A Brief History of Timepieces Trivia Quiz

Answer: A water clock

When they were first invented is not known, but physical evidence that the Egyptians were using water clocks exists from around the 16th century BCE. The name "clepsydra" was not given to these clocks until the Greeks developed their own version in the 3rd century BCE, possibly earlier if reports of Plato's use of such devices are to be believed.

The name "clepsydra" means "water thief" in Greek and goes some way to explaining how such clocks worked. The simplest devices discovered in Egypt consisted of two vessels placed one above the other. The upper vessel had a hole cut at its foot allowing water to drip out at a (reasonably) constant rate. The lower vessel was marked with 12 equidistant depth notches that marked the passage of each hour.

Answer: Timing sermons in church

An hourglass consists of two glass bulbs, one containing a certain volume of sand, connected via a small opening. The complete transfer of sand from one bulb to the other measures a defined period of time (not necessarily an hour despite the name).

Many churches contained hourglasses by the pulpit to allow the preachers to time their speeches. The amount of time that was measured differed from hourglass to hourglass, depending on the size of the glass containers and the amount of sand within. Therefore, it was important that if you couldn't find a church with a good speaker then you needed to find one with a small hourglass!

Answer: Astronomer

The nasally challenged Brahe, who wore a false nose made of silver and gold after losing his own in a duel, was a pioneering astronomer. His discovery of a supernova in the Milky Way, in 1572, changed the way that astronomers observed and recorded the night sky. Part of this revolution was the need to record the time of all observations accurately, hence the request to Swiss clockmaker Burgi to incorporate the minute hand on the clock face.

Of course, the addition of the minute hand was only of value if the time it indicated was accurate. Burgi improved on existing clocks with the invention of the remontoire. It improved the performance of his clocks by reducing the factor of the power fluctuations caused by the action of the mainspring. The remontoire was a secondary spring that took power from the mainspring but automatically re-wound itself once it reached the end of its coil, thereby providing the clock mechanism with a steadier impulse and a more regular oscillation. Burgi's clocks were said to improve timekeeping accuracy to within one minute per day.

Answer: The pendulum

Burgi's improvements on accuracy were eclipsed within a few decades of his inventions. Almost as soon as he had introduced the remontoire, Galileo Galilei was observing the swinging of a lamp in Pisa Cathedral and noting the predictability of its period. With his son, Vicenzo, he drew diagrams of a pendulum clock and attempted to build one but sadly both father and son died before it could be successfully completed.

By the time Huygens had refined the mechanism of his pendulum clock he was achieving an accuracy of approximately 10 seconds per day. He was so confident of his clock's timekeeping qualities that he fitted it with not just a minute hand but a second hand also. Whilst there were several changes in the types of escapement used in clocks over the period, the success of the pendulum clock was such that it remained the most accurate of timepieces for nearly 300 years.

Answer: Blaise Pascal

The first portable timepieces were the "Nuremberg Eggs" invented by German horologist, Peter Henlein, in the early 16th century. The innovation that allowed for these smaller clocks to be made was the use of a mainspring to drive the clock mechanism rather than heavy weights. Whilst Henlein's clocks were not the first to use a mainspring, they were the first to be made at a size where they did not require wall mounting and could be carried in a pocket (albeit they were a bit heavy to be carried around for long).

It was one such pocket watch that Blaise Pascal first wore upon his wrist. He attached it with a piece of string because he was supposedly fed up with having to reach into his pocket each time he wished to know the time.

Answer: A pocket watch

In 1714, the British government offered a prize of up to £20,000 to anyone who could demonstrate a means of reliably measuring longitude at sea. The terms for this considerable prize (several millions of US dollars by today's terms) were that the method must be accurate to within half a degree of longitude and workable at any point on the earth's surface. One way of achieving this was by devising a clock that would accurately keep time at sea, thereby allowing navigators to judge the difference between noon in their home port and noon where the ship stood.

