"Another difference in striking the time on board ship," continued the surgeon, "is, that they strike it by half hours instead of by hours. Scarcely any of the ship's company have watches. In fact, watches are of very little use at sea, the time is so continually changing from day to day. The sailors, therefore, and nearly all on board, depend wholly on the bells; and it is necessary, accordingly, that they should be struck often. Every two bells, therefore, means an hour; and a single bell at the end means half an hour. Now, I will strike the bells for you, and you may tell me what o'clock it is. We begin after twelve o'clock.
"Ding--ding!" said the surgeon again, imitating the sound of the bell with his voice.
"Ding--ding! Ding--ding! Ding-ding! Ding!"
"Ding--ding! Ding--ding! Ding--ding! Ding--ding!"
"Yes," said the surgeon, "that is eight bells, and that is the end. Now they stop and begin again with one bell, which means half past four; and so they go on to eight bells again, which makes it eight o'clock. The next eight bells is twelve o'clock at night, and the next is at four o'clock in the morning, and the next at eight o'clock. So that eight bells means four o'clock, and eight o'clock, and twelve o'clock, by day; and four o'clock, and eight o'clock, and twelve o'clock, by night."
"Yes," said Rollo, "now I understand it."
"Eight bells is a very important striking," continued the surgeon. "It is a curious fact, that almost every thing important that is done at sea is done at some eight bells or other."
"Why, in the first place," replied the surgeon, "at eight bells in the morning, the gong sounds to wake the passengers up. Then the watch changes, too; that is, the set of men that have been on deck and had care of the ship and the sails since midnight go below, and a new watch, that is, a new set of men that have been asleep since midnight, take their places. Then the next eight bells, which is twelve, is luncheon time. At this time, too, the captain finds out from the sun whereabouts we are on the ocean, and also determines the ship's _time_ for the next twenty-four hours. The next eight bells is at four o'clock, and that is dinner time. The next eight bells is at eight o'clock, and that is tea time. At all these times the watches change too; and so they do at the eight bells, which sound at midnight."