I mentioned that, last Saturday, we attended the South East Region Industrial Archaeology Conference [SERIAC], held at Dartford Grammar School. I attend Surrey Industrial History Group talks, which is where I learned of the conference.
SERIAC is an annual one-day conference organized by a group of Societies in the southeast of England who have an interest in industrial history and archaeology.
In the conference programme there was one talk I was keen to listen to. It was on the subject of Sound Mirrors, and in particular the recent uncovering of two lost sound mirrors at Fan Bay near Dover.
Sound Mirrors were built between the two world wars as early warning detectors of approaching enemy aircraft from the sound of their engines. The convex mirrors work by concentrating sound waves of the plane’s engine so it could be heard before it was visible.
There are Sound Mirrors on the coast in Kent and a number in Yorkshire, built to give advance warning of approaching enemy airships. The increase in speed of aircraft and the invention of radar rendered them obsolete.
I’ve seen the sound mirrors at Denge in Dungeness from a distance, and have long wanted to learn more about them and to visit some.
Robert Hall’s lecture, in which he briefly described their history, focussed on the uncovering of two lost sound mirrors at Fan Bay, near Dover. Here are a few photos of his slides.
To learn more about these interesting monuments in our landscape, I recommend these web sites,