The earliest alarm clock dates back to around 250 BCE, and was invented by the Greeks. It was nothing like the alarm clocks we use today; its mechanism was basically that of a water clock where rising water would keep time and eventually hit a mechanical bird that triggered an alarming whistle.
Closer to our modern-day alarm clocks was the first mechanical alarm clock invented by Levi Hutchins of Concord, New Hampshire, in 1787. He was a clock-maker, who was the figure of punctuality and promptness. His firm routine was to awaken at 4:00 am in order to be at his job on time, but he sometimes slept past that hour, which distraught him deeply.
He was determined to solve this problem and soon he came up with the idea of a clock that could sound an alarm. He constructed a pine cabinet of 29"x14", transferred the inner mechanism of one of his large brass clocks into it and inserted a pinion inside. “When the minute hand of the clock reached and tripped the pinion at 4:00 o'clock, the movement of the pinion set a bell in motion, and the bell made sufficient noise to awaken me almost instantly", he wrote.
The alarm clock he invented would only ring at 4:00 am, and it was not adjustable. He also never bothered to patent it or mass produce it as he clearly was not interested in money; only in being on time.
Years later, in 1847, the French inventor Antoine Redier invented and patented the first adjustable mechanical alarm clock that bears much resemblance to the alarm clocks we use today.
The article was published in the PSC Newslertter, 2nd School Semester 2010/2011.