AN IMPROVED SYSTEM AND APPARATUS FOR FACILITATING THE WORKING OF SUBMARINE CABLES AND OTHER CON- DUCTORS OF ELECTRICITY
Year: 1865

page_text: LETTERS PATENT to Silvanus Frederick Van Choate, of the City, County,
and State of New York, of the United States of America, Telegraph
Engineer, for the Invention of "AN IMPROVED SYSTEM AND APPARATUS
FOR FACILITATING THE WORKING OF SUBMARINE CABLES AND OTHER CON-
DUCTORS OF ELECTRICITY."
Sealed the 4th April 1865, and dated the 19th January 1865.
PROVISIONAL SPECIFICATION left by the said Silvanus Frederick Van
Choate at the Office of the Commissioners of Patents, with his Petition,
on the 19th January 1865.
I, SILVANUS FREDERICK VAN CHOATE, of the City, County, and State of
New York, of the United States of America, Telegraph Engineer, do hereby
declare the nature of the said Invention for "AN IMPROVED SYSTEM AND
APPARATUS FOR FACILITATING THE WORKING OF SUBMARINE CABLES AND OTHER
CONDUCTORS OF ELECTRICITY," to be as follows:-
Important difficulties which lead to the failure of submerged electrical con-
ductors may be briefly described as follows:-
First, mechanical imperfections in the structure of such conductors.
Second, imperfect insulation thereof.
And third, the formation of abnormal circuits, chiefly at the receiving end
of the line.

page_text: This Invention relates not to the difficulties named under the first two
heads, but to the obviating of the difficulties caused by the formation of
abnormal currents and also to increasing the distance within which it is
practicable to work a telegraphic line or cable. Theoretically a submarine
insulated conductor should operate with one battery at the sending end,
making the complete circuit by the return of the electric current from the
receiving end through the earth in accordance with the discovery of Prof.
Steinheil, of Munich. But for long distances the resistance to the passage
of the electric fluid through the conductor is greater than the resistance of
the insulator of the cable, and therefore the current of the fluid is lessened
by escape of the fluid through the insulator, and the fluid returns to its start-
ing point by the shortest available route, thus establishing and completing a
circuit or circuits which do not reach or include the receiving station. To
increase the sending power of a telegraphic submarine line a battery has been
placed at the receiving end, but the abnormal currents which this establishes
at the receiving end detracts from if it does not destroy the utility of this
arrangement. Attenuation of the current of the electric fluid takes place
along the line, increasing from the sending end where the battery is used at
that end only; but where a battery is used at both ends of a line the attenua-
tion begins at each end of the line, and is greatest in the middle, the points
where the greatest attenuating strain comes on the cable being where the
cable enters the water on either side. As there can be no current where the
circuit is not complete, or when it is broken, it follows that there will be no
abnormal currents formed at the sending end, as it is at said end that the
message is sent by breaking the circuit there, such breaking producing the
disturbances in the current that are translated into the message. But at the
receiving end, with the auxiliary battery there, to increase the amount or
strength of the current there is no break in the circuit during the receipt of
a message, consequently the escaping fluid forms at the receiving end an
abnormal and independent circuit, which interferes with even if it does not
wholly prevent the practical working of the line. Thus it will be seen, first,
that the electric fluid, owing to its becoming attenuated, fails to reach the
receiving apparatus in long stretches with a single battery located at the
sending end; second, that a battery placed at the receiving end forms a short
circuit at that point; third, that the manipulations or breaks and closings
of the circuit at the sending instrument fail to produce a corresponding dis-
turbance in the closed circuit at the receiving end, and consequently the
normal state of the receiving apparatus remains unaffected.
Now by my Invention I am enabled to use a battery at each end of the

