To construct such an A type frame 2 main sticks to serve as frame side members are necessary and are made from spruce. Each member should be 36″ in length, ³⁄₈″ in depth by ¹⁄₄″ in width. By rounding the edges and smoothing the various surfaces with sandpaper streamline effect will be secured and will add to the efficiency of the machine as well as to its appearance. When the side members are placed in A formation the extremity of the sticks at which they meet should be so tapered in the inner sides that when they meet and are permanently fastened the result will be a continuance of the general streamline effect. The permanent fastening of the frame side members at the point of the A may be accomplished by using either strong fish glue or better, a good waterproof glue and then have the jointure reinforced by securing a piece of ³⁄₃₂″ steel wire 3″ in length and placing the center of it at the point of the A, afterwards bending the wire along either outer edge of the frame side members, putting as much pressure on the wire as the strength of the structure will permit; after this the reinforced jointure should have threadwound around it to insure even greater strength. About ¹⁄₂″ of the wire on each side of the point should be left clear and afterwards turned into a loop as shown indiagram 6, for the purpose of attaching the hooks that hold the rubber strands. To hold the side members apart at the rear end and for a propeller brace, a piece of bamboo 10″ long, ¹⁄₈″ thick by ¹⁄₂″ in width is required and this should be fastened to the extreme rear ends of the frame side members, allowing the propeller brace to protrude on either side 1¹⁄₂″ as illustrated. To put the propeller brace in position a slot ¹⁄₂″ deep by ¹⁄₈″ wide should be cut into the rear ends of the frame side members for the reception of the propeller brace. After the brace has been placed in position the outer edge should come flush with the rear ends of the side members. To hold the brace in place thread and glue should be used in the same manner as described for the point of the frame side members. Between the point of the frame and the propeller brace two bamboo pieces, one 9″ long and another 2¹⁄₃″ long, should be used as braces for the general strengthening of the structure. The longest piece should be secured across the top of the frame about 9″ from the rear and the shorter piece about 9″ from the point.