By practice and experience a man can (if the wind be of the right strength) imitate the complete sailing flight of birds by availing himself of the s… - Otto Lilienthal

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.

The maintenance of equilibrium in forward flight is a matter of practice, and can only be learned by repeated personal experiment.

The increasing size of the apparatus makes the construction more difficult in securing lightness in the machine; therefore the building of small apparatus is to be recommended.