Note 41 — Chapter III · EXPERIMENTS WITH MODELS

In fact the setting of the tail at a negative angle and fastening it to the frame by an elastic or spring connection was only begun in 1896, and while it proved to be the key to the solution of the problem of automatic longitudinal stability, yet it was not at that time so recognized, although the first real test of the aerodromes after the elastic connection and negative angle of the tail were adopted resulted in the epoch-making flight of No. 5 on May 6. By comparing the angle of the tail on No. 5 in Plate 27A, Part I, with the angle of the tail on No. 6 in Plate 27B, Part I, it will be seen that while the first had an angle of much less than 5 degrees, the latter had an angle of about 15 degrees. But the wooden springs changed so that it was not accurately known what the angle really was at the time at either flight in 1896.