I was watching a police chase television show... The showed a chase that happend in England somewhere, the Constable who was involved in the chase was being interviewed. He stated that he was very scare and that his heart was beating "90 to the dozen".
Basically he was just saying that his heart was beating fast, the term can be related to anything that is being described as going fast. I have always said "ten to the dozen" though.
Thought I would google it to see how the saying came about, and apparently it might of originated over there in the states.
This is what I found:
* twenty to the dozen * 20 to the dozen * ninety to the dozen * 90 to the dozen * ninety to dozen * 90 to dozen * ninety * nineteen * twenty * dozen * going ninety to nothing * ninety to nothing * ten to the dozen * 10 to the dozen * 19 to the dozen * ten * nothing
at a great rate, very fast. Example: If we now are going to inform you about Johns life then we are going to talk nineteen to the dozen from a forged scripture. Synonyms: twenty to the dozen; ninety to (the) dozen; ten to the dozen History: This goes back to the times of the Cornish tin and copper mines. These mines were often hit by floods. In the 18th century, coal-powered, steam-driven pumps were installed to clear the water. When working maximally the pumps could clear nineteen thousand gallons of water for every twelve bushels of coal. This, quite clearly, was very fast compared to the rate at which the earlier hand-powered pumps had cleared water. On the other hand, some sources say that it was the amount of water a steam engine could pump out of a coal mine when burning a specific amount of coal (19,000 gallons and 12 bushels, respectively). Recently, it most often refers to speed of speaking, as in this instance from the "Daily Mail" of 23 October 2003: "Talking nineteen to the dozen, her conversation is still peppered with outrageous references and bawdy asides." The idea is that the rate of talking is so great that when other people say merely a dozen words, the speaker gets in 19. It's also sometimes used to describe rapid heartbeat in times of danger, and to refer to other fast-moving or fast-changing things. There are examples of "ninety to (the) dozen" to be found in various places, dating back to the late 1940s. But it's uncommon and seems to be a relatively modern variation on the older phrase. It may be linked to a characteristically North American expression, "going ninety to nothing", which the Dictionary of American Regional English records from 1950.