8/3/2019 Inventions for Measuring and Regulating Time
1/2
Inventions for measuring and regulating time
The early inventions were made to divide the day or the night
into different periods inorder to regulate work or ritual, so the
lengths of the time periods varied greatly fromplace to place and
from one culture to another.
Oil Lamps
There is archaeological evidence of oil lamps about 4,000 BCE,
and theChinese were using oil for heatingand lighting by 2,000 BCE.
Oil lampsare still significant in religiouspractices, symbolic of
the journeyfrom darkness and ignorance to lightand knowledge. The
shape of thelamp gradually evolved into thetypical pottery style
shown. It waspossible to devise a way of measuring the level in the
oilreservoir to measure the passing of time.
Candle Clocks
Marked candles were used for telling the time inChina from the
sixth century CE. There is a popularstory that King Alfred the
Great invented the candleclock, but we know they were in use in
England fromthe tenth century CE. However, the rate of burningis
subject to draughts, and the variable quality of thewax. Like oil
lamps, candles were used to mark thepassage of time from one event
to another, ratherthan tell the time of day.
8/3/2019 Inventions for Measuring and Regulating Time
2/2
Water Clocks
The water clock, or clepsydra,appears to have been inventedabout
1,500 BCE and was a devicewhich relied on the steady flow of water
from or into a container.Measurements could be marked onthe
container or on a receptacle forthe water. In comparison with
thecandle or the oil lamp, the clepsydrawas more reliable, but the
waterflow still depended on the variationof pressure from the head
of waterin the container.
Astronomical and astrological clock making was developed in
China from200 to 1300 CE. Early Chineseclepsydras drove
variousmechanisms illustrating astronomicalphenomena. The
astronomer SuSung and his associates built anelaborate clepsydra in
1088 CE. Thisdevice incorporated a water-drivenbucket system
originally inventedabout 725 CE. Among the displayswere a bronze
power-driven rotatingcelestial globe, and manikins thatrang gongs,
and indicated specialtimes of the day.
Improvements were made to regulate the flow bymaintaining a
constant head of water
Su Sung's astronomical water clock
Sandglass
Hour Glasses or Sandglasses
As the technology of glass-blowing developed, fromsome time in
the 14th century it became possible tomake sandglasses. Originally,
sandglasses were usedas a measure for periods of time like the
lamps or
candles, but as clocks became more accurate theywere used to
calibrate sandglasses to measurespecific periods of time, and to
determine theduration of sermons, university lectures, and
evenperiods of torture.
