revelation to the boys, for they had supposed it was only necessary to
tilt the ship and dive just like a porpoise.

To their great delight the recruits found that the _Dewey_, like other
submarines built since the beginning of the great world war, was
equipped with twin periscopes, and that, furthermore, they would be
allowed to watch the submersion of the _Dewey_ through the reserve
periscope if they so desired. Would they care to? Well, rather! For
the next few minutes they took turn about peering into the mirrors that
reflected the whole panorama before their eyes.

Gradually, they could see, the _Dewey_ was settling into the embrace
of the sea. Now she was down until the waves rolled completely over
the deck and splashed against the conning tower. Down, down they
dropped till only the periscope projected above the waves. Before
them stretched the wide sweep of water, the ocean rising slowly but
surely to overwhelm them. One after another the waves surged by.
Now the eye of the periscope was so close to the crest of the water
that it was only a matter of another moment until they would be under.
Up, up, up came the water to meet them. Ted's heart was in his mouth
while he viewed this awesome spectacle. Then he gave way for Jack to
take a squint through the tube that carried with it a last look at the
world of sunlight they were leaving. And now the eye of the periscope
was so near submersion that the swell of the waves swept over it and
momentarily blotted out the light. Then the spray dashed madly at the
"eye" of the tube---and they were under!

Down in the depths of the ocean! It was a moment to stir the pulses
of the two Brighton recruits. Wide-eyed in wonder, tense with the
strain of the experience, they stepped back from the periscope.