high-speed machines, which are used chiefly for racing purposes,
the planes have very little camber. This was particularly
noticeable in the monoplane piloted by Mr. Hamel in the Aerial
Derby of 1913: the wings of this machine seemed to be quite
flat, and it was chiefly because of this that the pilot was able
to maintain such marvellous speed.

The scientific study of the wing lift of planes has proceeded so
far that the actual "lift" can now be measured, providing the
speed of the machine is known, together with the superficial area
of the planes. The designer can calculate what weight each
square foot of the planes will support in the air. Thus some
machines have a "lift" of 9 or 10 pounds to each square foot of
wing surface, while others are reduced to 3 or 4 pounds per
square foot.



CHAPTER XXV
The Wright Biplane (Cont.)

The under part of the frame of the Wright biplane, technically
known as the CHASSIS, resembled a pair of long "runner" skates,
similar to those used in the Fens for skating races. Upon
those runners the machine moved along the ground when starting to
fly. In more modern machines the chassis is equipped with two
or more small rubber-tyred wheels on which the machine runs along
the ground before rising into the air, and on which it alights
when a descent is made.