IMPROVE- MENTS IN ELECTRO-MAGNETIC TIMEKEEPERS
Year: 1862

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN ELECTRO-MAGNETIC TIMEKEEPERS."-A communication from abroad
by John Henry Koosen, of Dresden, in the Kingdom of Saxony.
Sealed the 10th February 1868, and dated the 15th August 1862.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at.
the Office of the Commissioners of Patents, with his Petition, on the
15th August 1862.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for.
"IMPROVEMENTS IN ELECTRO-MAGNETIC TIMEKEEPERS," a communication from
abroad by John Henry Koosen, of Dresden, in the Kingdom of Saxony, to be
as follows:-
This Invention relates to a peculiar construction and arrangement of what
the Inventor terms a "galvanic chronometer with centrifugal regulator," and
consists, firstly, of a peculiar construction and arrangement of electro-magnetic
machine for actuating the works of the chronometer, and of which it forms a
part; and secondly, of a peculiar construction and arrangement of centrifugal
regulator for controlling the speed of the electro-magnetic machine, and so
regulating the movements of the chronometer.

page_text: The electro-magnetic machine as proposed to be applied, as a rotatory one,
so constructed and arranged that the accelerating force acts nearly uniformly
in all phases of its rotation, and that no intervals of suspension of the acting
power can interfere in any part of the revolution. This is accomplished by
ensuring that the several electro-magnets forming part of the apparatus sball
not be magnetized simultaneously but successively, so that no absolute inter-
ruption of the galvanic current can ever take place, the current being made to
proceed from the coil of one electro-magnet after the latter has acted upon the
corresponding soft-iron bar directly into the coil of a second electro-magnet,
which begins to act in a similar manner to the first on a second soft-iron bar,
and so on, thus keeping up a continual rotation.
In carrying out the above conditions it is proposed to employ three electro-
magnets, placed in a vertical position and so disposed that their six poles will
form points equidistant from each other in a horizontal circle, the whole of the
poles being in the same horizontal plane. The wire for the coils should be as
thin as possible, say, from one to two hundredths of an inch in diameter, well
covered with silk and strongly varnished. The ends of the two coils of each
electro-magnet are so connected that the current proceeds through both coils
successively, and the two poles receive opposite magnetic polarity. The wires
are further connected with the poles of the galvanic battery in such a manner
that the poles next to each other in the circle of electro-magnets shall have
opposite polarity, or be alternately north and south throughout the series.
Immediately above and as close as possible to the poles of the electro-magnets
are two soft-iron bars with cylindrical ends, which bars are secured to a ver-
tical axis or spindle at right angles to each other, so that their four extremities
shall form a rectangle in a perfectly horizontal plane. This axis or spindle is
terminated at its lower end by a steel centre point rotating in a suitable foot-
step also of hard steel, whilst its upper extremity is provided with a steel
spindle working in brass bearings. Immediately below this spindle is fitted a
wheel, which transmits the rotation of the spindle by suitable gearing to the
hands of the clock or chronometer. A commutator is employed for regulating
the entrance of the current into the different coils, consisting of a ring or disc
of wood permanently fixed concentrically to the main axis or spindle, and
having twelve plates of silver strongly gilt inlaid in its upper surface with
small interstices between the contiguous edges of the several plates. To the
outer edge of each plate is fitted or formed a small hook of silver wire, to each
of which is fastened one end of the wire coils in the order and succession
required by the relative positions of the magnetic poles and the corresponding
poles of the soft-iron bars. The other ends of the wire coils are connected

