Today, everything from coffee makers to refrigerators have clocks on them, and it's easy to take them for granted in the digital age. A saying for when things go well is, "It's going like clockwork" – a nod to the precision and skill with which all clock-making once required.

10 o'clock Clock Vintage on Wood Table with Sun Light
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How Does a Clock Mechanism Work?

What's taken for granted now was a revolutionary development in the evolution of humanity.

In the early days of humanity, the sun stretched across the sky, showing the passage of time. Time-telling took a turn in 293 BC, when the first sundial was created in Ancient Rome. Over a century later, Theodosius, a mathematician and astronomer from what is modern-day Turkey, made the first universal sundial that could accurately tell time no matter what the latitude or longitude it was used in – if the sun was shining, that is.

Clockmaking and the portability of the pocket watch changed everything. No longer did one have to guess how many minutes had passed or what the time of night was. In exploration and navigation, a reliable clock now made proper captain's logs possible, making mapping more precise all the time.

But how does a clock tell time? It depends on the kind of clock in question. Digital clocks, of course, use algorithms and math. Analog clocks, though, are all about instrumentation and artistry, which all come together through a series of geared wheels lined up with mathematical precision and skill.

Mechanical Clocks and Time Pieces

Commonly called "wind-up clocks," this name tells you what they are – they need to be wound in order to provide energy to the timekeeping mechanism. As the wound-up mainspring uncoils, it drives a geared power wheel that propels both the hour and minute wheels. The "escapement wheel" is responsible for transferring the wind-up energy to the timekeeping mechanisms, and as they move, a locking action happens and the oscillations are counted. The result of this is the tell-tale "tick tock" sound beloved in old clocks. This locking and oscillating results in the turning of the minute, hour and second hands on the exterior of the clock, allowing you to know what time it is.

Once the gears are correctly lined up, mechanical clocks need regular winding in order to keep time correctly. Wind-up clocks were common in all sizes as floor, wall and mantel clocks as well as pocket watches.

Pendulum Clocks

You know exactly what a pendulum clock is. That old grandfather clock swaying and ticking in your grandparent's living room or the cuckoo clock clacking and cuckooing on the hour in your favorite Bavarian restaurant are both types of pendulum clocks. The pendulum action needs a fairly level surface to work correctly, making these clocks limited to wall, floor and mantel pieces.

These clocks, also called "weighted clocks," have been common since 1656, when they were invented and became the first truly reliable time-tracking device. These clocks use weight and gravity to track time. They also use wind-up energy generated by inserting a butterfly-key in a keyhole often found on its face or the side of the clock's housing and turned until it's unable to turn anymore.

The inner-actions are often very similar with the wind-up clock. But it's how the energy is created and sustained that varies, and that starts with the key winding. This lifts a weight that stores energy and is designed to fall, which turns the power gears that drive the timekeeping mechanisms. But an object in motion stays in motion, so that weight's fall needs to be interrupted or the clock will move too quickly, and this is where the bob or pendulum comes in. Designed to have a perfect swing ratio based on gravitational pull and weight, the pendulum swings side to side and controls the speed at which the weight drops and the escapement turns in the clock. This, of course, regulates the ticking, chiming and movement of the minute, hour and second hands on the clock face.

The larger the pendulum clock, the heavier the weight and the longer it can go between windings, which is why there were so many grandfather clocks in the old days – much less fiddly.

Quartz Clocks and Watches

Clocks have always been driven by energy but, with the introduction of quartz crystal into clocks and watches, battery-powered electricity was finally used to create the most accurate time-telling yet.

Quartz is one of the world's most common minerals, and one of its qualities is that electricity causes it to vibrate at a whopping 32,768 times per second, making it kind of like nature's tuning fork.

In a quartz watch, a battery sends electricity to a microchip circuit, and this causes the quartz to vibrate. The microchip circuit counts the crystal's vibrations and then converts it to a generic electric pulse, one per second. These pulses power a miniature electric stepping motor that transforms the electrical energy into motion, which then turns the gears. The gears make the clock or watch's hands sweep around the clock face, and this is how the time is shown.

Minute movement and fluctuations in temperatures can affect a quartz's vibration by slight amounts, which is why quartz watches and clocks still weren't perfectly accurate 24/7.

However, where pendulum and wind-up clocks couldn't go, quartz watches could. In the 1970s, quartz-powered digital clocks changed the game, creating near-perfect time-keeping still in use today.

Then Clocks Ticked Into the Digital Era

In humankind's constant chasing of the perfect way to track time, it was inevitable society turned away from clockworks and hand-movement mechanisms, relying on battery-powered algorithms. Now, there's hardly a clock-free appliance in your home.

Today, it seems almost quaint when mystery movies use a tick-tocking of an old clock to build suspense in tense scenes. Luckily, the artistry and beauty of analog clocks wristwatches will never go out of style.