just before he took his dive.
He did this by standing in a drooping position, with his shoulders
sagging forward. He actually pressed from his lungs all the air
possible. This was to enable him to fill them again with a fresh
supply, rich in oxygen. For it is with the air he takes into his lungs
before he plunges into the water that a diver keeps himself alive.

Joe had watched Benny inflate his lungs, and Joe himself had a way of
his own of doing this, for he had often swum comparatively long
distances under water when a boy, and he had learned the necessity of
fully and properly filling his lungs with air.

"Well, it seems to be going all right so far," thought Joe as he found
that it was no harder to stay under water now than it was the time he
had practised before in the tank, with Helen timing him. "Now for a few
tricks."

It had been Benny's habit to swim about after entering the tank,
imitating a fish as nearly as possible. Perhaps it would be more
correct to say a seal; for a seal in the water more nearly resembles a
human being than does a fish, which has no need of breathing air into
the lungs, as a seal does. The gills of a fish are so constructed as to
extract the oxygen from water, serving the purpose the lungs do in the
air. Probably all know that a fish can "drown," if the functions of the
gills are interfered with.

"Now for some fancy swimming," thought Joe. He began whirling about in
the water, as he had seen Benny do, turning over and over in a graceful
fashion, just as a seal does. Joe really turned backward and forward
somersaults under water, but of course he did it more slowly than the
feats would be performed in the air. And in a sense it was easier, for
the water supported him all around.

For the present Joe was not trying for an endurance test, and when he
had shown three or four different styles of swimming--the old-fashioned
breast stroke, the Australian crawl, the overhand style, and so on--he
came up.

This was not done to get air, as he had not been under more than two
minutes, and he could stay much longer than that. But it was to make
the act last a little longer, and to give the ring-master a chance to
make a further announcement as to what was to take place.

Always, on a stage, in a theatre or in a circus, the effect of an act
is "heightened" as it is called, it is made more dramatic and the
public is more deeply impressed, if some one, even the performer,
states just what i