IMPROVED MODES OF SIGNALLING ON RAILWAYS BY MEANS OF SOUND, AND APPARATUS TO EFFECT THE SAME
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by William Hickling Burnett at
the Office of the Commissioners of Patents, with his Petition, on
the 3rd September 1869.
I, WILLIAM HICKLING BURNETT, of 13, Great Coram Street, Bruns-
wick Square, in the County of Middlesex, do hereby declare the nature
of the said Invention for "IMPROVED MODES OF SIGNALLING ON RAILWAYS BY
MEANS OF SOUND, AND APPARATUS TO EFFECT THE SAME," to be as follows:-
My improvements are twofold, viz., signalling from fixed stations to
trains in motion, and from trains in motion to fixed stations, and to
other trains in motion.
I propose at each station to have the means of producing at least two
distinct musical notes, one for each line, which may cither be caused by
a bell, a steam horn, a syren, or any other instrument capable of pro-
ducing a loud tone. As my object is to make this sound audible in all
weathers as far as possible, I concentrate it by means of a parabolic
mirror in the direction of the coming train, reserving to myself, however,
the power of turning it into any other direction if required.

page_text: Each engine must have the power of sounding two distinct notes, one
of which is always blowing when an engine is drawing an up train, and
the other when drawing a down train, so that no mistake can ever occur
as to the line on which another engine is travelling. Round these
sounders I have revolving parabolic mirrors, by means of which the
sound is thrown alternately up and down the line, and therefore serves
to give warning both to stations that the train is coming, and to any
following train that one is before them. I prefer that the sound
produced at the stations, although the same for every station, should
be distinct from those affixed to the engines, to prevent one train
following another from mistaking the note of a preceding train for that
of a fixed station.
As the notes at the fixed stations will never be sounded excepting as
a signal that "all is clear," any train approaching a station within a
certain distance not hearing the sound should be ordered to stop, and
by an agreed number of sounds enquire why they cannot proceed, which
can be answered by the station with a settled code.
I attach a clockwork apparatus to the sounding machinery, enclosed
in a box, of which some inspector of the line alone has the key, with a
tell-tale apparatus attached to shew at what hour the signal to advance
was made and when the sound ceased, by which means no question can
possibly arise as to whether or no the proper signal were made. The
same movement which turns on the sound may be made to turn the
points in the proper direction, and if points exist at any part where no
station is, the understood sound will be only produced, and then only
when the points are in the proper direction.
To prevent accidents from the hind part of a train being kicked off
down an incline, I have in the guard's van, which should always be the
last carriage of a train, a syren or other instrument to sound the same
note as the engine produces while running along the line, which may be
used for two purposes, viz., for the guard to correspond when necessary
with the engine driver by some simple code, or to be set in action by the
very act of running backwards, and thus giving warning in time for the
coming train to get out of its way.
Although I only speak of one signal for each line at the station,
silence being the danger signal, I may, if at any time I wish to do so,
have distinct sounds for safety and danger signals. And in order that
the engine driver may hear the correct note from the station at a con-

page_text: siderable distance, I have in front of the engine another parabolic
mirror, in the focus of which I have a tube that only vibrates to that
particular note of the station, connected with a bent tube directed
towards the ear of the driver. A similar tube for the use of trains
either before or behind directed to his other ear may also be used.
As instruments can easily be made from which the sound can be
heard at a sufficient distance in all weathers for the purposes of safety,
I hope almost entirely to avoid collisions on railways, which owing
to the uncertainties of visual signals from fogs, bends in the road,
inattention, color blindness, and other causes are now unfortunately
so frequent.