l spoil the camber
(curvature) of the surface, and result in changing both the lift and
the drift at that part of the surface. Such a condition will cause the
aeroplane to lose its directional stability and also to fly one wing
down.

I cannot impress this matter of tension upon the reader too strongly.
It is of the utmost importance. When this, and also accuracy in securing
the various adjustments, has been learned, one is on the way to becoming
a good rigger.

6. Wire Loops.--Wire is often bent over at its end in the form of a
loop, in order to connect with a turnbuckle or fitting. These loops,
even when made as perfectly as possible, have a tendency to elongate,
thus spoiling the adjustment of the wires Great care should be taken
to minimize this as far as possible. The rules to be observed are as
follows:

(a) The size of the loop should be as small as possible within reason.
By that I mean it should not be so small as to create the possibility of
the wire breaking.

(b) The shape of the loop should be symmetrical.

(c) It should have well-defined shoulders in order to prevent the
ferrule from slipping up. At the same time, a shoulder should not have
an angular place.

(d) When the loop is finished it should be undamaged, and it should not
be, as is often the case, badly scored.

7. Stranded Wire Cable.--No splice should be served with twine until it
has been inspected by whoever is in charge of the workshop. The serving
may cover bad work.

Should a strand become broken, then the cable should be replaced at once
by another one.

Control cables have a way of wearing out and fraying wherever they pass
round pulleys. Every time an aeroplane comes down from flight the rigger
should carefully examine the cables, especially where they pass round
pulleys. If he finds a strand broken, he should replace the cable.

The ailerons' balance cable on the top of the top plane is often
forgotten, since it is necessary to fetch a high pair of steps in
order to examine it. Don't slack this, or some gusty day the pilot may
unexpectedly find himself minus the aileron control.

CONTROLLING SURFACES.--The greatest care should be exercised in rigging
the aileron, rudder, and elevator properly, for the pilot entirely
depends upon them in managing the aeroplane.

The ailerons and elevator should be rigged so that, when the aeroplane
is in flight, they are in a fair true line with the surface in front and
to which t