Clock & Time Glossary

Acanthus:   A plant of the Mediterranean, whose beautifully shaped leaves form carved characteristic designs on many fine timepieces.

Arabic Dial: Most familiar numeral (1, 2, 3, 4, etc.) used on a dial as distinguished from Roman numerals (I, II, III, IV).

Ascending Alarm: Alarm that increases volume.

Atomic Clock Movement: This remarkable quartz (battery operated) movement contains a miniaturized radio receiver, which monitors a low frequency time signal broadcast from Fort Collins, Colorado. The signal allows the movement to self-correct everyday so it always shows the exact time according to the national time standard. You can now have accuracy to less than one second error in 100,000 years with the cesium atomic clock.

Beat: The tick of a clock, or the time taken for a pendulum or balance to swing from the center, or dead point, to one extreme and than return to center again. Most clock wheel rotations beat twice per cycle. The beats should be equally disposed about the center or dead point of the pendulum or balance. Single-beat rotations, such as the chronometer and duplex, have one beat on each alternate swing of the balance.

Beveled Glass: Glass used on the sides and front of a clock case, which has its outside edges ground and polished at an angle greater than a right angle providing a beautiful decorative effect.

Bezel: the grooved rim around the dial into which the crystal is set.

Bim-Bam: Descriptive term for clock chimes which sound only on the hour and half hour.

Bob: A polished round weight disk fitted to the lower end of the pendulum. The commonly found lenticular bob has the advantage of low air resistance. Regulators and electric impulse clocks are often fitted with cylindrical bobs.

Bookmatched: A piece of wood that is cut in half and folded open like a book so the wood pattern mirrors each other from right to left; to match the grains of (as two sheets of veneer) so that both sheets seem to be the mirrored image of each other.

Burls: A swirl or distortion in the grain of the wood often occurring near a knot but not containing a knot. Also described as a large rounded outgrowth on the trunk or branch of a tree when the wood is cut from a tree burl or outgrowth it is often used decoratively in veneer.

Cable Driven Movement: The weights in a cable driven clock power the clock and are held by a cable. A cable driven clock is wound once a week with a brass crank or key that fits into the dial of a clock. The weights are pulled to the top of the clock.

Canted: The architectural term describing part, or a segment, of a facade which is at an angle to another part of the same facade. Generally the angle is less acute than a right angle enabling the canted facade to be viewed, and remain, one composition.

Chapter Ring: A decorative ring on the clock dial upon which the hour markers are indicated.

Chain Driven Movement: A grandfather clock movement that requires the chain attached to the weights to be pulled down once a week to raise the weights. The weights will then fall over the course of the week and that is what powers the clock.

Chime Rods: The stationary metal rods which when struck by hammers create chimes and the hour gong.

Chime Selector: A step-up feature on many case clocks, which allows the chime tune or melody to be changed.

Clock: The word clock is derived from the Medieval Latin "clocca" which means a bell; the earliest alarm clocks did not have dials but simply sounded a bell at an appointed time.

Coordinated Universal Time (abbreviated UTC)

In the most commonly encountered usage, Coordinated Universal Time (abbreviated UTC) is the basis for the worldwide system of civil time. UTC is of particular importance to the astronomical community, where times are almost always given in the 24 hour UTC format. UTC is roughly (but not always precisely) equivalent to Greenwich Mean Time (GMT).

To obtain U.S. civil time from UTC, use the following table:

Atlantic Daylight Time: subtract 3 hours from UTC
Atlantic Standard Time: subtract 4 hours from UTC
Eastern Daylight Time: subtract 4 hours from UTC
Eastern Standard Time: subtract 5 hours from UTC
Central Daylight Time: subtract 5 hours from UTC
Central Standard Time: subtract 6 hours from UTC
Mountain Daylight Time: subtract 6 hours from UTC
Mountain Standard Time: subtract 7 hours from UTC
Pacific Daylight Time: subtract 7 hours from UTC
Pacific Standard Time: subtract 8 hours from UTC
Alaska Daylight Time: subtract 8 hours from UTC
Alaska Standard Time: subtract 9 hours from UTC
Hawaii-Aleutian Daylight Time: subtract 9 hours from UTC
Hawaii-Aleutian Standard Time: subtract 10 hours from UTC
Samoa Standard Time: subtract 11 hours from UTC

Thus, 11:00 UTC is the same as 5:00 CST. When converting zone time to or from UTC, dates must be properly taken into account. For example, 10 March at 02:00 UTC is the same as 9 March at 21:00 EST. The table can also be used to determine the difference between the time observed in any two zones. For example, the table shows that Eastern Standard Time is three hours "ahead" of Pacific Standard Time.

Crotch: The place where the limb comes off the tree (provides unique patterns of wood); an angle formed by the parting of two branches.

Crystal: A glass or plastic piece that covers the dial for both protection and decoration.

Dial: The face of the clock. A decorative plate on which the hours are indicated.

Escapement: The device in a clock that controls the action of its movement.

Escutcheon: An ornamental plate around a keyhole or in back of a handle or knob.

Finial: Decorative ornament, usually in wood or brass, placed on top of the clock cabinet, forming the upper extremity in a split pediment mantel and longcase clock. Used most frequently in mantel and long case clocks.

Fixed Moon Phase Dial: A non-functional image of a moon dial that enhances the look of the grandfather clock. It is often found on top of a grandfather clock.

Fluted: A rounded design derived from the look of small flutes side by side; having grooves or marked by grooves.

Hands: Pointed metal indicators, usually decorative, which mark the hour, minutes, seconds on the clock dial.

Kieninger: A Manufacturer of clock movements Kieninger builds many different movements with various features. All Kieninger grandfather clock movements are made in Germany and are owned by Howard Miller.

Key wound: Term used to describe clocks powered by a mainspring.

Liquid Crystal Display (LCD): Time is displayed continuously in digits. Electrical current is applied to a layer of liquid crystals between two layers of transparent material. The crystals form the digits.

Light Emitting Diode (LED): Numbers telling the hour and minutes light up. Electrical current transmits coded signals that translate into numbers.

Minute track: A square or circular track divided into 60 equal segments. It may appear on the outer perimeter of the dial or int he dial center.

Moon Phase Dial: A dial found at the top of the clock face which tracks the moon’s phases through the 29 ½ days of the lunar month. As the rotating moon dial passes behind the Eastern and Western Hemispheres, the phases of the moon are represented as they appear at each stage of the cycle: new moon, waning crescent, half moon, etc.

Movement: The inner mechanism of a clock: may be key-wound, weight-driven, battery-powered, electric or quartz.

Pediment: An ornamental top on a clock case, frequently curved in shape. An architectural term describes a triangular or shaped (like a swan neck) feature placed above the cornice of a bookcase, cabinet, tallboy, or longcase clock.

Pendulum: Swinging rod and weight (bob) suspended below the clock movement. Pendulum determines the rate at which the movement measures time.

Quartz Movement: An electronic oscillator and a quartz crystal are used to keep precise time. In 1928, W.A. Marrison of Bell Laboratories built the first quartz clock which is accurate to within 1-2 thousandths of a second per day.

Reeded: Columns formed with channels and ridges.

Spandrels: The four corners that square off round clocks dial, often featuring painted designs or metal decorations.

Tempus Fugit: A Latin term meaning "Time Flies," very often applied as a decorative inscription above a dial.

Veneer: A thin layer of wood which shows exquisite beauty; this layer of wood is of superior value and excellent grain.

Weight: Heavy metal piece, which provides the motive force, used to power certain types of chime clock movements. Usually decorative when used with quartz movements.

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