Today’s Favourite Word: Eprouvette


This is cool, and kind of dangerous too. When guns were packed with gunpowder one of the problems was knowing how much gunpowder to put in. So the eprouvette was used to test the strength of gunpowder. It went out of general use by the middle of the 19th century. A carefully weighed quantity of powder was placed inside it, followed by a standard weight shot. The charge was fired and the distance the shot flew was measured and compared to the expected standard distance. So then you knew how much to load your gun with.

It’s a pretty basic device, but I saw a very elaborate one at the Guildhall created by master guildsmen. It was as much an attractive object as a useful tool.

13 comments on “Today’s Favourite Word: Eprouvette”

  1. ediFanoB says:

    English is not my first language. Therefore I’m always keen to learn new words and expressions.
    Thank you.

  2. Dan Terrell says:

    Eprouvette is a French loan word containing at its core prove. Eprouvette is more commonly used now as the French word for test tube, etc. So, my French friends would sometimes say: “Come, it is time to prove the wine.” Excellent suggestion.
    Never realized what a eprovette looked like. If I recall correctly an eprovette was taken along to duels to assay the black powder to be used by both sides and assure it was of the same strength,
    More please.

  3. John Howard says:

    Are we sure that this isn’t the diminutive of prove? You know, if you don’t listen to me then I will prove how much I can hurt you? This is the lesser form. i.e: ‘I won’t hurt you as much as I could do but I will just tickle you with the feather that comes out of the end of my fancy pistol’.

    I’m sure I can see the end of the feather under the ratchet.

  4. snowy says:

    Though probably nowhere near as dangerous as loading a long gun with a powder of higher than expected strength. And having the barrel explode in your face when you pull the trigger.

    Looking again, did it use a shot? Or was the energy measured by the number of clicks the ratchet moved round, over-riding the pawl? It’s just there seems to be a pointer worked into the end of the saddle (bottom right). And there are too many teeth, for a simple latch mechanism.

  5. Helen Martin says:

    I couldn’t imagine what that ratchet was for, Snowy, but what you say makes perfect sense.

  6. Marc says:

    I’m intrigued. The device looks ancient – firearm design stopped using flintlocks from the 1830s/40s onwards, yet the packaging could be from the 1950s or 60s. Admin – can you tell us more about the illustrated eprouvette please?

  7. John Howard says:

    i don’t know, see these people who don’t read the blog. I would have thought that the ratchet was there to stop the end plate from bouncing back. The end plate being there of course to stop the ball falling out of the end of the barrel before a test shot was fired as this little object doesn’t seem to have the wad and rammer action of larger pistols.

    Any 150 year olds in the audience who might know the answer. Alternatively admin may have the instruction booklet and he can tell us what its for.
    As I was always told as a child, “read the bloody instruction” (although the bloody in the phrase didn’t come into use until I was in my teens).

  8. snowy says:

    I was following the description in the OP, and was with it, up to the point of measuring how far the shot went. And I just had an image of 50 liveried footmen searching the grass for a tiny little lead ball. This made me think something is not quite right.

    But I had a bit of a sniff round, there is an answer, a large Eprouvette looks like a small fixed mortar/cannon and takes a 3 or 4″ ball and works exactly as described.

    A number of small Eprouvettes, of slightly varing designs all seem to have a ratcheted wheel with calibrations on them. There is another view of the same piece out there that shows a scale that goes up to 10 (or perhaps 11).

    Marc, it’s a modern copy that takes percussion caps and it’s worth about $50.

    In other unrelated news I came across an ‘Otis King calculator’ at lunch, never seen a 66″ slide rule that would fit in a trouser pocket before. It was really rather nifty (as we say, en jolly old anglais profond.)

  9. Helen Martin says:

    Just looked up the Otis King. It’s 66″, yes, and would fit in a pocket – well…. It’s a helical scale so we’re not talking a long stick stuck down a pant leg. We’ve got a nice little disc shaped one.

  10. snowy says:

    While the English have a great weakness for puns involving pants, I shall resist the urge.

    Helen, may I ask you what the the disc shaped device does?

    And before I go may I say to all “Winter draws on” [except for those in Australasia naturally.]

  11. John Howard says:

    Snowy, are you a member of the Stark family? Their motto is, “winter is coming” even in summer. And yes, it is becoming summer in Australia as my brother never fails to remind me as he sits on the veranda picking a lemon from his lemon tree to cut a slice for his G&T.

  12. Dan Terrell says:

    Otis King was a grocer in London and an inventor. Ar first the name sounded like a ’60’s soul singer to me: Sitting on the Dock of the Bay. Wrong, but a good song.

  13. Helen Martin says:

    Our disc shaped device is a slide rule in the shape of one disc superimposed on the other. I can no longer remember how to operate a slide rule, however. Not that I ever really needed to use one either professionally or personally.

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