In a clock driven by a weight or a spring, the power is first transmitted by the main, or great, wheel. This engages with a pinion (a gear with a small number of teeth designed to mesh with a larger wheel), whose arbor (a turning rod to which gears are attached) is attached to the second wheel that, in its turn, engages with the next pinion, and so on, down through the train to the escapement. The gear ratios are such that one arbor, usually the second or third, rotates once an hour and can be used to carry the minute hand. A simple 12-to-1 gearing, known as the motion work, gives the necessary step-down ratio to drive the hour hand. The spring or weight is fitted with a mechanism so it can be rewound when necessary, and the arbor carrying the minute hand is provided with a simple slipping clutch that allows the hands to be set to the correct time.
Although it isn’t strictly an “alarm clock,” the Google Home Hub can wake you up in the morning and do so much more. One of the most drastic differences between the Home Hub and other comparable devices is its size; the Home Hub stands at a mere 4.5 inches tall. This makes it small enough to fit comfortably on a nightstand. That small frame is partly due to the lack of a camera, which may be a pro or a con depending on how much you value your privacy. The Home Hub connects to the various Bluetooth-enabled devices you might have throughout your home, including lights, speakers, thermostat, etc. You can set up the Home Hub to respond to your voice commands, or manage devices using the touchscreen. For the purposes of an alarm clock, the Home Hub works terrifically. You can set a normal alarm, or even have the Hub wake you with a specific song from your music library. Given the Hub’s lackluster built-in speakers, however, you may want to connect it to your sound system if you have one. For more details, read our full review.

Fortunately, Ruggie takes the ease and convenience out of simply rolling over and slapping “snooze.” With Ruggie, you must apply pressure to a plush mat for three seconds to stop the alarm. The alarm can be set to 120 decibels, too, to further annoy you out of bed. For sake of perspective, 120 decibels is on par with the noise level of a chainsaw. Pleasant.
About 1450, clockmakers working probably in southern Germany or northern Italy began to make small clocks driven by a spring. These were the first portable timepieces, representing an important landmark in horology. The time-telling dials of these clocks usually had an hour hand only (minute hands did not generally appear until the 1650s) and were exposed to the air; there was normally no form of cover such as a glass until the 17th century, though the mechanism was enclosed, and the cases were made of brass.
“Great little dual alarm clock. Super easy to set the two alarms. Easy to use. It has a night light feature with adjustable dimmer, which is great. You can adjust the display completely dark so you don’t see the numbers. Then you can just hit the snooze button when the alarm is not ringing and the display lights up. It’s powered only by 3 AA batteries: no electric cord, no USB, nothing that you need. If you need a fancy alarm clock that sprays water in your face, this is not it.”