I'm sure this has come round before, but I can't find the thread.

Anyway, it sounds extremely unlikely. Metal's expensive, difficult to work, and has the aforementioned shrinkage problem. Wood's cheap, easy to work, and doesn't shrink. So no-one would make anything out of metal if they could make it out of wood instead, and the Navy was nothing if not practical - remember that the British Navy invented the production line (unless the Egyptians got there first, anyway :-).

Any metalworking landlubber _would_ know about the effects of temperature on metals anyway.

Cannonballs weren't perfectly round anyway, so a plate with round indentations wouldn't be much use. If the bottom cannonballs were too small, they'd tend to be squirted out by the weight on them and the whole thing would collapse; if they were too big, they wouldn't sit properly so they'd fall out when the ship rolled.

Also, consider the angles involved. By simple trig, the cannonballs would always roll off the stack if the ship heeled to an angle of 30 degrees. But well before that point, a small knock would roll the cannonballs off anyway, so it likely wouldn't be safe beyond a heel of 20-25 degrees. And when you're caught in a storm, the last thing you want is bloody cannonballs dropping on your foot!

The Snopes urban legend site says that the source is unknown, but gives many other examples of what it would freeze off a brass monkey to illustrate that only the crudest version survived. And Norton's link says that the first recorded instance of the phrase was freezing the _tail_ off a brass monkey.

Graham.