The history of timekeeping goes as far back as ancient civilizations like Sumer and Egypt. Egyptians were the first to divide the day into fixed units of time, allowing them to develop more advanced methods of measuring time than ever before – like the sundial.
From there, civilizations like China, India, Greece, Babylon, and others developed their own clocks and calendars, even if most early timekeeping devices were wildly inaccurate compared to modern clocks. It’d take many scientific breakthroughs and fascinating attempts by various thinkers throughout history to reach the common, universally accepted time standard we all use today.
10. Sundial Cannon
The sundial cannon gained popularity across Europe in the 1600s, and one can still find old prototypes in museums and private collections around the world. At its most basic, it’s a timekeeping device based on the classic sundial, with a vertically-positioned magnifying lens and a cannon with a fuse. Every day at noon, or any other desired time of the day, sunrays would pass through the lens and ignite the charge, causing the cannon to go off.
At the time, sundial cannons were widely used across Europe to signal noon, though they were gradually made redundant by the advent of modern watches and clocks. By the 19th century, they were only built as miniature, novelty items for collectors, though some of the bigger ones still exist as tourist attractions, like the one in Åtvidaberg, Sweden.
9. Candle Clock
The first candle clock was described by a Chinese poet, You Jiangu, in 520 AD, though candles had likely been used as a rudimentary measure of time for much longer than that due to their simplicity. Jiangu’s clock was made with six candles of the same weight and thickness, enclosed inside a glass structure to protect the flames. Each candle was made to burn for exactly four hours, with equally-spaced one-inch markings denoting twenty minutes.
While the idea originated in China, candle clocks were soon adopted and improved by engineers around the world. It was a simple-yet-effective device for measuring time, though it had its limitations. For one, these clocks were closer to modern alarms or timers than clocks, as they could only be used to measure the amount of time elapsed. They were also probably quite inaccurate, owing to factors like the wind or quality of the wax. For regular, everyday tasks, however, they still provided a handy way of keeping track of time. Candle clocks were in use until the 18th century, before being outclassed by modern watches and clocks.
First built in ancient Egypt between 3500-2500 BC, the obelisk was one of the earliest timekeeping devices in history. It was made with a tapered rectangular slab of stone, designed to precisely indicate noon by the length of its shadow. Markings were later added to further divide the day into sections, along with indicators to mark the longest and shortest days of the year.
While the earliest examples have now been lost to time, obelisks were extensively adopted and built by other civilizations like Babylon. In Egypt, they were often built at the entrance of temples and served a higher purpose than just telling the time. Egyptian obelisks were heavily associated with the goddess Ra and sun worship, especially during the New Kingdom era from 1570-1069 BC.
With time, ancient-Egyptian timekeeping devices and methods got more complex, incorporating early designs like the sundial in various ways to come up with even more advanced clocks. The problem, though, was that they only worked during the day. A reliable method to measure the time at night wouldn’t be developed until as late as 600 BC, in the form of something called a merkhet.
Typically used with a sighting instrument called a bay, the merkhet was essentially a tool to determine the north-south axis. By tracking regular movements of the stars against that axis with devices like water clocks, Egyptian scientists could use the merkhet to accurately determine the hour of the night. It had other uses, too, like in architecture – merkhets are probably why so many Egyptian structures are perfectly aligned with the north-south and east-west axes.
6. French Decimal Time
The French Revolution had a profound impact on every aspect of life in France, including timekeeping. In 1793, the newly-convened National Convention decided that the old Gregorian system of time didn’t keep up with the ethos of the revolution. It was too… asymmetrical, compared to a simple system of decimal time that could be understood in factors of one and ten.
For about 17 months, French Decimal Time – also known as the Republican calendar – was adopted across the country. All units of time, including weeks, were now divided in sets of tens and hundreds. It was a novel idea, if people didn’t already have a system of time they followed. More importantly, the weekly holiday now came every 10 days instead of seven, with an added half day on the fifth day. While the French government tried to make it work for some time, the idea failed to gather popular support, and was officially scrapped on April 7, 1795.
5. Incense Clock
While the Egyptians were busy churning out timekeeping devices using the sun and stars, Chinese thinkers were working on an entirely new way of experiencing time – through smell. Dating back to at least the 6th century BC, Chinese incense clocks were essentially pieces of scented wood encased inside a well-ventilated box. The incense – usually designed like a maze – was made to burn at specific intervals of time, allowing one to tell the time just by the scent in the room.
The design could be modified to serve more complex purposes, like adding different types of incense to the queue to know the exact hour of the day. According to one historian, incense timers and clocks might have been in continued use in China for everyday tasks until as late as the 20th century.
4. Little Ship Of Venice
The Navicula De Venetiis – or ‘little ship of Venice’ – was a rare type of sundial extensively used in Europe during its age of exploration. We’re not sure where it came from, though some evidence suggests that an earlier prototype was first designed and built by engineers in Baghdad during the ninth century.
Regardless, the navicula went through many improvements and modifications in Europe. By the 14th century, it had turned into a useful tool for the calculation of time and latitude at sea. The device itself is shaped like a ship, with sighting holes at both ends of the deck to align with the correct latitude, and a plumb line to point towards the time marked at the bottom. In most designs, one side of the ship was marked with the latitudinal values of famous towns and cities in Europe, depending on where it was manufactured.
3. Time Ball
By the beginning of the 19th century, timekeeping devices like pocket watches and clocks were common. However, despite all the advances in mechanics and engineering, there was still no uniform reference to match those clocks with. Local sundials – still the only accurate measure of solar time for most people around the world – varied too much to be reliable, even over small distances.
While the difference was hardly noticeable before with slower modes of transport like horse carriages, it all changed with the advent of trains, which required a standardized, universal standard of time to function. To solve it, scientists and astronomers from around the world came together and decided to divide the globe into 24 time zones.
Giant time balls were installed on top of notable observatories like Greenwich to signal a particular time of the day, which was then used by regular folks to sync their clocks and watches. Thanks to the telegraph, time signals could now be instantly broadcast around the world, allowing railway timetables to be synchronized and uniform regardless of where you were. While the system is now too outdated to be of any real use, some of those balls continue to be used for novelty purposes.
2. Congreve Rolling Ball Clock
Sir William Congreve was an artillery officer and engineer in the British royal army, usually remembered for his invention of the Congreve Rocket in 1808. While military rockets had existed before, Congreve’s improvements made them deadlier and more efficient, allowing their use in large-scale conflicts like the Napoleonic Wars and the American War of Independence.
Congreve remained a prolific inventor of weapons and other military improvements throughout his career, though he also dabbled in other, less lethal inventions, like his famous rolling clock. First built in 1808, it worked a lot like the pendulum – still a popular method of timekeeping around this time. Instead of a swinging pendulum, though, Congreve’s clock used a steel ball on a horizontal zig-zag track to track fifteen seconds, which was then used to move the hands of the clock above it.
1. Al-Jazari’s Clocks
Al-Jazari was a 13th century polymath born in what is now southeastern Turkey. While we don’t know much about his early life, we know that he grew up to be one of the most important figures in early robotics – some even call him the ‘father of robotics’ due to the larger impact of his inventions.
Al-Jazari’s treatise – The Book of Knowledge of Ingenious Mechanical Devices – details more than 100 of the earliest automatons ever designed, complete with instructions on how to build them. Many of them were clocks of various kinds, including the famous Elephant Clock that has been reproduced by many engineers around the world in the centuries since. There’s also the Castle Clock, which may have been one of the first programmable analog computers in history. Some of al-Jazari’s designs were so elaborate that they inspired Renaissance-era engineers, including Leonardo da Vinci.