The second method of trussing is considerably harder to true up than the first, since when one diagonal of a rectangle is tightened, the other must be loosened. But since it makes an exceedingly firm and rigid structure, it may be well recommended to those who care to undergo the added expense and labor involved by the extra turnbuckles and wires.
To take the glider apart, first remove the bolts holding the rudder beams in the sockets on the machine. Then unfasten the wires which brace the rudder to the machine by loosening the turnbuckles until the spokes and nipples unscrew and come apart. The rudder may now be removed from the machine.
Next take off all the nuts on the eye bolts in the lower plane and pull the eyebolts out of the sockets. The two planes will then come apart. Remove the stanchions by pulling them out of the sockets. The two planes are then laid one on top of the other and will occupy very little room.
CHAPTER IV. Gliding.
The first words which may well be said upon this subject are to emphasize caution. But by this I do not wish to imply that gliding is exceedingly dangerous. Neither do I by caution mean timidity but rather judgment and common sense.
Canoeing is generally considered a safe sport, but who would think of canoeing on the ocean in a storm. It is exactly the same extreme to glide from a very high object, or experiment in a high wind.
The atmosphere near the earth is a mass of whirling and swirling currents which are constantly rising and falling and become very pronounced in a high wind. Even in a comparative calm these eddy currents exist but of course not to a dangerous degree. Evidence of this may be seen by watching the little dust particles floating in the air and made visible by a sunbeam coming through the window of a quiet room. Although the sense of feeling cannot detect the smallest air current, these little particles are whirling around and constantly changing their direction.
When the wind strikes some natural object such as a tree or a stone, the streams of air divide, part of them passing to the sides and part going over the top. The air begins to divide some distance before it reaches the object and the result is a rising current on one side and a falling current on the other.
These currents are the bugbears of aviators for when one end of their machine passes into such a current that end rises or falls depending whether or not the current is rising or falling.
