IMPROVEMENTS IN CHRONOMETER MOVEMENTS, APPLICABLE TO MARINE CHRONOMETERS, WATCHES, ASTRONOMICAL AND OTHER TIMEKEEPERS
Year: 1879

page_text: LETTERS PATENT to Edwin Ambrose Brydges, of the Firm Brydges and Co.,
Patent Agents, of 32, Belle Alliance Strasse, in the City of Berlin and Empire
of Germany, for the Invention of "IMPROVEMENTS IN CHRONOMETER
MOVEMENTS, APPLICABLE TO MARINE CHRONOMETERS, WATCHES, ASTRONOMICAL
AND OTHER TIMEKEEPERS." A communication by August Ernst Müller and
Johann Pollak, both of the City of Vienna, in Austria.
Canind the 20th T100A
JANA
PROVISIONAL SPECIFICATION left by the said Edwin Ambrose Brydges at
the Office of the Commissioners of Patents on the 31st December 1879.
EDWIN AMBROSE BRYDGES, of the Firm Brydges and Co., Patent Agents, of 32,
Belle Alliance Strasse, in the City of Berlin and Empire of Germany.
"IMPROVE
MENTS IN CHRONOMETER MOVEMENTS, APPLICABLE TO MARINE CHRONOMETERS,
WATCHES, ASTRONOMICAL AND
33
OTHER TIMEKEEPERS.' A communication by
August Ernst Muller and Johann Pollak, both of the City of Vienna, in Austria.
This is a new normal chronometer movement, and consists of the escapement wheel,
a ratchet mechanism, an impulsion mechanism, and a balance, with the necessary
springs.
The escapement wheel is shaped like a common chronometer escapement wheel,
only the teeth are a little more inclined; and another form I sometimes use is
formed to end in wedge shaped points whose upper wedge surfaces are in the line
of the periphery of the wheel. These wedge points of the teeth are of such size
that they find room in the cavity of a half cylinder, and do not hinder a turn of
30° of the same. The balance consists of the arbor to which two plates are
fastened, and also the shanks and weighted rim segments.
On one of these two plates of the arbor is mounted an elliptic stone, which causes
the detachment of the escapement, wheel, said plate having inserted thereon a
plate stone on which the impulses fall.
The second plate serves as a bearing and fastening for the balance shanks on
the arbor.
The shanks of the balance are of wood, boxwood being the most suitable

page_text: The wood must be rendered constant, and be impregnated. This is done in the
following manner.―
The roughly finished wooden shanks are laid upon wire nettings suspended in a
Inetal box. This drying apparatus is provided with a thermometer which shows
the interior temperature; below this box burns a spirit lamp with a flame sufficiently
hot to keep up a temperature of 160° to 180° Reaumur, but not to exceed this.
In this heat the wooden shanks are dried for say 12 hours, and then thrown into
copal varnish while hot. After a few hours the pores of the wood are filled with
this varnish. These wooden shanks, freed from the varnish adhering to the
surface, are again introduced into the drying apparatus and exposed to a heat of
60° to 100° Reaumur for say 24 hours. They are now constant, for they_undergo
no alterations of length by differences of temperature from 60° to 70° Reaumur,
and are not subject to hygroscopical influences.
Upon such wooden shanks rest rim segments fastened with screws, and screws
are used to serve for regulation, and to establish the equilibrium.
For a simple balance for watches, and such time pieces where the regulating is
done by means of a regulator plate on a spiral spring, rim segments are simply
fastened to the wooden shanks by means of screws.
These rim segments remain equidistant from the axis of the arbor under all
temperatures, the momentum of inertia of the balance being unchangeable. The
escapement mechanism consists of an anchor with anchor fork. On the plate of the
balance arbor is the elliptic stone, also the impulse stone as above stated, and
behind the elliptic stone the arbor has a notch.
