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frame pieces so the sleeve will slip on。
Push the sleeve well back out of the way。 Cover the
tongue thoroughly with glue； and also put some on the
inside of the groove。 Use plenty of glue。 Now press
the tongue into the groove； and keep the ends firmly
together until the glue is thoroughly dried。 Rub off the
joint lightly with sand…paper to remove any of the glue
which may have oozed out； and slip the sleeve into place
over the joint。 Tack the sleeve in position with small
copper tacks； and you will have an ideal splice。
The same operation is to be repeated on each of the
four frame pieces。 Two 20…foot pieces joined in this
way will give a substantial frame； but when suitable
timber of this kind can not be had； three pieces； each 6
feet 11 inches long； may be used。 This would give 20
feet 9 inches； of which 8 inches will be taken up in the
two joints； leaving the frame 20 feet 1 inch long。
Installation of Motor。
Next comes the installation of the motor。 The kinds
and efficiency of the various types are described in the
following chapter （IX）。 All we are interested in at
this point is the manner of installation。 This varies
according to the personal ideas of the aviator。 Thus one
man puts his motor in the front of his machine； another
places it in the center； and still another finds the rear of
the frame the best。 All get good results； the comparative
advantages of which it is difficult to estimate。 Where
one man； as already explained； flies faster than another；
the one beaten from the speed standpoint has an advantage
in the matter of carrying weight； etc。
The ideas of various well…known aviators as to the
correct placing of motors may be had from the following：
WrightsIn rear of machine and to one side。
CurtissWell to rear； about midway between upper
and lower planes。
RaichIn rear； above the center。
Brauner…SmithIn exact center of machine。
Van AndenIn center。
Herring…BurgessDirectly behind operator。
VoisinIn rear； and on lower plane。
BleriotIn front。
R。 E。 P。In front。
The One Chief Object。
An even distribution of the load so as to assist in
maintaining the equilibrium of the machine； should be
the one chief object in deciding upon the location of the
motor。 It matters little what particular spot is selected
so long as the weight does not tend to overbalance the
machine； or to 〃throw it off an even keel。〃 It is just
like loading a vessel； an operation in which the expert
seeks to so distribute the weight of the cargo as to keep
the vessel in a perfectly upright position； and prevent a
〃list〃 or leaning to one side。 The more evenly the cargo
is distributed the more perfect will be the equilibrium of
the vessel and the better it can be handled。 Sometimes；
when not properly stowed； the cargo shifts； and this at
once affects the position of the craft。 When a ship
〃lists〃 to starboard or port a preponderating weight of
the cargo has shifted sideways； if bow or stern is unduly
depressed it is a sure indication that the cargo has shifted
accordingly。 In either event the handling of the craft
becomes not only difficult； but extremely hazardous。
Exactly the same conditions prevail in the handling of a
flying machine。
Shape of Machine a Factor。
In placing the motor you must be governed largely by
the shape and construction of the flying machine frame。
If the bulk of the weight of the machine and auxiliaries
is toward the rear； then the natural location for the motor
will be well to the front so as to counterbalance the
excess in rear weight。 In the same way if the
preponderance of the weight is forward； then the motor
should be placed back of the center。
As the propeller blade is really an integral part of the
motor； the latter being useless without it； its placing
naturally depends upon the location selected for the
motor。
Rudders and Auxiliary Planes。
Here again there is great diversity of opinion among
aviators as to size； location and form。 The striking
difference of ideas in this respect is well illustrated in
the choice made by prominent makers as follows：
Voisinhorizontal rudder； with two wing…like planes；
in front； box…like longitudinal stability plane in rear；
inside of which is a vertical rudder。
Wrightlarge biplane horizontal rudder in front at
considerable distanceabout 10 feetfrom the main
planes； vertical biplane rudder in rear； ends of upper
and lower main planes made flexible so they may be
moved。
Curtisshorizontal biplane rudder； with vertical damping
plane between the rudder planes about 10 feet in
front of main planes； vertical rudder in rear； stabilizing
planes at each end of upper main plane。
BleriotV…shaped stabilizing fin； projecting from rear
of plane； with broad end outward； to the broad end of
this fin is hinged a vertical rudder； horizontal biplane
rudder； also in rear； under the fin。
These instances show forcefully the wide diversity of
opinion existing among experienced aviators as to the
best manner of placing the rudders and stabilizing； or
auxiliary planes； and make manifest how hopeless would
be the task of attempting to select any one form and
advise its exclusive use。
Rudder and Auxiliary Construction。
The material used in the construction of the rudders
and auxiliary planes is the same as that used in the main
planesspruce for the framework and some kind of
rubberized or varnished cloth for the covering。 The
frames are joined and wired in exactly the same manner
as the frames of the main planes； the purpose being to
secure the same strength and rigidity。 Dimensions of
the various parts depend upon the plan adopted and the
size of the main plane。
No details as to exact dimensions of these rudders and
auxiliary planes are obtainable。 The various builders；
while willing enough to supply data as to the general
measurements； weight； power； etc。； of their machines；
appear to have overlooked the details of the auxiliary
parts； thinking； perhaps； that these were of no particular
import to the general public。 In the Wright machine； the
rear horizontal and front vertical rudders may be set
down as being about one…quarter （probably a little less）
the size of the main supporting planes。
Arrangement of Alighting Gear。
Most modern machines are equipped with an alighting
gear； which not only serves to protect the machine and
aviator from shock or injury in touching the ground； but
also aids in getting under headway。 All the leading
makes； with the exception of the Wright； are furnished
with a frame carrying from two to five pneumatic rubber…
tired bicycle wheels。 In the Curtiss and Voisin
machines one wheel is placed in front and two in the
rear。 In the Bleriot and other prominent machines the
reverse is the ruletwo wheels in front and one in the
rear。 Farman makes use of five wheels； one in the；