<Li> The hour hand moves slowest of all, taking twelve hours (half a day) to make a complete rotation . It starts from "12" at midnight, makes one rotation until it is pointing at "12" again at noon, and then makes another rotation until it is pointing at "12" again at midnight of the next morning . </Li> <P> Clocks existed before clock faces . The first mechanical clocks, built in 13th - century Europe, were striking clocks: their purpose was to ring bells upon the canonical hours, to call the local community to prayer . These were tower clocks installed in bell towers in public places, to ensure that the bells were audible over a wide area . Soon after these first mechanical clocks were in place people realized that their wheels could be used to drive an indicator on a dial on the outside of the tower, where it could be widely seen . </P> <P> Before the late 14th century, a fixed hand (often a carving literally shaped like a hand) indicated the hour by pointing to numbers on a rotating dial; after this time, the current convention of a rotating hand on a fixed dial was adopted . Minute hands (so named because they indicated the small, or minute, divisions of the hour) only came into regular use around 1690, after the invention of the pendulum and anchor escapement increased the precision of time - telling enough to justify it . In some precision clocks, a third hand, which rotated once a minute, was added in a separate subdial . This was called the "second - minute" hand (because it measured the secondary minute divisions of the hour), which was shortened to "second" hand . The convention of the hands moving clockwise evolved in imitation of the sundial . In the Northern hemisphere, where the clock face originated, the shadow of the gnomon on a horizontal sundial moves clockwise during the day . This was also why noon or 12 o'clock was conventionally located at the top of the dial . </P> <P> During the French Revolution in 1793, in connection with its Republican calendar, France attempted to introduce a decimal time system . This had 10 decimal hours in the day, 100 decimal minutes per hour, and 100 decimal seconds per minute . Therefore, the decimal hour was more than twice as long (144 min) as the present hour, the decimal minute was slightly longer than the present minute (86 seconds) and the decimal second was slightly shorter (0.86 sec) than the present second . Clocks were manufactured with this alternate face, usually combined with traditional hour markings . However, it didn't catch on, and France discontinued the mandatory use of decimal time on 7 April 1795, although some French cities used decimal time until 1801 . </P>

When was the minute hand added to clocks