Gears in a watch

In a clock the gear system is connected to the seconds hand, minutes hand and the hour hand. The gear wheel attached to the seconds arm has 120 teeth and is connected to a pendulum having a period of half a second. This means that two teeth are able to advance in 1 second the entire revolution of the seconds hand takes 60 seconds or one minute.This gear is made to  drive another gear train with a ratio of 1:60 and  the minute hand is attached to the last gear in that train. A final train with a ratio of 1:12 is attached to the hour hand.

Here's the link where you can see this in action:

http://electronics.howstuffworks.com/gadgets/clocks-watches/clock3.htm

Regelation

The phenomenon due to which ice melts to water at a temperature below 0o C melts to water on the application of external pressure and refreezing of water formed into ice on the release of pressure is called regelation.

Examples of Regelation :

1. When two pieces of ice are pressed together they form a single piece on releasing pressure. This happens because pressure lowers the melting point and makes the ice melt at the surface of contact. On releasing pressure the melting point is raised once again and and the water formed refreezes once again.

2. Glaciers move slowly in the downward direction at sub zero ( below 0o C)  temperature due to regelation. Ice present at the base of the glacier experiences tremendous pressure due to the weight of the glacier. This causes the ice to melt at the base of the glacier. As the water formed flows out from the base of the glacier, it does not experience any pressure and refreezes to form ice once again.