The anchor moves over two teeth of the escapement wheel
The anchor teeth (Levéstones) move in circles, therefore when a tooth of the
escapement wheel rests upon an anchor tooth no retrograde motion of the escapement
wheel is caused by the lifting of the anchor tooth, only the even sliding friction
has to be overcome.
The anchor fork is of peculiar shape; it reaches to the arbor of the balance, and
has prongs, two of which do not touch the arbor. A third straight prong standing
above the forked prongs is a little longer.
When the balance turns, and with it the plate, the elliptic stone standing upright
gets between the two forked prongs, and leads the anchor fork in the same direction
until it rests against a pin. During this rotation of the arbor the prong gets into
the notch of the same.
Should (by continued rotation of the arbor) the anchor fork be inclined to go
back, this is prevented by the straight prong touching the arbor.
By means of the described proceeding the anchor has got into position, the
anchor tooth has been raised, and the tooth of the escapement wheel has become
free, in consequence of which the escapement wheel turns until the tooth rests on
the anchor tooth.
The ratchet mechanism can have, instead of the anchor, a half cylinder of ruby
or steel which encircles 200°, and is inserted in the arbor of the fork.
The wedge points of the escapement wheel teeth before mentioned move
exactly through the centre of this half cylinder, which is also the centre of the
forked arbor.
When the balance turns in a certain direction the elliptic stone of the plate
engages the fork and leads it to the other side of the balance arbor, through
which the middle straight prong engages with the notch of the balance-arbor, and
finally the arm rests against the stop pin. At this rotation the side of the half-
cylinder is raised, the tooth wedge point is liberated, a turn of the escapement
wheel ensues, until this wedge point rests against the inner wall of the half-cylinder
side, and the impulsion takes place.
When the balance returns from its swing it also leads the fork back until the
arm rests on the pin, the side of the half-cylinder rises, the tooth wedge point is
released, and a turn of the escapement wheel ensues until the wedge point of

page_text: one tooth falls upon the half-cylinder side, and the winding of the impulsion is
accomplished.
This escapement appertains to marine-chronometers and all kinds of time-pieces
The half-cylinder
which are intended to possess a high degree of correctness.
represents an anchor oscillating over one tooth. The difference of the resistance
of friction by weak and strong pressure of the escapement wheel against the
momentum of inertia of the perfectly balanced fork may be considered as nought,
consequently in many kinds of spring winding time pieces the endless screw with
chain might be omitted without danger to their correctness.
arbor.
The impulsion mechanisın consists of an arbor on which are arms, and underneath
is fastened a spiral spring; this spring is tightened and causes the rotation of the
The arm is straight and has a bond on its end; when this arm is lifted
by the escapement wheel the curve of this bend falls exactly upon the circum-
ference of the escapement wheel. The other arm of the impulsion consists of two
parts, namely, a short arm, upon which, as a second part, lies a spring which is
longer than it. By means of this spring the impulsion is effected, and the elasticity
Steel springs
of this spring is proper if at the stroke it sustains a small bend.
break easily, therefore gold springs only can be used.
The motion of the normal chronometer is as follows:-
The balance swings in a given direction when in a state of impulsion. After
complete impulsion the arm tests against a pin and the balance finishes its swing
completely undeterred.
On the return swing of the balance the impulsion stone passes the point of the
spring, the anchor fork is engaged by the elliptic stone and led to the other side of
the arbor, whereby the anchor tooth is raised and the escapement wheel tooth released,
consequently the escapement wheel begins the turn in given direction, and a tooth
of the same engages and lifts the arm till another tooth rosts on the anchor
tooth.
