Public ledger. [volume] (Memphis, Tenn.) 1865-1893, 1882-10-31
AN INGENIOUS INVENTION.
Automatic Block Signals for
Railways.
Philadelphia Record.

Tibet rain starts in fifteen minutes"
said William Z. Shaffer, the e%lectri.
cisn, at his workshop yesterday, as he
Proceeded to fire up a tiny locomotive
which was resting upon the rails of a
tack tb9t had been erected around
the loom in a circle. This was in
tended 70 illustrate the appliance of
an electric circuit to the systems Of
railroads 10 such a way as to make
accident By the collision or t~elescoping
Of trains an impossibility. Ia a few
minutes the miniature locomotive was
as reslive under the pressure Of steam
as the larger specimens. Small pas
sepger coaches were attached, the
little whistle emitted an infnitesimal
squeak. the electrician shouted "An
aboard aud away shot the train. In
a few moments another train was put
iuto motion, and, making a better rate
OF speed than the other, it soon over
took the first train, and a collision &C.
CURED. Several cars were wrecL ed
and a number of the toy passengers
lost heads and arms.
The electrician explained that this
was doOe to show how easily such
accidents could occur, and how they
could be prevented by the system Of
gignal boxes which he proposed to
put in operation. This system is
called the Railroad Safety Lock and
Signal System 1t proposes to place
at designated distances along the line
of the road iron boxes containing a
magnet and an armature. Every other
one of these act in accord,
thus forming a complete overlapping
block system, aud insuring a stoppage
between the locomotive aud the point
of danger. These iron boxes will
probably be placed one mile apart.
The locomotive in passing over the
rail 10 front of one Of these boxes
breaks the electric current and locks
the box for following trains, while the
box two miles 10 front is also locked
for trains coming toward it, and trains
at that distance in either direction
are brought to a stand. In order to
illustrate this two more trains were
started, one going in the opposite
direction TO the one already upon
the track. Both Of these trains came
to a sudden halt within two blocks Of
the first train. The breaking of the
electrical current in one of the iron
boxes by the first train had the
eject Of locking a projection Of the
boxes in the side Of the track for two
blocks away in each direction. An
examination Of the checked engines
showed that they had an attachment
Of rigid iron upon the Journal OF the
rear axle, and this had come in con,
tact with the projections before men.
toned. These two projections coming
in contact had applied The air brakes,
closed the throttle valve and blown
the whistle, and the trains had come
to a stand without the aid of human
agency. When the boxes are looked
the signals are automatically changed
from those of safety TO those of dan
ger, and the engineer is thus warned
Of danger before the appliances on his
engine notify him OF it,"
"How is the circuit made complete
agaiD2' was asked.
This was illustrated by starting up
the first train, aud when the last car
had passed over the rail ia front OF
the box a sharp clicking noise was
heard. The gentlemen witnessing the
experiment were asked TO Try The
locked projections in the tracks which
had stopped. the other trains. This
was doue aud they were found TO be
unlocked. The circuit had been
closed by an attachment to the rear
truck OF the last car which came In
contact with a projection on the side
Of the track. The train following
could come on only at q voryslow pace
as it would be stopped every two
blocks behind the first tfaln, aud dc
train coming in the opposite directioL
must take to a siding or 20 back
When the engineer desires TO breok
the lock that has been put upon hin
engine he touches a sping in the aoor