March 20 in Technology History: Standards, Patents and Breakthroughs

1883

On 20 March, Thomas Edison’s US Patent 274,293 for an electric lamp was issued, documenting design details for incandescent lighting components at a time when materials, vacuum techniques, and filament durability were central engineering challenges for practical electric light.

1883

On 20 March, an Edison patent document for an incandescing electric lamp, US Patent 274,294, was issued, capturing period engineering choices around lamp construction in the early incandescent era and providing primary technical text and drawings via the patent PDF.

1969

On 20 March, a pre-countdown test for Mariner G revealed problems affecting the spacecraft’s central computer sequencer and an infrared radiometer, triggering troubleshooting and ultimately a launch postponement and showing how end-to-end systems testing gates interplanetary missions.