"This model is made of soft pine and mahogany. The ribs are to be twenty-one inches from the centre of one to the centre of the next one. What looks to you like the space between the timbers, or ribs, is pine. The mahogany strips, which are comparatively narrow, represent the timbers. The pieces are transverse sections of the hull, made separately and put together.
"This is the stem," continued the principal, detaching the piece from the model. "A model of it is to be made of soft wood, enlarged to twelve times the size of this piece. Removing a piece of the pine, we come to a mahogany section. As the bow is round, these sections radiate from a shorter line on the keel than the horizontal line above it on the deck would be."
The captain held up one of these diagonal sections, the top or deck part of which was in the shape of a triangle with a very acute angle. The parts were in pairs, one belonging on each side of the bows.
"The outer edge of this half section gives the shape of the bow where this piece belongs. If you lay it on a smooth board, you can mark from it the exact curve of the timber which is to go where this piece is taken out. It must be enlarged to twelve times the size of the section. Of course the outer surface of the section only is of any use to you; but having obtained the exact shape of the outside, the rib may be made of any width and thickness we wish."
The principal removed several of the diagonal half sections, all of which were to be treated like the first one. At the widest part of the model he came to pieces which were of uniform thickness. These were also in pairs, separated on the vertical plane above the keel. The lines of the outer surface in these half sections were to be transferred and enlarged as before, and the mould or pattern was to be made from them.
In this manner the model was pulled to pieces, and from the edges of the transverse sections the shape of the craft was to be obtained. The stern-post, stern-knees and transoms were to be shaped in the same way. The captain stated that the model represented the craft after she was planked, and it would be necessary, in drafting the moulds, to allow for its thickness.
Mr. Jepson then took the platform and explained in what manner the outlines of the half sections were to be enlarged. To give all the details would take a whole volume, and doubtless it would be very dry reading to most young people. Only an idea of how the work was to be done can be given, and those who wish to build such a craft as the Lily, or even a boat or a canoe of a third of her length, need full drawings and very minute explanations.[A]
These lectures used up the rest of the afternoon. The next day was devoted to making the moulds. At the end of ten days the frame was ready to set up. The keel was laid down at an angle of three-quarters of an inch to the foot, so that it would readily slide off when the time came to launch it. The boys had been studying on the subject, and the principal had supplied the library with all the available works. They labored very hard because they were very deeply interested.
Setting up the frame was an exceedingly exciting labor with them; but when it was up they found the shape corresponded with the model. Some had done their work better than others, and here and there it was necessary to do considerable fitting. In another week the frame was ready for the planking. Captain Gildrock gave frequent lectures on the proper methods of doing the work, and explained the construction of larger vessels than the Lily.
A part of the Champlain mechanics, as they still called themselves, worked in the shop, and a part in the building-shed. There were a great many bolts of iron and copper, and a great many metal plates, braces and straps to be prepared, which gave abundant employment to the machinists, who had been instructed by the head of this department in forge-work, as well as filing and turning.