page_text: line, and to break the line and close it at the same instant at each end, and
by said breaking to avoid the formation of abnormal currents which heretofore
have been so troublesome. For facilitating the working of a line or cable of
a given length, I employ two revolving wheels, one at each end of the line,
both combined with proper mechanical devices, whose functions are such as
to keep said wheels in unison as regards their rotation. Each of them is
provided with projections alike in each, and which correspond exactly to the.
characters on the type wheel or other device arranged to give the signals to
be interpreted as the language of the despatch. The current starting from
the sending station would pass through the first wheel, when in its rotation
the break in its end of the circuit is closed by one of the projections, and the
key corresponding therewith when manipulated by the operator, and as the
other wheel at the receiving station moves synchronously with the sending
station wheel, and as both start to revolve from corresponding points, it is
clear that openings and closings of the circuit may be made at the same
instant. It will now be seen that I can avail myself of two batteries, one at
each end of the line, and that in so doing there will be no abnormal currents
formed at the receiving end, because the circuit is broken there as well as at
the sending end. It is to be understood that at both ends of the line there
are sets of keys, each key corresponding to one of the projections on the
revolving wheels, and each being so arranged that it may in connection with
its key complete the circuit at its end. The line may be made to operate
from either station as the sending station by closing the keys at the other
station, which operation does not keep the continuity of the line at the then
receiving station, as this is broken by the rotation of the wheel at that end,
and therefore abnormal currents are not formed, as the intermissions of the
circuit or the breaks are so frequent and the closings are so short that the
abnormal currents do not have time to set in, the clear metallic conductor
transmitting the instantaneous flash in less time than it takes for the ground
or abnormal currents to form.
In the second feature of my Invention I employ precisely the same arrange-
ments and apparatus at each end of the line as before described, and add
near the middle of the line a self-adjusting relay magnet and a perfectly
balanced armature or vibrator so arranged and combined as not to require an
adjusting spring. All of this is placed in an insulating case of hard rubber or
other suitable substance, and this case is hermetically sealed in a suitable
heavy metallic case provided with packing boxes through which the cable
can communicate with the devices within. By this arrangement the line is

page_text: divided into two parts, and each circuit is broken or disturbed at two distinct
places in each section. Between the armature and the receiving circuit the
arrangement is such as to leave a break except when the vibrator is attracted
by the electricity acting upon the magnet or helix which takes place at the
same instant that the operator closes the circuit by depressing a key corre-
sponding to one of the projections on the wheels and the signal which it is
desired to give. In order that either end of the line may be used to send
messages it is necessary to use a double conductor and corresponding con-
nections in this central repeating device, or a double arrangement of the
repeater with a single conductor may be used.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Silvanus Frederick Van Choate in the Great Seal Patent
Office on the 19th April 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SILVANUS
FREDERICK VAN CHOATE, of the City, County, and State of New York, of the
United States of America, Telegraph Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of January, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Silvanus Frederick Van Choate, Her special licence that I, the said
Silvanus Frederick Van Choate, my executors, administrators, and assigns, or
such others as I, the said Silvanus Frederick Van Choate, my executors, admi-
nistrators, and assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed, should
and lawfully might make, use, exercise, and vend, within the United King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "AN IMPROVED SYSTEM AND APPARATUS FOR FACILITATING THE
WORKING OF SUBMARINE CABLES AND OTHER CONDUCTORS OF ELECTRICITY," upon the
condition, amongst others, that I, the said Silvanus Frederick Van Choate,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal

