A LARGE PARABOLIC CONCAVE MIRROR

Parabolic reflectors have many uses including signalling lamps, search lights and lighthouse lens reflectors. Very large examples were used as part of acoustic detection early-warning devices designed to pick up sounds from approaching enemy aircraft. The structures were devised by the British air force in the 1920’s, as part of a plan to install a chain of “concrete ears” along the coast that would peer out over the English Channel. The current lot is by repute from Biggin Hill airfield and dates to World War II.