Having just finished watching Pirates of the Caribbean I am wondering about cannonballs. It seems that Hollywood always has them exploding on contact. How is it that a solid iron ball explodes? You would need a hollowed ball filled with TNT, wouldn’t you? And if you have a cannonball that’s hollow, how do you fill it without an opening? And if you make an opening, how do you seal it? Finally, how do you keep it from exploding when fired from the cannon? –daedalys, via the Internet

Seriously now, daedalys. (By the way, not to be old-fashioned, but would it be asking too much for you people to conclude your letters with, say, a proper name?) How many times do I have to tell you–there’s Hollywood, there’s real life, and the two only accidentally coincide. Particularly, if I may say so, in the case of Pirates of the Caribbean. This flick has a crew of pirates who, when they walk into moonlight, are revealed to be ghosts or something, although ghosts of the meaty, decaying, I-really-need-to-clean-out-the-fridge-more-often variety; it’s got an Ali Baba-type cave filled with glittering heaps of pirate booty; and above all it has Johnny Depp, playing the most over-the-top combination of macho and mince since Tim Curry in The Rocky Horror Picture Show. Do you think the guys who made this movie got together at any point and asked each other: How can we make this thing more realistic?

You’ve undoubtedly seen cannonballs at Civil War monuments and such. They look solid. They are solid. That was the idea. Blasted at a ship, fort, or rank of advancing troops, the shot (a generic term for nonexplosive ammo) wouldn’t explode but would definitely make an impression. Battlefield cannon were typically fired at dead level (“point blank”)–a single well-placed shot could mow down a column of men. Artillery was a devastating weapon that could decide a battle, even without the kind of big orange fireballs that look so spectacular in Panavision.

Simple cannonballs weren’t all the artillerymen of three centuries ago had to work with, of course. Other potential loads included grapeshot, a bundle of iron balls clustered around a wooden spindle and wrapped in a canvas bag, which worked like an oversize shotgun shell; canister shot, basically a tin can full of pellets; and chain or bar shot, which was a chain or bar (duh) with weights at both ends–think of a giant flying nunchaku. Chain was particularly useful in naval engagements since it could be used to bring down rigging; if it hit (erk) a man–well, no doubt a moviemaker of a certain sensibility could make an unforgettable moment out of it, but not without saying good-bye to his PG-13.

Some will quarrel with the above. They will tell you that even in the 18th century there was such a thing as a shell, a projectile filled with explosives that if all went well would detonate at approximately the time of impact; that early shells were essentially hollow cannonballs with a hole drilled for a fuse, the finished munition looking and working quite like the iconic bomb beloved of cartoonists; and that Francis Scott Key celebrated bombs “bursting in air” back in 1814–the apparent implication being that Pirates of the Caribbean is a work of cinema verite.

OK, shells existed. But let us consider the facts. Prior to the announcement by the French in 1837 that their naval vessels would henceforth rely primarily on shells (and the subsequent widespread adoption of such ammunition), warships generally carried shells only for special purposes–for the obvious reason that, given the state of the art, you’d be lucky if you could hit the broad side of a brig and didn’t blow up your own ship in the process. In the British navy, shells were used only by “bomb vessels” equipped with mortars, which lobbed explosives in a high arc (rather than a flat trajectory) into shore targets. In such cases if you were off by a couple hundred yards you were still bound to hit something, which you couldn’t count on during ship-to-ship combat.

To give Pirates its due, the movie commits only minor implausibilities involving artillery: flat-firing cannon would not have been used to launch shells into a town, and cannonballs hitting ships would have thrown up splinters and dust but no smoke. Then again, the French, ever in the avant-garde, experimented with shells in the 18th century, so maybe the combatants in Pirates imported their armaments from Paree. If you want me to explain the undead or Johnny Depp–sorry, mate, you’re on your own.

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

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.