Procure or make a small model boat, 12 or 18 in. long, and place in the hold one or two cells of dry battery. Make a small platform in the stern and mount on it a small battery motor with the shaft parallel with the length of the boat and in the center. Directly above and parallel with the motor shaft run a shaft - a hatpin will do - in bearings fastened to the deck. Attach a drive pulley directly over the pulley on the motor and belt it up with a cord or rubber band. Purchase or make a propeller blade and attach it to the rear end of the shaft. A switch can be located on the deck for controlling the motor. - Contributed by Geo. B. Riker, Ft. Wayne, Ind.

Ill: The Aerial Propeller is Driven by a Small Battery Motor Placed in the Boat