RECORDING THE HANDEL FESTIVAL IN THE CRYSTAL PALACE, 1888 

(PHOTO: THE MARY EVANS PICTURE LIBRARY) 

PSEUDO STEREO: THE TWO STYLI WERE LOCATED IN THE SAME GROOVE, THE REPRODUCED SOUND HAD AN ECHO EFFECT DEPENDENT UPON THE SPACING BETWEEN THEM

(PHOTO: TAGESCHBOUBOEMUSEUM, COPENHAGEN)

STENTORPHONE WITH COMPRESSOR FOR COMPRESSED AIR AMPLIFIER, c1910