Home > Pendulum clock
A pendulum clock uses a pendulum as its time base. From ancient times up until about 1930, the most accurate clocks were pendulum clocks. Pendulum clocks cannot operate on vehicles, because the accelerations of the vehicle drive the pendulum, causing inaccuracies. See chronometer for a discussion of the problems of navigational clocks.1 History
In 1656, Christiaan Huygens, a Dutch scientist, made the first pendulum clock, regulated by a mechanism with a "natural" period of oscillation. ( Galileo Galilei is credited with inventing the pendulum-clock concept, and he studied the motion of the pendulum as early as 1582. He even sketched out a design for a pendulum clock, but he never actually constructed one before his death in 1642.) Huygens' early pendulum clock had an error of less than 1 minute a day, the first time such accuracy had been achieved. His later refinements reduced his clock's error to less than 10 seconds a day.
Huygens obtained a patent in 1657 and within a few weeks, the English clockmaker Ahasuerus Fromanteel secured production rights, and began the tradition of English longcase (grandfather) clocks.
Around 1675, Huygens developed the balance wheel and spring assembly, still found in some of today's wristwatches. This improvement allowed portable 17th century watches to keep time to 10 minutes a day. And in London in 1671, William Clement began building clocks with the new "anchor" or "recoil" escapement, a substantial improvement over the verge because it interferes less with the motion of the pendulum.
In 1721, George Graham improved the pendulum clock's accuracy to 1 second per day by compensating for changes in the pendulum's length due to temperature variations. John HarrisonFor the recipients of the Victoria Cross, see either John Harrison (VC 1857) or John Harrison (VC 1917 John Harrison ( March 1693 March 24 1776) was an English clock designer, who developed and built the world's first successful maritime clock, one whose, a carpenter and self-taught clock-maker, refined Graham's temperature compensation techniques and developed new methods for reducing friction. By 1761Events January 16 British capture Pondicherry, India from the French. February 8 Earthquake in London breaks chimneys in Limehouse and Poplar March 8 Second earthquake in North London, Hampstead and Highgate In Dutch Guayana a “state” formed by escaped sl, he had built a marine chronometer with a spring and balance wheel escapement that won the British government's 1714 prize (worth more than $10,000,000 in today's currency) for a means of determining longitude to within one-half degree after a voyage to the West Indies. It kept time on board a rolling ship to about one-fifth of a second a day, nearly as well as a pendulum clock could do on land, and 10 times better than required to win the prize.
Over the next century, refinements led in 1889Events January-April January 8 Herman Hollerith receives a patent for his electric tabulating machine January 22 Columbia Phonograph is formed in Washington, DC. February 11 Meiji Constitution of Japan adopted; 1st Diet convenes in 1890 January 30 ? Crown to Siegmund Riefler 's clock with a nearly free pendulum, which attained an accuracy of a hundredth of a second a day and became the standard in many astronomical observatories. A true free-pendulum principle was introduced by R.J. Rudd about 1898Events January 1 New York City annexes land from surrounding counties, creating the City of Greater New York. The city is geographically divided into five boroughs: Manhattan, Brooklyn, Queens, The Bronx, and Staten Island. January 13 Emile Zola's J'accus, stimulating development of several free-pendulum clocks. One of the most famous, the W.H. Shortt clock, was demonstrated in 1921Events January 2 The first religious radio broadcast ( KDKA AM in Pittsburgh, Pennsylvania) January 2 Spanish liner Santa Isabel sinks off Villa Garcia 244 dead January 2 DeYoung Museum in Golden Gate Park San Francisco opens. January 20 Republic of Turke. The Shortt clock almost immediately replaced Riefler's clock as a supreme timekeeper in many observatories. This clock contained two pendulums, one a slave and the other a master. The slave pendulum gave the master pendulum the gentle pushes needed to maintain its motion, and also drove the clock's hands. This allowed the master pendulum to remain free from mechanical tasks that would disturb its regularity. Ths Shortt clock was the first device
accurate enough to detect seasonal variations in the rotation of the
Earth.
