WATCH, is another example of this kind of mechanism, which, without
being re-set from time to time for leap year and other changes, keeps
a perpetual register of seconds, minutes, hours, days, weeks, months,
and years, shows Old and New Styles, the phases of the moon, and
variations of heat and cold. It has also two separate trains of
wheels and two mainsprings, both of which are wound up by the button
at the pendant. It will be seen that the dial has two hour circles
with hour and minute hands showing separate time. Below the centre is
the sunk seconds dial with two seconds hands, the one over the other,
and each working independently, so that the one may be stopped by a
push at the button of the pendant and yet the other go on, to be in
its turn stopped, so that the operator may use it as a stopwatch.
Underneath the hour hands of each circle is the hand showing the month
and the day of the week. The two centre hands, with the letters G and
R, are pointing to the days of the month, and showing the Gregorian
and Russian day. In the small square space just below the centre is
the year, and below this and lying over the second hands is another
hand pointing to the degrees of temperature to which the watch is
exposed; near the top of the dial is a small plate showing the phases
of the moon,--the position indicated in this illustration is that of
full moon.
The MERIDIAN WATCH shows the time of day in any number of places in
any part of the world. It is set to Greenwich time, and marks the
difference between this and the time of all the great metropolitan
cities in both hemispheres,--as St Petersburg, Constantinople, New
York.
The name CHRONOMETER,--derived from the
+----------------------------------------------------------------------+
| [Illustration: The Meridian Watch.] |
+----------------------------------------------------------------------+
Greek, and meaning a time-measurer,--is chiefly applied to marine
time-pieces and to watches which have been carefully made with
chronometer or detached escapements and compensating balances serving
to equalize the effects of heat and cold. MARINE CHRONOMETERS are the
chief instruments for discovering the longitude at sea, and are
therefore subjected to special tests at Greenwich observatory and
elsewhere before being sent on board ship. They have dials of three or
four inches in diameter, hour, minute, and second hands, besides a
hand to indicate the day upon which the instrument was last wound
up,--and they are made to go from two to eight days. Being well
mounted on gimbals inside of an air and water-tight brass case they do
not toss about with the motion of the ship but always preserve their
equilibrium. For extra protection they are generally kept enclosed in
a mahogany case. Chronometers have for their motive power, like
watches and spring-clocks, a mainspring acting on the fusee by the
chain,--as the chain winds upon the fusee the force of the spring is
so equalized that it is exactly the same whatever the position of the
chain. When marine chronometers are sent to the Greenwich observatory
they are subjected, under the directions of the Astronomer Royal, to
extreme degrees of heat and cold, and up to the year 1835 prizes were
awarded to those makers whose instruments best stood these tests; but
such prizes are no longer given. It has even been found that
chronometers which are most capable of withstanding extremes of
temperature are not the most perfect in medium climates, and this
discovery brought about new endeavours and a new suggestion known as
the Auxiliary or Secondary Compensation.
MARINE TIME-PIECES FOR SHIPS AND YACHTS. These instruments possess the
character rather of clocks than of chronometers, inasmuch as they are
designed to hang against a bulk-head, and they would not appear
unsuitable to house purposes. They are portable and useful clocks, and
having a lever escapement with compensated balance, the motion of the
vessel does not affect them. Some yacht time-pieces are constructed so
as to chime the quarters or tunes, and to strike the ships' bells as
well as the hours. They are also sometimes placed in very handsome
cases of bronze or ormolu, decorated with special designs to
illustrate the name of the ship or yacht to which they belong. Their
movements are not as accurately adjusted as those of Marine
Chronometers, but they, nevertheless, are made to keep time
excellently.
KEYLESS WATCHES.
The keyless mechanism to a watch is one of the great modern
improvements in watch work; it does away with the old-fashioned key,
with which so many persons have ruined their watches, the watch is
wound by turning a knurled knob, placed on the handle or bow (see
illustrations, pp. 96-7) instead of by the ordinary means: the hands
are set in the same way, with the addition of pressing a small
projection on the side of the case. The advantages of these
improvements are obvious; the case, which never need be opened in
winding, is made air tight and dust tight, thus preserving much longer
the fluidity of the oil, and greatly prolonging the intervals between
the necessary cleaning of the watch. Besides which, the keyless
mechanism being attached to the watch, the key can never be lost or
mislaid, or worn out.
