The ancient Greek philosopher Plato (428–348 BC) was said to possess a large water clock with an unspecified alarm signal similar to the sound of a water organ; he used it at night, possibly for signalling the beginning of his lectures at dawn (Athenaeus 4.174c). The Hellenistic engineer and inventor Ctesibius (fl
285–222 BC) fitted his clepsydras with dial and pointer for indicating the time, and added elaborate "alarm systems, which could be made to drop pebbles on a gong, or blow trumpets (by forcing bell-jars down into water and taking the compressed air through a beating reed) at pre-set times" (Vitruv 11.11).
The late Roman senator Cassiodorus (c
485–585) advocated in his rulebook for monastic life the water clock as a useful alarm for the 'soldiers of Christ' (Cassiod
30.4 f.). The Christian rhetorician Procopius described in detail prior to 529 a complex public striking clock in his home town Gaza which featured an hourly gong and figures moving mechanically day and night.
In China, a striking clock was devised by the Buddhist monk and inventor Yi Xing (683–727). The Chinese engineers Zhang Sixun and Su Song integrated striking clock mechanisms in astronomical clocks in the 10th and 11th centuries, respectively. A striking clock outside of China was the water-powered clock tower near the Umayyad Mosque in Damascus, Syria, which struck once every hour
It was constructed by the Arab engineer al-Kaysarani in 1154
In 1235, an early monumental water-powered alarm clock that "announced the appointed hours of prayer and the time both by day and by night" was completed in the entrance hall of the Mustansiriya Madrasah in Baghdad.
From the 14th century, some clock towers in Western Europe were also capable of chiming at a fixed time everyday, the earliest of which was described by the Florentine writer Dante Alighieri in 1319. The most famous original striking clock tower still standing is possibly the one in St Mark's Clocktower in St Mark's Square, Venice
The St Mark's Clock was assembled in 1493, by the famous clockmaker Gian Carlo Rainieri from Reggio Emilia, where his father Gian Paolo Rainieri had already constructed another famous device in 1481
In 1497, Simone Campanato moulded the great bell (h
1,56 m., diameter m
1,27), which was put on the top of the tower where it's alternatively beaten by the Due Mori (Two Moors), two bronze statues (h
2,60) handling a hammer.
User-settable mechanical alarm clocks date back at least to 15th-century Europe
These early alarm clocks had a ring of holes in the clock dial and were set by placing a pin in the appropriate hole.
Another mechanical alarm clock was created by Levi Hutchins, of New Hampshire in the United States, in 1787
This device he made only for himself however, and it only rang at 4 AM, in order to wake him for his job. The French inventor Antoine Redier was the first to patent an adjustable mechanical alarm clock, in 1847.
Alarm clocks, like almost all other consumer goods in the United States of America, ceased production in the spring of 1942, as the factories which made them were converted over to war work during World War II, but they were one of the first consumer items to resume manufacture for civilian use, in November 1944
By that time, a critical shortage of alarm clocks had developed due to older clocks wearing out or breaking down