The Routefinder, 1920's navigation system (The British Library).
The ‘Routefinder’ showed 1920s drivers in the UK the roads they were travelling down, gave them the mileage covered and told them to stop when they came at journey’s end. The technology consisted of a little map scroll inside a watch, to be ‘scrolled’ (hence the word) as the driver moved along on the map. A multitude of scrolls could be fitted in the watch to suit the particular trip the driver fancied taking (source).
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