Roy,

Interesting history. I was not aware the British established a school. From the sound of it, it was a few years after the school in Liege.

Here is a bit about Allport's crusher gauge.

Report of the 56th annual meeting of the British Association for the Advancement of Science. Published by J. Murray, 1887

http://books.google.com/books?id=vzMUAAAAYAAJ&pg=PA820&dq=Samuel+Allport#PPA821,M1

Quote:
The instrument known as the ' crusher gauge ' is a cylindrical nozzle having an external screw to screw into any powder chamber. It is bored at one end to receive a perfectly fitting piston. On exploding powder in the chamber the piston delivers an impact upon a loose copper disc placed inside the crusher gauge, of which the rate of compressibility is ascertained previously. By carefully measuring the thickness of the copper disc before and after the experiment, the compression the disc has suffered is observed, and the powder force is deduced. Since the thickness of the barrel of a gun from breech to muzzle should diminish proportionally to the progressive decrement of gas pressure the lightest safe section can thus be found. This instrument has been screwed at equal distances along large guns for that purpose, and the principle seems capable of application to sporting guns. The paper then dealt briefly with the subject of impact.

The author exhibited a test gun of 73/100 of an inch calibre, designed for testing the pressures exerted by different powders upon the barrels of guns. The upper side of the barrel is pierced with six tapped holes, into which gun-metal stop-screws are screwed. On removing either of these, an instrument for measuring the pressure may be screwed on. The stem of the piston La this instrument extends to the inner surface of the barrel, and its outer extremity carries a toothed rack. This engages with a pinion, the axis of which carries an index finger ranging over a graduated arc.

On firing the gun, a gas-check wad upon passing the end of the piston-rod exposes it to the pressure of the gas then generated, forcing the piston upwards against a spiral spring and compressing it. The compression is automatically recorded on the graduated arc in terms of hundredths of a ton per square inch. By interposing a different piston the gun becomes a crusher gauge at the same places along the barrel, whereby a second test is established.


Pete

http://www.damascus-barrels.com/Movie.html