-
41 Shortt, William Hamilton
SUBJECT AREA: Horology[br]b. 28 September 1881d. 4 February 1971[br]British railway engineer and amateur horologist who designed the first successful free-pendulum clock.[br]Shortt entered the Engineering Department of the London and South Western Railway as an engineering cadet in 1902, remaining with the company and its successors until he retired in 1946. He became interested in precision horology in 1908, when he designed an instrument for recording the speed of trains; this led to a long and fruitful collaboration with Frank HopeJones, the proprietor of the Synchronome Company. This association culminated in the installation of a free-pendulum clock, with an accuracy of the order of one second per year, at Edinburgh Observatory in 1921. The clock's performance was far better than that of existing clocks, such as the Riefler, and a slightly modified version was produced commercially by the Synchronome Company. These clocks provided the time standard at Greenwich and many other observatories and scientific institutions across the world until they were supplanted by the quartz clock.The period of a pendulum is constant if it swings freely with a constant amplitude in a vacuum. However, this ideal state cannot be achieved in a clock because the pendulum must be impulsed to maintain its amplitude and the swings have to be counted to indicate time. The free-pendulum clock is an attempt to approach this ideal as closely as possible. In 1898 R.J. Rudd used a slave clock, synchronized with a free pendulum, to time the impulses delivered to the free pendulum. This clock was not successful, but it provided the inspiration for Shortt's clock, which operates on the same principle. The Shortt clock used a standard Synchronome electric clock as the slave, and its pendulum was kept in step with the free pendulum by means of the "hit and miss" synchronizer that Shortt had patented in 1921. This allowed the pendulum to swing freely (in a vacuum), apart from the fraction of a second in which it received an impulse each half-minute.[br]Principal Honours and DistinctionsMaster of the Clockmakers' Company 1950. British Horological Society Gold Medal 1931. Clockmakers' Company Tompion Medal 1954. Franklin Institute John Price Wetherill Silver Medal.Bibliography1929, "Some experimental mechanisms, mechanical and otherwise, for the maintenance of vibration of a pendulum", Horological Journal 71:224–5.Further ReadingObituary, 1971, Proceedings of the Institution of Civil Engineers 56:396–7.F.Hope-Jones, 1949, Electrical Timekeeping, 2nd edn, London (a detailed but not entirely impartial account of the development of the free-pendulum clock).See also: Marrison, Warren AlvinDVBiographical history of technology > Shortt, William Hamilton
См. также в других словарях:
State of Franklin — Free Republic of Franklin State of Frankland Amtssprache Engl … Deutsch Wikipedia
State of Franklin — Infobox Former Country native name = conventional long name = The State of Franklin common name = Franklin ag continent = North America region = Tennessee country = USA era = status = status text = empire = government type = Republic| event start … Wikipedia
Franklin — often refers to Benjamin Franklin, a Founding Father of the United States. It may also refer to: Franklin (given name) Franklin (surname) Contents 1 Entertainment 2 Places … Wikipedia
Franklin Area School District — (FASD) is a school system located in Franklin, Pennsylvania. [ [http://www.fasd.k12.pa.us/franklinasd/site/default.asp Franklin Area School District ] ] Vocational school Franklin Area High School, among others, sends some students between 10th… … Wikipedia
Franklin — ist ein englischer Familien und Vorname, siehe Franklin (Name) – dort auch zu Namensträgern die CGS Einheit für die elektrische Ladung, siehe Franklin (Einheit) der Name zweier Inseln, siehe Franklin Insel der Fluss Franklin River in… … Deutsch Wikipedia
Franklin Central High School — Infobox School name =Franklin Central High School motto = established = 1960 type =Public high school affiliation = district =Franklin Township Community School Corporation grades =9 12 president = principal =Mr. Kevin Koers head of school = dean … Wikipedia
Franklin Lakes, New Jersey — Infobox Settlement official name = Borough of Franklin Lakes, New Jersey nickname = motto = imagesize = image caption = image imagesize = image caption = image mapsize = 250x200px map caption = Map highlighting Franklin Lakes s location within… … Wikipedia
Franklin D. Roosevelt State Park — For other places with the same name, see FDR State Park (disambiguation). Franklin D. Roosevelt State Park is a state park in Westchester County, New York. It was formerly known as Mohansic Park and Mohansic State Park and is situated in Yorktown … Wikipedia
State Parks in New Hampshire — Dies ist eine Liste der State Parks im US Bundesstaat New Hampshire. Die Verwaltung erfolgt durch die New Hampshire Division of Parks and Recreation. Cardigan State Park … Deutsch Wikipedia
State Parks in New York — Inhaltsverzeichnis 1 State Parks 1.1 A 1.2 B 1.3 C 1.4 D … Deutsch Wikipedia
State of Jefferson — US state Name = Jefferson Fullname = State of Jefferson (proposed) Flaglink = Flag of Jefferson Nickname = State of Mind Capital = Yreka, California (proposed 1941) LargestCity = Redding, California Governor = None as of 2008 Lieutenant Governor … Wikipedia