John Harrison was the man who eventually built the clock that passed the test. It was his fourth attempt to create such a clock. H1 was the first one built but Harrison was unhappy with it. H2 never passed the blueprint stage before being abandoned. H3 was worked on for 19 years before Harrison had the revelation that the large chronometers that he was working on were impractical for the purposes of oceanic travel. So, H4 was designed as a large pocket watch.

Built by London clockmaker, John Jeffreys, it failed its first seabound test but was given a second chance. On its second voyage it was more accurate than the prize's requirements by a factor of three. Despite its clear success, it took Harrison several years to claim the prize owing to the self-interest of Astronomer Royal, Nevil Maskelyne, who believed he could solve the problem himself. Finally, in 1773, King George III tested an H4 replica watch personally and declared it to be the winning solution.

Answer: It could only ring the alarm at 4am

Hutchens' clock was invented for his own use only, as 4am was the time he needed to rise for work. Presumably for the next 60 years, you would have had to find a clockmaker who had built an alarm clock that went off at the right time for you.

The first alarm clocks go back a long way before Hutchens' mechanical invention. The clepsydra was used to sound an alarm in the 3rd century BCE. More than 2000 years later, in 1847, a patent was issued for a mechanical clock that could sound an alarm at any time of the owner's choosing. This clock was invented by Frenchman, Antoine Redier.

The first US patent for an adjustable alarm clock was granted to the Seth Thomas Clock Company in 1876. This company was also responsible for building the clock that sits above the concourse of Grand Central station in New York City and the clock that was used to signify 'High Noon' in the Gary Cooper movie.

Answer: Quartz

Quartz, otherwise known as silicon dioxide, is the most commonly used mineral in the construction of a crystal oscillator due to the consistency of its performance across a wide range of temperatures. By cutting the quartz in a particular way, it can be made to vibrate at a particular frequency, thereby providing a predictable electronic signal to a clock mechanism. This electronic circuit counts the number of oscillations of the quartz and once it reaches a specific number, usually 2^15 in most wristwatches, it moves the time on by one second.

The accuracy of quartz clocks, to within one second per day, persuaded the US National Bureau of Standards to set US time standards by them. It also allowed, for the first time, astronomers to establish that the earth's rotation was subject to minute variations from day to day and was not a constant.

Answer: Caesium

With the construction of Caesium I, for the first time the measurements of global time were no longer based on the rotation of the earth but on the more accurate measurements given by atoms. In particular, microwave transmissions of the electrons of caesium-133 atoms. These atoms gave Caesium I an accuracy of one second per 300 years.

The clock was built in Teddington, England by physicist Louis Essen. He had been working with timepieces for nearly 30 years, firstly working with quartz and creating the Essen ring, a particular shape of quartz which improved its accuracy three-fold over previous quartz devices. Having studied the work with the ammonia clock in the USA, Essen soon established that the principle of their work was sound but the choice of ammonia was poor. He experimented with hydrogen and rubidium clocks before discovering the supremacy of caesium in terms of accuracy.

Essen managed to improve his atomic clock's accuracy to one second per 2000 years. By the time the General Conference on Weights and Measures defined the second in terms of the "duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom at a temperature of zero Kelvin" in 1967, atomic clocks were achieving an accuracy of one second per 1.4 million years.

Answer: UTC (Universal Time Co-ordinated)

The difference between GMT and UTC is no more than a fraction of a second so, for everyday purposes of telling the time, the two are identical. However, when greater precision is required, UTC is the more accurate measure. It is based on International Atomic Time (TAI) but is adjusted occasionally by the addition of leap seconds to account for fluctuations in the earth's rotation.

When UTC was established as the standard for civil time, the difference between TAI and UTC was ten seconds. By the end of the millennium, the gap had risen to 32 seconds, with a leap second being added approximately every 18 months on average. Leap seconds are always added at the end of a UTC day so that the UTC clock ticks from 23:59:59 to 23:59:60 before ticking over to 00:00:00.