A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is an approximate harmonic oscillator: It swings back and forth in a precise time interval dependent on its length, and resists swinging at other rates. From its invention in 1656 by Christiaan Huygens, inspired by Galileo Galilei, until the 1930s, the pendulum clock was the world's most precise timekeeper, accounting for its widespread use. Throughout the 18th and 19th centuries, pendulum clocks in homes, factories, offices, and railroad stations served as primary time standards for scheduling daily life, work shifts, and public transportation. Their greater accuracy allowed for the faster pace of life which was necessary for the Industrial Revolution. The home pendulum clock was replaced by less-expensive synchronous electric clocks in the 1930s and '40s. Pendulum clocks are now kept mostly for their decorative and antique value.
Clockwork refers to the inner workings of either mechanical devices called clocks and watches or other mechanisms that work similarly, using a series of gears driven by a spring or weight.
A conventional idea of a sustainable fishery is that it is one that is harvested at a sustainable rate, where the fish population does not decline over time because of fishing practices. Sustainability in fisheries combines theoretical disciplines, such as the population dynamics of fisheries, with practical strategies, such as avoiding overfishing through techniques such as individual fishing quotas, curtailing destructive and illegal fishing practices by lobbying for appropriate law and policy, setting up protected areas, restoring collapsed fisheries, incorporating all externalities involved in harvesting marine ecosystems into fishery economics, educating stakeholders and the wider public, and developing independent certification programs.
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to the clock's timekeeping element to replace the energy lost to friction during its cycle and keep the timekeeper oscillating. The escapement is driven by force from a coiled spring or a suspended weight, transmitted through the timepiece's gear train. Each swing of the pendulum or balance wheel releases a tooth of the escapement's escape wheel, allowing the clock's gear train to advance or "escape" by a fixed amount. This regular periodic advancement moves the clock's hands forward at a steady rate. At the same time, the tooth gives the timekeeping element a push, before another tooth catches on the escapement's pallet, returning the escapement to its "locked" state. The sudden stopping of the escapement's tooth is what generates the characteristic "ticking" sound heard in operating mechanical clocks and watches.
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 (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, which surrounds and frames the dial, or clock face.
The vergeescapement is the earliest known type of mechanical escapement, the mechanism in a mechanical clock that controls its rate by allowing the gear train to advance at regular intervals or 'ticks'. Verge escapements were used from the late 13th century until the mid 19th century in clocks and pocketwatches. The name verge comes from the Latin virga, meaning stick or rod.
Bristol Bay is the easternmost arm of the Bering Sea, at 57° to 59° North 157° to 162° West in Southwest Alaska. Bristol Bay is 400 km (250 mi) long and 290 km (180 mi) wide at its mouth. A number of rivers flow into the bay, including the Cinder, Egegik, Igushik, Kvichak, Meshik, Nushagak, Naknek, Togiak, and Ugashik.
Verge, Le Verge, Vergé or The Verge may refer to:
A master clock is a precision clock that provides timing signals to synchronise slave clocks as part of a clock network. Networks of electric clocks connected by wires to a precision master pendulum clock began to be used in institutions like factories, offices, and schools around 1900. Modern radio clocks are synchronised by radio signals or Internet connections to a worldwide time system called Coordinated Universal Time (UTC), which is governed by primary reference atomic clocks in many countries.
The coaxial escapement is a type of modern watch escapement mechanism invented by English watchmaker George Daniels in 1976 and patented in 1980. It is one of the few watch escapements to be invented in modern times and is used in most of the mechanical watch models currently produced by Omega SA.
St Mark's Clock is housed in the Clock Tower on the Piazza San Marco in Venice, Italy, adjoining the Procuratie Vecchie. The first clock housed in the tower was built and installed by Gian Paolo and Gian Carlo Rainieri, father and son, between 1496 and 1499, and was one of a number of large public astronomical clocks erected throughout Europe during the 14th and 15th centuries. The clock has had an eventful horological history, and been the subject of many restorations, some controversial.
A turret clock or tower clock is a clock designed to be mounted high in the wall of a building, usually in a clock tower, in public buildings such as churches, university buildings, and town halls. As a public amenity to enable the community to tell the time, it has a large face visible from far away, and often a striking mechanism which rings bells upon the hours.
A mechanical watch is a watch that uses a clockwork mechanism to measure the passage of time, as opposed to quartz watches which function using the vibration modes of a piezoelectric quartz tuning fork, or radio watches, which are quartz watches synchronized to an atomic clock via radio waves. A mechanical watch is driven by a mainspring which must be wound either periodically by hand or via a self-winding mechanism. Its force is transmitted through a series of gears to power the balance wheel, a weighted wheel which oscillates back and forth at a constant rate. A device called an escapement releases the watch's wheels to move forward a small amount with each swing of the balance wheel, moving the watch's hands forward at a constant rate. The escapement is what makes the 'ticking' sound which is heard in an operating mechanical watch. Mechanical watches evolved in Europe in the 17th century from spring powered clocks, which appeared in the 15th century.
The Alaska salmon fishery is a managed fishery that supports the annual harvest of five species of wild Pacific Salmon for commercial fishing, sport fishing, subsistence by Alaska Native communities, and personal use by local residents. The salmon harvest in Alaska is the largest in North America and represents about 80% of the total wild-caught catch, with harvests from Canada and the Pacific Northwest representing the remainder In 2017 over 200 million salmon were caught in Alaskan waters by commercial fishers, representing $750 million in exvessel value. Salmon fishing is a nearly ubiquitous activity across Alaska, however the most valuable salmon fisheries are in the Bristol Bay, Prince William Sound and Southeast regions.
Deadbeat, deadbeats or dead-beat may refer to:
The Corpus Clock, also known as the Grasshopper clock, is a large sculptural clock at street level on the outside of the Taylor Library at Corpus Christi College, University of Cambridge, in the United Kingdom, at the junction of Bene't Street and Trumpington Street, looking out over King's Parade. It was conceived and funded by John C. Taylor, an old member of the college.
Servos are small, cheap, mass-produced servomotors or other actuators used for radio control and small-scale robotics.
Coaxial, co-axial, co-ax or coax describes a physical arrangement wherein two or more structures share a common axis.
Escapement is a 1958 British horror science fiction film directed by Montgomery Tully and David Paltenghi. The screenplay was by Charles Eric Maine based on his 1956 novel of the same title.
Salmon escapement is the amount of a salmon population that does not get caught by commercial or recreational fisheries and return to their freshwater spawning habitat. Estimates of these amount are calculated with statistical analysis using data collected during that particular run season. These estimations help produce fishing quotas for the return year of the juveniles born for that years run, or can be used to determine the health of a salmon stock.
