Is it possible that a submarine boat is being experimented with beneath the lake?

In his submarine boat Tom secured the valuables, and made a large sum for himself.

I came here by submarine boat.

Not at all, Professor," replied the Captain, with some hesitation; "since you may never leave this submarine boat.

But how admit that the construction of this submarine boat had escaped the public eye?

In its whiteness and intensity I recognised that electric light which played round the submarine boat like a magnificent phenomenon of phosphorescence.

It became necessary to renew the atmosphere of our prison, and no doubt the whole in the submarine boat.

The Canadian began to loosen the bolts which still held us to the submarine boat.

Those who have read of Tom Swift's submarine boat know how his special diving outfit was operated.

But I don't want to go because I am on the verge of perfecting a new apparatus for submarine boats.