The Brass Monkey Explained

One explaination circulating on the internet is:




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!"  (And all this time, you thought that was a dirty expression, didn’t you?)

The most likely explaination is, however, according to the United States Navy Historical Center, that this is a legend of the sea without true historical justification.  The Historical Center has researched this because of the large number of questions it gets and says the term "brass monkey" and a vulgar reference to the effect of cold on the monkey’s extremities, appears to have originated in the book "Before the Mast" by C.A. Abbey.  In that book, Abbey actually wrote that it was so cold that it would "freeze the tail off a brass monkey."   The Navy Historical Center says there is no evidence that the phrase had anything to do with ships or cannon balls. Ah, well.