OK, when I say “Go,” flap your arms and run toward the edge.
Dear Word Detective: My wife has been going through a tough project at work and as part of the work, they were attempting a “dry run” to see if things will work in a test environment. On a car trip, I had to ask, “What was the origin of ‘dry run'”? One of our ideas was it was from plumbing: to make sure the pipes didn’t leak, they put air in and tested the joints. Could we be close? — Rich Harrington.
Wow. Some people actually discuss word and phrase origins while they’re on a road trip? In our car the dialog seems to focus on questions like “Is that noise coming from our car?” or “Do you smell something burning?” Other big hits include “Did you see what that guy just did?”, often followed by “How could you not have seen what that guy just did?” and the ever-popular “Maybe I should drive.” By the way, did you know that the driver of a car has the absolute legal power to determine what music is played in the car? It’s in the US Constitution.
A “dry run,” of course, is a rehearsal or practice session conducted to make certain that a system works or that a procedure can be carried out without serious mistakes. While practice may not make perfect, it does make it a lot less likely that you’ll be scanning the help wanted ads the day after your snazzy new escalator pitches your boss into the koi pool.
Of course calling it a “dry run,” rather than just a “practice run” or the like immediately raises the question of why “dry,” and whether there might be such a thing as a “wet run.” The first citation for “dry run” in the “practice” sense listed by the Oxford English Dictionary (OED) is from 1941, although the OED does list earlier uses of “dry run” to mean a dry creek bed or desert arroyo. But since no one has ever come up with a plausible scenario linking the two senses we can safely assume that the two uses are unrelated.
As a matter of fact, until just a few years ago, no one had come up with a truly convincing explanation for the origin of “dry run,” and the only theories proposed were halfhearted attempts to connect the phrase to such phrases as “dry heaves” (slang for unproductive vomiting). But in 2004, Douglas Wilson, a poster to the mailing list of the American Dialect Society (ADS), offered (and, more importantly, documented) what I believe is a slam-dunk answer to the “dry run” question.
It turns out that “dry run” comes from the jargon of fire departments (where a “run” is a dispatch of a fire brigade).
Beginning in the late 19th century, fire departments in the US began conducting practice sessions where engines were dispatched and hoses deployed, but water was not pumped, thus making the exercises literally “dry” runs. Public exhibitions and competitions between departments also typically centered on such “dry runs.” Conversely, a real run to a “working fire” where water was pumped was known as a “wet run.” In his posting to the ADS list, Doug Wilson found instances of this use of “dry run” dating back to 1893. Just when the term came into more general use meaning “practice session” is uncertain, but it seems to have been after “dry run” was widely used in the US Armed Services during World War II.