The Electrical experimenter

54 THE ELECTRICAL EXPERIMENTER May, 1917
THE STORY OF FLASHLIGHT
MAKING.
All of us have undoubtedly found the
electric flashlight extremelj- useful at some
time or other, but very lew people are
privileged to know just how the flashlight
is made. One of the leading manufacturers
of these useful devices recently con-
interesting Exhibit Which Telis the Story
light Making Grafically. Every Important
Manufacture Is Clearly Shown.
structed a display board containing the essential
parts constituting a complete flashlight,
the appearance of which may be
judged from the accompanying illustration.
It was used by the bureau of visual instruction
of the University of California as a
traveling industrial exhibit. The upper two
rows represent the various stages of manufacture
thru which a coat pocket style
flashlight passes. The lower three rows
show the progressive steps in the making
of a tubular flashlight. A similar visual
exhibit prepared by the same concern
showed in a striking and educational manner,
the various stages of flashlight battery
make-up ; from the zinc plate to the assembled
battery, consisting of two or more
cells nestling comfortably in its paper carton.
The Detroit Edison Companj' has made
a number of tests with different methods
of electrically heating cars stored in unheated
garages. Various means of heating
insulated and uninsulated garages have
been tried and experiments made with
nearly all of the heaters sold for heating
the engine itself. The results of these tests
are now being worked up, and they will
probably be presented in a paper at one
of the conventions during the summer.
ELECTRIFYING THE AEROPLANE.
(Coiitiiuiid from fagc /)
ward the exact amount which is likewise
shown in degrees. The scale is coated with
Radium paint so that it is visible at night
by its own light.
One of the greatest problems of aeronautical
engineering is that of making the
aeroplane as safe as possible. Thousands
and even hundreds of thousands of dollars
have been spent in this direction and the
nearest conclusion to this problem is the
adoption of some automatic pilot, which will
control the machine automatically in case
the pilot is unable to get positive control
of the machine.
The only real solution so far to this problem
involves the use of the gyroscope and
the work done bv Mr. Elmer Sperry in this
line gives much light to the solution. Fig.
5 illustrates the Sperry automatic pilot
which relieves the pilot of the
labor and drudgery in operating
the controls of his machine. In
tlie military aeroplane it renders
it possible for the pilot to fulfill
the duties of both pilot and
iibserver. When dropping bombs
it enables the pilot to bring the
aeroplane laterally over the target,
makes a reference plane of
the aeroplane, which greatly increases
the accuracy of bomb
dropping, and creates a steady
platform from which to fire and
drop bombs.
The equipment consists principall}'
of three units—the generator,
servo motor and gyro unit
—which may be likened respectively
to the heart, muscles and
brain of the human pilot.
The g)"ro unit which is placed
in a metal case and shown in
the background utilizes the gyroscopic
effect of the four rotating
gyros w'hich it contains, in maintaining
a horizontal reference
plane. .\ny departure of the
aeroplane for its set relation to
this gyroscopic reference plane
causes an electrical contact to be
made which completes a circuit
of Flash-
Stage of
to one of the magnetic clutches
in the servo motor. The case is
equipt with a glass window to
enable the operator to note the
joperation of the four g\'ros. The power
generated in the servo motor air turbine
is now transmitted thru the engaged clutch
to one of the drums over which the control
wire passes.
The generator which is seen in the foreground
of the photograph supplies alternating
current for driving the gyros and
direct current for the servo motor clutches.
It consist^ of a double armature, one winding
of which is tilized for the generation
of the alternating current and the other
for direct current. It is driven by means
of an aluminum propeller driven by the air
current. The four leads are run from the
rear to the generator.
By means of a special set of clutches on
the gyro unit, the operator can set the
aeroplane to any position relative to the
horizontal which he may desire, by simply
pressing a button located convenientlj- on
the manual control and moving his controls
as tho no automatic nilot were installed
on the machine. When the aeroplane
reaches the desired altitude, the button
is released and control is again given
over to the automatic pilot, which will hold
the machine in that altitude until altered
by the operator.
Complete and unhampered control may
be instantly resumed at any time by pressing
on the push button on the controls.
WAR CONFERENCE WITH TELE-
GRAPH AND TELEPHONE
OFFICIALS.
Messrs. Theo. X. N'ail, president of the
.American Telephone and Telegraph Company:
Xewcomb Carlton, president of the
Western Union Telegraph Company;
Charles P. Bruch. 'ice-president of the
Postal Telegraph-Cable Company; F. B.
McKinnon, vice-president of the United
States Independent Telephone .Association,
and X. C. Kingsbury, vice-president of the
.American Telephone and Telegraph Com-
panj-, were in conference with war department
officials at Washington on March 19
to perfect plans to insure the government
rapid and efficient wire communication.
QUESTION BOX.
{Continued from fcinc ^j)
WAVE MOTORS.
(769.) G. H. G., Detroit, Mich., inquires
as to the efficiency and practicability
of wave motors
A. 1. We do not know just now of any
successful installation of such wave power
plants as described in the February issue of
this journal and while the initial cost of
installing such a plant is not so prohibitive,
there has always been more or less
prejudice against them, owing to the fact
tliat the power developed is so irregular.
There have been a number of attempts
made by inventors to overcome this difficulty,
but the fact of the matter remains
that we have yet to see a practical installation
of a wave motor on any large scale.
The proposition to our mind seems to
possess many practical and economic features,
and it seems very likely tliat in later
years a future generation may see the adaptation
of wave motors to a very large
extent.
Vou may obtain copies of the patents
issued on this interesting subject by communicating
with the U. S. Patent Office,
Washington, D.C., and with these before
you, you will be in a better position to see
just what has been done and what has
been proposed in solving this problem.
CONDENSER IN AERIAL CIRCUIT.
(770.) Antliony S. Detrees, Hartford,
Mich., asks
Q. 1. Can a series condenser be used
successfully in connection with a transmitter,
to reduce the natural wave length
of an aerial from 325 to 160 meters?
A. 1. Yes.
Q. 2. Would such an arrangement result
in low efficiency in transmitting?
A. 2. The addition of a condenser in
series with the antenna circuit increases
considerably the amount of losses and at
the same time increases the decrement due
to an increase in antenna resistance by the
series condenser.
^2 VOLT LIGHTING PLANT.
(771.) U. J. Grant, Apple Creek, Ohio,
writes
Wiring Diagram for 32 Volt Lighting Plant.