A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is a harmonic oscillator: It swings back and forth in a precise time interval dependent on its length, and resists swinging at other rates. From its invention in 1656 by Christiaan Huygens, inspired by Galileo Galilei, until the 1930s, the pendulum clock was the world's most precise timekeeper, accounting for its widespread use. Throughout the 18th and 19th centuries, pendulum clocks in homes, factories, offices, and railroad stations served as primary time standards for scheduling daily life, work shifts, and public transportation. Their greater accuracy allowed for the faster pace of life which was necessary for the Industrial Revolution. The home pendulum clock was replaced by less-expensive, synchronous, electric clocks in the 1930s and '40s. Pendulum clocks are now kept mostly for their decorative and antique value.
A cuckoo clock is, typically, a pendulum clock that strikes the hours with a sound like a common cuckoo call and has an automated cuckoo bird that moves with each note. Some move their wings and open and close their beaks while leaning forwards, whereas others have only the bird's body leaning forward. The mechanism to produce the cuckoo call has been in use since the middle of the 18th century and has remained almost without variation.
A chandelier is a branched ornamental light fixture designed to be mounted on ceilings or walls. Chandeliers are often ornate, and normally use incandescent light bulbs, though some modern designs also use fluorescent lamps and recently LEDs.
A pocket watch is a watch that is made to be carried in a pocket, as opposed to a wristwatch, which is strapped to the wrist.
A grandfather clock is a tall, freestanding, weight-driven pendulum clock with the pendulum held inside the tower or waist of the case. Clocks of this style are commonly 1.8–2.4 metres (6–8 feet) tall with an enclosed pendulum and weights suspended by either cables or chains which have to be calibrated occasionally to keep the proper time. The case often features elaborately carved ornamentation on the hood, which surrounds and frames the dial, or clock face. The English clockmaker William Clement is credited with the development of this form in 1670. Until the early 20th century, pendulum clocks were the world's most accurate timekeeping technology, and longcase clocks, due to their superior accuracy, served as time standards for households and businesses. Today they are kept mainly for their decorative and antique value, having been widely replaced by both analog and digital timekeeping.
A ceiling fan is a fan mounted on the ceiling of a room or space, usually electrically powered, that uses hub-mounted rotating blades to circulate air. They cool people effectively by increasing air speed. Fans do not reduce air temperature or relative humidity, unlike air-conditioning equipment but create a cooling effect by helping to evaporate sweat and increase heat exchange via convection. Fans may add a small amount of heat to the room mainly due to waste heat from the motor, though partially due to friction. Fans use significantly less power than air conditioning as cooling air is thermodynamically expensive. In the winter a ceiling fan can also be used to bring warm air, which naturally rises, back down to occupants. This can affect both thermostat readings and occupants' comfort, thereby improving climate control energy efficiency. Many ceiling fan units also double as light fixtures, eliminating the need for separate overhead lights in a room.
In horology, a movement, also known as a caliber or calibre, is the mechanism of a watch or timepiece, as opposed to the case, which encloses and protects the movement, and the face, which displays the time. The term originated with mechanical timepieces, whose clockwork movements are made of many moving parts. The movement of a digital watch is more commonly known as a module.
A mainspring is a spiral torsion spring of metal ribbon—commonly spring steel—used as a power source in mechanical watches, some clocks, and other clockwork mechanisms. Winding the timepiece, by turning a knob or key, stores energy in the mainspring by twisting the spiral tighter. The force of the mainspring then turns the clock's wheels as it unwinds, until the next winding is needed. The adjectives wind-up and spring-powered refer to mechanisms powered by mainsprings, which also include kitchen timers, metronomes, music boxes, wind-up toys and clockwork radios.
A hanging scroll is one of the many traditional ways to display and exhibit East Asian painting and calligraphy. The hanging scroll was displayed in a room for appreciation; it is to be distinguished from the handscroll, which was narrower and designed to be viewed flat on a table in sections and then stored away again.
Mantel clocks—or shelf clocks—are relatively small house clocks traditionally placed on the shelf, or mantel, above the fireplace. The form, first developed in France in the 1750s, can be distinguished from earlier chamber clocks of similar size due to a lack of carrying handles.
A repeater is a complication in a mechanical watch or clock that chimes the hours and often minutes at the press of a button. There are many types of repeater, from the simple repeater which merely strikes the number of hours, to the minute repeater which chimes the time down to the minute, using separate tones for hours, quarter hours, and minutes. They originated before widespread artificial illumination, to allow the time to be determined in the dark, and were also used by the visually impaired. Now they are mostly valued as expensive novelties by watch and clock enthusiasts. Repeaters should not be confused with striking clocks or watches, which do not strike on demand, but merely at regular intervals.
A striking clock is a clock that sounds the hours audibly on a bell or gong. In 12-hour striking, used most commonly in striking clocks today, the clock strikes once at 1:00 am, twice at 2:00 am, continuing in this way up to twelve times at 12:00 mid-day, then starts again, striking once at 1:00 pm, twice at 2:00 pm, up to twelve times at 12:00 midnight.
A lantern clock is a type of antique weight-driven wall clock, shaped like a lantern. They were the first type of clock widely used in private homes. They probably originated before 1500 but only became common after 1600; in Britain around 1620. They became obsolete in the 19th century.
Thomas Tompion, FRS (1639–1713) was an English clockmaker, watchmaker and mechanician who is still regarded to this day as the "Father of English Clockmaking". Tompion's work includes some of the most historic and important clocks and watches in the world, and can command very high prices whenever outstanding examples appear at auction. A plaque commemorates the house he shared on Fleet Street in London with his equally famous pupil and successor George Graham.
A "ring of bells" is the name bell ringers give to a set of bells hung for English full circle ringing. The term "peal of bells" is often used, though peal also refers to a change ringing performance of more than about 5,000 changes.
A lighthouse clock is a type of mantel clock manufactured in the U. S. from 1818 through 1830s by the American clockmaker Simon Willard, having the dial and works exposed beneath a glass dome on a tapered, cylindrical body.
A torsion pendulum clock, more commonly known as an anniversary clock or 400-day clock, is a mechanical clock which keeps time with a mechanism called a torsion pendulum. This is a weighted disk or wheel, often a decorative wheel with 3 or 4 chrome balls on ornate spokes, suspended by a thin wire or ribbon called a torsion spring. The torsion pendulum rotates about the vertical axis of the wire, twisting it, instead of swinging like an ordinary pendulum. The force of the twisting torsion spring reverses the direction of rotation, so the torsion pendulum oscillates slowly, clockwise and counterclockwise. The clock's gears apply a pulse of torque to the top of the torsion spring with each rotation to keep the wheel going. The Atmos Clock made by the Swiss company Jaeger-LeCoultre is another style of this clock. The wheel and torsion spring function similarly to a watch's balance wheel and hairspring, as a harmonic oscillator to control the rate of the clock's hands.
A turret clock or tower clock is a clock designed to be mounted high in the wall of a building, usually in a clock tower, in public buildings such as churches, university buildings, and town halls. As a public amenity to enable the community to tell the time, it has a large face visible from far away, and often a striking mechanism which rings bells upon the hours.
A bracket is an architectural element: a structural or decorative member. It can be made of wood, stone, plaster, metal, or other media. It projects from a wall, usually to carry weight and sometimes to "...strengthen an angle". A corbel or console are types of brackets.
In horology, a wheel train is the gear train of a mechanical watch or clock. Although the term is used for other types of gear trains, the long history of mechanical timepieces has created a traditional terminology for their gear trains which is not used in other applications of gears.
