56 
MINUTES OF PROCEEDINGS OF 
V. Action of the gunpowder when fired. —This is decided by the 
firing proof. It is of course impossible to predict, from observations 
made with one gun, what the action of different charges of powder will 
be in different calibres of guns. But this does not in any way affect 
the accuracy of the firing proof now employed; the only object of which 
is to ascertain whether certain samples of powder, when fired in equal 
charges and under the same conditions from the proof-gun, produce the 
same effects as have been previously obtained with standard powder of 
the same class. The present firing proof is not intended, and could not 
be employed to decide what nature and charges of powder are suitable 
for all arms, but is merely a means of comparing samples of powder with 
the standard fixed by previous experiment. The powders made must 
be not only identical in physical qualities, but must produce the same 
results, when fired in equal charges and under the same conditions. 
The firing proof now employed affords a very perfect means of com¬ 
paring the action of different powders. The old proof consisted in firing 
a 68-pr. shot with a charge of 2 ozs. (3 ozs. in the case of R.L.Gf.) from 
an 8-inch mortar, and comparing the ranges obtained. So much abuse 
has recently been heaped on the old proof mortar, that it is perhaps 
unnecessary to say anything on the subject. But it must be remembered 
that its advocates did not intend it to be used for the purpose of com¬ 
paring the effects of different descriptions of powder, any more than the 
supporters of the new proof make use of the perfect appliance at their 
command for the same purpose ; but only for comparing various samples 
of the same piowder with a standard. A proof mortar, if properly used, 
would probably afford a rude but tolerably exact means of comparing 
the strength of different samples of the same kind of powder. We say 
probably; because there are so many disturbing elements in the mortar- 
proof, which were never properly eliminated, that it never received a 
fair trial. Now, of course, such a trial would be useless, as far more 
accurate and delicate means of proof are at our command. 
The firing proof now in use at the Boyal Glunpowder Factory, consists 
in measuring the velocity imparted to a projectile fired from a gun by 
a fixed charge of the powder under examination. The two different 
classes of powder—that is, powder for cannon and powder for small- 
arms—are tested as nearly as possible under the conditions under which 
they would be used; powders of the first class being tested in a 12-pr. 
gun, those of the latter in a Snider-Enfield or Henry rifle. 
The arrangements of the proof range are shown in the accompanying 
figure. 
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The muzzle of the gun is 180 ft, from the face of the butt, The latter 