page_text: with each other and with one pole of the galvanic battery permanently. The
other pole of the battery conducts the current into the vertical axis, whence it
passes into a brass rod or arm fastened to the axis at right angles thereto a
little above the commutator, a bunch of fine gold wire being attached to each
end of the arm of brass rod, and sliding over the different sections of the com-
mutator when the axis is rotated, thereby leading the current into the different
coils successively. As the velocity of the rotation depends upon the intensity
of the current, it is proposed to adapt to the apparatus a peculiar regulator or
governor, in order that the velocity may be independent of the intensity of the
current and a uniform motion be produced. This regulator consists essentially.
of a steel rod pivotted at its centre of gravity, so as to be in equilibrium upon
a steel pin or axis supported in hard bearings in a metal ring secured to and
encircling the vertical main axis concentrically. The two ends of the steel rod
have screw threads formed upon them, and on to each is screwed a brass ball,
capable of adjustment towards or from the pivotting centre of the steel rod.
When the apparatus is at rest, the steel rod remains at an angle of from 30°
to 40° with the vertical axis, but on a rotatory motion being imparted to the
main axis, the rod, by reason of centrifugal force, approaches a horizontal
position, and it is this movement which is made to regulate the action of the
current upon
the coils. To the lower end of the steel rod is attached a brass
wire, the point of which is tipped with gold or platinum, and rests, when the
apparatus is not in motion, against a plate of platinum secured to the main
vertical axis of the apparatus, but insulated therefrom. To the upper end of
the steel rod is connected by means of a fine platinum wire one end of a thin
steel blade spring, the other end of which is secured into the supporting ring.
of the regulator, so that the tension of this spring shall always tend to keep
the point of the brass wire against the platinum plate herein-before referred to..
This plate is connected by means of a fine platinum wire with the brass rod or
arm before mentioned revolving above the surface of the commutator. The
current first enters the main vertical axis, passes thence into the brass ring of
the regulator attached thereto, along the steel spring and platinum wire into
the steel rod, and from that rod through the brass wire and platinum plate,
and into the brass rotating arm, from which it proceeds through the bunches
of gold wire into the different sections of the commutator, and passes thence
into the different coils successively, and sets the apparatus in motion. At a
certain proper velocity the centrifugal force of the steel rod with the brass
balls will be exactly counteracted by the tension of the blade spring, but should
that velocity increase in the least degree, the increased centrifugal force-so
generated will cause the steel rod to approach nearer to a horizontal position,

page_text: and will effect a breaking of the metallic contact between the metal point
and the platinum plate, when a momentary interruption of the current will take
place and an instantaneous slackening of the speed will follow, until the
decreased centrifugal action again establishes the contact.
pro-
For the obtainment of greater regularity of working, it is proposed to
employ two steel rods and pairs of balls in each apparatus, both rods acting
equally upon the same platinum plate. The adjustment of the working of the
clock may be effected either by adjusting the balls on their steel rods, or by
suitably varying the tension of the blade springs. Compensation for change of
temperature is afforded by having the regulator rods made of steel, whilst the
arms which form the contact with the platinum plate are of brass; the differ-
ence in the expansion of these metals compensating in a great measure any
variation arising from change of temperature. For the same purpose strips of
-platinum and silver soldered together are fixed to the blade springs and
vided with small adjustable balance weight. A modification of "Daniells'
battery" is employed for the purpose of ensuring an almost invariable strength
of current for a long period of time. In some cases it is proposed to work two
or more such chronometers from the same or different batteries, the different
electro-magnetic machines in each clock being regulated or controlled in a
great measure by the regulator or governor of the first of the series of clocks,
so that their movements may be perfectly isochronous. For this purpose the
ends of the wire coils belonging to the second clock are so connected with a
second commutator on the first clock, that by the rotation of the axis of the
latter instrument, the current by means of a bunch of gold wire connected to
an arm on the main axis and sliding over the metallic sections of the second
commutator, enters the wire coils of the second instrument in the same suc-
cession and in the same intervals as the corresponding coils of the first
instrument. In order to insure a perfect coincidence of rotation, however, it
is found advisable to apply a special commutator also to the second
instrument.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 14th February 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain,
Gentleman, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of August, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Henry Johnson, Her special license that I, the said John Henry
Johnson, my executors, administrators, and assigns, or such others as I, the said
John Henry Johnson, my executors, administrators, or 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 Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
ELECTRO-MAGNETIC TIMEKEEPERS," a communication from abroad by John Henry
Koosen, of Dresden, in the Kingdom of Saxony, upon the condition
(amongst others) that I, the said John Henry Johnson, my executors or
administrators, by an instrument in writing under my hand and seal, or
under the hand and seal of one of them, 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
Patent Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
The said Invention relates to a peculiar construction and arrangement
of what the Inventor terms "a galvanic chronometer with centrifugal
regulator," and consists,―
Firstly, of a peculiar construction and arrangement of electro-magnetic
machine for actuating the works of the chronometer, and of which it forms
a part.
And, secondly, of a peculiar construction and arrangement of centrifugal
regulator for controlling the speed of the electro-magnetic machine, and
thereby regulating the movements of the chronometer.
Figure 1 of the annexed Sheet of Drawings represents a full sized per-
spective view of the entire apparatus complete, with the exception of the
battery, which forms no part of the present Invention, and the rest of the
Figures are details herein-after more particularly described and referred to.
The improved electro-magnetic machine, as here applied, is one of rotation,

