Nancy Grayson, age 13, of Philadelphia, Pa., for her question:

How deep is a league?

The giants of old, so they say, strode swiftly along in seven league boots  but no one can tell the length of these leagues. However, we know that the league has grown longer through the ages. To the Romans, it was 1500 paces or about 1 1/3 miles. The Normans introduced the league to Britain, and at that time it was ten miles long. Nowadays, the league is reckoned to be equal to three miles.

The league is a measure of distance over land or sea. In the title "20,000 Leagues Under the Sea," this is misleading. The average depth of the ocean is only three and a half miles, just over one league. In the story, of course, a submarine travels a distance of 20,000 leagues below the surface of the sea.