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The Riefler escapement is a mechanical escapement for precision pendulum clocks invented and patented [1] by German instrument maker Sigmund Riefler in 1889. [2] It was used in the astronomical regulator clocks made by his German firm Clemens Riefler from 1890 to 1965, [3] which were perhaps the most accurate all-mechanical pendulum clocks made.
The Shortt was the first clock to be a more accurate timekeeper than the Earth itself; it was used in 1926 to detect tiny seasonal changes in the Earth's rotation rate. [3] [7] [8] Shortt clocks achieved accuracy of around a second per year, [3] [9] [10] [11] although a recent measurement indicated they were even more accurate. About 100 were ...
Electromagnetic escapements, which used a switch or phototube to turn on a solenoid electromagnet to give the pendulum an impulse without requiring a mechanical linkage, were developed. The most accurate pendulum clock was the Shortt-Synchronome clock, a complicated electromechanical clock with two pendulums developed in 1923 by W.H. Shortt and ...
Try visiting this estate sale packed with collectibles. Treasure hunt: Clock valued at $12,000 tops collectibles up for bid at Augusta estate sale Skip to main content
[32] [33] The most accurate mechanical clock to date is probably the electromechanical Littlemore Clock, built by noted archaeologist E. T. Hall in the 1990s. In Hall's paper, [ 34 ] he reports an uncertainty of 3 parts in 10 9 measured over 100 days (an uncertainty of about 0.02 seconds over that period).
In 1941, their most inexpensive alarm clock was the model 7H117 "Reporter," and it sold for $2.95, the equivalent of $30.00 in 2008 funds. But their beautiful design and amazing reliability assured a brisk market for them throughout the company's most prosperous years.
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A torsion pendulum clock, more commonly known as an anniversary clock or 400-day clock, is a mechanical clock which keeps time with a mechanism called a torsion pendulum. This is a weighted disk or wheel, often a decorative wheel with three or four chrome balls on ornate spokes, suspended by a thin wire or ribbon called a torsion spring (also ...