Map Ruler - 1:24,000 (USGS 7.5 Mnute Series)

Map Ruler - 1:24,000 (USGS 7.5 Minute Series)

Each ruler is designed for a specific scale map.
* *    You must use a ruler that matches the scale of your map.    * *

On the front side, the rulers have minutes and seconds on one edge and decimal minutes on the other edge, allowing you to use either notation. On the back side, the rulers have distance in meters on one edge, and distance in either miles or nautical miles on the other edge. Latitude is measured directly with the ruler. But, since a degree of longitude covers a shorter distance as you move towards the poles, the ruler is used on a diagonal to measure longitude. The rulers are printed on a sturdy 20mil white plastic stock for durability.