The San Francisco call., 1910-08-21

apparatus is one that advances
through the air after having mo-
tion impaired to it by the propelling
energy Of the hand. With no source
of power carried in the air. as is the
case in machines operated, for instance,
by twisted rubber, the duration of fight
is, naturally, more or less brief.
These "gliders," as they are called,
however, are valuable in teaching the
proper balance of models, because sur
faces that glide well without power will
fly well when propeller is added.
Probably the easiest made but most
successful small glider ever devised is
that which consists of a single middle
stick across which at each end is
fastened a thin strip Of wood or paste
board small vertical rudder being at
tached to the stick either under or at
the rear of the larger of the two cross
surfaces
1t has been found that with this type
Of glider-i e., when no motive power
is used, the best results are obtained
with the small plane In front. When
propeller is used it is placed in front
Of the large surface, which then be-
comes the leading plane, and the verti-
cal rudder is placed under the small
plane in the rear.
The proper material of which to make
the surface in order to obtain the long
est fight is straight grained spruce
about one e-sixteenth inch thick, the
edges being beveled until almost sharp,
ha oh tai
with cardboard especially if 1t is heavy.
One boy, not to be deferred by lack or
material, said he intended to try strip
from a beach basket. The stick that
supports the planes should be straight
grained spruce Cor ash), one-quarter by
three -sixteenths of an inch in diameter.
small wire may be twisted around
the stick in front of the small plane
and turned back, to act as shock ab-
sorber and protect the leading plane.
(See e. Fig. 80
Material and parts for models of all
kinds are now sold by number of
dealers but this article is written in an
endeavor to help those who are not yet
in touch with such sources of supply.
AS every boy can certainly get
pasteboard box, a piece of string,
stick about II inches long and one
quarter inch in diam eter, four ordinary
pins and have at least temporary use of
a knife or pair of scissors, if he will
add a stock of patience and persever-
ance he can have a glider If he desires.
BY adding a little more work and an
outlay of 10 cents for a pair of pliers
and some rubber bands and perhaps l
cent for a stick, he may have power
driven flying model.
If square stick is not available buy
a dowel, which is a round stick some
times used by carpenters and up
holsterers instead OF a nail They are
made of spruce, about SO inches long.
and from three -sixteenths OF an inch
to three quarters of an inch in diam
eter. These sticks may be obtained
from hardware stores. door and window
molding dealers. and carpenters, at
cost Of l cent each for the smaller
sizes. While we do not pretend that
a round stick will be as satisfactory as
a square one, it will be better than no
stick, especially If ii is fattened with
a knife where the edges of the planes
rest, as this will enable them to remain
in place better than on the rounded
surface.
1t must be borne in mind. however,
that all models, no matter what make,
must be "trued up" after each flight.
Having procured, say, a dOwe Cor its
substitute) one-quarter inch in diam
eter cut off length of one and one
half inches from the most perfect end,
lay carefully aside, and cut in half the
remaining piece OF dowel and use one
half OF IL for glider. the other half for
power machine.
Cut from very stiff cardboard or
pasteb0ard box 0f thin wood can not be
had) one piece Is inches long and 23s
wide, 'for rear supporting plane; one