Using Different Scaling in the X and Y Directions

Under some conditions, different map units are used for the X and Y directions.

Example

Consider a map of the state of Montana. When you plot the map on a one to one scale, the map appears stretched in the east-west direction. To understand this problem, consider that for Montana the latitude ranges from 44.36° to 49°. The latitude for the center of the map is determined from this to be 46.68°. The cosine of 46.68° is 0.686. The distance covered by one degree of longitude at this latitude is only 0.686 times the distance covered by one degree of latitude. To reduce the distortion on this map, you must correct for this difference.

You uncheck the Proportional XY scaling box on the Scale page and then set the map scaling so 1 unit in the X direction is not equal to 1 unit in the Y direction. The map is then plotted with different scales in the X and Y directions.