variations. When the motor slowed up or stopped, his ear would interpret
the sound made by the wind on the piano wires, the tension wires, the
struts and canvas; while his touch, still more sure, would know by the
degree of resistance of the controlling elements the speed action of the
machine, and his skillful hands would prepare the work of death. "In the
case of the bird," says the _Manual_, by M. Maurice Percheron, "its
feathers connect its organs of stability with the brain; while the
experienced aviator has his controlling elements which produce the
movement he wishes, and inform him of the disturbing motions of the
wind." But with Guynemer the movements he wanted were never brought
about as the result of reflex nervous action. At no time, even in the
greatest danger, did he ever cease to govern every maneuver of his
machine by his own thought. His rapidity of conception and decision was
astounding, but was never mere instinct. As pilot, as hunter, as
warrior, Guynemer invariably controlled his airplane and his gun with
his brain. This is why his apprenticeship was so important, and why he
himself attached so much importance to it--by instinct, in this case.
His nerves were always strained, but he worked out his results. Behind
every action was the power of his will, that power which had forced his
entrance into the army, and itself closed the doors behind him, a
prisoner of his own vocation.

He familiarized himself with all the levers of the engine and every part
of the controlling elements. When the obligatory exercises were
finished, and his comrades were resting and idling, he remounted the
airplane, as a child gets onto his rocking-horse, and took the levers
again into his hands. When he went up, he watched for the exact instant
for quitting the ground and sought the easiest line of ascension; during
flights, he was careful about his position, avoiding too much diving, or
nosing-up, maintaining a horizontal movement, making sure of his lateral