If you are a ham radio operator of a certain age, you probably remember ads for “The Instructograph,” a mechanical device for learning Morse code. [Our Own Devices] has an ancient specimen of the ...

Conventional wisdom holds that the best way to learn a new language is immersion: just throw someone into a situation where they have no choice, and they’ll learn by context. Militaries use immersion ...

A portable practice set in a case used for teaching telegraph and wireless operators Morse code. Spring-operated motor with winding crank on right side. A punched-paper tape is pulled around a spindle ...