While growing up in Cedar Rapids, Iowa, Milton Wright, the Wright Brothers' father, liked to purchase toys for his sons that he hoped would stimulate their imagination. One of the most memorable gifts was a toy helicopter that was designed by the French aeronautical experimenter Alphonse Penaud. Milton gave his sons this gift in 1878, and, though it was a simple device with a stick bound to a four-blade rotor set in a spindle, it had the intended effect-it caused them to dream. Twenty-five years separated the gift of this toy and their invention of the airplane, yet the Wright brothers were...