25 Pounder info needed.

[Tony Wheeler]

Originally Posted by David Dunlop

Could the last photo have captured the moment just after the firing of the gun

It's actually a time exposure David, not an ordinary hand-held photo. That's why the camera has been placed on the ground to steady it. The shutter would be opened in the pitch dark, just before the gun fires, then the light of the flash illuminates the scene. In other words the camera captures the entire duration of the flash and afterburn, which is long enough to observe some rising of hot gases.

Originally Posted by David Dunlop

and just before a facing wind starts to push the propellant gases away?

Yes a facing wind would definitely increase the effect. Even a 10 knot breeze equates to 5 metres per second, so it's bound to have some effect.