"In one sense you are right," the Doctor answered; "it is only about thirty years ago that the English and American ship-builders began the adoption of this principle. Nearly all the great steamers now navigating the Atlantic Ocean are divided into compartments--generally five or six; and even should two of these spaces become filled with water from any accident, the ship will continue to float. Several steamers have been saved after collision with icebergs, or with other ships, by reason of being thus constructed. Had they been of the old model, they would have infallibly gone to the bottom. "But the Chinese are ahead of us, as they have built their ships in this way for centuries. Six hundred years ago Marco Polo visited the East, and on his return wrote a book about the country and people. He describes the compartment ships that the Chinese built at that time, and explains their advantages. The wonder is that it took the European builders so long to copy the idea. Not till well into this century was it adopted." "But how about the half-dozen captains?" Fred asked. "Why should a ship like this have so many, when the _Great Eastern_ or the _City of Chester_ can get along with one?" "The way of it is," said Captain Clanchy, "that the junk has a lot of compartments--anyway from six to a dozen--and each compartment is let out to a merchant. He is captain of that compartment and all it contains; and if there are ten compartments, he is one-tenth captain of the whole. The crew is under a chief who gets his orders from the merchants, and they have a great deal to say as to how the junk shall sail. Sometimes they want her to go to half a dozen places at once, and in as many directions, and not infrequently they get into frightful rows about it. Don't understand me to say that this is always the case, or anything like it, as a good many of their junks are managed pretty much as an English ship would be. We will see how the matter stands on this one." A little inquiry revealed the fact that there were two men on board equally interested in the cargo, and with equal authority over the movements of the junk. But they were evidently working in perfect harmony, and so there was no chance that the strangers would be compelled to witness a row among the commanders. [Illustration: A JUNK SAILOR AT BREAKFAST.]