Yeah it cost me like two weeks pay! Had to save for a few weeks to get one.That was the first calculator I ever saw. I couldn't afford one though
Planes still use this technology. It sounds like a marker beacon used airport approaches, or a VOR before the direction needle was added.And here, thanks to Marconi's Wireless Telegraph Company, is the latest amazing wonder of directional wireless, which could allow London Croydon pilots to fly in a perfectly straight line, or to land, through cloud, or even at night!!!