The Origin of Hours and Minutes
The Egyptians had ten hours of daylight from sunrise to sunset (exemplified by a sundial described in 1300 B.C.E.), two hours of twilight and twelve hours of night.
The calendar year was divided into 36 decans, each ten days long, plus five extra days, for a 365-day year. Each decan corresponded to a third of a zodiacal sign and was represented by a decanal constellation.
In the summer sky the night corresponded to about twelve decans, although half a day would correspond to eighteen decans. This led to the division of the night into twelve hours.
The first hours were seasonal in that their length varied with the season. (Note that this system was also used in oriental clocks.) Later, Hellenistic astronomers introduced equinoctal hours of equal length.
The Babylonians (about 300-100 B.C.E.) did their astronomical calculations in the sexagesimal (base-60) system. This was extremely convenient for simplifying division, since 60 is divisible by 2, 3, 4, 5, 6, and 10. The first fractional sexagesimal place we now call a minute, the second place, a second.
All over the world the cuckoo clock is regarded a symbol of the Black Forest. Since the 18th century the clockmakers of their region have specialized in the development of this type of clock. The cuckoo clock became known throughout the world thanks to the peddling "clock carriers" from the Black Forest who literally carried the clocks on their backs in
The first model of a cuckoo clock was a painted wooden clock. The clock was composed of an almost square board for the clock face and a raised semicircle, and was lavishly decorated. The cuckoo itself was to be found in the semicircle behind a small door. This type of clock was made from approximately 1730 on and was considered to be the specific clock style of the Black Forest. However, the exact origin of the cuckoo clock is not totally clear to this day.
In the middle of the 19th century there were two principal visual forms of the cuckoo clock. The "framed clock", as its name suggests, had a strong wooden frame and a wide painted inner section to which the clock face was attached. The cuckoo was situated in the upper section of the decorated surface and was occasionally included in the other decorative scenes.
The "railway house clock" came into being at the same time and essentially represents the style which is still used today. The basic form is very simple; a rectangle or square on which an isosceles triangle is placed. The house-shaped basic form with wooden decorative elements was developed to include scenes from every day life. The earliest clock of this type had a wooden clock face with white numbers and hands and fir cone shaped weights. Today vine leaves, animals and woodland plants as well as hunting scenes are features of this typical form of cuckoo clock. Dancing couples in traditional dress automatically move to music or the mill wheel rotates on the hour, while a farmer chops wood. The cuckoo itself moves its wings and beak and rocks back and forth when calling. Despite fluctuations in demand on the clock market, the production of the cuckoo clock in the Black Forest has remained uninterrupted to this day.
The Exact Sciences in Antiquity, 2nd Edition, O. Neugebauer, Dover Publications, New York, 1969 (paperback reprint)
A History of Ancient Mathematical Astronomy, O. Neugebauer, Springer-Verlag, Berlin, 1975