IMPROVEMENTS IN RAIL AND TRAMWAYS, IN LAYING ELECTRIC TELEGRAPH WIRES, AND IN COMPOSITIONS FOR INSULATING THE SAME
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Richard Archibald Brooman at the
Office of the Commissioners of Patents, with his Petition, on the 31st
January 1865.A communication from abroad by Jean Arnaud Emile
Laloubère, of Paris, France.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN RAIL AND TRAMWAYS, IN LAYING ELECTRIC TELEGRAPH WIRES,
AND IN COMPOSITIONS FOR INSULATING THE SAME," to be as follows:-
This Invention mainly consists in what may be called a telegraphic rail
composed of a tube of circular or other shaped section filled with an insulating
bituminous composition, formed by preference as hereafter described. I leave
a passage or channel about one-third of an inch in diameter through the
centre of the bituminous composition' to receive a telegraph wire. The rails
may be formed of any convenient length. The object of the bituminous com-
position with which the rails are filled is not only to insulate the telegraph
wire, but to give the rail sufficient solidity or strength to bear the rolling stock!
The tubes are laid end to end, one against' another, in two parallel lines at the
required distance, and rest on blocks of mastic or' wood' to which the tubes are
secured by collars or otherwise. The telegraph' wire may be passed through
the central passage of several tubes at a time. Where a joint or connection
is necessary, say every five yards for example, the contact from one section of
the wire to the following may be obtained by several methods.
ن

page_text: 1st, the head of each section of the wire may be provided with a circular
plate or disc about a third of an inch in diameter, even with the end tubes or
extending a little beyond them, so that when the way is formed by placing
these tubes together, end to end, the disc of the wire of one section may be in
contact with the disc of the wire of the next section. To obtain more perfect
contact the wire at the extremities of each section may be twisted spirally so
as to act as springs behind the discs and press them against each other.
2nd, the wires of each section may extend a short distance beyond the
tubes. Suppose then a ring just large enough to receive the two wires, and
fixed on one of the wires at the other end of the tube, it will be seen that by
engaging the other wire in the remaining space of the ring the necessary
continuous contact of the electric conductors for the transmission of the fluid
will be obtained.
3rd, one end of each section of wire may be twisted spirally, and contact
obtained by forcing into the central space of the spiral the straight end of the
following section of wire, and so on. For greater precaution, fine, bitumen
may be run between the joints of the rails. By the method before described
each rail or tramway will be furnished with two telegraph lines, but several
lines may be laid in each tube if required, provided the wires be properly
insulated. To provide means for ascertaining the point of rupture of the
electric current without apparent cause, I form in the sides of the tubes, say
about every ten yards, small holes following the radius of the section of the
tubes, and communicating with the central channel in which the telegraph
wire is laid; these holes are carefully stopped. Then to ascertain the point
of rupture I open one of the holes and introduce the wire of an electometer
or of a portable telegraphic apparatus, the galvanic current along the line
being maintained; if the current at this hole is perfect I introduce a wire at
another hole, and so on until the point of rupture is met with. To maintain
the telegraph line during repairs of the way, the repairs being always performed
in sections, I connect the telegraph wires, which are disconnected by the
removal of the rails, by a supplementary wire supported on insulating posts,
which may be removed when the repairs are completed. From the foregoing
description it will be understood that the telegraphic rail serves two purposes,
viz., to support the rolling stock and to contain the telegraph wires. When
the rails are circular I lay them without sleepers or girders in two parallel
trenches or cuttings filled with concrete up to within a short distance of the
rails; I then fill the remainder of the cuttings up nearly to the surface
of the rails by preference with one of the bituminous compositions hereafter
described. Where a level road is required I fill up to the top of the rail, and

page_text: leave at the right and left thereof a small gutter for the flanges of the wheels,
which I prefer to be grooved like a pulley. The gutters just mentioned may
be dispensed with if wheels with curved tyres be employed. In case of need
such wheels may run on ordinary roads.
The following two bituminous compositions or mastics are what I prefer to
employ for the purposes herein-before mentioned:-
COMPOSITION.
Pitch (brai) distilled at 25 per cent. about
Fine river sand -
Granulated river sand
Pulverized coke -
Puddlers' offal (machefer)
Meudon white (blanc de Meudon)
Fire-clay (terre à four) or broken stones