Equipment used by Dr. Ludwig Koch for recording bird song comprising: (1) disc recording and play-back desk, (2) amplifier, (3) loudspeaker, (4) wooden box containing leads, and headphones. Equipment was made by M.S.S. [Master Sound System] Recording Company in Slough, England. Equipment used by Dr. Ludwig Koch for recording bird song comprising: (1) disc recording and play-back desk 1943
