CHAPTER XXX. THE STUDENTS CELEBRATE THE COMPLETION OF THE BUILDING OF THE HOUSE.
The framing was finished, and the stone posts or the foundation in the water were ready. Captain Gildrock had decided to have a submarine diver to make a sure thing of the chinking up at the bottom. It was thought best to make two cargoes of the foundations, especially as it was necessary to carry a considerable quantity of other stone.
Seven of the posts had been loaded upon the caisson, and the Sylph went up to tow it down. The derrick had been erected in the centre of it, and everything was ready to drop the foundations into their places. With the handling of the stone the students had nothing to do; but they manned the steamer, and moved the caisson as required. The experience obtained in towing the caisson from Burlington had fitted the boys for their work, and the tow was soon brought into position for setting the first post.
The two four-oar boats and the quarter-boats of the steamer were manned, and were useful in carrying out the various guys and stays in mooring the caisson. The posts were lowered into the water over one end of the craft, the boom of the derrick being thirty feet long, so that the equilibrium of the float could be better secured.
The Goldwing was appropriated to the use of the sub-marine diver and his assistants. He was the novelty of the occasion, for not one of the students, with the exception of the two from New York city, had ever seen the working of the apparatus. It was hardly a full exhibition, however, for the water was not over the diver's head in any part of the bay where he was to make a descent.
The man dressed himself and put on his copper helmet in the standing-room of the yacht; and the students gave him three cheers when he was in full rig. The air-pump was placed on the forward deck, and the hose through which the air was to be supplied to the diver was conveniently arranged. A tub of stone chips of various size was ready to be lowered down to him.
"I don't see how they are to sling the post so as to drop it down into the water plumb," said Oscar Chester, in the pilot-house of the Sylph, which was alongside the caisson.
"The quarrymen have drilled a hole in the top of each; the inside of which is in the shape of the frustrum of a pyramid on two sides," replied Dory Dornwood. "They have an iron made in the same shape, but considerably smaller, which they drop into the hole. On the two slanting sides they insert pieces of iron of uniform thickness, which just fill up the hole. When these are in place you cannot pull out the middle iron, to which the hoisting apparatus is attached."