Fig. 133.—Screw Eye
Fig. 134.—Rear Elevation
The floats are three in number, and are of equal dimensions, 6 in. by 2 in. by ¾ in. at the greatest depth, which is about three parts of the way from the front. To construct the floats, two side pieces of ¹/₂₀-in. birch are cut to the shape given in Figs. [130] to [131A], and these are nailed to the ends of a piece of whitewood measuring 2 in. by ¾ in. by ⅛ in. Joining each end of the side pieces is a piece of whitewood, cut to fit so as to form a nice entry, the forward piece being flat on top and the rear piece flat on the bottom. At the place marked G ([Fig. 130]) there is an additional piece to strengthen the float and keep the silk covering taut. Running from front to back there is a ⅛-in. by ¹/₁₆-in. strip of bamboo to keep the silk from sagging when running on the water. The front floats are nailed to the bamboo cross-piece, and the adjustment is made by bending the small pieces of piano-wire F. The rear float attachment is shown by [Fig. 132], and the adjustment is made in the same way. The wire is attached to the floats with small hooks as shown by [Fig. 133], these being screwed into the distance pieces of the float. The connecting wires are bound to the fuselage with strip silk and glued. The flat portion of the under-side of the front floats has an angle of incidence of 1 in 6, the rear float angle being 1 in 8.
Another type of float is quite practicable, if preferred.
Fig. 135.—Model Hydroplane
The propellers are 10 in. in diameter with a pitch of 23 in., and are carved from a solid piece of mahogany. The blades are glasspapered to a thickness of about ¹/₂₀ in., and are strengthened with silk stuck on one side.
The floats are covered with the same proofed silk as the planes; but to ensure complete imperviousness to water, coat with a mixture of 2 parts of boiled oil and 1 part of gold size. [Fig. 134] is a rear elevation.
The main plane rests flat on the fuselage, and is held in place by means of two 9-in. by ⅛-in. by ¹/₁₆-in. pieces of bamboo, which are secured to the framework with elastic. This method allows the plane to be readily removed. There are six strands of thick ¼-in. strip elastic to each propeller, and the number of turns given is about 900 when well lubricated.