History lesson...

Given the >>>>>>>>>forwarded this deep email I got this from, I don't know how much I should trust this, but I like it anyway:

In the heyday of sailing ships, all war ships and many freighters carried iron cannons. Those cannon fired round iron cannon balls. It was necessary to keep a good supply near the cannon. But 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/rolling from under the others. The solution was a metal plate called a "Monkey" with 16 round indentations. But if this plate was 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 cannon balls would come right off the monkey. Thus, it was quite literally, "Cold enough to freeze the balls off a brass monkey!" (And all this time, you thought that was an improper expression, didn't you?)

Enquiring minds want to know...

Alright, first I posted the above, then I decided to look this up. You know, those Snopes folks are no fun at all. They say

Somebody's fanciful imagination is at work cooking up spurious etymologies again. In short, this origin for the phrase "cold enough to freeze the balls off a brass monkey" is nonsense because:

They seem awfully sure of this - why?

For one, they say they didn't find such usage in the Oxford English Dictionary. Hmm. Something allegedly dating back ~150 years ought to have made it there by now, but I wonder what Snopes would say to a claim that the OED was complete.

They offer this:

When references to "brass monkeys" started appearing in print in the mid-19th century, they did not always mention balls or cold temperatures. It was sometimes cold enough to freeze the ears, tail, nose, or whiskers off a brass monkey. Likewise, it was sometimes hot enough to "scald the throat" or "singe the hair" of a brass monkey. These usages are inconsistent with the putative origins offered here.

Not really. Once brass monkeys became the standard for durability it wouldn't surprise me to see people sanitize the expressions or extend the concept in various ways.

Next we get this:

Warships didn't store cannonballs (or "round shot") on deck around the clock, day after day, on the slight chance that they might go into battle. Space was a precious commodity on sailing ships, and decks were kept as clear as possible in order to allow room for hundreds of men to perform all the tasks necessary for ordinary ship's functions. (Stacking round shot on deck would also create the danger of their breaking free and rolling around loose on deck whenever the ship encountered rough seas.) Cannonballs were stored elsewhere and only brought out when the decks had been cleared for action.

OK. But cannonballs had to be stored somewhere, and this storage had to keep them from rolling around. I don't know whether sailing ships fought much in rough weather or not, but they'd still need storage of cannonballs near the guns to achieve any sort of fire rate.

Similar logic applies to this:

Particularly diligent gunners (not "masters," who were in charge of navigation, sailing and pilotage, not ordnance) would have their crews chip away at imperfections on the surface of cannonballs to make them as smooth as possible, in the hopes that this would cause them fly truer. They did not leave shot on deck, exposed to the elements, where it would rust.

Actually it seems to me that they could make cannonball restraints out of wood. It would be a lot cheaper, lighter and easier to fabricate, if not as durable. I'll have to make it to Boston and tour Old Ironsides one of these days and see for myself.