NO. 3 LANGLE1 MEMOIB ON" MECHANICAL PLIGHT 213 



bridle (11) to the upper side of the Penaud tail (12). The other end of the piston 

 rod (3) passes through the head in the oilier end of the cylinder, and has con- 

 nected to it a cord (14) which passes over the pulley (15) fastened to the tube 

 (2), whence it, is continued over the pulley (16) and is joined to the spring ( 17), 

 which is connected by the bridle (18) to (lie lower side of the tail. Mounted 

 on top of the cylinder (1) is a valve chamber (20) having ports Leading to the 

 two ends of the cylinder. Mounted in the valve chamber is a rocking valve sur- 

 rounded by a bushing having ports in it, and to which is fastened a rod (25) 

 which passes through the said valve and the head of the valve chamber. Fastened 

 to the rod (25) of the bushing is a lever (26), which by means of the link {27) is 

 connected to the piston rod (3). Fastened to the rocking valve is a roil ( 28) which 

 telescopes over the rod (25) and also passes through the same head of the valve 

 chamber, and carries at its outer end a pendulum (29) on the lower end of 

 which is the bob (30). 



If steam or any other fluid under pressure is furnished to the valve cham- 

 ber through the pipe (31), none will be admitted to the cylinder so Ion-- as the 

 pendulum is vertical or at right angles to the axis of the cylinder; and the tail 

 will be in its normal position, which we will suppose to be an upward inclina- 

 tion of five degrees. If, now, the front of the machine be depressed, thereby 

 causing the pendulum to move to the right, such movement of the pendulum 

 will cause the valve to open, admitting fluid to the left-hand end of the cylin- 

 der. This, acting on the piston, will force it towards the right, which, by means 

 of the cord, will cause the angle of the tail to he increased, thereby cans 

 ing the rear of the machine to be depressed and the front to be raised. But as 

 soon as the piston begins to move under the action of the fluid pressure it simul- 

 taneously moves the bushing which surrounds the valve by means of the con- 

 necting links and levers, so that as soon as the piston has moved a distance 

 proportional to the amount that the valve has been opened by the pendulum, 

 it causes the bushing to shut off the port and thus prevents further fluid en- 

 tering the cylinder. As soon as the aerodrome responds to the action of the 

 tail the pendulum will, of course, begin to move back to its normal position 

 of perpendicularity to the cylinder, and will then open the valve to the other 

 port, thereby causing fluid to pass into the opposite end of the cylinder. This 

 fluid acting on the piston will move it in the opposite direction and thereby 

 cause the tail to he drawn back to its normal position at the same time that 

 the pendulum gradually reaches its normal position, owing to the return of 

 the aerodrome to its normal position. In the explanation given above it was 

 assumed that the slidable tube (2) was in a fixed position. It was planned to have 

 the equilibrium normally maintained automatically and at the same time permit 

 the operator to modify the automatic control and even to assume full manual 

 control. To secure this, the slidable tube (2) was connected at each end to an 