page_text: and has this peculiar property, that the accelerating force acts almost uniformly
in all phases of its rotation, and that no intervals of suspension of the acting
power can intervene in any part of the rotation. This is effected on the
principle that the several electro-magnets forming part of the machine are not
magnetised simultaneously, but successively, so that no absolute interruption
of the galvanic current can ever take place, but the current proceeds from the
coil of one electro-magnet, after the latter has performed its action on the
corresponding soft-iron bar, directly into the coil of a second electro-magnet,
which begins to act in a similar manner to the first on a second soft-iron bar,
and so on.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed,
the same letters of reference indicating corresponding parts in all the
Figures.
On a brass plate A (Figure 1), of about six inches diameter, provided with
three elevating screws B, B, B, are fitted permanently three electro-magnets
C, C, C, with cylindrical arms, so that their six poles are directed upwards,
each of which is about three-quarters of an inch in diameter, the series of
poles forming a regular hexagon, laying all six in the same horizontal plane.
Figure 2 shows a detail of one of these electro-magnets, the dotted lines
indicating the extension of the wire coils. Both arms of the electro-magnet
can be screwed off from their connecting plate D by means of short screws
at E, E.
The wire for the coil must be selected as thin as possible, about 1th to
ths of an inch in diameter, it should be well covered with silk, and strongly
warnished. The ends of the two coils of each electro-magnet are so connected
that the current proceeds through both coils successively, and the two poles
receive opposite magnetic polarity; the wires are further connected with the
poles of the galvanic battery in such a manner that the poles next to each
other in the hexagonal plane are magnetised with opposite polarity during the
rotation of the machine. Immediately above and as close as possible to the
poles of the electro-magnets rotate two soft-iron bars F, F, with cylindrical
ends; they are screwed on to a brass pin or axle G at right angles to each
other, so that their four ends or poles form a regular rectangle in a horizontal
plane. The brass pin or axle terminates below in a hard steel point, resting
in a conical hollow also made of hard steel; its upper end is also provided
with a steel spindle running in brass bearings, and immediately below the
spindle it carries a wheel, which transmits the rotation of the axle by means