page_text: Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said Silvanus Frederick Van Choate, do-
hereby declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement :-
In order to describe fully and comprehensively the peculiar features of my
Invention for facilitating the working of submarine or subterranean cables,
as well as land lines, I shall first proceed with the aid of Drawings forming
part of this Specification to point out some of the important difficulties
which lead to the failure of cables of considerable length. I will then
describe the system and apparatus I have designed to obviate and remedy
the same.
A description in detail of the printing instruments with their various devices
and arrangements, as well as of the other machines and mechanisms intended
to be employed in connection with my system and apparatus for working
cables, &c., being unnecessary to a full understanding of my Invention herein
set forth, will be excluded from this Specification.
The failures heretofore in operating long cables have not altogether been
owing to the imperfections of such cables. The difficulties seem not to have
been attributed to the real causes. The true principles of circuits, conductors,
and electric currents have been mainly overlooked, while the proper mechanical
devices for operating them successfully were not to be had. Unnecessary im-
portance has been attributed to the "principles of the Leyden jar" induction,
and what is termed "earth currents," &c. &c.
It will be
In the Drawing at Figure 1, I have represented a diagram of a cable, the
batteries, instruments, &c. arranged as they generally are for working a line.
Also a section of the earth with the banks on either side, the sea or water
between, and the cable or conductor lying near the bottom, while on each
bank or shore may be seen a representation of an office, A¹ being the sending
or transmitting station, and A' that of the receiving station.
observed that in this arrangement there are two distinct batteries to supply
the galvanic current, one at the sending station, marked B, and the other
at the receiving station, marked M, it being found that one battery would
not have sufficient, power, that is to say, intensity to project a current
through the entire length of the cable owing to the resistance or retardation
the great length of the conductor offers to the action or passage of the
electric fluid. The practical effect is that the current is diminished or
,

page_text: attenuated as it recedes from the fountain or battery; and a battery is
placed at each end of the conductor in order to maintain the equilibrium
or intensity of the current throughout the cable necessary to work the
apparatus.
Electrical phenomena, so far as practical telegraphy is concerned, are based
upon the idea that there are two kinds of electricities or polarities to a
current, positive and negative, and that when a circuit of wire is formed
enclosing a battery a circulation of the fluid from the positive to the negative
poles takes place. Practice seems to confirm this theory. It is well known
that when to each pole of a battery two pieces of wire are connected, there
will be no perceivable electrical action while the other ends of the wires are
separated as in Figure 3; but when the ends of the wires are brought
together, as in Figure 4, a circuit being completed, action is instantly produced.
This should be distinctly understood in order to perfectly comprehend the
matter beyond.
It was discovered by Próf. Steinheil, of Munich, that the earth might
be made the equivalent of one part of such an electric circuit. That when a
wire is connected with the ground at one end, and is run out to any given
point, and the other end connected with the ground also, there is then an
equivalent to a metallic circle.
It is necessary to mention the fact that the electric fluid will invariably
take the shortest route, conductors being equal, in order to complete a circuit,
passing sometimes in a mysterious manner to accomplish this purpose. It is
important that this fact should also be remembered, so that the most im-
portant difficulties as affecting practical "cable telegraphing" may be fully
comprehended and explained.
Returning to the idea of the attenuation of the current, by the aid of the
Drawing (Figure 1), I will endeavour to illustrate it, showing by the arrows
intended to represent the currents and their direction that the greatest inten-
sity is at the starting point, battery B, and that at D where the cable first
meets the water the current is stronger than it is at E, and that at F near
the centre of the ocean there is scarcely any current at all. The same thing
may be observed at the other end or [receiving station, battery M supplying
the current at that point. The greatest strain upon the insulation of the
cable is at D and at K where the first contact with the water is made
near each shore; consequently the greatest escape of the current through the
coating or insulation of the cable takes place at these points, diminishing at
the distance from the battery increases toward the centre at E and J. The

