For a time the way of the Seal slackened, but not for long. Within ten minutes she was sweeping on as fast as before.

Again Silas grasped the tube, and there was a note of irritation in his voice as he called sharply, “Half speed astern!”

There came a clank from the engine-room as Wilson flung over the levers; then a jarring, grinding crash, that shook the vessel from stem to stern, and the purr of the engines ceased.

With an exclamation of annoyance, Mervyn left the turret, and went below. As he disappeared a cry broke from Seymour.

“Land ho!”

Far away on the horizon a dark, cloud-like shadow rose out of the sea, growing in size each moment as the vessel raced on.

Glass in hand, Seymour sprang to the door; but though he exerted all his huge strength, it defied his efforts to open it.

“Lock the wheel for a second, Silas,” he said, “and give me a hand with this door; it’s got jammed somehow.”

“I guess the wheel don’t need any locking,” retorted the Yankee, as he loosed the spokes.

“What do you mean?” Seymour asked.