One of the simplest methods consists in providing a universally pivoted hand lever and pivoted foot lever. The latter operates the rudder through two crossed cables which connect the rudder tiller with a cross piece on the spindle of the rudder bar. Upon releasing the pressure on the left foot, the machine turns to the left, and acting similarly with the right foot the machine turns to the right. The general method for controlling the elevators is by cross wires which pass from their tillers to the ends of a fore and aft bar passing through the centre of the universal action of the vertical centred rod. One wire cables to the balancing flaps, or the warping cables are attached to a horizontal crosspiece, whose axis is set transversely in the machine and passes through the same centre of motion of the control rod. In this the method is such that a forward or backward movement of the rods rocks the fore and aft bar and pulls on the elevator cables to make the machine go up or down. A side movement of the control rod rocks the traverse bar and pulls on the warp or flap cables. Another control system consists in replacing the universally pivoted rod by a simple pivoted rod, the pivoting of which, fore and aft, controls the elevators, and having a handwheel and drum upon which the warp or flap cable is wound or unwound. The winding in and out of the balancing cables has been likened to the wheel control system of a motor boat or small steamer. By duplicating the cables on single control the safety of the machine is enhanced, and by duplicating the controls both the pilot and the passenger are given power. This duplication is, of course, most useful in the event of the pilot becoming incapacitated from action. The experienced pilot, in virtue of his keen sense of touch, has an almost infallible guide as to what the air is doing with his machine. His hand is upon his lever, holding the elevator in the desired position, and the slightest increase or decrease in the speed of the air causes an increase or decrease of the lever’s pressure against his hand. ‘He has his hand on the machine’s pulse, and feels instantly any change in its conditions.’ In the event of the elevator pulling, he knows that the wind is increasing and that there is a call for reducing the ‘up-starring action’ of the elevator. If, on the contrary, the wind slackens, his lever gives toward him and is drawn in a little, till the normal tension is gained. The ‘feel’ of the lever tells him what to do, and with practice the necessary correcting movements are made by instinct.