Children of the Geissler Tube

Interesting. But not really the history of electronic tubes.

Geissler tubes are gas-discharge tubes. There's a whole family of those - neon lamps, gas-discharge rectifiers, thyatrons, ignitrons, krytrons, etc. Those were the first electronic devices with significant power-handling capacity. All have some gas inside that can be ionized. They usually don't have a heated filament, and don't work by thermionic emission. They're definitely the ancestors of fluorescent light bulbs. As power devices, they were used in specialty devices such as lamp dimmers (rarely, but I've seen one), motor controllers (rarely, but done during WWII), and, of all things, centrally controlled school clocks (IBM/Simplex). Niche.

Then there were vacuum tubes. Their genealogy starts with the Edison Effect (put an extra element in a vacuum light bulb, and there's some current flow), and go on to Fleming's diode and then De Forest's triode. At last, gain! These were all low-power devices, but they could amplify small signals. They made radio, TV, and computers go before semiconductors.

Gas-discharge tubes and vacuum tubes aren't that closely related. They work on different physical principles. During the tube era, they often came in the same tube packages, so people think they're similar.

Core claim: “Geissler tubes as a computer ancestor” I was really surprised at this and had to verify it “: Fair: Geissler’s 1857 gas-discharge tubes popularized controlled glow discharges and directly led to Crookes tubes, cathode rays, and gas-discharge lighting. Earlier glow experiments existed (Hauksbee, Faraday), but Geissler standardized the form that kicked off the tech tree. https://en.wikipedia.org/wiki/Geissler_tube” It is odd that Heinrich Geissler does not have a bigger place in history. I guess he was just a “toy” builder… Also interesting: Most keyword searches treat ß ≈ ss, so “Geißler” and “Geissler” have the same search results.