Freeze the balls of a brass monkey?

Answer 1

The expression comes from the heyday of sailing ships, all war ships carried iron cannons, those cannons fired round iron cannon balls, it was necessary to keep a good supply near the cannon, but to prevent them from rolling about the deck, the best storage method was to make a square-based pyramid with sixteen balls at the bottom building up to one at the top. But the problem was how to prevent the bottom layer from sliding or rolling from under the others. So they devised a metal plate called a "Monkey" with 16 round indentations.

The plate was made of iron so the iron balls would quickly rust to it. The solution to the rusting was to make "Brass Monkeys", but brass contracts much more and much faster than iron when cold. So when the temperature dropped too much, the brass indentations would shrink so much that the cannonballs would come right off the monkey. So this is were the quote, "Cold enough to freeze the balls off a brass monkey" comes from!

Answer 2

The expression comes from the heyday of sailing ships, all war ships carried iron cannons, those cannons fired round iron cannon balls, it was necessary to keep a good supply near the cannon, but to prevent them from rolling about the deck, the best storage method was to make a square-based pyramid with sixteen balls at the bottom building up to one at the top. But the problem was how to prevent the bottom layer from sliding or rolling from under the others. So they devised a metal plate called a "Monkey" with 16 round indentations.

The plate was made of iron so the iron balls would quickly rust to it. The solution to the rusting was to make "Brass Monkeys", but brass contracts much more and much faster than iron when cold. So when the temperature dropped too much, the brass indentations would shrink so much that the cannonballs would come right off the monkey. So this is were the quote, "Cold enough to freeze the balls off a brass monkey" comes from!

ANS2:

"The Phrase Finder" takes exception to the previous answer. See the link, below.

Brass is a non-magnetic material, monkey is an archaic term for a mechanical adjustable support, balls are iron Kelvin spheres used for magnetic correction for a ship's magnetic compass. The compass is contained in the binnacle, the Kelvin balls are mounted port and starboard sides of the binnacle on brass monkeys. The binnacle is at the helm, and the helm on the poop or stern deck near the tiller or rudder post, traditionally exposed to the elements.