IMPROVEMENTS IN the County of, for the Invention of ELECTRIC TELEGRAPH APPARATUS
Year: 1871

page_text: LETTERS PATENT to Edward Bull, of Porthcurno, near Penzance, in
“IMPROVEMENTS IN
the County of Cornwall, for the Invention of
ELECTRIC TELEGRAPH APPARATUS.”
Sealed the 23rd June 1871, and dated the 25th April 1871.
PROVISIONAL SPECIFICATION left by the said Edward Bull at the
Office of the Commissioners of Patents, with his Petition, on the
25th April 1871.
I, EDWARD BULL, of Porthcurno, near Penzance, in the County of
5 Cornwall, do hereby declare the nature of the said Invention for "Iы-
PROVEMENTS IN ELECTRIC TELEGRAPH APPARATUS," to be as follows:-
This Invention has more especially for its object to produce a set of
apparatus by which the current or currents from the terminal station
may put into play or complete the circuit for the transmission of a fresh

page_text: current or currents from a battery or batteries at each intermediate
station or intermediate stations, so as to enable the stations at the two
ends of a line to have or to hold direct communication with each other,
or for any intermediate station along the line to have direct communica-
tion with either of the termini or with any other particular station along
the line.
The instrument or translator is available for using different strengths
of current, that is to say, a weaker current for a cable line and any
strength of current as may be required for a land line.
This system is also available for using alternate positive or negative
currents or a single current giving the long and short signals of the
Morse alphabet, which are recorded on paper in a manner similar
to that done by an ordinary Morse instrument, or by a double Morsc,
making marks by means of two levers giving a double row of signals
one above the other below the centre of the band of paper by the action
of a local current or currents. To effect this according to my Invention
I connect a needle which is suspended between a coil or coils of wire or
fixed on a pivot in a coil or coils of wire, through which said coils the
line current passes similar to a delicate galvanometer or other indicator
of a current by means of two silk fibres or other insulating strings to
another light needle or bar of aluminium, brass, or other metal, or wood,
straw, or other material, which said needle or bar is suspended by a metal
or fibre connection on the translator stand, or may be connected to a
similar bar or needle supported by means of a bulb of glass, cork, or
other light material floating in oil or in any other liquid, this said needle
or bar of the translator being in metallic connection with the line wire,
be it either cable, subteranean, or land wire. On the motion of the
galvanometer needle, which is produced by the current passing along one
section of the linc, the needle or bar of the translator by the connection
above described is made to connect the line of the next section to thic
pole or poles of a relay of battery or batteries, thus giving fresh signals
of a single current or alternate currents, positive or negative, on to the
next or second section of the line, giving the ordinary Morse signals of
long and short marks, as in the ordinary Morse instruments, or by two
rows of signals, one above and the other below the centre of the paper,.
or by means of two styles insulated from each other resting on a band of
paper
drawn over a drum or between rollers by mechanism similar to
that of a Morse instrument. The currents from a local battery passing

page_text: down the styles on to the paper, which is chemically prepared, giving the
dots or marks by electro-chemical decomposition produced by a local
battery. These local batteries which record the signals on a single or
double Morse, or by clectro-chemical decomposition, are put into
action by means of a single relay for the single long and short marks,
or by two relays, such as those of Varley, Siemens, or Whitehouse,
or by an electro-magnetic relay, such as shown in the plan 1, and marked
No. 6, being connected in the circuit of the line, cither cable or land line,
the movements of the needles or armatures of these relays completing the
local battery circuit through the coils of the Morse instruments or along
the styles on the instrument producing the marks by electro-chemical
decomposition. The motions of these relays may be further guided
in their direction according as the line is worked up or down by
means of a reversible switch, the line and relay wire being connected
with the same, or furthermore an ordinary galvanometer or single needle
instrument may be connected in the circuit of the line, thus enabling
a person to read by the Morse or the single needle alphabets, or serving
as a guide to the direction of the current or currents. In order to make
this translator more sensitive to feeble currents passing through the
linc and the coils of wire which gives motion to the needle suspended
between them, and which is connected by fibres or by the means before
mentioned to the needle or bar of the translator, I have two adjustable
screws working in two brass slides, which are insulated from each
other and sliding or moving between two arms of vulcanite, and working
backwards and forwards or drawn from and to each other equally by a
reverse screw. Between the right and left screw a piece of vulcanite
or other non-conducting substance is inserted, as shown in the Drawing,
this non-conducting substance being inserted to prevent metallic con-
nections between the two slides or the poles of the battery or batterics.
On the surface of the brass slides which are worked by the screw are
fixed two terminals, to which the two different poles of the battery or
batteries are connected. The intermediate portion of the battery, or in
the case of a double set of batteries being used, the opposite poles which
are not connected to the terminals on the brass slides, are connected with
the earth or through the coils to an electro-magnetic switch and then
to carth, the object of which electro-magnetic switch is herein-after
described. This battery or the batteries producing the translation
currents for the second section of the line, and this form of translator
at different stations producing the currents for the different sections of
⋅

