And will you believe it? I have found out considerable about the signals
that a diver gives to the man at the pump on deck.

If he wants to be pulled up, be gives the life-line four sharp pulls.
If he wants more air, he gives one pull at the air-pipe. Two pulls on
the life-line, and two pulls on the air-pipe, given quickly one after
the other, mean that he is in trouble, and wants the help of another
diver. One pull on the life-line means "all right."

There are many other signals I could not find out the meaning of, so can
say nothing about. My instincts, as well as what I have noticed, tell me
that a diver must be in the best of health, must be rather thin, have
excellent eyesight, sound lungs, steady nerves, and a strong heart. The
work is not easy. I wonder if work that pays well is often easy? I do
not believe it is.

There used to be a strange machine in use called the "diving-bell." A
great cast-iron cage, shaped something like a bell, let down by ropes,
and so heavy that its own weight would sink it. Divers could sit inside,
and fresh air was supplied by a force-pump. Bull's-eyes of heavy glass
let in the light.

This must have frightened the fishes quite as much as did the diver,
although it was not as frightful in appearance.

After a time, when the diver came down, some of my mates, seeing I was
not a bit afraid if only hidden from sight myself, stayed near me under
the broad seaweeds, but most of them fled far and wide at his approach.