with the needed articles.

"Now we'll make another start," said Mr. Henderson, as soon as all were
on board once more. "This time I hope we will keep on until we reach the
south pole!"

He started the engine, the _Porpoise_ sank beneath the waves, and with a
hum of the big screw that throbbed and vibrated, was away again.

CHAPTER X

ATTACKED BY A MONSTER

For several days the _Porpoise_ plowed her way beneath the surface of
the ocean. Obedient to the directing hand of Professor Henderson she
rose or sank as the tanks were emptied or filled. He put the craft
through several rather difficult movements to test her under all
conditions. In each one she was a success.

Dinner was sometimes eaten five hundred feet below the surface. Then
while Washington washed the dishes and cleaned up the galley, Jack and
Mark looked from the side windows at the strange life under water.

They were getting farther south now and the water was warmer as the
equator was approached. This produced a great variety of animal life,
and the ocean fairly swarmed with fishes, big and little, strange and
curious that could be seen from the glass bull's-eyes.

Great sharks swam up alongside of the _Porpoise_, keeping pace with her
in spite of her speed. Their cruel tigerish eyes and ugly mouths made
the boys shudder as they looked at the creatures. Then came odd
creatures that seemed neither of the land or sea, but which swam along
with their horrible bodies flapping up against the glass. One and all,
the inhabitants of the ocean seemed to resent the intrusion of the
submarine.

One day the boys turned the light out in the cabin and sat in the
darkness the better to observe the fishes. The sea, in the vicinity of
the ship, was illuminated with a sort of glow that diffused from the
searchlight.

Suddenly, as the boys were watching, there came a thud on the glass
window at the port side. They glanced in that direction to see some
horrible thing peering in at them through the window.

At first they were greatly frightened. Two big eyes of green, with rims
of what looked like red fire, stared at them, and, there was an ugly
mouth lined with three rows of teeth.

"It's only a fish," said Mark.

"Well, I wouldn't like to meet it outside," said Jack. "I'd rather be
here. My, but it's a nasty sight!"

"Let's give Washington a little scare," suggested Mark.

"How?"

"We'll go out and tell him some one in the cabin wants to see him.