The group of five mid-century concave searchlight parabolic mirrors, with wonderful aged patination to the plates, to include one rare prism shaped mirror, each etched and stamped with various markings, the circular mirrors having bronzed metal encasements and each surviving from World War II Period England and later.
Unknown.
A parabolic mirror is a concave mirror that has the form of a paraboloid of revolution so that rays emanating from the geometrical focus and reflected from the surface are all parallel to each other and to the axis of symmetry and rays from a distant source are reflected to the focus and that is used in reflecting telescopes, searchlights, and headlights.
Most of these examples are probably from a World War Two anti-aircraft searchlight or ships signal as 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. One of the mirrors shows the marks verso for 1968 and the company of Clarke, Chapman & Co Ltd who were founded in Gateshead in 1864 and still in operation today.
Rare to find as a mini collection, they work wonderfully well as a group of optical wonderment; each being like an ancient planet.
The condition of the mirrors are completely untouched, and no damage is present aside from some nibbling to the edges of the prismed example. There is wear to the finishes as one would expect, and natural foxing and spotting to the glass which is very attractive with varying degrees to each as photographed. We have cleaned each mirror.
Diameters: 10.5” (x2), 11”, 20”
The Prism: 7” w x 8.5” d x 3” h
By appointment only.
