The framework is light and is spread well at the rear. The two spines are 3/16” × ¼” × 33” and they come together at the forward end, the vertical section being ¼”. Nine inches back from the front end is a cross-piece that is just under ⅛” in thickness, ¼” wide and 2½” long. The cross-piece is on the upper side of the spines, and is fastened by a small ¼” brad, is lashed with thread and coated with glue or shellac. The other cross-piece is 1” forward from the rear end, is of the same dimensions in cross-section as the forward piece, but is 8” long and is secured in the same manner as the other, see Fig. 234. The framework is further stiffened by two fine wires that run diagonally from the ends of one cross-piece to the ends of the other. They are secured to the inside vertical face of the spines by means of small pieces of tin that have two small holes, one at each end, the one receives a ¼” brad that is driven into the spine, while the wire is attached to the other hole. The little pieces of tin are about 3/16” × ½” and are lashed to the spine in addition to the fastening by the small brad. This kind of fastening prevents slipping, also the cutting into the wood, either of which would destroy the efficiency of the wire. In order to increase the tension of the wire, a small turn-buckle is inserted, Fig. 235. [Illustration: FIG. 238.] [Illustration: FIGS. 239, 240.] [Illustration: FIG. 241.] The bearings for the propeller shafts are lashed to the outside face of the rear end of each spine, Fig. 236. The bearing is a piece of brass 1/16” × ¼” × 1”, and is bent to a right angle at the middle. A small hole is drilled for a brad into the side of the spine and the other hole is drilled to receive the propeller shaft, which is 1/16” steel wire. The shaft is bent into a hook after it passes thru the bearing. To prevent the rubber of the motor from touching the steel wire, which is injurious to the rubber, a small rubber hose is slipped over the hook. In this model, the propellers are pieces of veneer steamed and pressed into the spiral shape. The propeller shaft then is bent around the center of the propeller, has two little washers between this and the bearing, after which comes the covered hook, see Fig. 237. A piece of tin ½” wide and 1¼” long is folded about the propeller before the shaft is bent around. The shaft is soldered to the tin, the tin being secured by two small brads and shellac. A small tin rudder with a small fold in its upper portion may be slipped over the back cross-piece, Fig. 238. The fore plane is made of very thin spruce, shaped like Fig. 239, and is bent up almost like a butterfly’s wings, Fig. 240. The wood is less than 1/16” thick. A double hook as anchors for the double motors, is bent and secured about the fore end of the framework. The hooks are covered with the rubber hose, the same as the propeller shaft, Fig. 241. [Illustration: FIG. 242.]