Timeline · three sections
WristwatchPocket watchTimekeeping

Before the watch.

How people learned to keep time, from the first counted months to the first coiled spring. Each record is dated by the object or text that survives.

The bookkeeper’s yearc. 3100 BCThe bookkeeper’s yearUruk bookkeepers reckoned every month as 30 days and the year as 360.Counting the day
Twelve hours of nightc. 1900 BCTwelve hours of nightStar tables inside Egyptian coffins split the night into 12 hours by the rising of decan stars.Counting the day
Why 60 minutesc. 1800 BCWhy 60 minutesScribes counted in sixties. Through Greek astronomy, the habit survives in our minutes and seconds.Counting the day
The shadow clockc. 1450 BCThe shadow clockA raised end throws its shadow along a marked bar; summer hours ran longer than winter ones.Sundials
The water clockc. 1350 BCThe water clockWater drains from a stone bowl; twelve scales inside, one per month, give the hours of the night.Water clocks
The courtroom timerc. 400 BCThe courtroom timerAthenian courts timed speeches by water jar: equal shares, and bigger cases got more water.Water clocks
A float and a gearc. 270 BCA float and a gearCtesibius lets water lift a float; a rack turns a toothed wheel and a figure points to the hour.Water clocks
The gift from Baghdad807The gift from BaghdadIn 807 the caliph Harun al-Rashid sent Charlemagne a brass water clock that rang the hours.Water clocks
893Six candles a dayAsser records Alfred’s six marked candles, each burning four hours inside a lantern of horn.Candle and sand
Su Song’s clock tower1088Su Song’s clock towerIn Kaifeng a water wheel turns one scoop at a time, held and released by a weighing lever.Water clocks
Al-Jazari’s elephant clock1315Al-Jazari’s elephant clockA 1315 copy of al-Jazari’s 1206 book: water, floats and falling balls drive an elephant clock.Water clocks
The sand glass1338The sand glassSand through a waist of glass. First seen in a Siena fresco; by 1345 ships bought them by the dozen.Candle and sand
Wells Cathedral clock1392Wells Cathedral clockA falling weight, let out tick by tick by a verge and foliot, struck the hours. The movement has no dial.Weight and spring
The Burgundy clockc. 1430The Burgundy clockThe oldest surviving clock driven by a coiled spring instead of a hanging weight, so it could be carried.Weight and spring
Continue: the pocket watch →The wristwatch timeline →
c. 3100 BC — c. 1430