Oh, this is a classic. I can hardly believe that I’ve never heard it before; the amazing BS claim, made by the so-called ‘History Project’ on YouTube (and apparently tour guides on HMS Victory), that the phrase ‘pull your finger out’ derives from the world of artillery.
‘…cannons [sic] were loaded with black powder through a small ignition hole which was held in place by a wooden plug. In the rigours of battle though, this job was carried out by a crewmember who used his finger. Artillerymen hadn’t just to [?*] engage the enemy, would shout at the crewmember to ‘pull his finger out’ enabling him to fire.’
*I’m actually from the UK and have tried three times to get what the presenter is saying here; I still have no idea.
Although garbled and inaccurate, this is based on real historical drill, which you can read about here. I don’t know what they mean by ‘held in place by’, but the real need top ‘stop the vent’ was to prevent premature ignition of the next charge being loaded. By preventing air (and therefore oxygen) being sucked into the chamber as the sponge was pulled out, any embers left still glowing might be reignited, resulting in premature ignition of the fresh charge as this was rammed home (more on this here).
Importantly, the gun’ captain was to cover the vent with the thumb, not insert a finger! Vents in gun breeches weren’t even big enough to achieve that – typically they were just .2” or 5mm – see this National Parks Service manual! Not to mention the risk of getting it stuck if you could somehow jam it in there. Then there’s the heat problem; gun captains were supposed to wear thumbstalls to protect them, but if you had to stop the vent in the ‘rigours of battle’ you’d suffer far worse if you had your fingertip, never mind your finger, stuck in a red-hot vent. Then there’s the ridiculous idea that an order of command would be as long as five syllables. In a world where even the two syllable word ‘Present’ was shortened to one for speed and convenience (‘P’sent’), there’s no way this phrase would have been used; and sure enough, there’s zero evidence that it was.
At this point I’ll hand over to the superb Phrases.org.uk:
‘The first known use of it in print is in Aussie: The Australian Soldiers’ Magazine, March 1919 :
“Tell the bloke who issues the prizes to pull his finger out.”
It began to be used in the UK during the Second World War, presumably due to the mixing of Australian and UK forces.
What finger was being referred to and where it was supposed to be pulled out from we can only speculate.’
In other words, it’s an Empire/Commonwealth version of ‘pull your thumb out your ass’.
Verdict: total BS. But it made me chuckle at least. I feel that I must point out that ‘The History Project’ also has a video on ‘the whole nine yards’, another bogus phrase origin that I’ve debunked before. They also have one on ‘bite the bullet’, which is still wrong, but more plausible/arguable. I might do that one next. Or maybe I’ll be nice and cover their explanation of ‘Sweet FA’, which actually seems to be true…