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.[9] 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.[10]
But where OK to Wake! really shines (pun intended) is in its unique feature that parents love; the clock will glow green and show a cute face when it's an acceptable time for your little one to get out of bed. That means even very young children can learn when it's okay to go looking for mommy or daddy — no need to be able to actually read the time. As your child grows, you can stop using the glow feature, and simply use the device as a regular, albeit cuter than average, alarm clock.
If the four alarms you scheduled to go off 10 minutes apart wake your neighbors but not you, you might want to try this noisy clock; it has a 113-decibel alarm—about as loud as a jackhammer. And if the volume alone won't do it, the red flashing lights and accompanying bed-shaker unit (which goes beneath your mattress) should deliver the full sensory message that grave danger awaits unless you get out of bed.
Here is a clock that will look great in any room in the house and it never needs a plug! This Water Clock is powered by ordinary tap water. Never needs batteries or electricity. Just fill this Water clock with water and you are on your way to more eco-friendly home. After about 6 months to a year you may need to dump the water out (your can pour it into a plant) and refill. The clock will remember the time as you do so. It even has an alarm. Great for traveling as well. Why would you ever use...
Never squint to see what time it is again, especially when you're waking up 20 times in the middle of the night to, you know, see exactly what time it is. We love the projection feature that displays the time on your wall or ceiling for easy viewing. Plus, it'll even toss up the temperature — so you'll already know what you should wear to work before you even get out of bed.
Need a little extra incentive to pry yourself out of bed? You'll have plenty of it with this no-nonsense wheeled alarm clock. After the first time you press snooze, this unit automatically starts moving away from you, creating enough distance to literally force you out of bed in order to shut it off for good. Plus, it also comes in pastel blue, white, red, and more.
If it has the iHome name attached to it, you know it’s going to be flashy. Their Bluetooth color changing clock hits home on all the necessary marks, allowing you to talk and end phone conversations with the touch of a button, as well as the five multiple LED color settings. It isn’t all about waking up in the morning; this alarm clock has you ready to go with a fully charged iPhone, fed sweet, sweet energy while you sleep. The last alarm clock you’ll ever need is staring you right in the face – it’s time to complete your iHome collection in style.
Clockmakers developed their art in various ways. Building smaller clocks was a technical challenge, as was improving accuracy and reliability. Clocks could be impressive showpieces to demonstrate skilled craftsmanship, or less expensive, mass-produced items for domestic use. The escapement in particular was an important factor affecting the clock's accuracy, so many different mechanisms were tried.
Don't worry, Zeus didn't show up to your home, but you'll certainly feel that way when waking up to this unit's thunderous, 113-decibel buzzing. Fair warning: It's definitely loud, so it's a good pick only if you're a heavy, heavy sleeper. Just in case the noise somehow isn't enough to pry you out of bed, this alarm clock flashes multiple bright red LEDs and comes with a bed shaker that'll really get you going. Trust us, if that sensory overload doesn't get the job done, nothing will.

Traditional mechanical alarm clocks have one or two bells that ring by means of a mainspring that powers a gear to propel a hammer back and forth between the two bells or between the interior sides of a single bell. In some models, the back encasement of the clock itself acts as the bell. In an electric bell-style alarm clock, the bell is rung by an electromagnetic circuit and armature that turns the circuit on and off repeatedly.[1]


Use your wall space as the board to create your scalable clock. The Blink wall clock by Umbra is a set of black metal indicators and 12 number that mount to the wall with adhesives. Comes with a template to set the scale of the clock on a wall. Clock mechanism mounts to the wall with a screw or nail operate on one AA battery (not included). Designed by Edward Lee and Adrienna Matzeg Umbra original, modern, casual, functional and affordable design for the home.


This dual tone wall clock features a handsome Rustic Cherry finish with a contrasting Vintage Umber inset panel. The wood stick moving pendulum features a spun brass-finished bob. Beneath a convex glass crystal, the dial features a two color wood-tone dial with gold Arabic numerals and aged brass-tone spade hands. Finished in distressed Rustic Cherry on select hardwoods and veneers. Quartz, non-chiming battery operated movement.
Slave clocks, used in large institutions and schools from the 1860s to the 1970s, kept time with a pendulum, but were wired to a master clock in the building, and periodically received a signal to synchronize them with the master, often on the hour.[71] Later versions without pendulums were triggered by a pulse from the master clock and certain sequences used to force rapid synchronization following a power failure.
Now, RCA Digital Alarm Clock is pretty basic, but for some of us, that’s all we need, right? With a bright, beaming red LED display, you’re certain to rub your eyes and wonder what weird light is pulsating from your nightstand. There’s an alarm indicator and the classic AM/PM light that we all remember from early-2000 models. You can do something different from your late 1990s-inspired clock, and that is change the brightness levels so you don’t completely burn out your retinas.
Place Sense by Hello on your bedside table, and it will help you fall asleep, stay asleep, and wake up without the grogginess or fatigue you may be used to. The small, white orb plays ambient noises to help ease you into dreamland, and a small monitor clipped to your pillow tracks your movements throughout the night, and sends feedback to an app on your smartphone. By monitoring your sleep cycles, the alarm knows the best time to wake you up in the morning so you're feeling refreshed.
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,[22][23] and modern reproductions have been made.[23] 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.

Here at the Strategist, we like to think of ourselves as crazy (in the good way) about the stuff we buy (like pillows), but as much as we’d like to, we can’t try everything. Which is why we have People’s Choice, in which we find the best-reviewed (that’s four-to-five-star reviews and lots of ‘em) products and single out the most convincing. While we’ve tried to find the nicest-sounding alarm clocks and ended up with picks for the best alarm clock and a voice-controlled alarm clock, we wanted to see what other ways to wake up were out there. So we found the best alarm clocks on Amazon, according to hyperenthusiastic reviewers. (Note that reviews have been edited for length and clarity.)
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