page_text: of a system of toothed gearing to the hands of a clock, and so indicates the
number of rotations of the machine, or the hour upon the dial.
The entrance of the galvanic current into the different coils is regulated by
the commutator H, consisting of a ring or disc of mahogany, permanently
fixed concentrically to the axle of the machine, and kept in this position by a
brass bracket or arm. The upper surface of this ring is inlaid with twelve
plates of silver a, a, strongly gilt, and separated from each other by small
interstices, as shewn in the detail plan (Figure 3). Each of these plates is
provided on its outer edge with a small hook 6 of silver wire whereon to
fasten one end of the wire of the coils in such order and succession as is
required by the relative positions of the magnet poles and the corresponding
poles of the rotating soft-iron bars. The other ends of the three wire coils are
permanently connected with each other and with one pole of the galvanic
battery, whilst the other pole of the battery conducts the current into the
axle G through its bearings, thence into a brass rod I fastened to the axle at
right angles thereto, and carrying a bunch of the finest gold wire, which slides
with easy pressure over the different sections a of the commutator, and in this
manner during the rotation of the machine leads the current into the different
coils. As, during each rotation of the axle the current enters the series of
coils twelve times, it consequently enters each coil four times during each
revolution. This contrivance produces a continuous and uniform accelerating
power on the moveable parts of the machine. The velocity of the rotation
being of course entirely dependent upon the intensity of the galvanic current,.
it is requisite in order to render it independent of this intensity, and to
produce a uniform velocity to employ a contrivance called a regulator, which
is fixed on the axle G.
This regulator, the principle of which is shewn in detail at Figure 4,
consists essentially of a steel rod K, through the centre of gravity of which
passes a steel pin or axle L (Figure 5); this pin is provided at the ends with
conical points of hard steel, which rest in conical steel or jewelled bearings,
carried in set screws M, M, so that the whole rod may turn round its centre
of gravity with the least possible amount of friction. The two ends of the
steel rod K are provided with screw threads and a brass ball screwed on to
each end, which can be adjusted higher or lower accordingly. The bear-
ings M, M, in which the axle L of the rod rests are let into the circumference
of a brass ring N, which is fixed concentrically on to the axle of the machine,
and turns with it. By the rotation of the machine and the easy suspension of:
the steel rod, it is evident that the latter will at the smallest velocity of rotation
assume a horizontal position by the action of its centrifugal force as soon as

page_text: the brass balls are brought in such a position that the centre of gravity of the
whole rod passes through its axis of suspension. By the latter condition the
action of the gravity on the rod is excluded, and in any position of the whole
instrument or of its axle (which therefore need not be a vertical one) the
conditions for the equilibrium of the steel rod will be independent of the
action of gravity, and solely influenced by the velocity of rotation of the whole
instrument. This greatly facilitates the keeping of the velocity of rotation
uniform by means of the centrifugal force of the steel rod. On its lower end
the steel rod carries a brass arm O (Figure 4), tipped with gold or platinum;
this gold or platinum point rests while the machine is not in motion against a
thin and slightly feathering plate of platinum P, which is fastened to the axle
of the machine by a non-conducting substance, such as a ring of ivory, so that
the current cannot pass directly from the axle into the plate P. To the upper
end of the steel rod is fastened, by means of a thin platinum wire Q, the end
of an elastic steel spring R, the other end of which is secured at S into the
brass ring N, so that by the tension of this spring the arm O is pressed with
its point against the platinum plate whilst the machine is not in motion. The
galvanic current enters through the main vertical axle into the brass ring N,
whence it passes at S into the steel spring R, thence at Q into the rod K,
from there at O into the platinum plate P; this plate is connected through a
fine platinum wire T (Figure 4) with the brass rod I, which carries a bunch
of gold wire sliding on the metallic sections of the commutator, and so the
current enters the different coils successively, and sets the instrument in motion.
At a certain velocity the centrifugal force of the rod K, with the brass balls
will be exactly counterpoised by the tension of the spring, and the velocity of
the machine will remain always uniform; for the least increase of velocity
would, by the consequent increased centrifugal action of the steel rod, effect a
separation of the arm O from the platinum plate, consequently effecting an
interruption of the galvanic current, and an instantaneous slackening of the
rotation until the decreased centrifugal action of the steel rod again produces
the metallic contact at O, and renews the action of the galvanic current. In
fact, during the uniform rotation of the machine the point of the arm O either
vibrates within an immeasurable distance from the platinum plate P, or touches
it with the slightest pressure. The steel rod K forms an angle of from 30
to 40 degrees with the axle of the machine; there are two such rods or
regulators to every machine, both of the same construction, and the arms of
both touching the same platinum plate on the opposite sides of the same.
They are further so regulated that at a given velocity of rotation both rods
interrupt the galvanic current nearly at the same moment. By introducing

