Inside Out LibraryThe principles underlying radio communication (1922)United States. National Bureau of Standards, Ould, Richard Sheldon, 1889-, United States. Army. Signal Corps · Washington, Govt. Print. Off. · leaf 107Magnetic field about a bar magnet as .shownby iron filings flG.<Z»©Telegraph, Wireless · RadioInternet Archive · Public Domain Mark 1.0. Free to use for anything.More pictures from The principles underlying radio communicationMore like this
