For those who really wish to build a flying machine that will actually fly with very little experimental work, I have given an outline sketch sufficiently explicit to enable a skilful draughtsman to make a working drawing in which Fig. 40 is a front elevation, Fig. 41 a side elevation, and Fig. 42 a plan. Fig. 41, _a_, _a_, shows the two forward or main aeroplanes; _b_, _b_, the two after aeroplanes, which are smaller and shorter; _c_, the rudder; _d_, the forward horizontal rudder; _e_, the screw; _f_, the motor; _g_, the condenser or cooler; _h_, the steering gear; _i_, and _j_, atmospheric buffers; _k_ and _l_, wheels attached to a lever pivoted to the body of the machine; _q_, a shield for protecting the screw. It will be observed that the framework is extremely long, and, consequently, the distance between the aeroplanes is very great; but it should be borne in mind that the longer the machine, the less any change of center of lifting effect, as relates to the center of gravity, will be felt. Moreover, it is much easier to manœuvre a machine of great length than one which is very short, because it gives one more time to think and act. If the length was infinitely great the tendency to pitch would be infinitely small. I have shown a steering gear consisting of a lever with a handle _n_, arranged in such a manner that it moves both the vertical rudder _c_, and the horizontal rudder _d_, so that the man who steers the machine has nothing to think of except to point the lever _n_, _p_, in the direction that he wishes the machine to go. This lever is mounted on a universal joint at _h_, and is connected with suitable wires to the two rudders. In order to prevent shock when the machine alights, it is necessary to provide something that is strong and, at the same time, yielding, and able to travel through a considerable distance before the machine comes to a state of rest. In the machines which I have seen on the Continent, a very elaborate apparatus is employed, which is not only very heavy, but also offers a considerable resistance to the forward motion of the machine through the air. It consists of many tubes, very long levers and heavy spiral springs, etc. In the device which I am recommending, all this is dispensed with, and something very much simpler, cheaper, and lighter is substituted. Moreover, with my proposed apparatus a certain amount of lifting effect is produced. The levers _k_, _k_, to which the wheels are attached, should be of thin wood, light and strong, and say about a foot wide, strongly pivoted to the frame and held in position by an atmospheric buffer made of strong and thin steel tubing, shown in section (Fig. 51). These pneumatic cylinders may be pumped up to any degree, so as to support the weight of the machine, and then, as it comes down, the compression and escape of air arrest its motion. The condenser _g_, is placed in such a position that it will act even while