talk, Nat! I guess you'll make out all right. Now
I'll have to go to help look after Mr. Weatherby. He is in a bad way."

"Do you think he will--die?"

"Oh, no, it's not as serious as that, but he's quite sick."

As the captain turned away the rumbling of thunder grew louder, and
there came fitful gleams of lightning from the black clouds.

Nat drew a long breath, and prepared himself for what he felt sure was
coming. Then, almost as calmly as if it had been Mr. Weatherby
himself, he gave his orders. The lookout was stationed in the bow, and
the great searchlight, on a mast back of the pilot-house, and some
distance above it, was set aglow. This was to disclose, during the
storm, any vessels or other obstructions in the path of the _Mermaid_.
This done, Nat prepared for his difficult task.

It grew darker, but with the blackness came the flashing of the beacon
lights on dangerous reefs and islands. Nat was able to pick out his
position fairly well, and he began to feel less nervous.

Suddenly, with a furious burst of wind, and a dash of rain, the storm
enveloped the vessel. Great waves arose on the lake, and the ship
began to pitch and toss. In fact, a storm on one of the great lakes is
almost as bad as one at sea, if not worse, for it does not take long
for the comparatively shallow water to become very much agitated.

[Illustration: "The storm enveloped the vessel"]

Nat signaled for full speed ahead, as he knew he would need all the
steerageway possible to take the vessel through the waves that, every
moment, were becoming larger.

He had his supper in the pilot-house, for he would not leave to go to
the cabin for it. Captain Turton came in during the evening to report
that while Mr. Weatherby was resting easily, he was still quite ill.

"Do you think you can stick out through the night?" the commander
asked.

"I'm going to," was Nat's plucky answer, though the boy was very tired
from his long vigil the night previous, and his lack of sleep during
the day. But Nat was not going to give in.

After the first outburst the storm settled into a steady blow, with
torrents of rain, and an occasional brilliant flash of lightning, and
loud peals of thunder. Through it rode the ship, urged on by her
powerful engines.

The night wore on. Wearily, Nat clung to the small wheel in front of
him, shifting the course of the vessel now and then, as he picked out
the route on the chart, or made a quick shift to avoid som