"How can they see where they are going?" asked Bertha.

"There are glass openings in their helmets, and they can look through
these. They go out in boats. The crew generally consists of six
men. Two of them are divers, and four men have charge of the
air-pumps. These pumps force fresh air down through tubes fastened
to the helmet of each diver. Besides these men there is an overseer
who has charge of everything.

"Sometimes the divers stay for hours on the bed of the sea, and work
away at the amber tangles."

"But suppose anything happens to the air-tubes and the men fail to
get as much air as they need?" said Hans. "Is there any way of
letting those in the boat know they are in trouble? And, besides
that, how do the others know when it is time to raise the divers with
their precious loads?"

"There is a safety-rope reaching from the boat to the men. When they
pull this rope it is a sign that they wish to be drawn up. But I
have told you as much about amber now as you will be able to
remember."

"Are you very tired, father dear?" said Bertha, in her most coaxing
tone.

"Why should I be tired? What do you wish to ask me? Come, speak out
plainly, little one."