Square and Compasses; Or, Building the House

by Oliver Optic

Oscar watched the process of making fast to the first post, and a sight of the apparatus enabled him to comprehend its working. There were four sheaves in the blocks used on the derrick; and the process of hoisting and lowering, when the rope was wound up on a small cylinder, like that on the machine, was very slow. But great power is obtained only at the expense of speed. Bolly Millweed had been up to see the loading of the posts on the caisson, and with two men at the winches it took hours to put a single one on board.

On his return he had a talk with Mr. Jepson, and the result of it was that a cylinder was rigged in the shop which could be worked with the engine. The distance of the derrick from the cylinder made it necessary to use a very strong rope, which Captain Gildrock selected for the purpose. A gong bell was rigged in the shop, to be rung with a cord.

There was something for every student to do, and the work of each one had been assigned to him. There were eight on the steamer, eight in the boats, two on the Goldwing, four on the caisson, one of whom was to put his whole mind upon the ringing of the gong bell, while Bolly Millweed, who was regarded as the architect and engineer of the work, had three assistants.

Bolly was a great man on this occasion, and his father and mother stood on Chowder Point, observing him with admiration. Doubtless Bolly "felt his oats," but anyone who had been with Captain Gildrock a while did not put on airs, and the architect conducted himself with becoming modesty. He was really entitled to a great deal of credit, for not only the plans, but many of the contrivances for setting the posts and raising the building had been originated by him.

Mr. Brookbine had insisted that it was next to impossible to set the foundations properly in the water. Bolly thought there was no great difficulty in doing this part of the work. He addressed himself to the problem, and asked the master carpenter to select for him two straight eight-inch timbers, thirty-two feet long. These were pinned together in the form of a steel square, though with arms of equal length. Braces were put on to keep the timbers exactly at right angles with each other.

At the heel and the ends of this floating square he set up three poles, straight and plumb, which were painted red. In the apparatus of the school there was a surveyor's compass, with sights upon it. With this instrument, used on the shore, he got the square in position, so that the heel was where the first post was to be set. His three assistants were in a boat, and moved the square by the signals he made. It was then moored to the bottom, so that it could not be readily moved.

The floating square was placed so that the outer corner would just touch the inner corner of the post when it was set. At this point the architect nailed a couple of laths so as to form two sides of a square of the size of the foundation stones. In the middle and at each end of the arms of the square, he also nailed laths, to mark the position of four other posts, one of which formed the second corner of the end of the building.

Mr. Brookbine commended the engineer, though he had some doubts about the floating square. The swinging of the caisson, or a slight rap from the stone in lowering it, would knock the square out of place. Bolly could only reply that the caisson must not swing, and the post must not touch the square.

At the order of the principal quarryman, Jim Alburgh rang the gong, the long rope straightened, and the end of the post began to rise. The square was three feet from one end of the caisson, which was moored at the other end from the west side of the bay. Bolly was in one of the boats with two of his assistants, the third being stationed on shore with the compass, sighting along the red poles, to give notice of any change in the position of the square.

When it was raised high enough, the post was lowered slowly into the water, a foot from the guides on the square. Bolly was nervous, and kept telling the quarrymen not to let the stone touch the guides or the square. The diver dropped into the water, and waded to the stone. When the end of it was nearly on the bottom, the post was swung into place so carefully that the marks were not disturbed. The diver chinked up the stone, and it was accurately plumbed.