The position of escapement remains inactive so long as the balance swings back,
catching the anchor fork and leading it along, consequently the anchor tooth is
raised, the escapement wheel tooth disengaged, and the rotation of the escapement
wheel ensues. At this turn the impulsion arm is released and the impulse by
spring is given just at the moment when the impulse stone is before the point of
this spring. The lenst exertion of live force of the balance is obtained when the
lift of the anchor teeth is as small as possible. It may be 8°, but may be made
still less, if either the diameter of the arbor is reduced (in this case the elliptic
stone must be brought nearer to the arbor and the angular speed is lessened in
proportion), or if instead of the anchor teeth a half-cylinder is used. In the
description of the balances it is demonstrated that their momenta of inertia are
unchangeable, for which reason they require no compensation, but the spiral spring
of the balance requires compensation, for its flexibility and length alter considerably
under different degrees of temperature.
The spiral spring of the balance is compensated with mathematical correctness
by the spiral spring of the impulsion mechanism if both springs are made of one
and the same wire, and possess equal length, equal number of turns, and equal
diameter.
The impulse is always equally strong at equal temperature because the lifts of
the impulsion by the escapement wheel are decidedly of equal height. In getting
warm the spiral of the balance slackens; should the impulses now remain equally
strong, as they were before the balance spiral got warm, greater swings of the
balance would result, but the elasticity of the impulsion spiral altering quite
analogous to that of the balance spiral the impulses will be exactly so much weaker
as is required to maintain perfect uniformity of the swings. Equally large swings
of the balance take place in equal spaces of time.
Through this Invention all compensation mechanisms on balance wheels are
superfluous which, on account of their diverging effects, only allow an approximate
compensation, ranging at the most between 20° to 25° Reaumur difference of

page_text: temperature, while in this Invention, by mathematically and physically correct
arrangement and action of the parts of the escapement, the compensation of
expansions and of the module of elasticity for all temperatures on earth has been
attained. The mechanism for tightening the impulsion spiral are as follows:-On
a main plate is fastened with screws a disc which with its slanting edge holds a
disc in such a manner that it permits it to be turned by means of a nose, but that
the friction is greater than the tension of the spiral. On this disc is rivetted a
spiral block serving as a fastening to a spiral spring. Now if this spiral spring is
fastened to the impulsion arbor and by means of the nose the disc is turned in a
given direction the tightening of the spiral is effected, and by this disc being turned
backward or forward the impulses may be made stronger or weaker, consequently
the swings of the balance greater or smaller, and at last that point may be found
and fixed where the motion is reliable, that is, where the least exertion of force of
the escapement wheel is still more than sufficient to lift the impulsion mechanism.
On to the supporting plate is attached the regulating mechanism. Pins enclose the
impulsion spiral, and with them a proportional strengthening of the impulse is
effected in case when in use a difference of the impulsion spiral and the balance
spiral should be detected. Screws serve for regulation. The most exact regulation
is effected by enlarging or diminishing the swings of the disc. Watches retain the
usual regulating mechanism.
It will be obvious that many important advantages are obtained by the use of
my Invention, and I consider the following as important points therein :—
The new escapement mechanism.
The anchor which oscillates over two teeth of the escapement wheel, and whose
teeth (Levéstones) have the described form and position.
The long fork rod with three pronged fork, of which the middle straight one
stands higher and is longer than the two lower prongs, and
The notch in the balance arbor serving as a passage for this longer prong.
The second escapement mechanism where, instead of the anchor, a half cylinder
of steel or ruby is used, upon which fall the wedge points of the escapement wheel
teeth, as described, regarding the entire combination of the escapement wheel with
half cylinder and fork, balance arbor, and impulsion mechanism in the described
form, shape, and preformance of these single parts.
The described construction and combination of the anchor with the escapement
wheel and the half cylinder with the same, whereby the escapements of the escape-
ment wheel teeth ensue in the following manner, viz. :-The escapement wheel only
makes a short turn when the impulsion is to take place and a long turn when the
impulsion mechanism is to be raised.
The form of the impulsion arms with the described bend at the end.
The arrangement of the impulsion arm consisting of a spring, and the striking
against the pin being done by a shorter arm attached alongside.
The constant balances, their peculiar shape, and their combination of shanks of
prepared wood and rim segments, with or without regulating screws.
