A pair of Richter Spielgeräte concrete sound mirrors in a small park on the banks of the River Thames at Kew in west London. Photographs taken on 11 March 2018.
This tweet about the Sunderland sound mirror was a little bit popular!
Delighted to discover Sunderland's sound mirror hidden behind the VW garage in Fulwell. It was built around 1917 to detect Zeppelins after deadly airship attacks on the city in 1916. More info athttps://t.co/Qn1K2qXZ2R pic.twitter.com/H9Wvbwd48d
— Birmingham 81 (@Birmingham_81) January 22, 2018
Kent, UK. Between the World Wars, before the invention of radar, parabolic sound mirrors were used experimentally as early-warning devices by military air defence forces to detect incoming enemy aircraft by listening for the sound of their engines. #drone #dji pic.twitter.com/ncSkWVMcww
— Bryan Bruner (@Therobotarmy1) January 3, 2018
Acoustic Mirror – sketchbook drawing of an acoustic mirror for a current project, also known as a sound mirror, there’s lots of lovely stuff on them here: https://t.co/8Ro14bdA7z #wip #workinprogress #soundmirrors https://t.co/0xTjf86FoM pic.twitter.com/HYovst5Muw
— Brian McHenry (@lostcont) January 20, 2018
The National Heritage List for England identifies the buildings, sites and landscapes which receive special protection.
— Historic England (@HistoricEngland) December 19, 2017
Accoustic Mirrors, Fan Bay, St Margaret’s at Cliffe, Kent
The threat of aerial warfare in the 20th century provoked new systems of strategic air defence. Acoustic mirrors reflected the sound of distant aircraft onto a focal point where it was detected. The examples at Fan Bay are unusual as they are carved from the cliff face. The eastern mirror is one of the earliest, dating from about 1916. A second mirror dates from the early 1920s. The development of radar in the 1930s rendered sound mirrors obsolete. (Scheduled Monument. List Entry Number: 1442235)
There is a mention of sound mirrors in the article Mirrors and smoke: A. V. Hill, his Brigands, and the science of anti-aircraft gunnery in World War I, William Van der Kloot. DOI: 10.1098/rsnr.2010.0090 Published 20 July 2011.
Another visit to the Abbot’s Cliff sound mirror, while walking the North Downs Way long distance footpath.
Abbot’s Cliff Sound Mirror – Strait of Dover is a picture of a “sound mirror” built during the World War II era for the purpose of amplifying the noise of approaching aircraft. […] Beam’s camera translates light and shadow into a negative, and then a print, the sound mirror takes what is unheard out of thin air and translates it to something we can hear. The old Zen question about the tree falling in the woods is meditative, but it is also scientific: If there is no one around to hear it, it definitively does not make a sound. Similarly, if there is no eye, there is no image.
The effectiveness of Beam’s pursuit is deepened by Section of Abbot’s Cliff Sound Mirror, prints made from charcoal rubbings of the stone mirror itself. […]
Source: “Robert Collier Beam: Scry” at Pump Project, The Austin Chronicle, 26 May 2017.