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.
Otto LilienthalArtificial 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.
Otto LilienthalBut 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.
Otto Lilienthal