_Strict attention to the following simple Directions is necessary for
the proper Management of a Watch._
1st.--Wind your watch as nearly as possible at the same time every
day--the morning is the best. Care should be taken to avoid sudden
jerks.
2nd.--Be careful that your key is in good condition, free from dust
and cracks. It should not be kept in the waistcoat pocket, or in any
place where it is liable to rust or get filled with dust.
3rd.--Keep the watch while being _wound_ steadily in the hand, so as
to avoid all circular motion.
4th.--The watch, when hung up, must have support, and be perfectly at
rest; or, when laid horizontally, let it be placed on a soft substance
for more general support, otherwise the action of the balance will
generate a pendulous motion of the watch, and cause much variation in
time.
5th.--The hands of a duplex or chronometer watch should never be set
backwards; in other watches this is a matter of no consequence, but to
avoid accidents it is much better to set them always forward.
6th.--Should the watch vary by heat or cold, as when worn or not worn
in the pocket, the hands may be set to time, but the regulator should
not be altered; but when it is found necessary to alter the regulator,
it should be done gently, and very little at a time.
7th.--_The glass should never be opened in watches that are set and
regulated at the back._
8th.--Keep your watch-pocket free from dust or nap, which generally
accumulates in the pocket when much used.
9th.--Be cautious to whom you give your watch for repair; the best
watches being frequently irretrievably damaged by inexperienced
workmen. Never allow your watch to go longer than two years without
being cleaned.
HOUSE CLOCKS.
Between the small wooden Dutch Clock of the value of but a few
shillings, and the carefully-made Regulator Clock which costs ten
times as many pounds, there is necessarily a wide difference; but both
may be considered as within the general designation, 'House Clocks.'
The former sometimes go for many years with a fair amount of
regularity, and are found to be useful to the humblest classes, whose
hours for early morning labour are frequently regulated thereby. The
latter are made with such accuracy as to correct the time of other
clocks, such as turret and church clocks, which are more exposed to
the influence of the weather, and are necessarily made upon a coarser
scale. In large mansions there is no handsomer or more necessary
appointment for the hall or vestibule than a fine eight-day clock, 'to
welcome the coming, speed the parting guest,' and to give the time of
day to the entire household.
It would be worth while, did our purpose admit of it, to write a
chapter on the longevity of Clocks, by way of showing the comparative
cheapness of the solid, well-built piece of mechanism whose every item
has been carefully put together of the very best and most durable
materials by the most skilled horologers. For generation after
generation such a sound, well-made time-piece shall keep accurate
time, and put to shame by both its performance and the insignificant
expense of keeping it in order, the instruments of, it may be, more
showy appearance, but less careful construction. Such a clock descends
from father to son until its own age is scarcely to be remembered, and
is regarded as one of the family heir-looms,--nay, as more,--almost,
we would say, as a friend familiar with all the scenes and experiences
which have made up family history. It was of such a clock that
Longfellow wrote--
'By day its voice is low and light,
But in the silent dead of night,
Distinct as a passing footstep's fall,
It echoes along the vacant hall,
Along the ceiling, along the floor,
And seems to say, at each chamber-door,
For ever--never,
Never, for ever.'
It was such an one that Dickens apostrophized in that
wonderfully-genial style which won for him so much love and fame:--'My
old cheerful, companionable clock. How can I ever convey to others an
idea of the comfort and consolation that this old clock has been for
years to me!... What other thing that has not life could cheer me as
it does! what other thing that has not life (I will not say how few
things that have) has proved the same patient, true, untiring friend!
How often have I sat in the long winter evenings feeling society in
its cricket voice! how often in the summer twilight, when my thoughts
have wandered back to a melancholy past, have its regular whisperings
recalled them to the calm and peaceful present! how often, in the dead
tranquillity of night, has its bell broken the oppressive silence, and
seemed to give me assurance that the old clock was still on guard at
my chamber-door!'
