tor's cabin, and related to Mr.
Henderson all that had occurred.

"Well I guess your detective friend will have a hard time to find you in
a few hours," said the old man. "We start on our trip for the south pole
this evening."

There were busy times for the next few hours. Many supplies had to be
placed on board, and, while the boys, with Tom and Bill, saw to this, the
professor and Washington were occupied with putting the last touches to
the submarine boat's machinery.

Most of the supplies from the cabin were placed in the _Porpoise_,
including food and clothing and a good quantity of minerals that, with
sea water, generated the gas that made steam.

An early supper was made on shore, as the professor said they might be
so busy for the first few hours of the starting trip that they would get
no chance to eat. Then the cabin and buildings where the submarine had
been built, were securely fastened.

"I guess we're all ready," announced the professor, taking a last look
around.

One by one they went aboard the _Porpoise_ crawling down through the man
hole. The inventor was the last one to enter. He clamped the cover on by
means of the cam levers and switched on the electric lights. Then he
took his place in the conning tower with Andy Sudds.

"Forward, to the South Pole!" exclaimed Mr. Henderson.

With a turn of his wrist the inventor started the engines. The big screw
in the shaft revolved, pulling the water in at one end of the craft and
sending it out in a swirling stream at the other. The trip was fairly
begun.

For several miles the _Porpoise_ glided along on the surface of the
ocean. It was a calm evening, and the boys down in the cabin of the
craft could look into the reflecting mirrors on the wall, which were
connected with observation magnifying glasses in the conning tower, and
view what was going on, though their heads were below the surface of the
sea.

As it grew darker the view of shore and water faded away. The engine
kept up its speed with Washington to see to it every now and then,
oiling the bearings, some of which did not run quite smoothly because of
their newness.

"I'll send her down a bit now," observed the professor. "I don't want to
run into any more warships or scare the crews by making them think we
are a foreign torpedo boat."

He opened the sea cocks in the ballast tanks and soon the _Porpoise_
sunk about two hundred feet beneath the waves. The craft, which had been
pitching