page_text: current thus escaping takes the shortest distance through the earth to the
other pole of the battery, forming at each end a perfect circuit; that at the
sending station completing a circle through battery B, and C, D, O, ground
plate A, and back to B; that at the receiving station through battery M,
The resistance that the
ground plate N and O, K, L, and back to M.
increased length of the cable offers to the passage of the current being greater
than the resistance of the coating or insulation the fluid finds an easier transit
through such insulation and the earth back to the opposite pole of the battery
than through the entire cable from shore to shore.
:
I will illustrate by the aid of Figure 2 a line or cable whose conductor is
supposed to be perfectly insulated, so that the current is made to circulate
through the entire length from shore to shore, returning through the ground
below, forming a perfect galvanic circle including both the sending and
receiving apparatus. Should a break or disconnection be made at any
point within this circuit, a perfect disturbance of the galvanic action would
be produced. In this case the insulation offers a greater resistance than
the retardation or resistance offered by the length of the wire or conductor,
so that the current finds an easier passage through the entire length of the
cable circuit than it would to pass back through the insulation and ground
at D, O, and K, O, eonsequently a short circuit at the two ends of the cable
is not formed.
.
I have shown before that the current cannot pass unless the circle is com-
plete. It will be seen by referring to B¹, Figure 2, that the wire or line is
disconnected at C, which point we are to suppose is at the manipulating key
of the sending instrument. It will be noticed that when this space or opening
is closed that a circuit is completed following the direction of the arrows to-
ward D, and through the cable to K, receiving instrument E, battery M,
ground plate N, and the earth to ground plate A, completing the circle at
battery B. This circuit is based upon the supposition that the wire is per-
fectly insulated, as before remarked, and that no escape of the battery fluid
takes place along the cable. This should be the condition of every line of
telegraph, the practical working of which depends upon the perfect state of
the insulation, and the proper mechanical devices for producing perfect dis-
turbances of the normal condition of the galvanic fluid.
The operation of telegraphing consists simply in systematically breaking
and closing the galvanic circle, which breaking and closing produce dis-
turbances upon receiving magnets. These disturbances are translated into
letters of the alphabet, or made to operate mechanical devices combined .to

page_text: print the letters upon paper; the former being termed the dot and line or
signal system, and the latter the printing system.
In all cases heretofore the breaking and closing of the galvanic circle has
been at the sending station or instrument. If an attempt was made to
make more than one break in a circuit at a time the operator immediately
lost control of the line, that is to say, he could not again close the circuit,
except at the point where his breaking key was. Hence the breaking of
the circuit has been only practicable at the position occupied by the trans-
mitting operator.
I now refer back to Figure 1, where I have shown that the retardation,
resistance, and imperfect insulation of the conducting wire of the cable has
caused the electric fluid generated by batteries B and M to escape and move
back, passing through the earth and water to the respective poles of the
batteries, thereby forming two distinct circuits, one at the sending station and
one at the receiving station. I have shown that if the insulation was perfect
and the resistance not too great, the current from the batteries would circulate
freely through the cable from end to end and return through the ground to
the starting point, as indicated in Figure 2. Now suppose. the illustration in
Figure 1 to represent a cable of 2000 miles in length successfully laid down,
but the insulation imperfect and the resistance great, and the batteries and
instruments all arranged for working in the usual way, if the line circuit be
closed through the batteries the current will pass out on the line, but meeting
with the resistance and imperfect insulation, it escapes and turns back at each
end in the direction indicated by the arrows as at D and K, forming the two
circuits before described at A1 and A2, Figure 1. Suppose a message is to
be sent from the instrument at A', Figure 1, to the receiving apparatus at A,
same Figure. The operator at the sending station opens his key or breaks
the circuit at C. It will be observed that this would of course cut off the
entire current from battery B, and consequently destroy the circuit formed
through C, D, O, A, and B, Figure 1. But the object is to disturb the
receiving instrument at the other end of the cable, and it will be seen that
that instrument is enclosed within a circuit formed through M, N, O, K, L,
Figure 1, at that end of the cable, and that this circuit, which is abnormal, is
entirely beyond the control or influence of the operator at the sending station.
This abnormal circuit is the great difficulty; can it be obviated? Heretofore
no remedy has been successfully employed to overcome it. Suppose I take
away the battery at the receiving station which forms this abnormal circuit
beyond the control of the sending operator? The consequence would still be

