Wallingford's clock had a large astrolabe-type dial, showing the sun, the moon's age, phase, and node, a star map, and possibly the planets. In addition, it had a wheel of fortune and an indicator of the state of the tide at London Bridge. Bells rang every hour, the number of strokes indicating the time. Dondi's clock was a seven-sided construction, 1 metre high, with dials showing the time of day, including minutes, the motions of all the known planets, an automatic calendar of fixed and movable feasts, and an eclipse prediction hand rotating once every 18 years. It is not known how accurate or reliable these clocks would have been. They were probably adjusted manually every day to compensate for errors caused by wear and imprecise manufacture. Water clocks are sometimes still used today, and can be examined in places such as ancient castles and museums. The Salisbury Cathedral clock, built in 1386, is considered to be the world's oldest surviving mechanical clock that strikes the hours.
In 1675, Huygens and Robert Hooke invented the spiral balance spring, or the hairspring, designed to control the oscillating speed of the balance wheel. This crucial advance finally made accurate pocket watches possible. The great English clockmaker, Thomas Tompion, was one of the first to use this mechanism successfully in his pocket watches, and he adopted the minute hand which, after a variety of designs were trialled, eventually stabilised into the modern-day configuration. The rack and snail striking mechanism for striking clocks, was introduced during the 17th century and had distinct advantages over the 'countwheel' (or 'locking plate') mechanism. During the 20th century there was a common misconception that Edward Barlow invented rack and snail striking. In fact, his invention was connected with a repeating mechanism employing the rack and snail. The repeating clock, that chimes the number of hours (or even minutes) was invented by either Quare or Barlow in 1676. George Graham invented the deadbeat escapement for clocks in 1720.
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More than just a tool for keeping track of the time, this eye-catching wall clock helps turn any empty wall into an artful display. Crafted from injection plastic finished in a sleek metallic tone, it features a circular center with rods all around extending to stage the numbers of an analog dial. Measuring 16'' in diameter, it makes a statement on your kitchen or entryway wall without dominating the decor.
The word horologia (from the Greek ὥρα, hour, and λέγειν, to tell) was used to describe early mechanical clocks, but the use of this word (still used in several Romance languages)  for all timekeepers conceals the true nature of the mechanisms. For example, there is a record that in 1176 Sens Cathedral installed a ‘horologe’ but the mechanism used is unknown. According to Jocelin of Brakelond, in 1198 during a fire at the abbey of St Edmundsbury (now Bury St Edmunds), the monks 'ran to the clock' to fetch water, indicating that their water clock had a reservoir large enough to help extinguish the occasional fire. The word clock (from the Celtic words clocca and clogan, both meaning "bell"), which gradually supersedes "horologe", suggests that it was the sound of bells which also characterized the prototype mechanical clocks that appeared during the 13th century in Europe.
Water clocks, also known as clepsydrae (sg: clepsydra), along with the sundials, are possibly the oldest time-measuring instruments, with the only exceptions being the vertical gnomon and the day counting tally stick. Given their great antiquity, where and when they first existed is not known and perhaps unknowable. The bowl-shaped outflow is the simplest form of a water clock and is known to have existed in Babylon and in Egypt around the 16th century BC. Other regions of the world, including India and China, also have early evidence of water clocks, but the earliest dates are less certain. Some authors, however, write about water clocks appearing as early as 4000 BC in these regions of the world.
“I am the heaviest sleeper and was setting four or five alarms on my phone to wake me up. After being late a few times, I decided to purchase this alarm clock to help me wake up on time. I couldn’t be happier with my purchase. … The bed shaker is super important. I put it under my pillow, and it shook me awake; the loud beep helped too. If you can sleep through earthquakes and shouting family members, this is the alarm clock for you.”