The compensation of the spiral spring of the balance through the spiral spring of
the impulsion mechanism. The application of two springs compensating each
other, of equal or unequal form and quality, belongs to the range of this division
because simple reckonings lead to it.
The arrangement for tightening the spiral spring of the impulsion whereby the
springs of the balance may be lengthened or shortened at will, and the timepiece
even be regulated.
The application of a regulating plate for the impulsion spiral spring.
The combination of all these parts to form a sure normal chronometer motion for
time pieces of various description.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edwin Ambrose Brydges in the Great Seal Patent Office on the
30th June 1880.
$5
EDWIN AMBROSE BRYDGES, of the Firm of Brydges and Co., Patent Agents,
of 32, Belle Alliance Strasse, in the City of Berlin and Empire of Germany.
IMPROVEMENTS IN CHRONOMETER MOVEMENTS, Applicable to MARINE CHRONO-
METERS, WATCHES, ASTRONOMICAL AND OTHER TIME KEEPERS." (A communication
by August Ernst Muller and Johanu Pollak, both of the City of Vienna, in
Austria.)
11
This new normal chronometer movement consists of the escapement wheel, a
.ratchet mechanism, an impulsion mechanism, and a balance, with the necessary
springs. The escapement wheel is shaped like a common chronometer escapement
wheel, only the teeth stand a little inore inclined (see Figs. 1, 3, 4, 5, 8, A, A,).
The escapement wheel A, A, Fig. 8, differs from those at present used owing to its
teeth q, qº, q', q", ending in wedge shaped points u, u, u¹, u¹¹, . . . whoso
upper wedge surfaces are in the line of the periphery of the wheel. These wedgo
points of the teeth are of such size that they find room in the cavity of the half-
cylinder k, k, and do not hinder a turn of 30° of the saine The balance b, b, (Figs.
4 and 5) consists of the arbor a, a, to which two plates b, b, and b', b', are fastoned,
also of the wooden shanks and the weighted rim segments. On the plates b, b, of
the arbor (Figs. 1, 2, and 3) is mounted an elliptic stone c, which causes the
releasing or detachment of the escapement wheel, and the plate stone d, upon which
the impulses fall, is further inserted. The plate b', b', (Fig. 5) serves as a bearing
and fastening for the balance shanks on the arbor. The shanks of the balance
(e, e, Figs. 4 and 5) are of wood, boxwood being the most suitable. The wood
must be rendered constant and be impregnated. This is done in the following
manner: The roughly finished wooden shanks are laid upon wire netting
suspended in a metal box. This drying apparatus is provided with a thermometer
which shows the interior temperature; below this box burns a spirit lamp with a
flame sufficient to keep up a temperature of 160° to 180° Reaumur, but not to
exceed this. In this heat the wooden shanks are dried for, say, 12 hours, and then
thrown into copal varnish while hot. After a few hours the pores of the wood aro
filled with this varnish. These wooden shanks, freed from the varnish adhering to
the surface, are again introduced into the drying apparatus and exposed to a heat
of from 60° to 100° R. for, say, 24 hours. They are now constant, for they undergo
no alterations of length by differences of temperature from 60° to 70° R., and are
not subject to hygroscopical influences Upon such wooden shanks rest the rim
segments ff, and f, f, fastened with the screws h, h, and h¹, h¹, Fig. 4. The
screws g, g, and g', g', serve for regulation and to establish the equilibrium.
Fig. 7 shows a simple balance for watches and such time pieces where the
regulating is done by means of a regulator plate on the spiral spring. The rima
segments f. f. are simply fastened to the wooden shanks e, e, by ineans of screws.
These rim segments ff, and, f, remaining equidistant from the axis of the arbor
under all temperatures the inomentum of inertia of the balance is unchangeable.
