940 REPORT—1890. 
higher energy of recoil, no less than four tons weight per gun had to be added to 
strengthen the mounting, the deck, and the port pivot fastenings. 
The chamber pressures with which our guns are worked do not generally 
exceed seventeen tons per square inch, or say 2,500 atmos. It must not be sup- 
posed that there is any difficulty in making guns to stand very much higher initial 
tensions; but little would be gained by so doing. Not only can a higher effect be 
obtained from a given weight of gun if the initial pressure be kept within moderate 
limits, but with high pressures the erosion (which increases very rapidly with the 
pressure) would destroy the bores in a very few rounds. 
In fact, even with the pressures I have named, the very high charges now em- 
ployed in our large guns (1,060 Ibs. have frequently been fired in a single charge), 
and the relatively long time during which the high temperature and pressure 
of explosion are maintained, have aggravated to a very serious extent the rapid 
wear of the bores. In these guns, if the highest charge be used, erosion, which no 
skill in construction can obviate, soon renders repair or relining necessary. Reduced 
charges, of course, allow a materially prolonged life of the bore, and there is also 
a very great difference in erosive effect between powders of different composition, 
but giving rise in a gun to the same pressures. Unfortunately, the powder which 
has up to the present been found most suitable for large guns is also one of the 
most erosive, and powder-makers have not so far succeeded in giving us a powder 
at once suitable for artillery purposes, and possessing the non-eroding quality so 
greatly to be desired. 
An amide powder made by the Chilworth Company, with which I have, not 
long ago, experimented, both gave admirable ballistic results, and at the same 
time its erosive effect was very much less than that of any other with which 
Iam acquainted. It is by no means certain that the powder would stand the 
tests which alone would justify its admission into the service, but the question 
of erosion is a very serious one, and has hardly, I think, received the attention its 
importance demands. No investigation should be neglected which affords any 
prospect of minimising this great evil. 
On the introduction of rifled artillery the muzzle velocities, which you will 
remember had been with smooth-bore guns and round shot about 1,600 f. s., were, 
with the elongated projectiles of the rifled gun, reduced to about 1,200 f.s. Inthe 
battle between plates and guns these velocities were with armour-piercing projectiles 
gradually increased to about 1,400 f.s., and at about this figure they remained until 
the appointment by the Government of a Committee on Explosives. By the experi- 
ments and investigations of this committee it was shown that, by improved forms of 
gunpowder and other devices, velocities of 1,600 f. s. could be obtained without 
increasing the maximum pressure, and without unduly straining the existing guns. 
Similar advances in velocity were nearly simultaneously made abroad, but in 
1877 my firm, acting on independent researches on the action of gunpowder made 
by myself in conjunction with Sir F. Abel, constructed 6-inch and 8-inch guns 
which advanced the velocities from 1,600 to 2,100 f.s., and this great advance 
was everywhere followed by a reconstruction of rifled artillery. 
With the present powder the velocities of the powerful armour-piercing guns, 
firing projectiles considerably increased in weight, may be taken at from 2,000 to 
2,100 f.s. The distance of 3,000 yards, which I said practically represented the 
extreme range of smooth-bored guns, is attained with an elevation of only 2° in the 
case of the 68-ton gun, and of 34° in the 4'7-inch quick-firing gun, while at 10° the 
ranges are 9,800 and 5,900 yards respectively, and, as an instance of extreme 
range, I may mention that with a 9:2-inch guna distance of over 13 miles has 
actually been reached. 
Nor is the accuracy less remarkable. Bearing in mind the mode of comparison 
which I have already explained, at 3,000 yards range the 68-ton gun would put half 
its shot within a plot of ground 7:2 yards long by 0:3 broad, and the 4°7-inch gun 
within a plot 19 yards long by 1:3 broad; or, to put it in another form, would put 
half their rounds in vertical targets respectively 0°92 yard broad by 0°34 yard 
high and 1:3 yards broad by 1°6 yards high. ; 
Rut it cannot be assumed that we are at the end of progress, Already, with 
