For Hal, the lessons seemed to go on interminably about the valve, the piston, ignition, spark, carburetor. He endured all the miseries of a brilliant pianist given to performing by "ear" who is set down in a primer class to learn note reading and scales. He began to feel that the outside of the ship, wing beauty, pull of propeller, soaring power, were what had fascinated him--not greasy, grimy intricacies of engines. In fact, heretofore engines had not entered very much into his aerial plans. He had known how to crank them, and fly them, and that had seemed enough.