Cannon Balls

One more: bet you didn’t know this!
In the heyday of sailing ships, all war ships and many freighters carried iron cannons. Those cannons fired round iron cannon balls. It was necessary to keep a good supply near the cannon. However, how to prevent them from rolling about the deck? The best storage method devised was a square-based pyramid with one ball on top, resting on four resting on nine, which rested on sixteen. Thus, a supply of 30 cannon balls could be stacked in a small area right next to the cannon. There was only one problem, how to prevent the bottom layer from sliding or rolling from under the others. The solution was a metal plate called a “Monkey” with 16 round indentations.
However, if this plate were made of iron, the iron balls would quickly rust to it. The solution to the rusting problem was to make “Brass Monkeys.” Few landlubbers realize that brass contracts much more and much faster than iron when chilled. Consequently, when the temperature dropped too far, the brass indentations would shrink so much that the iron cannonballs would come right off the monkey. Thus, it was quite literally, “Cold enough to freeze the balls off a brass monkey.” (All this time, you thought that was an improper _expression, didn’t you.)

Oh, it’s a good story, but highly unlikely. At a thermal expansion rate on the order of 10 x e-6 inches per inch per degF (or mm per mm per degF)(don’t know just what it is for brass, and I don’t feel like looking it up, but this won’t be far off), and a 100 degF change in temperature, and a length of, say, 30 inches, the change in distance will be only 0.00001 x 100 x 30 = about 0.030 inches. This is not likely to topple any stack of cannon balls. If it were enough, then the normal roll of the boat would be enough, too. And as it’s the difference in thermal contraction between the brass and the steel, not just the contraction of the brass, we have probably over estimated the effect by a factor of two or three.

Don’t you just hate it when scientific fact gets in the way of a good story?

Mike Biggs

Either way it IS a good story. I like it.