The Original Sat-Nav Wristwatch

A new exhibition has opened at the British Library Business & Intellectual Centre and features some weird gadgets such as a clockwork burglar alarm from 1852, a grenade to put out fires from 1890 and a 'sat-nav wristwatch' from 1920.

The watch contained tiny map scrolls that drivers could interchange. As they drove they would wind the map a little to reveal more of the road.

The exhibition runs until November 14th. [via]