We returned home, after these experiments, with the conviction that sailing flight was not the exclusive prerogative of birds.

One can get a proper insight into the practice of flying only by actual flying experiments. . . . The manner in which we have to meet the irregularities of the wind, when soaring in the air, can only be learnt by being in the air itself. . . . The only way which leads us to a quick development in human flight is a systematic and energetic practice in actual flying experiments.

No one can realize how substantial the air is, until he feels its supporting power beneath him. It inspires confidence at once.

Artificial flight may be defined as that form of aviation in which a man flies at will in any direction by means of an apparatus attached to his body, the use of which requires personal skill. Artificial flight by a single individual is the proper beginning for all species of artificial flight, as the necessary conditions can most easily be fulfilled when man flies individually.

All flight is based upon producing air pressure, all flight energy consists in overcoming air pressure.

Of all the men who attacked the flying problem in the 19th century, Otto Lilienthal was easily the most important. ... It is true that attempts at gliding had been made hundreds of years before him, and that in the nineteenth century, Cayley, Spencer, Wenham, Mouillard, and many others were reported to have made feeble attempts to glide, but their failures were so complete that nothing of value resulted.

But we must admit the possibility that continued investigation and experience will bring us ever nearer to that solemn moment, when the first man will rise from earth by means of wings, if only for a few seconds, and mark that historical moment which heralds the inauguration of a new era in our civilization.