The history of pendulum and its

Social Audit Network and global networks Historical roots The first use of the term "social audit" is generally attributed to George Goyder in the s. The roots of the idea lay within the perceived need at that time to make business more accountable to the community, and to ensure that the impacts of business — both beneficial and non-beneficial — are understood by society.

The history of pendulum and its

See Article History Clock, mechanical or electrical device other than a watch for displaying time. A clock is a machine in which a device that performs regular movements in equal intervals of time is linked to a counting mechanism that records the number of movements.

All clocks, of whatever form, are made on this principle. See also atomic clock ; nuclear clock. The first mechanical clocks to which clear references exist were large, weight-driven machines fitted into towers and known today as turret clocks.

These early devices struck only the hours and did not have hands or a dial. Components of a simple weight-driven clock. The oldest surviving clock in England is that at Salisbury Cathedralwhich dates from The Salisbury clock strikes the hours, and those of Rouen and Wells also have mechanisms for chiming at the quarter hour.

These clocks are large, iron-framed structures driven by falling weights attached to a cord wrapped around a drum and regulated by a mechanism known as a verge or crown wheel escapement. Their errors probably were as large as a half hour per day. The first domestic clocks were smaller wall-mounted versions of these large public clocks.

They appeared late in the 14th century, and few examples have survived; most of them, extremely austere in design, had no cases or means of protection from dust.

Paul Almasy Aboutclockmakers working probably in southern Germany or northern Italy began to make small clocks driven by a spring. These were the first portable timepieces, representing an important landmark in horology.

The time-telling dials of these clocks usually had an hour hand only minute hands did not generally appear until the s and were exposed to the air; there was normally no form of cover such as a glass until the 17th century, though the mechanism was enclosed, and the cases were made of brass.

Typical components in a watch powered by a mainspring. About Galileo noticed the characteristic timekeeping property of the pendulum. The Dutch astronomer and physicist Christiaan Huygens was responsible for the practical application of the pendulum as a time controller in clocks from onward.

Clocks, weight-driven and with short pendulums, were encased in wood and made to hang on the wall, but these new eight-day wall clocks had very heavy weights, and many fell off weak plaster walls and were destroyed.

The next step was to extend the case to the floor, and the grandfather clock was born. In the long, or seconds, pendulum was introduced by English clock makers with the anchor escapement. The anchor escapement, which was invented in the 17th century, allowed pendulum clocks to be regulated.

Mechanical clocks The pendulum The pendulum is a reliable time measurer because, for small arcs, the time required for a complete swing period depends only on the length of the pendulum and is almost independent of the extent of the arc.

The length of a pendulum with a period of one second is about 39 inches mmand an increase in length of 0. Altering the length of a pendulum is therefore a sensitive means of regulation. The alteration is usually carried out by allowing the bob to rest upon a nut that can be screwed up or down the pendulum rod.

Any expansion or contraction of the rod caused by changes of temperature will affect the timekeeping of a pendulum; e. For accurate timekeeping, the length of the pendulum must be kept as nearly constant as possible.

This may be done in several ways, some of which use the differing coefficients of expansion the amount of expansion per degree change in temperature of different metals to obtain a cancelling-out effect.

In one popular compensation method, the bob consists of a glass or metal jar containing a suitable amount of mercury. The gridiron pendulum employs rods of different metal, usually brass and steel, while in the zinc-iron tube the pendulum rod is made of concentric tubes of zinc and iron. An improved method, however, is to make the pendulum rod from a special alloy called Invar.

This material has such a small coefficient of expansion that small changes of temperature have a negligible effect and can easily be compensated for if required.

In a pendulum clock an escape wheel is allowed to rotate through the pitch of one tooth for each double swing of the pendulum and to transmit an impulse to the pendulum to keep it swinging.

An ideal escapement would transmit the impulse without interfering with the free swing, and the impulse should be as uniform as possible.

The double three-legged gravity escapement, which achieves the second of these but not the first, was invented by Edmund Beckett, afterward Lord Grimthorpeand used by him for the great clock at Westminster, now generally known as Big Benwhich was installed in It became the standard for all really accurate tower clocks.

The most common escapement was the verge-and-foliot. The verge-and-foliot was the most common mechanism for controlling the descent of a weight in a weight-driven clock.

The history of pendulum and its

In a typical verge-and-foliot escapement, the weighted rope unwinds from the barrelturning the toothed escape wheel. Controlling the movement of the wheel is the verge, a vertical rod with pallets at each end.In the years after the Civil War, the pendulum of American history was perhaps at its most obvious.

(Many have seen this period’s echoes in recent events; for example, Slate’s Jamelle Bouie. The Foucault pendulum (English: / f uː ˈ k oʊ / foo-KOH; French pronunciation:) or Foucault's pendulum is a simple device named after French physicist Léon Foucault and conceived as an experiment to demonstrate the Earth's pendulum was introduced in and was the first experiment to give simple, direct evidence of the .

Beginnings. Humankind has always recognized the passing of time and has tried to measure and record that passing. The simple alarm clock at your bedside table owes its existence to more than 6, years of thinking about time and tinkering with devices to accurately mark its passage.

Pendulum dowsing has also been called divining; for its ability to provide information and predict the future. The term pendulum dowsing is often used to refer to the search for specific targets, while the term pendulum divining is most often used in reference to seeking precise information.

The Pit and the Pendulum by Edgar Allan Poe - In Edgar Allan Poe’s short story “The Pit and the Pendulum,” written , and “using the anguish of imminent death as the means of causing the nerves to quiver” (Edgar Allan Poe, ), he takes the reader into the mind of a man who is tortured by various means by some unknown person or persons for reasons that are not given.

This card is not a member of the "Pendulum" archetype, because its Japanese name does not contain 「ペンデュラム」. Pendulum Machine 振(ふ)り子(こ)刃(やいば)の拷(ごう)問(もん)機(き)械(かい) English Pendulum Machine Chinese 單擺刃拷問機械 Check translation French Machine Pendule Check translation German Pendelmaschine Check.

Pendulum | Define Pendulum at