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. Artific…"

"The sailing flight of birds is the only form of flight which is carried on for some length of time without the expenditure of power."

"Gradual development of flight should begin with the simplest apparatus and movements, and without time complication of dynamic means."

"15 Thoughts on Flight from Otto Lilienthal"

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

"Actual practice in individual flight presents the best prospects for developing our capacity until it leads to perfected free flight."

"The supporting powers of time air and of the wind depend on the shape of the surfaces used, and the best forms can only be evolved by free flight through the air."

"The difficulty of rising into the air increases rapidly with the size of the apparatus. The uplifting of a single person, therefore, is more easily attained than that of a large flying machine loaded …"