The building blocks of our Silicon-Information Age -- oscillators for generating radio, TV, and computer signals; the amplifiers and electronic switches that make them useful -- are variations of the amplifier Dr. De Forest invented at 913 Emerson, Palo Alto, California. The communications and information revolution these devices enabled is rivaled in its impact only by the invention of writing and the printing press.

In a famous lab demonstration De Forest placed a quietly ticking pocket watch by a telephone mouthpiece which was connected to his Audion amplifier whose output fed a telephone earpiece attached to a Victrola record player horn. Everybody in the lab clearly heard the ticking when he connected the wires.

* He later rated the performance of improved amplifier circuits in terms of the number of city blocks from this laboratory from which he could hear their emissions. Homer Avenue is was at the one-block mark, a major milestone. One literally walks in history here.

 Photo: Palo Alto Historical Association

De Forest's laboratory was located in this modest house, which was demolished in 1965 to make way for a vacant lot. The office building currently occupying its site was built many years later.