page_text: the same, because the battery at B will not project a current through the
entire length of the cable to the receiving station, and without electricity the
receiving apparatus cannot be operated.
From this it will be seen that the sum of the difficulties affecting
the successful working of long stretches of cables lies in these simple
facts:-
First, that the electric fluid, owing to its becoming attenuated, fails to reach
the receiving apparatus in long stretches with a single battery located at the
sending end.
Second, that a battery placed at the receiving end forms a short circuit at
that point.
Third, that the manipulations or breaks and closings of the circuit at the
sending instrument fail to produce a corresponding disturbance in the closed
circuit at the receiving end, and consequently the normal state of the receiving
apparatus at the receiving end or station remains unaffected.
Having thus fully described the difficulties attending the working of cables
and land lines of telegraph with rapidity, I will now more particularly refer to
the mechanical devices and the system I have invented to overcome these
difficulties and operate such lines with rapidity.
In my plan or system the employment of printing instruments is contem-
plated, although other kinds of apparatus may be used in their place.
This Invention possesses two distinct features, and the mechanisms are
arranged to perform two important functions.
First, to facilitate the working of lines and cables of a given length; and,
Second, to practically work and with rapidity lines and cables twice the
length or distance that can be done by any other systems or apparatus ever
before known or used.
I will first describe my plan and arrangement to facilitate the working of a
line or cable of a given length, and which is represented by the Drawings at
Figure 5, wherein A, A, indicates the two ground terminations of the line,
and B, B, the two batteries, one at each end of the line or cable C, C, repre-
senting two revolving circuit breakers or closers, one located at each end of
the cable, while D is intended to represent the cable which connects the two
revolving circuit disturbers C, C. The mode of operation of the apparatus
arranged in this way is as follows:-
The two revolving wheels C, C, Figure 5, are both combined with proper
mechanical devices, whose functions are such as to keep them (the two
revolving wheels C, C,) in unison, that is, moving at exactly the same speed,

page_text: and so arranged that where they both start or are set in motion at the sam
time they perform their revolutions precisely in the same space of time, an
by proper mechanism their speed is regulated as desired. Each of thes
revolving wheels is armed with exactly the same number of projections, teeth
or pins, which pins or projections correspond exactly in number to the type
or letters or characters on the type wheel or other fixture arranged to giv
the signal, or produce the signs or characters which are to represent the
letters of the alphabet, or the signals which are to be interpreted as the
language of the dispatch produced by or through the influence of the electri
wave or impulse. The line starting at the sending station at A, or battery B
would take the direction of the arrows, and the metallic connections being
suitably arranged, the current would pass through the revolving wheel C, and
whenever one of its teeth, pins, or projections came in contact with a con
trivance properly arranged at d, the open space at that point for the instant
would be closed, thus completing metallic connection with that portion of the
conductor between the ground A, battery B, wheel C, space d, and key or
circuit closer h. I have shown before that the magnetic circle cannot be
formed unless the conductor is perfect or continuous. It will be seen (at
Figure 5 sending station) that the current has started from A, or battery B, and
has passed through wheel C, and space d, but has reached another open space e
at the key h. Now, by the manipulation of the sending or transmitting
operator or otherwise, space e can be closed, when it will be seen that the
electric current would then proceed in the direction of the arrows along the
conductor line or cable D, and on uninterruptedly to g, where is seen another
open space which would again stop its further passage.
I have already stated that the two wheels C, are arranged and supposed
to be turning at the same time and speed, having started at a corresponding
similar point, and that the wheel at the sending station has brought one of its
teeth or projections in contact with the other point at d, and that the space e
is also temporarily closed. Now suppose at precisely the same instant wheel C,
at the receiving station, should bring one of its metallic teeth-points or projec-
tions in contact with the end of the conductor or mechanism at g, this would
complete a perfect metallic conductor from the sending station to the receiving
station, whereby the electric spark, fluid, or current, might complete its circuit
from battery B (sending station) to battery B (receiving station), and through
the earth or water E, as the case may be, in the direction of the arrows back
to the starting point. A repetition of the wave or current would pass through
this circuit, while the space e (sending station) was kept closed as often as the

