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596 ILLUSTRATED WORLD
gas pipe and three elbows, a piece of a
worn out inner tube, a diaphragm of
hard rubber from a telephone receiver,
an old scarf pin, various pieces of wood,
nails, bolts and one pie tin. There were
also two iron washers. The tools I used,
were a pair of pliers, a pocket knife and
a hammer.
The clock movement I removed from
its case, then took from it, the dial and
hands, its hour and minute wheels.
Then I removed its escapement, which
is the mechanism which controls its
speed. In some clocks, this is simply the
pendulum and verge, but in this clock it
was the balance wheel and hair spring,
pallet fork, and escape wheel. You can
tell what these are by going over the
wheel train. The first wheel or pinion,
is the one on which the mainspring is
wound, the second is the center wheel
or pinion, on which the minute hand is
mounted and from which the hour wheel
is geared. The third is an idler. The
fourth is the one on which the second
hand is mounted, but it is always present,
whether there is a second hand on it or
not. The fifth is the escape wheel, the
sixth is the pallet pinion, and the seventh
is the balance wheel, which has a very
fine spring on it, and which turns in
opposite directions alternately. The balance
wheel, the pallet and the escape
wheel form the escapement.
The rest of the wheel train could now
turn at high speed, from the power of
the mainspring. Using two of the wheels
I had removed, and two pieces of the
hairspring, I made a speed governor and
set it so that the train would turn the
center pinion at eighty-five revolutions
per minute. I attached the governor to
the fourth pinion, or the one which was
now last in the train.
I now whittled a little block of wood
into the shape of a spindle and fastened
it rigidly to the center pinion, in the
place where the minute hand had been.
It should be tight enough so that it will
not wobble, and it must run true. In the
bottom of a pie tin, to one side of which
I had glued a disc of cloth, taken out of
an old overcoat, I now punched a hole
in the exact center, and fastened it to
the spindle with a screw and another
piece of wood to act as a continuation
of the spindle.
My tin pan now would revolve by the
power of the clock spring. I made a
friction brake with a lever and a piece
of wood, to act against the fourth wheel.
Then I mounted the whole in a soap box,
so that the spindle with the tin pan on
it was on top and on the outside. By
means of a hole in the side of the box, I
could reach in with my hand and wind
the spring, or control the brake.
The next step was to make the reproducer
and its conducting line to the
horn. Two large iron washers, about
two inches in outside diameter, I fastened
together, first sandwiching between
them two rubber washers of the
same size, with the telephone diaphragm
between them. The washers were held
together with three small bolts and six
nuts, not through them, but against the
outer edge, like clamps. A long, strong
scarf pin with its head and point cut off,
I now fastened to the center of the
diaphragm with wax, and at the point
where the pin passed the edge of the
iron washers, I doubled it around on
itself, to form a loop. Through the loop
I ran a small piece of wire and fastened
both ends of it between the washers to
act as a support for the pin. On the end
of the pin I impaled a small block of
wood, which had a small hole in the
other end, about the size of a regular
phonograph needle. With a very small
wood screw, I fastened the needles in
the hole.
I then took the shell of an electric
light socket, the small end of which was
fortunately a good tight fit to the inside
of the washer behind the diaphragm, and
the other end was an equally tight fit
over the outside edge of an elbow for
three-quarter-inch pipe. The elbow, I
screwed to a ten-inch length of threequarter-inch
pipe, with another elbow at
the other end, and a second length of
pipe with a third elbow was then put on.