Before Radar, Militaries Used Gigantic Headphones for Land-Based Sonar
Radar is wonderful, sure, but militaries didn’t always have the benefit of radar to pinpoint enemy locations. Before that, there was sonar. Underwater is one thing, though. On land, you needed big victrola-like contraptions that looked uncomfortable as all hell. These acoustic locators worked in much the same way as a submarine or bat’s sonar…
