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Nate Lockwood has posted 81 annotations/comments since 10 April 2013.


Second Reading

About Monday 9 April 1660

Nate Lockwood  •  Link

Dick, my understanding of "corning" is to make gunpowder in "corns' or tiny evenly sized particles. Gunpowder burns on the surface and to keep the pressure in the gun barrel constant it should burn about a long as it takes to evenly accelerate the cannon ball or or shot out of the barrel. If it takes longer than that to burn it's being wasted.

I believe that corning was achieved by wetting the gunpowder mixture allowing it to be handled more safely. The paste was mixed and extruded through a sieve or plate with lots of holes of even size. I don't know how the extruded paste was cut to size. Since the gunpowder was wet some of the potassium nitrate dissolved and was carried in to the charcoal resulting in a more intimate placement of the oxidizer, potassium nitrate, and the fuel, the porous charcoal.

A problem with early manufacture of gunpowder was that the some of it was dust and that more dust was created by the grains jostling against one another. The dust would collect in the bottom of the containers. When fired the dust would just about instantly burn creating an unwanted pressure spike that could cause the gun barrel to burst. Another problem is that the dust could get into the air without being seen and could ignite and cause an explosion. I've been present at an accident of this type and it's quite impressive.

So corning was a real improvement. I have not bought gunpowder for some decades but I recall that if I was using it in a pistol I would purchase 'ball' whose particles were spherical, quite small, and burned rapidly; but that to reload rifle cartridges were not ball shaped and were a little bigger.

Modern "gunpowder" for larger naval guns was in the form of little cylinders (or not so little for the really large guns) with longitudinal holes that served to keep the surface area approximately constant during burning.

I suspect that you are correct and that the containers would be inverted every once in a while to attempt evenly distribute the dust. At some point the charges were packaged in silk bags which would contain any dust.