British Pneumatic Railway Signal Company (later British Power Railway Signal Co.) tapered and ribbed Signal Arm and spectacle. A significant and historic item from this company, established in 1900 and under licence from America, pioneering the use of low-pressure air operated points and signals. Initial installations were on the L&SWR around Grateley and Andover, later Basingstoke and Clapham Junction. However, this one was fitted during the 1925 scheme at Cambridge, confirmed by a picture of the Cambridge signals adjacent to Cambridge South Signal Box in 'An Illustrated History of Signalling' by M.A. Vanns on page 62. Further, quality photographs are held at the Kidderminster Railway Museum.