24th December 1947

The Germanium Transistor.
The Photograph below is a replica of the first working transistor built by John Bardeen (1908-91), William Bradford Shockley (1910-89) and Walter Houser Brattain (1902-87) Bell Telephone Laboratories USA. It was first demonstrated on December 24th 1947.  Today thousands of transistor circuits can be etched on to a single silicon chip the size of a match head.

Photo Copyright Bell Labs USA

Milestones by: http://www.AudioUk.com