The Propeller-shaft requires a short piece of wire with one end bent into a hook (F, [Fig. 56]). Stick the straight end of this shaft through one hole in the propeller, and the hooked end through the other hole, then twist the hooked end over on to the main part of the shaft, as shown in [Fig. 57]. Make a tight twist so the propeller will be held perfectly rigid on the shaft.
The Bearing Plate G ([Figs. 54] and [58]) supports the propeller. Cut it out of a piece of tin 1½ inches wide by 3 inches long, bend it in half crosswise to give it stiffness, and then bend it lengthwise to the angle shown so it will fit over the slanted stern of the boat. Punch two holes through the upper end for nailing the plate to the stern, and a hole at the lower end for the propeller-shaft to run through.
For a Thrust Bearing, slip a couple of beads over the propeller-shaft, between the propeller and bearing plate G. Probably you can find glass beads in your mother's button bag.
Fig. 54.—Longitudinal Section of Assembled Motor-boat.
Figs. 55-59.—Details of Propeller.
Fig. 60.—Rubber-band Motor.
After slipping the beads on to the shaft, and sticking the shaft through the hole in bearing plate G, bend the end of the shaft into a hook; then screw a small screw-hook into the bottom of the hull, at the bow end (I, [Fig. 54]), and you will be ready for
The Rubber-band Motor. Rubber-bands about 1½ inches in length are best for the purpose. Loop these together end to end ([Fig. 60]) to form a strand that will reach from hook I to the hook on the propeller-shaft; then form three more strands of this same length, and slip the end loops of all four strands over the hooks.
To Wind the Motor, give the propeller about one hundred turns with your finger; then, keep hold of the propeller until you launch the boat.