page_text: teeth, projections, or pins of the two revolving wheels C, C, synchronously
came in contact with the proper mechanisms and closed up the two spaces e
and g.
I will now describe more particularly the function and operation of the sending
or manipulating key or device. In order that the synchronous closings of the
open spaces e and 9 (Figure 5), and the consequent passage of the electric fluid
through the circle may be practically utilized for telegraphic purposes, it is ne-
cessary that the key h (sending station) should be arranged in connection with
the other parts of the mechanisms, so that it should correspond by proper con-
trivances with a certain and particular letter, character, or signal of the type
wheel or other indicating disc or device. Suppose, for example, the key or
device h was so arranged that when it was depressed or moved the space was
closed at e exactly when the signal or character representing the letter A
arrived at a certain point or place; there being but one letter or signal A for
each revolution of the revolving wheel c it would show that at every revolu-
tion of the wheel C the same letter A would appear at the same place. As
the sending and receiving revolving wheels C, C, and signal mechanisms
exactly correspond, and both wheels start at the letter A and revolve in the
same space of time, the same letter would arrive at both stations or instru-
ments at a certain corresponding point at the same time.. These points and
times corresponding exactly to the depressed key or moved lever would con-
sequently produce closings of the spaces e and g, and the electric fluid would
also pass through the circuit at the same instant, producing the effect, or
moving or indicating the alarm or device at the receiving apparatus, which
would operate properly arranged receiving devices, or notify the clerk of the
corresponding signal or letter at that moment in unison with the depressed
key or lever at the sending instrument, and also the character or letter
corresponding to the one indicated by his own receiving apparatus. A
sufficient number of these keys or levers are arranged in this manner to
correspond with and represent the signal alphabet. To produce the various
signals, characters, or letters, the same repetition of movement is performed,
the operator manipulating the various keys, &c. according to the signal or
letter desired.
The great and very important feature in this Invention thus arranged
(Figure 5), consists in the fact that the circuit at the receiving apparatus is
mechanically and perfectly disturbed at certain intervals. In all the systems
and apparatus heretofore devised and used, nothing has been produced that
synchronously disturbed the circuit at the receiving apparatus. Consequently.

page_text: the current from battery B (receiving station) formed and produced the ground
return or short circuit at or near that apparatus or station, which I have
before so fully and particularly described and illustrated so perfectly in
Figure 1.
By my Invention and system the wire or conductor is kept free from all in-
fluences of return currents, circuits, &c., and all "principles of Leyden jar," &c.
are entirely obviated. The battery current never passes upon the line until at
the instant closing of the spaces e and 9, when a single flash is transmitted
through a conductor free from all influences of abnormal circuits, as the open
spaces e and g are in both cases between the battery and the conductor or
cable, and the intermissions of the circuit, or breaks and closings of the
spaces and g (Figure 5), are so short that the ground circuit or return
currents, do not have time to set in or form the clear metallic conductor trans-
mitting the instantaneous flash in much less time than it takes for the ground
or abnormal circuits to form. My apparatus is capable of producing these
disturbances of the circuit, that is, breaks and closings at the rate of fifty-eight
in a second, and may be increased to a much more rapid speed. The letters
of the alphabet may be printed through cables at this rate by the employ-
ment of this apparatus, that is if an operator can be found so expert as to
finger the keys correspondingly. In order to write or operate back from the
other side it is only necessary to close the key h at e, and open and manipulate
the key fat the other end.
Having thus fully described the difficulties attending the practicability of
cables, and long or imperfectly insulated land lines of telegraph, and described
the mode of operation and apparatus I have invented to facilitate their working
and obviate these difficulties, I will now proceed to describe my apparatus
and manner of operating lines and cables at least twice the distance that can
possibly be done by any other system or apparatus ever invented or used.
This is the second grand feature in my Invention.
Figure 6 will be referred to in order to illustrate this second arrangement.
In this Figure will be seen precisely the same arrangement and apparatus that
I have already described above and shown in Figure 5, except the additional
mechanism and plan of the circuits at the middle of the line or cable. This
additional contrivance is of great importance. It is a simple but perfectly
self-adjusting repeater or relay magnet, consisting of only one small spool of
two to four ounces of insulated copper wire, and a perfectly balanced armature
or vibrator, arranged and combined in such a manner as not to require an
adjusting spring. It regulates itself to the variations in the strength of the

