"It's Captain Dory Dornwood now, I suppose," suggested Life Windham, as all hands glanced at the first pilot.

"Not at all," replied the principal. "On sea steamers they don't have pilots, for the captain navigates the vessel. The pilots on river and lake steamers are a sort of independent officials. In our plan the first pilot is the fourth in rank, and if the captain should be lost overboard, he would not succeed to the command. The first officer is next to the captain, and he takes charge of the steamer in the absence of the captain."

"Thad Glovering!" exclaimed half a dozen students in the same breath.

"Glovering will be the captain in my absence, and you will respect and obey him accordingly," added the principal. "Captain Glovering, you will tow the caisson to the quarry, and I must leave at once."

"Three cheers for Captain Glovering!" called Ben Ludlow; and they were given.

Captain Gildrock went on shore, and disappeared at once. Some of the first-class students did not like it very well to have a second-class fellow put in as captain over them; but they were too well disciplined to find any fault.

"Of course Dory will have to show him how to do it," said Bob Swanton.

"The captain can ask the advice of anyone he likes, but he can do as he pleases," added Corny Minkfield, rather smartly.

But Thad did not ask anybody's advice just then. In spite of some gentle sarcasm uttered by the older boys, the new captain soon showed that he knew what he was about. The large hawser by which the caisson was to be towed lay on the top of the timbers with which it was loaded, the upper ones serving as a deck. It had been made fast to a huge pin in the centre of one end, indicating that the box was to be towed by a single line.

There were also big cleats at the four corners of the structure, placed there for the stays to the derrick. The new captain directed the second officer to take two hawsers and make one fast to each of the corner cleats. Will Orwell obeyed the order, and the other ends of the hawsers were sent on board the Sylph. They were carefully secured to cleats in the stern of the steamer.