28 JULY 1923, Page 20

Mr. Weiss has dedicated this book to the memory of

his father, Jose Weiss, and its object may be given best in his father's words. "The question of flight is not one of great power ; it is proved by the motionless flight of the larger. birds,7

. " Gliding " is not to be confused with " soaring "—rising without the help of an upward wind current, an art which is still the exclusive property of the bird. The lack of this knowledge keeps us from a real conquest of the air. The power-driven aeroplane of the War has given. no help in the search for that knowledge.