page_text: magnetism produced in the coil by the electric current, and works as well up-
side down or on its side as it does in any other position, and it will also work
as well while the magnet or helix is in constant motion as when it is stationary!
The size of this repeater is such that it may be incased in a box about three
inches long, two inches wide, and two inches deep. I arrange this relay or
repeater inside of a hard or bone-rubber case, or other suitable contrivancé
hermetically sealed, the proper connections of the conductors being made, after
which this hard-rubber box containing the repeater is itself incased in another
vessel or contrivance similar in its exterior appearance to a bombshell, aś
shown at A and B, in Figures 7 and 8. This shell is formed in two parts
and put together by means of a screw thread. On each side of it are two
projections, y and z, which are designed and arranged for making a perfectly
tight joint at the places where the cable or conductor passes through to the
interior case and repeating device, and they are arranged something like
packing-box joints in steam engines and elsewhere. I make this outside casé
of copper, but it may be of any substance suitable to resist the pressure in
deep water. The repeater being properly arranged and the movable pivots
set in jewels, the electrical points of contact armed with a metal which does
not corrode, the whole is securely placed in the hard rubber or other suitable
case and hermetically sealed; then this case is fixed inside of the bombshell-
like case, or other similar contrivance, when the top or movable piece or cover
is firmly fastened down and hermetically sealed by brazing or otherwise. The
cable or line conductors project out at each side, as shown in Figure 7,
at w and x.
F:
The mode of laying the cables and repeating device may be as follows:-
At mid-ocean, or other given point, after the proper splices and connections
are made between the repeating device and the ends of the cables, and after
the connections are properly made and tested, the repeater may be thrown
overboard with the cable from the carrying vessels, which may then sail for
each shore, paying out the cable or line as they proceed; or a vessel may start
from one shore and proceed to the other, and when at the desired place to have
the repeater, proper connections may be made when the repeater may be thrown
overboard, as in the first case, and the vessel proceed to pay out the balance of
the cable. The necessary ground connections of the repeating circuits may be
made with the outside metallic casing, or copper chains with anchors may be
arranged for such connection, and serve also to anchor the repeater down. By
this arrangement it will be seen that I hermetically seal and submerge operators
in the middle of the ocean, which practically perform the duties of signal

