For a model of this size, wooden planes are entirely practical and very simple to construct. Much depends upon the modeling of the planes and the smoothness of both of their surfaces. For the planes you will need two thin boards, one eight by two inches and another four by two inches, each one-eighth of an inch thick. Select a wood such as poplar or spruce, which will not split easily. The ends of the planes should be rounded in front and cut sharply away at the rear edge, as described elsewhere. If the wood will stand reduction without breaking, plane or sandpaper away the surfaces until they are about one-sixteenth of an inch thick. The planes may be flexed by steaming, but there is a still simpler method. Paint your planes with a thin glue or varnish, and while they are still wet and pliable, bend them to the desired shape. To shape them, procure a strip of wood one-quarter of an inch square, tack it to a board and bend the planes over it, and fasten them in position with brads driven about the edges and bent over to hold it down. The stick should be placed parallel to the entering edge and one-half an inch back of the line. This will give you planes flexed with a dipping edge. Later you will probably want to experiment by changing this curve, which is very easily done by bending over a stick of different size and altering its position. The model is driven by the propeller with the small plane forward. Attach the planes to the stick with the curved or entering edge forward by tying them with a rubber band. This will hold them in position and allow them to give when they fall. Slip the planes back and forth until the proper position has been found. A small block of wood may be inserted between the planes and the stick to raise the wing to the desired elevation. Practise throwing the model as a glider until it sails across the room on an even keel, when the motor may be installed. Directional stability may be gained by adding a vertical rudder. It may be made from a thin board similar to that used in the planes. Cut a piece two inches square and round off the corners, and shave to a knife edge. Attach this, curved edge downward, to the edge of the stick directly beneath the rear plane, taking care that the motor does not touch it. To complete the model, attach skids to the under surface at the front and rear. These should be of light reed, cane or bamboo, glued to the main frame and curved downward and backward like runners. MODEL WITH MINIMUM PLANE SURFACE.