THE HISTORY OF AIRPLANES, AND THEIR MODERN COMMERCIAL USE Before the end of the 18th century, few people had applied themselves to the study of flight. One was Leonardo da Vinci, during the 15th century. Leonardo was preoccupied chiefly with the bird flight and with flapping-wing machines, called ornithopters. His aeronautical work lay unknown until late in the 19th century, when it could furnish little of technical value to experimenters but was a source of …showed first 75 words of 1394 total…

…showed last 75 words of 1394 total…