13/05/2020
HISTORY OF CLOCKS.
TIME
Time, a central theme in modern life, has for most of human history been thought of in very imprecise terms.
The day and the week are easily recognized and recorded - though an accurate calendar for the year is hard to achieve. The forenoon is easily distinguishable from the afternoon, provided the sun is shining, and the position of the sun in the landscape can reveal roughly how much of the day has passed. By contrast the smaller parcels of time - hours, minutes and seconds - have until recent centuries been both unmeasurableand unneeded.
Sundial and water clock: from the 2nd millennium BC
The movement of the sun through the sky makes possible a simple estimate of time, from the length and position of a shadow cast by a vertical stick. (It also makes possible more elaborate calculations, as in the attempt of Erathosthenes to measure the world - see Erathosthenes and the camels). If marks are made where the sun's shadow falls, the time of day can be recorded in a consistent manner.
A tower clock in China: 1094
After six years' work, a Buddhist monk by the name of Su Song completes a great tower, some thirty feet high, which is designed to reveal the movement of the stars and the hours of the day. Figures pop out of doors and strike bells to signify the hours.
Clockwork in Europe: 13th - 14th century
Europe at the end of the Middle Ages is busy trying to capture time. The underlying aim is as much astronomical (to reflect the movement of the heavenly bodies) as it is to do with the more mundane task of measuring everybody's day. But the attraction of that achievement is recognized too. A textbook on astronomy, written by 'Robert the Englishman' in 1271, says that 'clockmakers are trying to make a wheel which will make one complete revolution' in each day, but that 'they cannot quite perfect their work'.
Domestic clocks: 15th century
After the success of the clocks in Europe's cathedrals in the late 14th century, and the introduction of the clock face in places such as Wells, kings and nobles naturally want this impressive technology at home.
Watches: 16th - 17th century
The first watches, made in Nuremberg from about 1500, are spherical metal objects, about three inches in diameter, designed to hang on a ribbon round the neck. They derive from similar metal spheres used as pomanders, to hold aromatic herbs which will protect the wearer against disease or vile odours.
The pendulum clock: 1656-1657
Christiaan Huygens spends Christmas day, in the Hague in 1656, constructing a model of a clock on a new principle. The principle itself has been observed by Galileo, traditionally as a result of watching a lamp swing to and fro in the cathedral when he is a student in Pisa. Galileo later proves experimentally that a swinging suspended object takes the same time to complete each swing regardless of how far it travels.
The pocket watch: 1675
Nineteen years after making his model of the pendulum clock, Huygens invents a device of equal significance in the development of the watch. It is the spiral balance, also known as the hairspring (an invention also claimed, less convincingly, by Robert Hooke). This very fine spring, coiled flat, controls the speed of oscillation of the balance wheel. For the first time it is possible to make a watch which is reasonably accurate - and slim.
A millennium clock: 1746
In 1746 a French clockmaker, Monsieur Passemont (his first name is not known), completes a clock which is almost certainly the first in the world to be able to take account of a new millennium. Its dials can reveal the date of the month in any year up to9999.