Clocks

1. Ancient Time Mechanisms

Disclaimer

Whilst some care has been taken to check externally linked websites no responsibility is offered nor implied for the suitability, legality or reliability of content therein.

Introduction

To some people looking at, owning, let alone building, a clock might seem the most boring subject in the world. Planes, trains, cranes and automobiles have a certain obvious caché when it comes to subjects that we are familiar with. Yet my experience of people’s reaction at exhibitions is quite different. Not everyone rushes across a room to gaup at a stupid ticker just sitting there making an intermittent click but I’m constantly surprised by people’s fascination with mechanisms that move and even better: move with a purpose. Clocks are just such a subject. A simple AC synchronous motor driving a number of hands on a dial might seem rather boring but it needn’t be if it’s a Krazy Clock with entertaining whirly parts (see right).


And not only entertaining but along with printing and weaving our forebear’s development of timekeeping is inextricably connected with their development of technology.  Let’s look at the variety of clocks that have existed down the years..

2. Old Clock Escapements

Keith Cameron’s Krazy Clock

(built by Bob Palmer)

This page has been developed to identify types of clock that are, or could

become, subjects for model making. Often in the best medium in the world, Meccano, but not exclusively so.

The Antikythera Mechanism

However, even today, we are just beginning to learn of leaps that we had not heard of before. From a shipwreck by the island of Antikythera in Greece in 1901 a lump of rusty metal was pulled to the surface that would change our entire modern day perspective of who understood what technology at what time in human history. Sadly the bronze and other metals had seriously corroded but the shipwreck was accurately known to have sunk around 70-60 BC so the mechanism certainly predated that.

This following short film by Philippe Nicolet gives a simplified introduction to the astounding knowledge of lunar phases and eclipses, the sun’s 19 year cycles, trivia like which cities were due to hold which Olympic Games next and even the paths of Mercury, Venus, Mars Jupiter and Saturn across the night sky eg venus. However the wikipedia page is far more informative (see right).

           YouTube: The Antikythera Mechanism-2D.

Thankfully the discoverer and subsequent historians sought not to split the lump into pieces and destroy what could later be discovered by modern radiological methods. Instead it has been treated carefully and its 37 gear wheels and various setting dials have been slowly deciphered. It is easy to dress this hand-driven machine up in cliches but suffice to say that nobody even started on the road to such sophistication until at least 14 centuries later.

Water Clocks

It’s obvious that in arranging to meet, engage in rituals or hunt together our earliest ancestors must have used the position of the sun in the sky to coordinate their actions. But how would they do that if the sun was obscured by cloud for long periods of time in Winter for instance ? Some Indian and Chinese historians claim that their ancestors used a method of measuring water flowing from a hole in a vessel some 4000 years ago. Evidence shows that this was later employed by the Babylonians, Egyptians and then Ancient Greeks.

Escapements

As we’ve seen a clock generally consists of a method of storing energy that is supplied to a system that reliably allows that energy to escape in a regulated way. Rather than water it was quickly realised that the system had to be mechanical. At the heart of any mechanical clock this is known as the escapement and so it is these that will become the focus of the examples given on the remainder of this page.

Rotating Weights

John Of Wallingford

Water Thief by Ctesibius

(artist’s impression)

Swinging Weights

Galileo

Deduced Antikythera Gearing

(with link to Wikipedia)

Obviously all technology is a development of previous experience. Naturally development can come in leaps and bounds. Pythagorus is famously placed early in the chain. Another such leaping person was a mathematician and inventor in Greek occupied Alexandria in Egypt. Ctesibius researched the movement and compression of liquids and air by pistons in cylinders

and of closure of pathways by valves. As a result he became known as The Father Of Pneumatics. Had he noticed that enclosed boiling water developed pressure who knows when the Industrial Revolution may have started. Amongst many things he devised the Water Thieve, a form of timekeeper, in 250BC (see right).


Perhaps Ctesibius rigorous research methods were what the beginnings of modern technology as we now know it needed ? His ideas must certainly have influenced Archimedes, Hipparchus, Gallileo, Newton etc. As ground breaking as this was fluid flow systems were never going to be accurate and can hardly be counted as portable.