Captain March straightened up.
"Bring me the glasses, Mr. Medbury," he said.
Medbury brought them, and the captain slowly swept the horizon; then he crossed the deck and walked to the main-rigging. Coming back, he handed the glasses to Medbury.
"Go forward and take a look," he said.
In five minutes the mate came back, and went up the main-rigging to the crosstrees. When he descended, he came aft.
"It's getting thick," he said; "she ought to blow her whistle."
"Better get your fog-horn forward," said the captain, and took the glasses for another look as Medbury went below. A moment later the mate returned to the deck with the long box of the patent fog-horn, and presently the dreary wail began to sound at intervals from the forecastle-deck. Hetty shivered as she heard it.
"It frightens me!" she murmured, with a little catch in her voice. "It frightens me!"
The crew were at the rail forward, silent and listening. The fog had blotted out the fore part of the vessel, but the forecastle door was open, and the swinging lamp was like an orange center of light in a nebulous haze. Once a sailor passed before it, and his shape loomed black and huge against the luminous interior. At short intervals the fog-horn sounded like a wailing banshee through the darkness; but there was no answering signal: only at long intervals came that strange, throbbing beat, like an uncanny chuckle, but seemingly neither nearer nor farther away than at first. Hardly two aboard agreed as to its direction, for the opaque walls of fog deflect sound-waves at sea, as a crystal breaks a ray of light.
Back on the quarter-deck Medbury was telling a curious story.