A tall, freestanding, weight-driven pendulum clock
8-day longcase clock. This example dates back to 1700 and the case to late 19th – early 20th century. The original dial of this clock was replaced by a brass dial with Tamil numerals, perhaps around the same time as the case. The original long-case was also replaced by a mandapa-shaped wooden carved case done in South Indian style. The front and the side panels are done in metal repoussé work with floral meanders. The lower part of the case depicts mythological scenes and the case was manufactured at the Madras School of Arts. This clock is on display in The Prince of Wales Museum in Mumbai and was donated by Dorab Tata.
A grandfather clock (also a longcase clock, tall-case clock, grandfather's clock, or floor 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 occasionally calibrated to keep the proper time. The case often features elaborately carved ornamentation on the hood (or bonnet), which surrounds and frames the dial, or clock face.
The English clockmaker, William Clement, is credited with developing the form in 1670. Pendulum clocks were the world's most accurate timekeeping technology until the early 20th century, 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 Today, they are kept mainly for their decorative and antique value, having been superseded by analog and digital timekeepers.
The song was composed by the American songwriter Henry Clay Work, who discovered a longcase clock in The George Hotel in Piercebridge, County Durham, England. When he asked about the clock, he was informed that it had had two owners. After the first owner died, the clock became inaccurate, and when the second owner died, the clock stopped working altogether. The story inspired Henry to create the song.
Grandfather clocks are of a certain height, usually at least 1.9 metres (6 ft 3 in). There are also so-called "grandmother" and "granddaughter" clocks, which are slightly shorter.[2][3]
The world's tallest grandfather clock is 35 feet 10 inches (10.92 m) tall and is fully operational, with chimes on each quarter hour. It was made by Svoboda Industries in 1976 as a Bicentennial project and is located in Kewaunee, Wisconsin.[4][5]
Clock-face signature of Tim Mason
Origin
Lateral view of a longcase clock movement without striking mechanism, mid-1800s
The advent of the longcase clock was due to the invention of the anchor escapement mechanism by Robert Hooke in about 1658. Before adopting the anchor mechanism, pendulum clock movements used an older verge escapement mechanism, which required very wide pendulum swings of about 80–100 degrees.[6] Long pendulums with such wide swings could not be fitted within a case, so most free-standing clocks had short pendulums.
Lateral view of a Timothy Mason longcase clock movement with striking mechanism, circa 1730The "tick-tock" of a grandfather clock
The anchor mechanism reduced the pendulum's swing to around 4 to 6 degrees,[6] allowing clockmakers to use longer pendulums, which had slower "beats". They consumed less power, allowing clocks to run longer between windings, caused less friction and wear in the movement, and were more accurate.[6] Almost all longcase clocks use a seconds pendulum (also called a "Royal" pendulum[7]) meaning that each swing (or half-period) takes one second. They are about 1 metre (3 ft 3 in) long (to the centre of the bob), requiring a long, narrow case. That case pre-dated the anchor clock by a few decades, appearing in clocks in 1660, to allow a long drop for the powering weights. However, once the seconds pendulum began to be used, the long case proved perfect for housing it as well.[8][9]
British clockmaker William Clement, who disputed credit for the anchor escapement with Robert Hooke, had made the first longcase clocks by 1680.[10] Later the same year, Thomas Tompion, the most prominent British clockmaker, was making them too.[10] Longcase clocks spread rapidly from England to other European countries and Asia.
The first longcase clocks, like all clocks prior to the anchor escapement, had only one hand; an hour hand. The increased accuracy made possible by the anchor motivated the addition of the minute hand to clock faces in the next few decades.
Between 1680 and 1800, the average price of a grandfather clock in England remained steady at £1 10s. In 1680, that was the amount paid by an average working family for a year's rent, so the purchase of clocks was confined to the wealthy. But by 1800, wages had increased enough to allow many lower middle-class households to own grandfather clocks.[11]
Modern longcase clocks use a more accurate variation of the anchor escapement called the deadbeat escapement.
Description
Most of a longcase clock's height is used to hold the long pendulum and weights. The two chains attached to the weights and the lack of winding holes in the dial show this to be a 30-hour clock.
