or grand strike which marks each passed quarter hour. Not to be
confused with a chiming clock. At 9:15 the clock strikes 9 times
for the hour followed by the one quarter, 9:30 the clock strikes 9
times for the hour followed by 2 quarters, 9:45 the clock strikes
9 times for the hour followed by the 3 quarter strikes and so on.
Normally a clock with this feature has a selectable setting for no
strike, hours only, or hours and quarters and an additional repeat
indicator from which the hours are read.
ribbon of steel which when wound powers the clock. The length of
the spring determines the duration of the period which the
timepiece runs down and requires rewinding. Typical running
durations are 30 hours, or 7 days with some clocks going longer as
much as 1 year. Modern clocks with 31 day movements should be
avoided as the additional duration increases friction and wear to
indicator from which the minutes are read.
Disk indicating the age of the moon, often inaccurate.
regulating device. By adjusting its length and affecting the
period of the swing, the timepiece may be adjusted to keep exact
adjustable regulating weight.
stick portion of the pendulum, its length is paramount to the
clock keeping time and cannot be haphazardly replaced or repaired
without affecting the time keeping. Even broken parts can be help
to ensure a proper replacement can be procured.
can be recalled by means of a pushbutton. This allowed one to get
the time in the dead of night without having to fumble around for
a candle. An hour repeater only repeats the last passed hour, a
quarter repeater will repeat the last passed hour and quarter and
a minute repeater can strike out the time to the last hour,
quarter, and minute passed.
thumb-screw normally at the base of a pendulum unit. The pendulum
disk rests on this screw.
indicator from which seconds are read.
key used to determine size, should never be used as a winding key
as serious harm could result if the mainspring breaks.
point for the suspension and pendulum. Its bridge may be connected
to the movement or directly to the case back.
thin metal spring which allows a otherwise rigid pendulum a
flexible pivoting point, connected to
the suspension post by means of a tapered pin or screwed in pin.
verge (or crown wheel) escapement is the earliest known type of
mechanical escapement, it is the mechanism in a mechanical clock
that controls the advancing the gear train with each tick. While
its origin is unknown, Verge Escapements have been used from 1550
about 1800 in both pendulum clocks and balance wheel pocket
iron or lead mass attached to a cable or chain provides power via
the falling mass. The same general rules apply as to the number of
weights as related to the clock functions.
shaft which carries the power source and is wound with the key.
Look on the dial for the arbor hole with its square end which
mates with the proper sized winding key. Most time-only clocks
will have one, a second arbor normally indicates an additional
hour and half-hour strike and a third arbor indicates a musical
chime like Westminster played each passed quarter hour.
means to rewind the springs of a clock.
means to rewind the weights of a cable driven clock.