet!”
It was as the skipper said. Although the illumination of the sea was so vivid that it lit up the ship’s sails with flashes as the water was stirred, it died away when the moon shone out. Then, too, the sky lightened all round and the clouds cleared away before the approaching wind which had thus apparently heralded its coming.