The escapement mechanism consists of an anchor with anchor fork (Figs. 1, 2,
and 3). On the plate b, b, of the balance arbor is the elliptic stone c the impulse
stone d, and behind the elliptic stone the arbor has a notch i. The anchor k, k',
moves over two teeth of the escapement wheel A, A. The anchor teeth
(Levéstones) move in the circles L, 1, and U, V, Fig 1; therefore when a tooth of
the escapement wheel rests upon an anchor tooth no retrograde motion of the
escapement wheel is caused by the lifting of the anchor tooth, only the even sliding
friction to be overcome. The anchor fork m has a peculiar shape (as shown in

page_text: Figs 1 and 3) and it reaches to the arbor of the balance. Two prongs o, o, do not
touch the arbor; a third straight prong n (Figs. 2 and 3) standing above the
forked prongs o, o, is a little longer. When the balance turns, and with it the
plate b, b, in the duection of the arrow x (Fig 3) the elliptic stone c standing
upright gets between the two forked prongs o, o, and leads the anchor fork in the
same direction until it rests against the pin p. During this rotation of the arbor
the prong n (Figs. 2 and 3) gets into the notch of the same. Should, by
continued rotation of the arbor, the anchor fork be inclined to go back, this is
prevented by the prong n touching the arbor. By means of the described
proceeding the anchor k, l, has got into the position shown in Fig. 1, the anchor
tooth has been raised, and the tooth of the escapement wheel q¹, Fig 3, has
become free, in consequence of which the escapement wheel turns until tooth q¹ is
rested on the anchor tooth. The ratchet mechanism, Fig. 8, shows, instead of
the anchor shown in Figs. 1 and 3, a half cylinder k, k¹, of ruby or steel, which
enciicles 200° and is inserted in the arbor of the fork m.
"
The wedge points uº, u, u¹, u¹¹,. . . of the escapement wheel teeth qº, 9, 9², q¹¹,
move exactly through the centre of this half cylinder, which is also the centre
of the fork arbor. When the balance turns in the direction of the arrow x¹, Fig 8,
the elliptic stone c of plate b engages the fork m and leads it to the other side of the
balance arbor, through which the middle straight prong engages with the notch i
of the balance arbor, and finally the arm w, w, rests against the stop pin p. At
this rotation the side k of the half-cylinder is raised, the tooth wedge point u is
liberated; a turn of the escapement wheel ensues until this wedge point u rests
against the inner wall of the half cylinder side ', and the impulsion takes place;
when the balance returns from its swing it also leads the fork back until the
arm w, w, rests on the pin p, the side k¹ of the half cylinder rises, the tooth wedge
point is released, and a turn of the escapement wheel ensues until the wedge
point uº of one tooth 7° falls upon the half cylinder side, and the winding of the
impulsion is accomplished. This escapement apertains to marine chronometers and
all kinds of time pieces which are intended to possess a high degree of correctness.
The half-cylinder represents an anchor oscillating over one tooth. The difference
of the resistance of friction by weak and strong pressure of the escapement wheel
against the momentum of inertia of the perfectly balanced fork may be considered
as nought, consequently in many kinds of spring winding time pieces the endless
screw with chain might be omitted without danger to their correctness.
The impulsion mechanism consists of an arbor r, r, Fig. 2, on which are the
arms 8, 8, and s¹, 8¹ (Figs. 1, 3, and 8), and underneath is fastened a spiral spring t,
Fig. 5. This spring is tightened, and causes the rotation of the arbor in the
direction of arrow y (Figs. 1 and 3) The arm 8, 8, is straight and has a bend on
its end. When this arm is lifted by the escapement wheel (as shown in Fig. 1) the
curve of this bend falls exactly upon the circumference of the escapement wheel.
