GRANDFATHER CLOCKS FOR HOME

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Interesting Factoids:

(Long Case Clock / Grandfather Clocks)

Understanding Grandfather Clocks: Part IX Nancy Sander

H T T P : / / G R A N D F A T H E R C L O C K S F O R H O M E . C O M /

Understanding Grandfather Clocks

Part IX: Interesting Factoids: (Long Case Clock / Grandfather Clocks)

In the following, you will discover more facts about Grandfather clocks and all pendulum clocks.

Originally, these clocks were called longcase clocks. These clocks also go by other names, the tall-case clock, grandfather clock or floor clock are some of these names. Longcase Clocks are generally freestanding, weight-driven, pendulum clocks.

The pendulum is in the center of tower (waist) on these ‘tall’ clocks. They range in height from 6 to 8 feet. The original longcase clocks, and many of the higher end clocks of today, often feature elaborately carved ornamentation on the hood, or bonnet, which surrounds the dial, or clock face (See “Grandfather Clock Terms”).

The English clockmaker William Clement (See “Grandfather Clocks, Famous Clockmakers…”) is credited with the development of this clock form in 1670. Most longcase clocks are striking clocks, which means they sound the time audibly with a bell or song.

The terms "grandfather,” "grandmother,” and "granddaughter" in relation to longcase clocks tends to define differences. There is a general perception that a clock smaller than 5 feet is a granddaughter; over 5 feet is a grandmother; and over 6 feet is a grandfather clock.

The introduction of the longcase clock is due to the invention of the anchor escapement

mechanism around 1670 (See “Grandfather Clock Terms”). (An escapement is the mechanism in a mechanical clock that maintains the swing of the pendulum and advances the clock's wheels with each swing. An anchor escapement is a type of escapement used in pendulum clocks. Another escapement introduced by clockmaker George Graham in 1715 is called the deadbeat escapement. This is the mechanism most often used today in pendulum clocks.) (I’ve read that there is some controversy regarding crediting the introduction of the anchor escapement. Some references credit clockmaker William Clement, who popularized it in his invention of the longcase clock. The anchor escapement was most likely invented by a scientist in Britain, Robert Hooke.) Prior to that, pendulum clock movements used an older verge escapement mechanism,

which required very wide pendulum swings of about 100°.(The verge (crown wheel) escapement is the earliest known type of mechanical escapement. It is the mechanism in a mechanical clock that controls its rate by moving forward the gear train at regular intervals or 'ticks'. The origin is unknown. At the heart of every clock are oscillating instruments for recording or keeping time. The

invention of the verge escapement has an important role in the history of technology. It made the invention of all mechanical clocks possible. This moved the processes of time keeping from the flow of liquid in water clocks (continuous process) to pendulum clocks (oscillatory process).

Most clocks had short pendulums to be contained within a case. Long pendulums with such

wide swings were used in open clocks usually outside. The anchor mechanism reduced the pendulum's swing to around 4° to 6°. This allowed clockmakers to use longer pendulums, which had slower "beats.” These needed less power to keep going. They had less friction and wear in the movement, and were more accurate.

Most longcase clocks use a ‘seconds’ pendulum ("Royal" pendulum). These are about 39 inches long.

(A seconds pendulum takes 2 seconds to make the full swing. In 1670 the ‘seconds’ pendulum was employed by William Clement in his improved version of the original pendulum clock by Christian Huygens. An interesting factoid is that in Britain around 1855, the British ‘yard’ was defined as a specified fraction of the length of the ‘seconds’ pendulum.) (Christiaan Huygens was a prominent Dutch mathematician born in 1629. He was also known as an astronomer, physicist, and horologist (Horology is the art and science of time.). He was also a writer of early science fiction. His work included many areas of study, including investigations and inventions related to time keeping and the pendulum clock. He was a fascinating man.) Modern longcase clocks use a more accurate variation of the anchor escapement called the

dead beat escapement (See “Grandfather Clock Terms”). The deadbeat form of the anchor escapement was initially used only in precision clocks, but due to its superior accuracy, its use spread during the 1800s to most quality pendulum clocks. Most pendulum clocks made today use it.

Most of a longcase clock's height is used to hold the long pendulum and weights. The two chains attached to the weights. The lack of winding holes in the dial or clock face show this to be a 30-hour clock.

Traditionally, longcase clocks were made with one of two types of movements, the eight-day and one-day (30-hour) movements. Today we have 31 day and quartz movements in some longcase or grandfather clocks. Eight-day clocks are often driven by two weights, one driving the pendulum and the other the striking mechanism. Such movements usually have two keyholes on either side of the dial or clock face to wind each one.

By contrast, 30-hour clocks often had a single weight to drive both the timekeeping and striking mechanisms. Some 30-hour clocks were made with false keyholes, for customers who wished that guests to their home would think that the household was able to afford the more expensive eight-day clock. Cable clocks are wound by inserting a special crank (called a "key") into holes in the clock's face and turning it.

Others are chain-driven and have weights suspended by chains that wrap around gears in the clock's mechanism. To wind a chain-driven longcase clock, the end of each chain is pulled, lifting the weights. In the early 20th century, quarter-hour chime sequences were added to longcase clocks.

Learn more in the last article in the series, “Understanding Grandfather Clocks…” The “8 Tips for the Care and Set-up of Grandfather Clocks” Grandfather Clocks for Home Grandfather Clocks: All Product Page The Longcase Clock Article