new icn messageflickr-free-ic3d pan white
Map Measuring Tool | by The Central Intelligence Agency
Back to album

Map Measuring Tool

With this tool, cartographers could measure linear distances on maps by running the tiny wheel along the line between two points. Then they calculated the actual ground distance using the dial reading and the map’s scale.

 

20,179 views
0 faves
0 comments
Uploaded on November 9, 2016