without a gun who needs it most. So I'm taking no chances."

They sailed all that afternoon without meeting with a craft of any
kind. Straight to the east they went, and when night began to settle
down Washington got supper. It was decided to run slowly after dark
until all hands were more familiar with the ship.

Morning found the Mermaid about a hundred miles from the island where
she had been launched. The night had been uneventful, except that Mark
told Jack he heard some strange noise near his bunk several times. He
was nearest the storeroom where spare parts, and the curious cylinder
the professor had brought aboard, were kept.

"I guess it was rats," said Jack. "They are always in ships."

"Old wooden ships, yes," admitted Mark. "But I'll bet there's not a
rat aboard the Mermaid."

"Then you were dreaming," said Jack, as if that settled it.

Mark did not speak further of the noise, but he did considerable
thinking. However, the next night there was no further disturbance.

The fourth day out, when everything had passed off well, the engines
doing their best, the professor decided to speed them up a bit, since
he was satisfied they had "found" themselves as mechanics term it.

"We'll see how fast we can go through the water," said Mr. Henderson,
"and then I think we can safely turn our course south. We are well
beyond the ordinary lines of travel now."