page_text: the line, and enabling the two terminal stations to communicate direct
with each other, whatever the distance. The sensitiveness of this
translator is increased by the screwing of the brass slides which move
between the arms of vulcanite farther apart from each other, or it is
rendered less sensitive for strong signals by screwing them nearer to each
other. On the upright brass stand of this translator is fixed the needle
or bar by the suspension between the two terminals, as indicated in the
Drawing on a float in a cup of liquid.
Or in place of obtaining the adjustment by means of right and left
handed screws, the arrangement shown in plan No. III. may be
employed, the contacts being on two compass-like 'legs suspended by
threads from an axis on to and from which they are wound to regulate
the distance between the contact pieces; these translators may be
worked by means of insulating connecting threads from an ordinary
electro-magnetic relay or relays. The connection by insulating threads
removes all risk of atmospheric electricity passing from the land line
into the cable. A special advantage is obtained by connecting by
means of this translator a land line with a cable for telegraphic purposes,
without putting them into metallic connection or in electric con-
ductibility with each other, so as to enable London to work direct with
Bombay or Singapore, or through any long lengths of submarine cables,
through which long lengths of cable it has been hitherto found impossible
to hold direct communication as contradistinguished between that and
holding direct communication with two stations, being long distances
apart, such distances being chiefly composed of long lengths of land
lines and a short length of cable. I also by such translator am able to
work or record signals on theso long lengths of cables by a single
or double Morse, or other ordinary descriptions of telegraphic recording
instruments, such as are put into play or working by the several different
kinds of relays such as are in use on land lines and ordinary circuits on
these long submarine and combined circuits where hitherto the mirror
galvanometer and syphon recorder instruments have only been found
available for working or recording signals.
For the purpose of breaking the circuit to prevent the current which
is generated at translator No. 4 (see plan No. 1) passing through the
coil or coils of translator No. 1, the battery current passes through an
electro-magnetic switch or coil of wire wound round coils of soft iron,
over which is a soft iron armature. The current in its passage attracts

page_text: .
this armature or lever down towards the coils, at the same time
raising the other end of this lever from the insulated brass connection,
to which is attached or connected the wire from the condenser, thus
breaking the circuit or passage of the current generated at No. 4
translator from passing through the coils of translator No. 1, thus
leaving no other path or circuit for the current or currents of No. 4
translator or relay battery or batteries to pass but on the second or
other sections of the line, according to whatever intermediate stations
these translators may be in use at. For each intermediate station I use
two of these translators, one for the up line or up communications, the
other for the down line or down communications; and I call the one
No. 1 translator, and the other No. 4 translator. Condensers are used
on cable or subteranean circuits between the end of the line of each
particular section and the earth. The surface of these condensers is
increased in size according to the length of the submarine or subteranean
section. In place of setting the needle or bar translators in motion by
the movement of a needle suspended or fixed in a coil, or between coils
as before described like a galvanometer, I connect the said needle
or bar of the translator to a coil of wire or coils of wire suspended in a
field of magnetism, or between the poles of an electro-magnet or electro-
magnets, or between the poles of a permanent magnet or permanent
magnets by fibre or fibres. This system of translator can be applied
to either the use of the syphon recorder or mirror galvanometer for
recording signals.