The other arm 81, 81, of the impulsion consists of two parts, namely, a short arm,
upon which, as second part, lies a spring, which is longer than it. By means of
this spring the impulsion (Fig. 3) is effected, and the elasticity of this spring is
proper if at the stroke it sustains a small bend. Steel springs break easily,
therefore gold springs only can be used. The motion of the normal chro-
nometer is as follows.-The balance swings in direction of arrow x¹, Fig. 3,
and is in a state of impulsion After complete impulsion the arm 8² rests against
the pin z, Figs 1, 3, and 8, and the balance finishes its swing completely undeterred.
At the return swing of the balance in direction of arrow a the impulsion stone d
passes the point of the spring, the anchor fork is engaged by the elliptic stone c
and led to the other side of the ai bor, whereby the anchor tooth is raised, and
the escapement wheel tooth q¹ released, consequently the escapement wheel begins
the turn in direction of arrow, and the tooth 93 of the same engages and lifts the
arın 8 till the tooth q°, Fig. 1, rests on the anchor tooth k. The position of escape-
ment shown in Fig. 1 remains inactive till the balance swings back in the direction

page_text: of arrow 2, catching the anchor fork, and leading it along; consequently the anchor
tooth k is raised, the escapement wheel tooth disengaged, and the rotation of the
escapement wheel ensues, At this turn the impulsion arm & is released, and the
impulse by spring & is given just at the moment when the impulse stone d is
before the point of this spring s¹. The least exertion of live force of the balance is
obtained when the lift of the anchor teeth is as small as possible. In the Drawing
it is 8°, but it may be still smaller; if either the diameter of the arbor is
reduced, (in this case the elliptic stone c must be brought nearer to the arbor, and
the angular speed is lessened in proportion), or if instead of the anchor teeth a half
cylinder k, k, (Fig. 8) is used. The construction of this motion is shown in the
Drawings (Figs 4, 5, and 6). In the description of the balances it is demonstrated
that their momentum of inertia are unchangeable, for which reason they require no
compensation, but the spiral spring of the balance requires compensation, for its
flexibility and length alter considerably under different degrees of temperature.
The spiral spring of the balance (G, G, Figs. 4 and 5) is compensated with
mathematical exactness by the spiral spring of the impulsion mechanism, if both
springs are made of one and the same wire, and possess equal length, equal number
of turns, and equal diameter. The impulse is always equally strong at equal
temperatures, because the lifts of the impulsion by the escapement wheel are of
equal height. In getting warm the spiral of the balance slackens; should the
impulses now remain equally strong, as before, the balance spiral gets warm, and
greater swings of the balance would result, but the elasticity of the impulsion spiral
altering quite analogous to that of the balance spiral, the impulses will be exactly
so much weaker, as is required to maintain perfect uniformity of the swings.
Equally large swings of the balance take place in equal spaces of time. Through
this Invention all compensation mechanisms on balance wheels are superfluous,
which on account of their diverging effects only allow an approximate compensation,
ranging at the most between 20° and 25° Reaumur difference of temperature, while
in this Invention, by mathematically and physically correct arrangement and action
of the parts of the escapement, the compensation of expansions and of the module of
elasticity for all temperatures on earth has been attained. The mechanism for
tightening the impulsion spiral may be seen in Figs. 5 and 6. On the main plate c, c,
is fastened with screws v, v, a disc V, which, with its slanting edge, holds the disc t, t,
in such a manner that it permits it to be turned by means of the nose w, but that the
friction is greater than the tension of the spiral. On this disc is rivetted the spiral
block t serving as a fastening to the spiral spring t, t. Now if this spiral spring is
fastened to the impulsion arbor, and by means of the nose the disc T, T, is turned
in direction of arrow w the tightening of the spiral is effected, and by this disc
being turned backward or forward the impulses may be made stronger or weaker,
and consequently the swings of the balance greater or smaller, and at last that point
may be found and fixed upon where the motion is reliable, that is where the least
exertion of force of the escapement wheel is still more than sufficient to lift the
impulsion mechanism; on to the supporting plate H, H, Figs. 5 and 6, is attached
the regulating mechanism D, D. The pins u, u, enclose the impulsion spiral,
and with them a proportional strengthening of the impulse is effected, in case
when in use a difference of the impulsion spiral and the balance spiral should be
detected.
