After getting the machine snugly up under the arm pits, face the wind, elevate the front of the machine slightly, run a short, distance and leap into the air. If you are in the right position you will sail to the foot of the slope in free flight. To land, push yourself towards the back of the machine, so that the glider tips upward slightly in front. It will then rise slightly but loose its momentum and slowly settle so that you drop gently on your feet.
Balancing is accomplished in flight by moving the legs and body towards that side which is highest.
Fig. 30—Lines of Flight
Shifting the centre of gravity by swinging, the legs forward or moving the body in the same direction, will naturally cause the centre of gravity to assume a forward position, and being a force exerted downwards, the machine will dip and descend. A reverse movement of the centre of gravity will cause the front of the machine to tip up and ascend. But if the upward slant is continued too long the glider will loose its forward velocity and settle.
The tendency is always to place the weight of the body too far to the rear. After a little experience the experimenter will learn how to dip his machine to acquire velocity for a rise and to otherwise handle it.
Fig. 29 illustrates two lines of flight in their successive stages. At 1 the operator is running along the top of the hill and the dotted line from 1 to 2 represents his course immediately after leaving the ground. In case the weight is back slightly too far and is not shifted much during the glide, the machine will follow the upper line indicated by 3, 4, 5 and land at 6. If instead, at 2, the body is moved forward, the machine will travel down as shown by 7 and approach the earth. Having attained considerable velocity at S, the operator moves back and the machine rises, travels upwards as at 9 and then settles about at the point 6. This latter line of flight is to be preferred since the machine does not rise quite so high in the air and moreover has more velocity so that the operator may rise if necessary.
If during a flight a gust of wind strikes the machine from the front, it will accelerate its vertical motion in regard to the earth. That is, if the machine is already rising it will rise higher and if descending will fall more quickly. A gust of wind from the rear will cause the machine to drop suddenly and so always glide into the wind.
CHAPTER V. Remarks.
In a little booklet such as this it is even impossible to cover the subject of gliding flight fully much less power driven aeroplanes, but a short description of such a machine built by the author, assisted by Mr. Harold Dodd and Mr. Safford Adams will no doubt interest many since it has been used successfully as a glider in towed flights.