The Hall clock is often a plain, simple, undecorated instrument, where
all others are perhaps somewhat ornamented. Bracket clocks for the
staircase or landings, Mantelpiece clocks for the drawing and dining
rooms, for the study, the boudoir, and the best bed rooms, have each
their separate shape and character specially designed, and are to be
found in simple black-stained wood or real ebony, in marble of different
colours, in bronze, in buhl, and in ormolu, with or without enamel
ornaments, and with or without miniature figures at base, sides, and
top. Until lately most of our ornamental mantelpiece clocks were
imported from the continent, although French workmanship is generally
inferior to our own, but preference was shown by the public to the
former on account of the greater attention given by the French to
external decorations and variety of pattern. I am endeavouring to
provide that for the future this branch of clockmaking shall not be
abandoned entirely to our continental neighbours, whose exports of this
kind to our country yearly are very considerable. Henceforth by means of
new designs specially made for me and by me, and of a sufficiently
skilled staff of artistic workmen, selected for the purpose of working
under my superintendence, on my own premises, I shall be able to compete
on equal, nay, as to mechanism, on superior, terms with the best
specimens of decorated clocks from foreign _atéliers_. There is no
reason why the admitted superiority of English mechanism should not be
coupled with the best designs for decorated clock-cases; there is every
reason why handsome clocks should be made which will keep time well, and
add not only by their beauty but their usefulness to the enjoyment of
domestic life. If the proverb, 'handsome is that handsome does,' applies
to clocks, English workmanship should soon obtain pre-eminence, for it
is well known that the principle upon which French clocks are generally
made renders them less durable time-pieces.
The most ancient clocks differed in many respects from those now in
use. Clocks of the earlier period had, as we have said, instead of the
pendulum now in use, a _balance_, vibrating on the top of the clock,
as the regulating medium. The escapement was of the verge
construction, a sketch of which will be seen below, which represents a
clock of a most ancient character.
+----------------------------------------------------------------------+
| [Illustration: Old Balance-Clock.] |
+----------------------------------------------------------------------+
Without entering into any very minute detail of the manner in which
motion in a clock is successively communicated from one toothed wheel (G
or R) or pinion (_e_ or _g_) to another, which, indeed, would only tend
to perplex the mind of the general reader, it will be sufficient to
state the following. S is a square piece of steel fixed to and forming
part of the pinion P. In winding the clock the key is placed upon this
square, and being turned round continuously in one direction, the pinion
P turns with it. This communicates its motion to the wheel R, which is
fixed to the cylinder B, and which in its revolution coils or winds up
the cord to which is attached the weight A. While this takes place the
wheel G is held in check by another wheel, called the 'ratchet,' and a
click (neither of which is seen in the sketch), but when the operation
of the winding is completed, and the weight A begins to descend, the
cylinder B, together with the wheel G, turn on their common pivots V, V,
and the motion is thus communicated from wheel to pinion until it
reaches the escapement-wheel I. The teeth of this wheel, in its
revolution, act alternately on the pallets _i_, _h_, which project from
and form part of the spindle or verge K, M, and thus produce a vibratory
or backward and forward motion of the balance L, L.
Were it not for this detention, the duration of which is much
increased by the swing of the balance, the weight A would descend with
gradually accelerated speed, till, in a few moments, the cord would be
entirely unwound from the cylinder, and the clock be at rest.
