[Thermodyne]

Brass Monkey

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, 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 or 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 ............