Steve Thomas, age 12, of Peoria, Illinois, for his question:

How does north differ from true north?

These terms were used more in the time of old sailing ships when voyagers depended upon a compass and upon the sun and lode stars such as Polaris. Modern ships and planes have more refined instruments and methods for charting a course.

True north is the direction of the north pole. North is the direction on the compass. This is one end of the axis around which the earth rotates one of the two poles from which the lines of latitude and longitude are charted. Directly over the north pole hands the north star, Polaris. This is why, north of the equator, Polaris points out the true north direction. The compass points directly to the earth s north and south magnetic poles and these magnetic poles are several hundred miles from the true poles. A world traveler, depending entirely upon a compass, could come off course.