+----------------------------------------------------------------------+
| [Illustration: Clock Spring.] |
+----------------------------------------------------------------------+
The SPRING CLOCK as ordinarily made is thus constructed. The frame
consists of two oblong plates of brass pinned together by short
pillars, and pierced with holes, in which run the arbors of the
various wheels. Next, the mainspring, the moving or motive power of
the clock, which is a riband of steel, highly tempered, and enclosed
in a cylinder or barrel. In the middle of this barrel is the spring or
barrel arbor, to which the spring is hooked at one end, the other end
being fixed to the circumference of the barrel. Outside the frame or
plate, and at the end of the arbor, is the ratchet, a wheel with
saw-like teeth. This is acted upon by a click, which, falling into the
ratchet teeth, prevents the recoil of the mainspring, so that the
spring has no means of uncoiling itself, except by the moving of the
train of wheels. This click is screwed to the outside of the oblong
plate. The power of the mainspring is transmitted to the train of
wheels by means of a chain or gut, one end of which is fastened to the
outer edge of the barrel, and the other end to the fusee, which is of
conical shape, securely fastened to the arbor or axis of the main
wheel; on this same arbor is the square, on which the key is put for
winding. When this square is turned in winding, the fusee draws the
chain or gut from off the outer edge of the barrel, and coils up the
spring within it. The spring when fully wound, and consequently at its
greatest power, acts by means of the chain or gut on the small end of
the fusee, which in turning drives the train of wheels. As the spring
becomes gradually uncoiled, and the power exerted less, the leverage
is increased in the same proportion by the increased width of the
fusee on which it acts.
To prevent the straining of the spring, a little contrivance called
the stop-work is introduced. It consists of a piece of steel somewhat
in the shape of a bayonet, which is so fixed and contrived that the
last turn of the gut or chain on the fusee forces the stop into
contact with a projection on the end of the fusee, which abutting
against it, forms the check felt when the clock is wound up. On the
same arbor with the fusee is fixed the main wheel, which with the
before-described contrivance of click and ratchet, permits the turning
of the fusee or winding-up of the clock, while it itself remains
stationary. This wheel acts in the centre pinion (a pinion is a little
wheel playing in the teeth of a larger wheel, and has six, eight, ten,
or twelve teeth, or, as they are called, leaves), which is fixed to
the centre arbor, and carries the minute hand. This pinion is so
constructed in relation to the other parts of the clock as to make one
revolution in an hour; the centre wheel being firmly riveted on the
pinion, it must also revolve once an hour. The centre wheel acts into
another pinion, which is called the third wheel pinion, upon the arbor
or axle of which is securely fixed the third wheel, which again acts
in the escape-pinion carrying the escapement-wheel. On the top of the
back plate is firmly screwed the back cock, or the support of the
pendulum, which is suspended from it by a flexible spring, as before
described. This pendulum receives impulsion from the wheel-work by
means of the crutch, a small part attached to the arbor of the
pallets, and which projects downwards about three inches, parallel
with the pendulum rod. To the lower part of the crutch is screwed or
riveted at a right angle a piece of steel, in such a direction as to
penetrate the pendulum rod, which has a slot or hole cut to receive
it; impulsion is thus given to the pendulum. Between the frame and
dial-plate is the motion work, consisting of three wheels; the first,
called the minute wheel, is attached to the arbor of the centre wheel,
which, it will be recollected, makes one revolution an hour, and acts
in a wheel of the same size, whose axle carries a pinion serving to
drive the hour wheel. This hour wheel is supported by a bridge screwed
over the minute wheel. The dial is pinned on to the front plate; the
hour hand is fixed on a socket communicating with the hour wheel, and
the minute hand on the arbor of the centre wheel.
When a clock is intended to strike, a separate train of wheels has to
be introduced into it,--one train of wheels serving to keep the time,
and another train for the striking part. It may be as well to add that
a greater amount of labour is required to make the striking than the
going part of a clock.
