MODERN gunpowder and cordite. 
291 
known to themselves, the Navy put their magazines near their boilers to get them 
as hot as possible. That will not suit cordite at all—they will have either to shift 
their magazines, or to stick to black powder. But the change in velocity is very 
small—the reason being that the density is only 110 cubic inches to the lb. 
There is much more chamber room in the gun, and therefore the variation in 
pressure and velocity is not so great as it is when cordite is packed in a compar¬ 
atively small space. 
I may mention (to show what great things we may hope from cordite) that the 
new Naval 12-inch gun, 35 calibres long, will have an 850 lbs. projectile against 
the service projectile of 714 lbs.; it will have a muzzle velocity of 2400 feet at 
least (2500 I had hoped for) against the present velocity of 1800 feet, or some¬ 
thing like that; and the breaching mechanism of this 12-inch gun will be only 
very little larger than the breaching mechanism of the 8-inch gun—the reason 
being that the charge of cordite is so small comparatively that the gun can be 
made much smaller; and the breach-screw will only be, if I remember rightly, 
12^ inches diameter—that is just the size it is for the 8-inch gun. So you see 
that the direct advantage we shall get in a gun specially made for cordite will be 
that all the breaching mechanism will be lighter. 
With regard to erosion we do not know much yet; but a 4'7-inch gun has 
fired over 1200 rounds and is still serviceable; whereas the same gun fired with 
a much lower muzzle velocity with black powder becomes unserviceable after 800 
or 900 rounds. I think it extremely probable that, from the absence of any 
liquid or solid matter mixed up with the gasses produced by the explosion, our 
larger guns will suffer much less in proportion than the smaller ones; but that is 
of course a matter that has still to be proved by actual experiments. 
The Chairman — I think there is nothing left for us to do but to thank 
Colonel Barker for his most interesting lecture. 