Traditionally, longcase clocks were made with two types of movement: eight-day and one-day (30-hour) movements. A clock with an eight-day movement required winding only once a week, while generally less-expensive 30-hour clocks had to be wound daily. Eight-day clocks are often driven by two weights – one driving the pendulum and the other the striking mechanism, which usually consisted of a bell or chimes. Such movements usually have two keyholes, one on each side of the dial, to wind each weight.
By contrast, 30-hour clocks often had a single weight to drive the timekeeping and striking mechanisms. Some 30-hour clocks were made with false keyholes for customers who wanted guests to think that the household was able to afford the more expensive eight-day clock. All modern striking longcase clocks have eight-day mechanical quarter chiming and full hour striking movements. Most longcase clocks are cable-driven, meaning that cables suspend the weights. If the cable was attached directly to the weight, the load would cause rotation and untwist the cable strands, so the cable wraps around a pulley mounted to the top of each weight. The mechanical advantage of that arrangement also doubles the running time allowed by a given weight drop.
Cable clocks are wound by inserting a special crank (called a "key") into holes in the clock's face and turning it. Others, however, are chain-driven, meaning that the weights are suspended by chains that wrap around gears in the clock's mechanism, with the other end of the chain hanging down next to the weight. To wind a chain-driven longcase clock, one pulls on the end of each chain, lifting the weights until they are just under the clock's face.
Elaborate striking sequences
In the early 20th century, quarter-hour chime sequences were added to longcase clocks. A full chime sequence sounds at the top of each hour, immediately followed by the hour strike. At 15 minutes after each hour, 1/4 of the chime sequence plays. Proceeding that, at the bottom of each hour, 1/2 of the chime sequence plays. Then finally, at 15 minutes before each hour, 3/4 of the chime sequence plays. The chime tune used in almost all longcase clocks is Westminster Quarters. Many also offer the option of Whittington chimes or St. Michael's chimes, selectable by a switch mounted on the right side of the dial, allowing one to silence the chimes if desired. As a result of adding chime sequences, all modern mechanical longcase clocks have three weights instead of only two. The left weight provides power for the hour strike, the middle-weight provides power for the clock's pendulum and general timekeeping functions, and the right weight provides power for the quarter-hour chime sequences.
Types
Comtoise clock
Comtoise
Comtoise clocks, also known as Morbier clocks or Morez clocks, are a style of longcase clock made in the French region Franche-Comté (hence their name). Features distinguishing this style are a curving "potbellied" case and a greater use of curved lines. A heavy, elongated, highly ornamented pendulum bob often extends up the case (see photo).
Production of these clocks began in 1680 and continued for about 230 years. During the peak production years (1850–1890) over 60,000 clocks were made each year. These clocks were trendy across the generations; they kept the time on farms throughout France. Many Comtoise clocks can be found in France but they are also frequently found in Spain, Germany, and other parts of Europe, less in the United States. Many Comtoise clocks were also exported to other countries in Europe and even farther, to the Ottoman Empire and as far as Thailand. A wooden sheath usually protected the metal mechanisms during transport.
Bornholm and Mora
Bornholm clock made by Edvart Sonne, from Rønne, Bornholm in the late 1700s
Bornholm clocks are Danish longcase clocks and were made on Bornholm from 1745 to 1900. In Sweden a special variety of longcase clocks was made in Mora, called Mora clocks.
Bornholm clock-making began in the 1740s when an English ship, which had longcase clocks in its hold, was stranded. They were sent for repair to a turner named Poul Ottesen Arboe in Rønne and as a result of his repair of them he learned enough about clocks to begin to make his own.
Historical manufacturers
Longcase clock from about 1750 in the District Museum in Tarnów in Poland, mounted with use of imported components marked Wiliam Jourdain London and adorned with chinoiserie motifs
^"Oxford English Dictionary"(available online to subscribers, also in print). Retrieved April 19, 2009. Grandfather's clock [suggested by a song which was popular about 1880], a furniture-dealer's name for the kind of weight-and-pendulum eight-day clock in a tall case, formerly in common use; also grandfather clock (now the usual name): [1876 H. C. WORK Grandfather's Clock, My grandfather's clock was too large for the shelf, So it stood ninety years on the floor.]