+----------------------------------------------------------------------+
| [Illustration: Rack Striking Work.] |
+----------------------------------------------------------------------+
There are only two kinds of striking parts now in use, and these are
characterized by the terms 'Rack' striking work, and 'Count-wheel,' or
'Locking-plate,' striking work. The Rack striking work (see next page)
is the best and safest ever introduced, because with it the clock may be
made to strike any number of times within the hour. A, the minute wheel
revolving in the direction of the arrow, and driving the wheel B, which
is of the same size, and has the same number of teeth. C, a pin fixed in
the wheel B, and acting on the lever D, which has its centre of motion
in the point E. L, the click, the lower point of which acts in the teeth
K of the rack M. S, the rack-spring, which acts upon the lower end of
the rack, or, as it is called, the rack-tail, and brings it in contact
with the snail P. Q and R are the jumper and its spring, by which the
snail P, fastened to the star-wheel O, is kept in its place. Y, the
centre of motion of the rack, on which it acts freely. In the wheel A is
fixed a pin U, which, as the wheel A rotates, gradually forces before it
a tooth of the star-wheel O, which carries with it the snail P, until
at last the second step of the snail is opposite the rack-tail. While
this is going on, the wheel B, driven by the wheel A, is advancing in
the opposite direction, and, by means of the pin C, is pushing before it
the end of the lever D. It is obvious that the other end, F, of the
lever will be gradually raised, and this will lift the lower point of
the click L out of the teeth of the rack. The latter being now free will
yield to the action of the spring S, which will force its lower end into
contact with the second step of the snail, and throw back the head of
the rack to a corresponding extent. By this action the striking train of
wheels is released, and the two wheels, G and I, seen in the upper part
of our cut, begin to rotate, but are stopped by H, a pin that is caught
by a stud which projects from the end F of the lever. As the wheel B
advances, the pin C gradually frees itself from the long arm of the
lever D, which drops by its own weight into its original position, and
frees the wheels G and I, which immediately commence once more to
rotate. At the centre of the wheel I is fixed the gathering pallet,
that, as it revolves with the wheel, gathers up one by one the teeth of
the rack, which is prevented from falling back by the lower end of the
click L, and thus gradually draws it forward until the last tooth is
reached, when the end of the gathering pallet abuts on the end of the
rack head, and the train of wheels is once more at rest. It is obvious
that for every tooth of the rack which is gathered up, there is one
revolution of the wheel I, and this communicates with the tail of the
hammer, causing at each revolution a blow on the bell. There is, as will
be at once seen, an important connection between the various parts. When
the second step of the snail is presented to the rack-tail, the head of
the rack is thrown back a distance corresponding to the width of two of
its teeth. This requires two revolutions of the gathering pallet to
return it to its place; and these two revolutions of the pallet and the
wheel which carries it govern the two blows on the bell which signify
the hour. At three o'clock the third step of the snail will be presented
to the hammer-tail, and so on.
On the next page is an illustration of the back part of a French
Clock, as seen upon opening the door of the case. At the right hand
side will be observed the count-wheel A, fitting tightly upon a
prolonged square arbor of the second wheel in the train, and having
twelve openings of unequal length around its outer edge, 1, 2, &c.
Just above the wheel towards the right will also be seen the 'Dog,' or
'Detent,' F, which falls into these notches, and is a part of the
locking similar to that which is represented at the stud and the pin
H. So soon as the stud is lifted the pin becomes disengaged, the
wheel-work revolves, and the count-wheel being firmly fixed to the
prolonged arbor of one of those wheels, advances with it in the
direction indicated by the arrow, the detent resting upon the plain
part of the locking-wheel. When the required number of hours have
struck, the notch approaches the detent, the gravity of which allows
it to fall therein.
+----------------------------------------------------------------------+
| [Illustration: Back of French Clock.] |
+----------------------------------------------------------------------+
In connection with this detent is also another projecting piece, which
is carried inside the frame, and when it falls presents a broad
surface to a pin fixed in the rim of one of the wheels. Thus the
motion of the wheel-work is stayed until this piece is again lifted by
the going parts from the pin, and held in that position by the outer
rim of the locking-wheel A, until again the next notch is presented to
the detent. When it falls, the stud is carried with it, against which
the pin becomes engaged. The number of strokes depends on the distance
which the count-wheel has to revolve before being stopped by the
detent F. The chief objection to the locking-plate being used for
striking, arises from the fact that, if ever the clock is allowed to
run down, or if the clock gets otherwise stopped, it strikes wrong
afterwards, until it has been properly re-set to the hour.
Clocks are made of all manner of shapes, patterns, and sizes, for all
manner of places, positions, and persons.
BRACKET CLOCKS, which are intended to occupy but a small space, say on
a staircase, or lobby, or landing, are sometimes made with extreme
finish, care, and elegance, sometimes are simply plain and devoid of
embellishment. They are constructed with or without striking work.
CHIME CLOCKS are a great addition to the attractions of a house. They
are usually made to go eight or fifteen days; to strike the hours and
quarters on four or eight bells or gongs.