Origin and meaning of "Cold Enough to Freeze the Balls off a Brass Monkey"

The only consensus to the explanation of this expression is that there is no consensus.
The most popular version is that in the days of sailing ships, armed with cannons, the iron cannon balls had to be close to the cannon itself. In combat there would not be time to run around fetching and carrying cannon balls. The principle makes sense. So, myth has it that the cannon balls were stacked in a square based pyramid next to each cannon. 30 balls to a stack, 16 at the bottom level and obviously one at the top level. The problem was how to keep the pyramid in one piece. Legend has it that a brass plate with 16 indentations was made and placed at the bottom of the “pyramid”. One indentation for each of the balls on the lower level. This brass plate is called the Brass Monkey. It had to be of brass, as iron on iron would rust. Why it was called a monkey I could not determine. Anyhow, when it became very cold the brass plate would contract faster than the iron, and the balls would no longer fit snugly into the indentations, and fall off, causing the pyramid to collapse.
Hence “ Cold enough to freeze the balls off a brass monkey”.
This is the popular explanation, and at some museums one can see cannon balls stacked in this way.
In practice however this was not possible. 74 gun ships were common. 74 x 30 = 2,220 cannon balls rolling around the deck in cold stormy weather. This would have caused serious problems, imagine trying to go about your business under these conditions. Guns were lashed securely to prevent them from running around the decks causing damage and killing sailors. Per definition ships decks were, and still are, kept clear at all times. (Origin of a Loose Cannon!!!)
In addition, there is no reference in either the Royal Navy or the US navy of this practice being used, as it is not practical. Naval records refer to a “garland” made of wood with circular holes cut into them. I found no reference as to where theses garlands were placed.
In addition, this weight on deck was not a good thing, and cannon balls were used as ballast.
The only reference I found to “monkey” was that young boys were used to carry powder to the guns were called “powder monkeys”.
First written references to this expression are circa 1850. Not only to freeze the balls of a brass monkey, but also
- Freeze the tail off a brass monkey (Maybe balls was not polite)
- Gall of a brass monkey
- Talk the tail off a brass monkey
- To melt the nose off a brass monkey
- There are lots of them.
OK, so where did the expression come from. The most popular reference is to the statues of the three brass monkeys. “Hear no evil, see no evil, and speak no evil”. These souvenirs were made in the East and were popular amongst sailors. In addition to the three-monkey version, there was a four-monkey version, the fourth monkey covering his balls.
I have my doubts about that one as well.