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Horology

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TimePieces

Orrery. Mechanical model of the solar system A small orrery showing Earth and the inner planets An orrery is a mechanical model of the Solar System that illustrates or predicts the relative positions and motions of the planets and moons, usually according to the heliocentric model. It may also represent the relative sizes of these bodies; however, since accurate scaling is often not practical due to the actual large ratio differences, a subdued approximation may be used instead.

Though the Greeks had working planetaria, the first orrery that was a planetarium of the modern era was produced in 1704, and one was presented to Charles Boyle, 4th Earl of Orrery – hence the name. They are typically driven by a clockwork mechanism with a globe representing the Sun at the centre, and with a planet at the end of each of the arms.

History[edit] Ancient versions[edit] Early versions[edit] Modern orreries[edit] That is, 0.4, 0.7, 1.0, 1.6, 2.8, 5.2 ... A 1766 Benjamin Martin Orrery, used at Harvard See also[edit] The Astronomical Clock of Richard of Wallingford. This is one of four essays that I wrote for my M Phil degree in History and Philosophy of Science at Clare College, Cambridge, in 1990-91 (the others, on the transmission of science from the Greeks to the Arabs, medieval timekeeping and Sir Robert Ball, are also on this site as is my dissertation and a 1992 lecture based on some of the same material). I think it is the most interesting of the four. Unfortunately it was also the first written, which means that the style is very unpolished and there are far too many footnotes left hanging.

I changed my mind about a couple of issues when I came to write the essay on medieval time-keeping, and this means there is a real unevenness of style between the two. My biggest regret about this essay is that I did not press home the idea that I had had about why Richard of Wallingford designed an elaborate and fantastically accurate astronomical clock for St Alban's Abbey. What does this have to do with the clock? A great deal. This page has had R. Front Page. Watchclocks.org. Joe Monincx All-Wood Clocks. Customer Showcase. This year we are celebrating Classic Clock Kits' Silver Jubilee.

Well over a thousand of our clocks have been made and are on display in homes all over the world. From time to time we have participated in international and local Model Engineer and Clock exhibitions, and on occasion have been able to give customers the opportunity to put their clocks on show to the public and to compete for awards. We are interested in submissions from kit builders who have embellished or adapted a kit in some attractive or interesting manner.

The rationale behind our kits is that half of the total time and cost in building a well-presented clock is in the hand finishing; commercial polishing (or Black and Decker) rounds the edges! This means that the appeal of a Classic Clock kit is not confined only to those who do not have engineering skills. Horology - The Index: Types & Notable Pieces. Horology - The Index.