細節
A Folding Wireless Map of the World
published by George Philip & Sons Ltd., and officially compiled by Marconi's Wireless Telegraph Co. Ltd., in folder with advertisements for Gamages, Russell & Shaw, The British Telegraph Instrument Co. Ltd, W.H. Smith and Crypto Variable Frequency Alternators, n.d., circa 1912 -- 22½ x 34in. (57 x 86cm.); and two valve catalogues: Marconi, issued Feb. 1926 and Osram, 1933-4 (3)
published by George Philip & Sons Ltd., and officially compiled by Marconi's Wireless Telegraph Co. Ltd., in folder with advertisements for Gamages, Russell & Shaw, The British Telegraph Instrument Co. Ltd, W.H. Smith and Crypto Variable Frequency Alternators, n.d., circa 1912 -- 22½ x 34in. (57 x 86cm.); and two valve catalogues: Marconi, issued Feb. 1926 and Osram, 1933-4 (3)