page_text: two equally constructed regulating rods, any irregularity in the working of the
clock through any moinentary interruption of the galvanic current (as might
sometimes happen if only a single regulator were used) is rendered impossible.
The regulation of the working of the clock is effected either by altering the
tension of the steel spring R, or by adjusting the brass balls on their screws;
the latter correction must always be effected so that the position of the centre
of gravity of the whole regulator is not materially changed.
Compensation for change of temperature is afforded by the regulator rods
being made of steel while their arms O touching the platinum plate are of
brass, the different expansion by heat of the two metals compensating the
influence of this expansion in a certain measure. The action of change of
temperature on the tension of the steel spring is counteracted by strips of
platinum and silver soldered together, and fastened on the steel rod; these
strips being provided with small brass weights, which can be adjusted higher
or lower along the strips.
In order that the regulation of the clock may not be affected when the axis
of revolution is brought out of its usual vertical position, it is not only necessary
that the centre of gravity of each of the regulator rods should pass through the
axle of its suspension; but it is likewise requisite that the centre of gravity of
the whole system in rotation should fall as close as possible within the axis of
revolution, so that in every position of the latter equilibrium in reference to the
action of gravity will be obtained. Although the working of a chronometer of
the above description ought to be independent of the intensity of the electric.
current, yet for the exactness of the instrument it is advisable that the alte-
rations of the galvanic power should be kept within certain limits. For this
purpose a modified form of battery is employed, and although this battery
forms no part of the present Invention, it construction should be explained, as
by means of this battery alone, can a galvanic current of almost invariable
strength for months, and even years, be obtained at a trifling expense.
This battery consists of a modification of Daniells' battery; the copper plate
surrounded by sulphate of copper fills the lower half of a common tumbler,
whilst its upper half contains an unamalgamated zinc cylinder, surrounded with
slightly acidulated water. The separation of both fluids is effected either by a
layer of paper fibre (torn into small pieces) of about one inch thickness, and
pressed into the glass with great force, or what appears to be still better by a
sheet of vulcanized paper several times folded together, into which sheet the zinc
cylinder is wrapped perfectly water-tight and lowered down into the tumbler.
The vegetable membrane of the above description appears to be the only
substance capable of preventing entirely the diffusion of beth fluids for any

page_text: great length of time. For an instrument of the size mentioned, a single
Daniells element of six inches in hight, and three inches diameter is
sufficient to keep the clock in motion for a year, without further attention.
The present Invention relates also to an arrangement, by which two or
more chronometers of the description above referred to, placed at any
dis-
tance from each other, can be made to perform their revolutions absolutely
isochronous for any length of time, both being worked either by the same, or
by different galvanic batteries. This is effected in the following manner:-
Supposing for example that A is a chronometer of the description above given;
this instrument may be made to regulate the revolutions of a second instru-
ment B, without the latter being provided with a special regulating rod, when the
ends of the wire coils, belonging to the instrument B, are so connected with the
metallic plates of a second commutator U belonging to the instrument A
(Figure 1), that by the rotation of the axis of that instrument, the current, by
means of a bunch of gold wire, connected with the axis, and sliding over the
metallic sections of the second commutator enters the wire coils of the instru-
ment B in the same succession, and at the same intervals as the corresponding
coils of the instrument A. In other respects the second commutator has no
further connection with the instrument A, or with its coils; this contrivance
serving the purpose only of conducting a galvanic branch current into the plates
of the second commutator, and thence into the coils of the instrument B, at the
same moments and at the same intervals in which the main current enters the
coils of the first instrument A, through the plates of the first commutator
regulated by the mechanism of the centrifugal governor. The instrument B
does not absolutely require a special regulator or commutator of its own, as
the exciting of its electro-magnets, and consequently its velocity of rotation is
already regulated through the revolution of the first instrument, by means of
the second commutator fixed thereon.
But in order to ensure a more perfect coincidence of rotation with the
successive exciting of its coils, and therefore with the rotation of the first
instrument A regardless of any great variations in the intensity of the galvanic
branch current, the instrument B is likewise provided with a special commutator
with whose twelve metallic plates the other wire ends of the coils are connected
in such a manner, that the branch current coming from the instrument A into
the coils of the instrument B only finds a passage open to return back to the
other pole of the galvanic battery, when the position of the movable soft iron
bars in the instrument B is such a one, relative to the corresponding poles of
the electro-magnets, that mutual attraction between these parts in the direction
of rotation will ensue at an absolute equal velocity of rotation in both instru-

