page_title: Grandfather clock
section_title: Origin
hierarchical_section_title: Grandfather clock / Origin
caption_attribution_description: English: Drawing of cross section of English longcase (grandfather) clock movement from the mid-1800s. It is described as: "The going part of a common regulator, or house-clock of superior character... The movement is that found in long-cased hall clocks..." This is a weight driven, pendulum clock with a one second (1 meter) pendulum, anchor or deadbeat escapement, second hand, and no striking mechanism. Drawing also appears in Paul Nooncree Hasluck (1889) The Clock Jobber's Handybook, Crosby, Lockwood &amp; Son, London, p.63, fig.14 with more information in text. Alterations: removed figure number. Labeled parts are identified in the text as: (A) escapement pallet (a) escapement arbor (C) center wheel (c) center wheel pinion (D) second wheel (d) second wheel pinion (E) scape wheel (e) scape wheel pinion (F) crutch (f) fork (G) great wheel (H) hour wheel (K) square winding arbor (L) bridge (M) minute wheel (N),(n) Motion works (together with M and H) (P) pendulum (Q) pendulum support (R),(r) maintaining power ratchets (S) pendulum suspension spring (X) lower pillar (Y) snail (only used in striking clocks) (Z) top pillar
context_page_description: 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 tall. 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.
context_section_description: The advent of the longcase clock is due to the invention of the anchor escapement mechanism by Robert Hooke around 1658. Prior to the adoption of the anchor mechanism, pendulum clock movements used an older verge escapement mechanism, which required very wide pendulum swings of about 80–100°. Long pendulums with such wide swings could not be fitted within a case, so most freestanding clocks had short pendulums.
  The anchor mechanism reduced the pendulum's swing to around 4° to 6°, allowing clockmakers to use longer pendulums, which had slower "beats". These consumed less power allowing clocks to run longer between windings, caused less friction and wear in the movement, and were more accurate. Almost all longcase clocks use a seconds pendulum (also called a "Royal" pendulum) meaning that each swing (or half-period) takes one second. These are about a metre (39 inches) long (to the centre of the bob), requiring a long narrow case. The long narrow case actually predated 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, this long weight case proved perfect to house it as well. 
  British clockmaker William Clement, who disputed credit for the anchor escapement with Robert Hooke, made the first longcase clocks by 1680.  Later the same year, Thomas Tompion, the most prominent British clockmaker, was making them too. Longcase clocks spread rapidly from England to other European countries and Asia. 
  Between 1680 and 1800, the average price of a grandfather clock in England remained steady at £1 10s. In 1680, this was the amount paid by an average working family for a year's rent, so the purchase of clocks was confined to the relatively well-off. But by 1800 wages had increased enough so that many lower middle class households owned grandfather clocks.
  Modern longcase clocks use a more accurate variation of the anchor escapement called the deadbeat escapement.
caption: Lateral view of a longcase clock movement without striking mechanism, mid-1800s.
exif: {}