PTER VI.

A CONVERSATION.

Rollo at first felt quite disappointed that the officer seemed so little
disposed to give him information; but immediately after the officer had
gone another man came by, one of the passengers, as Rollo supposed, who
proved to be more communicative. He wore a glazed cap and a very shaggy
greatcoat. He sat down by the side of Jennie, Rollo being on the other
side, and said,--

"He does not seem inclined to tell you much about the bells, does he,
Rollo?"

"No, sir," replied Rollo; "but how did you know that my name was Rollo?"

"O, I heard about you down in the cabin," replied the stranger; "and
about _you_ too, Jennie, and your beautiful little kitten. But I will
explain the meaning of the bells to you. I know all about them. I belong
on board this ship. I am the surgeon."

"Are you?" said Rollo. "I did not know that there was any surgeon in the
ship."

"Yes," replied the gentleman. "It is quite necessary to have a surgeon.
Sometimes the seamen get hurt, and require attendance; and then
sometimes there are cases of sickness among the passengers. I have got
quite a little apothecary's shop in my state room. I will show it to you
by and by. But now about the bells.

"You must know," continued the surgeon, "that people strike the time at
sea in a very different manner from that which is customary on land. In
the first place, they have a man to strike it; they cannot have a
clock."

"I do not see why not," said Rollo.

"Because at sea," rejoined the surgeon, "the time changes every day, and
no clock going regularly can keep it. Time depends upon the sun, and
when the ship is going east she goes to meet the sun; and it becomes
noon, that is, midday, earlier. When the ship is going west, she goes
away from the sun, and then it becomes noon later. Thus noon has to be
fixed every day anew, and a clock going regularly all the time would be
continually getting wrong. Then, besides the rolling and pitching of the
ship would derange the motion of the weights and pendulum of the clock.
In fact, I don't believe that a clock could be made to go at
all--unless, indeed, it were hung on _gimbals_."

"What are gimbals?" asked Rollo.

"They are a pair of rings," replied the surgeon, "one within the other,
and each mounted on pivots in such a manner that any thing hung within
the inner ring will swing any way freely. The lamps down in the cabin
are hung on gimbals."

"Yes," said Rollo, "I saw th