The origin of the all-mechanical escapement clock is unknown; the first such devices may have been invented and used in monasteries to toll a bell that called the monks to prayers. 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.
In mechanical clocks, the power source is typically either a weight suspended from a cord or chain wrapped around a pulley, sprocket or drum; or a spiral spring called a mainspring. Mechanical clocks must be wound periodically, usually by turning a knob or key or by pulling on the free end of the chain, to store energy in the weight or spring to keep the clock running.
It’s vital to your personal health. When you rest at night, after about twenty to thirty minutes, your body begins to enter REM sleep (if you’re lucky). Either way, your body slows down. Your heart rate hits around 40-50 BPM when you’re sleeping, compared to the 60-100 BPM you go through while you’re awake. This gives your body time to give your heart a rest, repair blood vessels, and repair muscle tissue if you worked out, or physically strained yourself during the day.
After a long day at work, school, or running errands, it's tough to beat the feeling of climbing into your bed for a good night's rest. When you're feeling tired, it's tough to get back out of bed in the morning to start all over again. With the right alarm clock, you can wake up to pleasant sounds that make it a little easier to get up and going. With a wide selection of alarm clock options available at JCPenney, you can find the style that fits with the look and feel of your bedroom while delivering the functionality you need.
Besides the Chinese astronomical clock of Su Song in 1088 mentioned above, in Europe there were the clocks constructed by Richard of Wallingford in St Albans by 1336, and by Giovanni de Dondi in Padua from 1348 to 1364. They no longer exist, but detailed descriptions of their design and construction survive, and modern reproductions have been made. They illustrate how quickly the theory of the mechanical clock had been translated into practical constructions, and also that one of the many impulses to their development had been the desire of astronomers to investigate celestial phenomena.
Howard Miller 625-323 Alton wall clock. Matte black case with shatter-resistant acrylic crystal. White dial and large, easy-to-read black Arabic numerals. Auto Daylight-Savings movement automatically adjusts for Daylight Savings Time. The hands of the clock follow an LCD display on the back of the clock and make corrections to keep the correct time including Daylight Saving Time corrections.
In Chinese culture, giving a clock (送鍾/送钟, sòng zhōng) is often taboo, especially to the elderly as the term for this act is a homophone with the term for the act of attending another's funeral (送終/送终, sòngzhōng). A UK government official Susan Kramer gave a watch to Taipei mayor Ko Wen-je unaware of such a taboo which resulted in some professional embarrassment and a pursuant apology.
“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.”