From Ananova: World’s first sat nav — from 1920.
It doesn’t speak to you or give live traffic updates, but this is the world’s first sat nav — invented in the 1920s.
The Plus Fours Routefinder was designed to be worn on the wrist — relying on good old-fashioned paper maps wound around wooden rollers, which the driver turned en route.
The tiny scrolls also showed the mileage and gave a "stop" instruction at the journey’s end. [continue, see photo]
- Weird and Wonderful Gadgets and Inventions Display – British Library