What’s the difference between an alligator and a crocodile? –Michael J. Healey, Washington, D.C.

Not much. They’re both “crocodilians,” members of the order of reptiles known as the Crocodilia. But they’re not the exact same species, as many people seem to think. In the U.S., crocs are confined to south Florida, whereas gators may be found in rivers and swamps throughout the south. Crocodiles are snaggle-toothed (some lower teeth protrude when the mouth is closed), narrow-snouted, and reputedly evil-tempered. Alligators have better dental work, wide snouts, and comparatively sweet dispositions. Probably explains why they wind up as handbags and crocs wind up as lawyers.

At the bottom of the copyright page in books there is often a string of consecutive numbers counting backward like so: 10 9 8 7 6 etc. Sometimes they count all the way down to 1, sometimes not. Why? –Larry Anderson, Brooklyn, New York

The numbers are a monument, as if one were needed, to the legendary tightfistedness of the nation’s book publishers. The lowest number shown indicates which printing your copy of the book came from. Thus 10 9 8 7 6 indicates the sixth printing. Sometimes you’ll see numbers like this: 88 89 90 10 9 8 7 6. In this case the number on the far left indicates the year of printing. You might think that this information could be as easily (and less mysteriously) conveyed by inserting a line saying “Sixth Printing, 1988,” but this would require a certain amount of hassle, not to mention typesetting expenses of as much as 15 or 20 dollars. Instead, each time the book goes back to press the printers merely obliterate one more number. The savings don’t go to the lowly authors, who wouldn’t appreciate them anyway, but rather are spent on private cars, New York real estate taxes, and other essentials of big-time corporate publishing.

Where does the phrase “the dickens” come from, as in “he scared the d. out of me”? I presume this refers to Charles Dickens, but I don’t get the logic. –B.L., Dallas

Presume nothing, pal. “Dickens” is thought to be a euphemism for “the devil,” much as “gosh” is a sub for “God,” “heck” for “hell,” and “mofo” for . . . well, no point getting graphic. Some speculate that “dickens” is a short form of an earlier term “devilkin,” little devil, but this has never been firmly established.

I’ve discovered that the world isn’t what it appears to be. When National Geographic, for instance, publishes a map, they use Mercator projection, which distorts the physical size of many countries. Although it looks like Greenland and Africa are the same size on a Mercator map, Africa is actually nine times as large! This is due to the fact that they have placed the equator two-thirds of the way down the page, elongating the northern hemisphere and shrinking the southern. Is this a snide western plot to diminish the physical impact of continents like Africa and South America? –Gina Brown, Montreal, Canada

Remain calm, my love. For starters, distortion in Mercator maps is not caused by placing the equator two-thirds of the way down the page; on the contrary, on a Mercator map of the world, the equator is a straight line in the exact center. The distortion arises from the way Mercator maps deal with the essential mapmaking problem, namely, trying to make a flat representation of a spherical surface.

On a globe, the lines of longitude converge as they approach the poles; on a Mercator map, the lines of longitude are parallel. Making such a map means taking each equator-to-pole globe segment, which is roughly triangular, and stretching it into a rectangle. Obviously the stuff near the poles gets stretched the most, greatly exaggerating its size. Despite this, Mercator maps are useful in navigation. If you draw a line between you and your destination on a Mercator map and then calculate the angle relative to north, you’ll get the compass bearing needed to get you where you’re going (though it won’t necessarily be the shortest route). Other methods of map projection reduce the distortion of land area but aren’t anywhere near as handy for charting a course.

Art accompanying story in printed newspaper (not available in this archive): illustration/Slug Signorino.

Cecil Adams

Cecil Adams is the world’s most intelligent human being. We know this because: (1) he knows everything, and (2) he is never wrong. For more, see The Straight Dope website and FAQ.