2 inches above the lower plane, and 4 feet from the central axis of the machine. The propellers, designed by Capt. Carden, are of solid wood, 7 feet in diameter, 7 feet 6 inches pitch, each weighing 21 lb. The chassis comprises two main wheels, with a small wheel-and-skid fore and aft. The system of controls is extremely simple. The trailing edge of each extremity of the upper plane forms a hinged flap, measuring 7 feet 2 inches by 1 foot 9 inches. These are independently controlled by two levers, one on either hand of the pilot a couple of mirrors allow the pilot to ascertain the working of the steering-flaps when in flight. The throttle control is fixed to the right-hand lever. On several occasions, while flying on this machine, the pilot used both hands for writing and making notes, leaving the machine uncontrolled, and came down with his hands raised above his head. Germany has many forms of aëroplanes, and these will be treated of in the next chapter. [Illustration: _AVIONS ALLEMANDS_ TIREZ sur ces Appareils MONOPLAN TAUBE TAUBE MONOPLAN GOTHA GOTHA MONOPLAN RUMPLER RUMPLER BIPLAN ALBATROS ALBATROS ZEPPELIN A DIAGRAM ISSUED BY THE FRENCH WAR OFFICE FOR THE GUIDANCE OF THE MEN IN THE TRENCHES. It gives a silhouette of some Aëroplanes and an Airship in the German service, and bears the injunction--“German Aëroplanes--fire on these machines.”] CHAPTER VIII GERMANY’S AËROPLANE EQUIPMENT The history of Germany’s developments in aërial navigation on the heavier-than-air principle during the last few years is the history of preparation for war. France was, indeed, the first nation to realise that though there was a war use for the aircraft on the lighter-than-air principle there would, in time, be no comparison between the advantages of aëroplanes over airships.