Monday, 22 July 2013

The Roman light bulb


Okay, so it looks like the Romans may have had batteries and did a bit shock therapy or gold electroplating to mug the less wary jewellery shoppers, but as we know, there's a lot of different uses for electricity. And there's one thing that pretty much put electricity on the map for 19th-century society and gave every household the reason to invest in copper wires...this of course was Thomas Edison's light bulb. I mean, wow, what an invention, right? Well, here's where history gets a little bumpy. Edison didn't invent the light bulb, his patent for a carbon filament light bulb in 1880, was simply an improved filament for an existing light bulb design. In fact, the first vacuum glass light bulb was tested in 1820 by Warren De La Rue, but unfortunately his platinum filament made the bulb too expensive to produce commercially. Prior to that, the first carbon arc lamp was demonstrated by Humphrey Davy in 1809.

So, as it stands the carbon arc lamp has been around for a long time, and all it needs is a strip of carbon as a filament - Davy used a thin slice of charcoal, Edison used carbonised bamboo - which could burn for 1200-hours. The one thing you will notice is that the light bulb is pretty simple. Glass and various kinds of carbonised wood were available during and well before the Roman age, as was, it appears, batteries of similar power to those Davy used. Did these ingredients all end up with an ancient glowing filament? Well, it appears, just possibly, it did. Within the ancient Dendera Temple complex in Upper Egypt the walls of the 2nd or 1st-century BC Hathor Temple reveal something of a mystery. A long transparent vessel containing what appears to be a snake stretched lengthwise is held at one end by a man. Is it a mythological image? Or is it a very large carbon arc light bulb with wires running from it to a battery? The carving does date to a time just when glass blowing was becoming mainstream, it does date to the same era as the Baghdad batteries, and this was the age of classical invention by the Greek scholars living to the north in Alexandria. Does this make a light bulb? Well, I don't think it can be completely ruled out. For more on day to day Roman Technology, you can read 'Mischance and Happenstance', available from Amazon, just follow the links