The Sylph lay at the new wharf, and as soon as the students had put on their uniforms they went on board of her. Chief-engineer Minkfield was directed to get up steam at once. Captain Dornwood ordered one of the quarter boats to be lowered into the water and manned. Taking Thad Glovering, the first officer, with him, he embarked. At the order of the coxswain the bowman shoved off, and the oars were dropped into the water. The boat was pulled up the little lake to the stone quarries. Mr. Miker, the lessee of the quarries, had made good use of some of the ideas of Bolly Millweed, the architect of the boat-house. The _caisson_, on which the stone posts for the foundations of the structure had been transported, had suggested to him the building of a huge raft, or scow. He called the craft a "gundalow," which appears to be a corruption of gondola, though the affair bore but little resemblance to the airy boat of the Venetians. It was fifty feet long and sixteen feet wide. It was decked over and caulked, so that it was as tight as a ship on the ocean. It had a stow-hole at each end; but these compartments were perfectly tight, so that if any water flowed into them it could not get into the large middle chamber upon which the craft depended for its power of flotation. When heavily loaded with stone, the deck was only a few inches above the level of the water outside. Mr. Miker's principal market for the production of the quarries was at Genverres, though he had sold a large quantity of stone to be delivered in Burlington. In the centre of the deck was a derrick, which was used as a mast when the gundalow went out upon Lake Champlain. She was provided with a large, square sail, but it could be used only when the wind was fair. On her trips to Genverres she was poled by four or six men, and made very slow progress. But Captain Gildrock had offered Mr. Miker the use of the Sylph to tow her when he wished, for this was nothing but fun to the ship's company, and, as it looked like business to them, they enjoyed it more than mere sailing without a purpose. The principal made no charge for the use of the steamer, and Mr. Miker was grateful for the service rendered by the yacht and the students. The gundalow was just the thing Captain Dornwood wanted for the operations of the night. When the boat reached the quarry, the captain went on board and measured it. But the derrick was in the way, and unless it could be removed, the craft would be useless to him. Returning to the boat, he proceeded farther up the creek, to a point near Mr. Miker's house. Landing again, he found the quarryman in his garden. He stated his business. Of course he could have the use of the gundalow, and the derrick could be taken out of her. The man of stone was enthusiastic to serve the students, and he did not even ask to what use the craft was to be applied, though Dory volunteered the information that the plan he was to carry out was approved by the principal.