How did the inventor of the first watch know what time it was?
While this question might sound silly, it isn’t – big time (and the wordplay is intended).
The long path towards establishing a universal time system is long and convoluted, and starts from the beginning of history. The first clocks were invented around 1300, but the first watch – that is, a portable clock – comes from around 1505, invented in Nuremberg, Germany, by a certain Peter Henlein.
This would be one of the earlist watches. You cannot see its dial because the lid is closed, but this kind of watch (called Nuremberg Egg) had only one hand – the hour’s – because it wasn’t precise at all. The precision of watches would improve only later, with the invention of the hairspring around 1650.
Also, remember that the calendar was unlike ours, as well.
The old calendar
At that time, people still used the Julian Calendar, as the Gregorian Calendar that we use today was introduced in 1582 only. And the majority of people still used variable hours, not fixed ones as we do. Variable hours were introduced as a divider of the day and the night so to follow prayers which had to be uttered in some moments, dictated by specific books called “Liber Horae”.
This meant that in winter, when the daytime is less, the day hours were shorter, and in summer they were longer, and for the night hours it was the opposite. But well, it was enough for the needs of the population.
Of course, this made no sense for scientists. Especially, to track the activities that were not influenced by the hours of the day and the night – and with this I mean the movement of the stars.
Fixed time vs. variable time
The need for a fixed time standard happened very early in the development of human civilization.
Astronomers understood that to measure the movement of the stars (which do not move – the Earth moves, but anyways) they had to use fixed units and not variable units. This would go as far away as the Babylonians and the Sumerians, which established the numerical system that we use even today both for tracking time and angles, based on a sexagesimal division. Of course, back then they did not use it to measure time, because they did not have the tools to do that.
This clay disc, here, tracks the night sky dividing it into eight regions. This Assyrian star planisphere found in the library of the Assyrian king Ashurbanipal (Aššur-bāni-apli – reigned 668-627 BCE) at Nineveh. The function of this clay tablet, in which the principal constellations are positioned in eight sectors, is disputed, but the function seems to be astronomical and magical.
Eventually, people switched to use the current system, that is, fixed time, based on the division of time in 24 hours, calculated from mid-day to the next mid-day, and watches proliferated around Europe.
Every major city had an observatory, and the observatory was the official time tracker for the city and its neighborhood.
This means that each city had its own way of tracking time, as the mid-day depends on where your city is located in respect to any other city of the planet. The astronomers would measure it, and so, decide the official time for the city.
The problems with city-based fixed time
Of course you understand that this was a huge mess, since every city would be regulated on its local time. There was no universal time – but we have to add that there was little need to have one.
Today, the situation is way different.
We all know that the world is today divided into 24 major timezones, all set apart of one hour to one-another, and we have established that the so-called GMT (Greenwich Mean Time) is calculated at the Observatory of Greenwich, in London. The line is known as the Prime Meridian. All other timezones are expressed as + or – X hours from this measurement.
Also, remember that this convention was agreed upon only around 1880, proposed by Sir Sanford Fleming, a Scottish-born Canadian scientist who was very active in railroads.
Before then, each and every city on the Earth had its own time – which proved to be a nightmare for any kind of communications (like telegraphs or railways). As you can see, establishing a common time reference allowed the creation of more reliable communication, and avoiding mishaps, like two trains coming in opposite directions and crashing because of bad timing (most railways were single-track).
The work of men like Sandford Fleming and Webb C. Ball, the founder of the Ball Watch Company, were instrumental in developing the acceptance of the Universal Time and the precision of watches as well: in that time, railroad chronometers were among the most precise watches on the planet.
The solution of Universal Time
As you can see the map here, this system was and is hardly ideal. For example, there are some countries, like China, that adopt a single timezone, but their extension is so great that it spans a five-hour solar time difference!
Spain actually is mostly located on the west of Britain, still it uses the GMT +1 timezone, and so on.
If we were to use the old system, that is, based on the mid-day of each city, it would be much more precise – but it would be impossible to track all the different timezones. And what would happen on trains and planes?
So, if we step back a little and arrive to our friend Henlein in 1505, and his ancestors creating clocks before him, he would set his clock based on the official time set by the city of Nuremberg, as each city set its own time.
And the clock and watch makers and users referred to this “official” time when setting their own watches.
You can find much more about horology and its fascinating history in The Watch Manual, a thorough e-book that explains all the basics about watchmaking and its protagonists.