The screws g, g, and gl, g', Fig. 4, serve for regulation. The most exact regulation
is effected by enlarging or diminishing the swings of the balance by means of the
dise T, T, (Figs 5 and 6). Watches retain the usual regulating mechanism.
The advantages of this Invention are,-
(a.) Exclusion of all hand work and of difficult construction of the escapement
parts, consequently
(b.) All parts of this motion can be made by machinery, and
(a) This normal chronometer can be manufactured at the same cost as patent

page_text: (d.) Exclusion of all compensation and auxiliary compensation devices on the
balance, on the contrary
(e) The compensation of expansions and elasticity for all temperatures is
obtained to perfection by the quality, form, action, and arrangement of the escape-
ment parts to each other being based upon principles mathematically and physically
correct.
(f.) Independence of the motion of the driving parts, in consequence of which
the unequal exertions of force of the escapement wheel have no influence.
(9.) The endless screw and chain, the isochronous spring, as well as the brake,
may be done away with entirely.
(h.) Short spiral springs may be used, which give smaller expansions and
differences of elasticity.
(.) The use of lighter balances, because the escapement requires far less power
than those of the chronometer and lever motions now in use, consequently
(k) Saving of traction power, less resistance of friction, and greater durability 1
of time pieces with this chronometer motion.
(.) Infallably sure motion, which
(m.) Does not stop, for it starts of itself at beginning of exertion of force by the
escapement wheel, and finally
(n.) The regulation of these time pieces is easier because one has entire and easy 2
control over the swing of the balance.
•
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed or carried out in
practice, I hereby declare that I claim,-
(1.) The new escapement mechanism, shown in Figs. 1, 2, and 3, consisting (a) 2
of the anchor which oscillates over two teeth of the escapement wheel, and whose
teeth (Levestones) have the described form and position; (b) of the long fork rod
with three pronged fork, of which the middle straight one stands higher and is
longer than the two lower prongs; and (c) of the notch in the balance arbor,
serving as a passage for this longer prong.
(2.) The second escapement mechanisın (shown in Fig. 8), where, instead of the
anchor a half-cylinder of steel or ruby is used, upon which fall the wedge points of
the escapement wheel teeth as described, and as regards the entire combination of
the escapement wheel with half-cylinder and fork, balance arbor, and impulsion
mechanism in the described form, shape, and performance of these single parts.
(3.) The described construction and combination of the anchor with the escape-
ment wheel and the half cylinder with the same, whereby the escapements of the
escapement wheel teeth ensue in the following manner, viz., the escapement wheel
only makes a short turn when the impulsion is to take place, and a long turn
when the impulsion mechanism is to be raised.
(4.) The form of the impulsion arm with the described bend at the end.
(5.) The arrangement of the impulsion arm, consisting of a spring, and the
striking against the pin being done by a shorter arm attached alongside.
(6.) The constant balances, their peculiar shape, and their combination of shanks
of prepared wood and rim segments, with or without regulating screws.
(7.) The compensation of the spiral spring of the balance through the spiral
spring of the impulsion mechanism; the application of two springs compensating
each other, of equal or unequal form or quality, belongs to the range of this
division, because simple reckonings lead to it.
4
(8) The arrangement for tightening the spiral spring of the impulsion, whereby 5
the swings of the balance may be lengthened or shortened at will, and the time
piece even be regulated.

page_text: (10.) The combination of all these parts to form a sure normal chronometer
motion for time pieces of various descriptions.
In witness whereof, I, the said Edwin Ambrose Brydges, have hereunto set
my hand and seal, this Twenty third day of June, in the year of our Lord
One thousand eight hundred and eighty.
Witnesses,
GUSTAV EHTEN,
MAX NESSELRODE.
EDWIN AMBROSE BRYDGES. (L.S.)