Photograph entitled 'The large mirror drum, housed in the caravan at Epsom'

Photograph with caption 'The large mirror drum, housed in the caravan at Epsom in 1932, with its stroboscopic sectors for accurate speed adjustment. This was part of the equipment used for a 3-zone televising of the Derby direct to the Metropole Cinema, London.' From a collection of photographs illustrating the early experimental television work of John Logie Baird, 1924-1938.