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As soon as you spot the top pocket watches collection, you will feel happy. The gnomon is the device that produces the shadow is usually a piece parallel to the Earth's axis, pointing to the sky. The reading surface is marked by time of day. Each sundial is designed for specific latitude. To calculate the standard time from daylight tables are used, because the solar time is irregular to vary the apparent speed of the sun throughout the year. Sundials were used to determine the time of day before the clocks are widespread in the eighteenth century.
Hourglass
The hourglass is a device of ancient origin, and consists of two narrow-mouthed transparent cavities facing each other and connected at their ends open. One of the cavities contains a granular or liquid substance, usually sand. By rotating the instrument, the substance begins to flow from one cavity to another. The hourglass can measure one or more periods of hours or a few minutes. Many retro pocket watches included top quality parts.
The water clock or clepsydra timed based on how long it takes an amount of water to move from one container to another, of equal size, which is below. It is very similar to the hourglass only that instead of containing sand contains water.
Modern Watches
Mechanical pocket watches are great. The first mechanical clocks attach a pendulum, a gear system, and a weight. By its nature, the pendulum swings with a constant rate and this can be adjusted. Each oscillation allows the first gear tooth turn by the force of the weight. The gear system moves clockwise. The oldest clock of this type appeared around the thirteenth century.
Other types of mechanical watches use a spring as a source of motion instead of a weight hanging and / or other instead of the pendulum, which is an advantage because it takes up less space. The first watches of this type appeared in the mid-fifteenth century.
Timers
The high-precision mechanical timepieces known as chronometers were used by mariners to determine longitude and calculate its position at sea. Also, astronomers and jewelers used to calibrate measuring instruments. Effective the first timer was built in 1761 by British clockmaker John Harrison, was mounted on a portable rocker to keep the delicate mechanism horizontally.
Electrical and electronic pocket watches are part of our modern society. In some small household electric clock motor rotates in unison with the generator power plant, which is regulated to provide an alternating current frequency. Also, electric currents can.
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