page_text: ments, this relative position will always be maintained; but if the velocity in
the instrument B should gain in the least on that of A, as indeed it always
has the tendency to do, then a change in the symmetrical position of the
movable iron bars in both instruments in reference to the fixed-poles of the
electro-magnets takes place, and the branch current coming from A does not
find any return circuit through the two commutators simultaneously open, and
therefore cannot pass through the coils of the second instrument, or it will
pass into these coils only at such periods when the position of the moveable
iron bars in reference to the poles of the electro-magnets is such a one that
their mutual attraction will act contrary to the direction of rotation, in both
cases the velocity of the second instrument will decrease until the normal
position of the respective parts be restored, and then the galvanic current will
again be able to act with full power.
Although the instrument B does not require a special centrifugal regulator,
as its revolutions are entirely regulated by those of the instrument A, yet for
the sake of greater certainty in case of sudden jerks in consequence of a great
increase of galvanic force, I have thought it advisable to place a single regulator
rod in this instrument likewise, but this regulator is so constructed that it
opens and interrupts the galvanic current at à velocity only which is greatly
above the normal velocity of rotation. Two such chronometers with isochronous
rotation may be kept going for several months if there be no great distance
between them with one of the above-mentioned Daniells' elements, but in
order to insure the continual coincidence of their revolutions, a current from
two such elements will be necessary.
According to this arrangement of the two instruments, a connection between
them by means of four isolated wires is indispensable, namely, three for the
entrance of the current into the three electro-magnets of the second instrument
and one wire for the return of the current into the battery; but it is evident
that the action of two of the electro-magnets in the second instrument may be
entirely dispensed with, in which arrangement only one single isolated wire is
employed, the current being led back through the soil, but in this case, in order
to keep the twin chronometers in proper action and coincidence, as regards
their revolutions, a battery of three Daniells' elements is required. It is
evident that by means of these twin chronometers, two discs or cylinders might
be made to revolve at two different stations absolutely isochronous in all the
different phases of their motions, and that these instruments may be applied to
the use of astronomical observation, and to the simplification of telegraphic
correspondence.
Having now described and particularly ascertained the nature of the

page_text: Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel
and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent, is,―
First, the general construction and arrangement of chronometers or time-
keepers actuated by galvanic currents, as herein-before described and illustrated
by the annexed Sheet of Drawings.
Second, the peculiar construction and arrangement of electro-magnetic
machines, and their applications, as herein-before described.
Third, the herein-before described peculiar construction and arrangement of 1
governor or regulator, and its application in combination with the above
described electro-magnetic machine, for the purpose of controlling the move-
ments of chronometers or timekeepers.
In witness whereof, I, the said John Henry Johnson, have hereunto set
my hand and seal, this Thirteenth day of February, One thousand eight I
hundred and sixty-three.
J. HENRY JOHNSON. (L.S.)