The wood from which this model was made was taken from a bamboo fish-pole, such as may be bought anywhere for a dime. The pole was split up, and the suitable pieces whittled and planed down to the proper sizes, as given in the plans. In putting the framework of the planes together, it is well to notch very slightly each rib and spar where they cross. Touch the joint with a bit of liquid glue, and wind quickly with a few turns of sewing silk and tie tightly. This must be done with delicacy, or the frames will be out of true. If the work is done rapidly the glue will not set until all the ties on the plane are finished. Another way is to touch the joinings with a drop of glue, place the ribs in position on the spars, and lay a board carefully on the work, leaving it there until all is dry, when the tying can be done. It either case the joinings should be touched again with the liquid glue and allowed to dry hard. [Illustration: The Lynn model monoplane in flight, from below and from the rear.] The best material for covering these frames is the thinnest of China silk. If this is too expensive, use the thinnest cambric. But the model will not fly so far with the cambric covering. The material is cut one-fourth of an inch too large on every side, and folded over, and the fold glued down. Care should be taken that the frame is square and true before the covering is glued on. The motive power is produced by twisting up rubber tubing. Five and three-quarter feet of pure rubber tubing are required. It is tied together with silk so as to form a continuous ring. This is looped over two screw-hooks of brass, one in the rear block and the other constituting the shaft. This looped tubing is twisted by turning the propeller backward about two hundred turns. As it untwists it turns the propeller, which, in this model, is a “traction” screw, and pulls the machine after it as it advances through the air. [Illustration: Details and plans of the Harold Lynn model monoplane. _W_, tail block; _Y_, thrust-block; _S_, mounting of propeller showing glass bead next the thrust-block, and one leather washer outside the screw; _B_, glass bead; _C_, tin washer; _M_, _M_, tin lugs holding axle of wheels.] The propeller in this instance is formed from a piece of very thin tin, such as is used for the tops of cans containing condensed milk. Reference to the many illustrations throughout this book showing propellers of flying machines will give one a very good idea of the proper way to bend the blades. The mounting with the glass bead and the two leather washers is shown in detail in the plans. [Illustration: Method of forming propeller of the laminated, or layer, type. The layers of wood are glued,in the position shown and the blades carved out according to the sections. Only one blade is shown from the axle to the tip. This will make a right hand propeller. ]