"Of all the men who attacked the flying problem in the 19th century, Otto Lilienthal was easily the most important. … …"

"The contrivances which are necessary to counteract the wind effects can only be understood by actual practice in the …"

"The supporting powers of time air and of the wind depend on the shape of the surfaces used, and the best forms can on…"

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

"Experience alone can teach us the best forms of construction for sailing apparatus in order that they may be of suffi…"

"By practice and experience a man can (if the wind be of the right strength) imitate the complete sailing flight of bi…"

"Actual practice in individual flight presents the best prospects for developing our capacity until it leads to perfec…"

"To design a flying machine is nothing. To build one is something. But to fly is everything."

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

"I, too, have made it a lifelong task of mine to add a cultural element to my work, which should result in uniting cou…"