Greg Chaffins 
A wrist mounted GPS for navigation would be really handy, but it has been done before. In the 1920s the discerning gentleman traveler could use a wrist mounted navigation aid that showed him the way. As the journey progressed, the traveler simply turned the knobs to position the map in a new area – easier than even using a stylus.
Of course, if the traveler got off track, then they have to spend some quality time fumbling thorough their map scroll collection. That is, if they remembered to pack the other scrolls. Sure, there are some issues, but the wrist navigation is way cool for its time.
The wrist navigation unit, along with 50 other antique marvels that never really took off, are on exhibit at the British Library Business and Intellectual Property Centre. The collection is owned by retired businessman Maurice Collins, so a big thanks out there for sharing.
