Image Dissector, a pioneering television camera tube invented by Philo T. Farnsworth.

 This is a museum placard describing the Image Dissector, a pioneering television camera tube invented by Philo T. Farnsworth.

The placard highlights some remarkable facts about Farnsworth's achievement:

• He demonstrated the first all-electronic television system on September 7, 1927
• He was only 21 years old at the time
• He worked in a small loft at 202 Green Street in San Francisco
• He had originally conceived the idea at age 15 and shared it with his high school science teacher
• He filed the patent for the "image dissector" camera tube the following year (1928)

The artifact shown is a 1940s version of the tube, from the collection of the Electronics Museum of the Perham Foundation.

Farnsworth's story is quite fascinating—he's often considered one of the most important but under-recognized inventors in American history. He essentially beat RCA and David Sarnoff in the race to develop electronic television, though RCA's resources eventually dominated the market.