"Then, besides," continued the surgeon, "if the men strike the bells themselves, the sound, coming regularly every half hour, proves that they are at their posts and attending to their duties. So that, even if a machine could be invented to strike the time on board ship ever so truly, I do not think they would like to adopt it.
"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!"
"Half past twelve," said Rollo.
"Ding—ding!" said the surgeon again, imitating the sound of the bell with his voice.
"One o'clock," said Rollo.
"Ding—ding! Ding!" said the surgeon.
"Half past one o'clock."
"Ding—ding! Ding—ding!"
"Two o'clock!"