- Letter Writer
- Early warships
- RAN Ships
- None noted.
- March 2009 edition of the Naval Historical Review (all rights reserved)
The origin of the phrase ‘cold enough to freeze the balls off a brass monkey’ was discussed in the last issue of NHR (December 2008, p20) but contains a number of popular assertions that fail to stand up to scrutiny. In short, the anonymous writer presents the old myth that the ‘brass monkey’ was a brass dish in which the iron cannon-balls were stacked and when exposed to freezing weather, the brass shrunk a greater amount and more quickly than the iron so the balls fell off the monkey. This explanation appears to be a legend of the sea without any historical or scientific justification.
As a physicist I thought I’d do some back-of-envelope calculations about the relative shrinkage of brass and iron with temperature. But first, I’d like to discuss three historical points:
1. During the 19th and 20th centuries, small monkeys cast from brass were very common tourist souvenirs from China and Japan. They usually came in a set of three representing the Three Wise Monkeys carved in wood above the Shrine of Toshogu in Japan. These monkeys were often cast with all three in a single piece. In other sets they were made singly.
2. ‘Freezing the balls’ is a more recent variant of an old saying about removing other anatomical parts of brass monkeys. The first recorded use of freezing a ‘brass monkey’ dates from 1857, in Before the Mast by C.A. Abbey, where he says ‘It would freeze the tail off a brass monkey’ referring to the brass tourist souvenir mentioned above. An even earlier expression ‘hot enough to melt the nose off a brass monkey’ dates from 1847. References to ‘brass monkeys’ in the 1800s make no mention of balls at all, but instead variously say that it is cold enough to freeze the tail, nose, ears, and whiskers off a brass monkey; or hot enough to ‘scald the throat’ or ‘singe the hair’ of a brass monkey. All of these variations imply that an actual monkey is the subject of the metaphor. It is not about cannon balls. ‘Freezing the balls’ came later in line with a general trend in the 20th century towards both sexually oriented or obscene references in colloquial English.
3. Cannon balls were not stacked in pyramids on the deck in Napoleonic times. Ready-service shot was kept on the gun or spar decks in shot racks (also known as shot garlands in the Royal Navy) which consisted of longitudinal wooden planks with holes bored into them, into which cannon balls were inserted for ready use by the gun crew. Shot was not stored on deck continuously on the off-chance that the ship might go into battle. Indeed, decks were kept as clear as possible. Furthermore, such a method of storage would result in shot rolling around on deck and causing a hazard in high seas. Shot was not left exposed to the elements where it could rust. Such rust could lead to the ball not flying true. Indeed, gunners would attempt to remove as many imperfections as possible from the surfaces of balls. Try to find that sort of brass monkey on eBay or in a naval museum and you’ll be sorely disappointed. They never existed and are thus not for sale.
4. The science behind the writer’s claim is faulty. While it is true brass shrinks more than iron when cooled, we need to look at both the relative and absolute amounts of shrinkage. A 10 cm length of iron shrinks by 1-millionth of a metre for every degree C it is cooled whereas the same size piece of brass shrinks by 2‑millionths of a metre per degree. A 10 cm diameter ring of brass (part of the so-called `monkey’) will shrink by 0.5 mm when cooled from 50°C to 0°C. So the cannon ball will lift by about the same amount (note: that’s half a millimeter). But the cannonball will also shrink – but not as much. It works out to 0.25 mm, so the ball will sink into the monkey by that amount. In total, the ball will rise up the monkey by one-quarter of a millimetre – about the thickness of a fingernail. This will make no difference and can’t explain the old saying. It is just nonsense.