Thursday, 13 September 2012

Counting the minutes

The Clepsydra - stealing time
So we know the Romans were able to tell the time...otherwise estimating 'midnight' for the beginning of a new day would have been a very hit and miss affair. Imagine waking someone up for their midnight shift...only to see the sun come up a few minutes later - I know, embarrassment. Obviously they had timers of some sort, and for most people it was probably a Clepsydra (a time thief) - this was simply two bowls, one emptying into the other, with lines on their insides to mark off minutes or quarters of an hour. Once the water finished emptying out of the top bowl, time effectively stopped...and this is where our modern day term "time is running out" comes from. The Roman army probably used these to time their three nightly watches, because these timers were simple and easy to transport and had been around for more than 1600-years before the Roman Empire.

The self-restoring water clock -
plug and play Roman style
But the clepsydra was just the beginning of classical era time machines. Far more advanced water clocks began appearing in the 3rd-century BC - these needed a constant water supply from the nearest tap, but they were self-restoring every twenty-four hours, counted every hour of the day and could chime or whistle on the hour just like modern clocks. As long as the local aqueduct didn't run dry the Roman water clock could work unattended almost for perpetuity and no doubt was a fixture in most higher status houses, temples and public squares. There was no need to worry about the sun going behind a cloud or someone forgetting to refill the water reservoir.

As for the mechanical clocks that have set the time for us since the middle-ages, well, there's no evidence for them dating back to the classical era, but the Romans did have the technology to build the internal machinery and weight driven pendulums that would have been needed. Whether they put these two elements together as a clock is pure conjecture, but I don't think it should be ruled out...after all, almost everyday someone digs up something from the classical world that can't be quickly explained. So keep an eye on the Internet news, maybe one day they will find a Roman cuckoo clock.

  Find out if Calvus could keep the time