"Oh, there's no danger with Tom Swift!" exclaimed Mr. Damon.
"I've been under the sea and above the clouds with him, and,
bless my rainbow! he always brought us safe home."

"And I'll try to do the same this time," said the young
inventor.

Busy days followed for Tom Swift and his friends. The force at
work on the submarine turned night into day to rush her
completion, and in due season she was set afloat in the dry dock
basin and formally rechristened the M. N. 1.

Mary blushed as she gave the boat her new name, and there was a
little cheer from the group of workmen gathered at the dock.
There was no launching in the real sense of the word, since as
the Advance that ceremony had been gone through with for the
undersea craft.

She had been greatly changed interiorly and outwardly. Her
skin, or plates, having been doubled and strengthened. For Tom
proposed to go to a much greater depth than ever before.

In addition to using the submarine herself in a search for the
gold on the Pandora, Tom had installed on board some new kinds of
diving apparatus and also a diving bell. If one would not serve,
the other might, he reasoned.

"Well, Tom," remarked his aged father the night before they
were to start on the trial trip, "I understand you have