page_text: officers. The signal being sent from the starting point to them (which may
be at a distance equal to the extreme length that an electric impulse or wave
can be transmitted through a conductor or cable), these signal men, as it were,
automatically send it on again to the next point or station, which may be just
as far as the first stretch. This arrangement I call the double-stretch circuit,
while the one represented at Figure 5 I term the single-stretch circuit. The
mode of operation of the electric current through the circuits, and also the
office and action of the mechanism of the repeater, differs but little from the
plan in Figure 5. The apparatus and batteries are exactly the same. The
only difference being in the repeater and the change of the single circuit into
a double one. The first circuit being formed by commencing at battery B
(sending station) and passing through wheel C, line or cable D, and coil E of
the repeater, and to the ground F, L, back to the battery. The second stretch
commences at the battery at the receiving station, and passes through wheel C,
and line or cable J, and armature or vibrator H of the repeater or relay, and
on through G, K, and A, back to battery B. It will be seen by this
arrangement that the line is divided into two parts, and each circuit is broken
or disturbed at two distinct places in each section. The more a line or circuit
can be broken up the more effectually is the return current destroyed and pre-
vented from forming. I have shown before, Figure 5, that two breaks or
openings in the circuit were produced in the arrangement for the single
stretch. Suppose this line or cable to be one thousand miles long. Now, in
Figure 6 I place the repeating signal or circuit closing and breaking apparatus
in the middle of the entire distance, which I will say is two thousand miles,
so that each stretch is just as long as the single stretch in Figure 5. Under
the former system of operating there never need be any difficulty at the sending
station with the ground or return current, as the circuit breaker or key can be
placed between the line and the battery, and when an opening or break is
made at this key point the battery current is entirely and effectively cut off
from the line, but under the old system it is not so at the receiving end or
station, as I have before described and shown at Figure 1, where there is no
break or disturbance produced in the abnormal current and circuits formed at
the receiving end by the receiving battery. In my plan it is quite different.
The space at e, Figure 6 (receiving station) is kept open alternately, accordingly
as a tooth or notch of the revolving wheel C comes in contact with the correspond-
ing mechanism which closes and opens space e (Figure 6). In order that no
ground circuit should be produced from the continual intermission of the
battery current by the continuously revolving wheel C, I form another opening

page_text: in the receiving circuit at I, and armature or vibrator H. This opening is
never closed except when the vibrator H in the repeater is attracted or drawn
forward by a current of electricity acting upon magnet or helix E. The.
magnetization of the coil E, and consequent attraction of the vibrator H,
takes place precisely at the same instant that the tooth or point corresponding
to the depressed key closes the spaces e and b, and the current from the battery.
produces the effect upon the magnet E, &c. at the same time the vibrator H
is drawn forward which closes the space at I, and the wheel C at the receiving
station being in unison with the sending revolving wheel, the space at e is
synchronously closed with I at the repeater, and e, b at the sending instrument.
The resultant action being the indicated signal or letter at the receiving
station. In order that the receiving mechanism may be used to send back to
the other or sending side,. a double conductor and corresponding connections.
in the repeater are necessary, or a double arrangement of the repeater with a
single conductor may be employed.
What I claim as my Invention and desire to secure by Letters Patent is,-
First, the revolving wheel C, Figures 5 and 6, located at or connected with
the receiving apparatus, arranged and operating as described, and for the
purposes set forth.
Second, arranging the circuit conductor and the battery at the receiving
station or instrument as described, so that the revolving wheel C, or other
equivalent device, may produce disturbances in the current and in the abnormal
circuit at that point, for the purpose set forth.
Third, the employment and arrangement of the self-adjusting repeating
device, with its balanced vibrator, and the locating of the same in mid-ocean or
practically so, and below the surface of the water or otherwise, and for the
purposes set forth.
Fourth, hermetically sealing the repeating apparatus described, or its
equivalent, when located between the sending and receiving apparatus, and
below the surface of the water or otherwise, and when employed for tele-
graphic uses.
Fifth, the forming of telegraphic submarine cables into two distinct parts,
stretches, or circuits, in the manner described, the division being located in the
ocean, and in the manner above indicated, or equivalently, for the purposes of
facilitating the working or extending or increasing the capacity of telegraphic
submarine conductors.

page_text: Sixth, in the operating of submarine or subterranean conductors of elec-
tricity, I claim the combination in the manner specified of the revolving
wheel C, C, magnet E, with the balanced vibrator and repeating fixtures, the
two circuits formed through B, D, E, F, L, and A on the side of the sending
station, and through B, A, K, G, H, and J on the side of the receiving
station, as represented in Figure 6, and for the purposes and uses named and
described.
In witness whereof, I, the said Silvanus Frederick Van Choate, have
hereunto set my hand and seal, this First day of Marcb, A.D. One
thousand eight hundred and sixty-five.
SILVANUS FREDERICK VAN CHOATE. (L.S.)