48 
ARMOUR AND ITS ATTACK BY ORDNANCE. 
The guns have increased in power during the period dealt with, 
partly owing to the introduction of smokeless powder, which gives a 
higher muzzle velocity than brown or black powder fired in the same 
gun. Besides this, Q.F. guns are now being made of a length, 
generally considered extravagant, amounting in some instances to 
80 calibres, discharging projectiles with a muzzle velocity exceeding 
3000 f.s. Such a velocity rapidly decreases, nevertheless at short 
ranges Q.F. guns may possess an increased energy and power of 
perforation that has a practical bearing on the lighter armour em¬ 
ployed in gun shields, &c. This may become of greater importance 
owing to the fact that at very high velocities the perforation may 
probably be greater than would be calculated by any of the English 
formulae. The truth is that formulae for perforation of armour have 
been partly based on theory and partly empirically corrected on series 
of trials extending over a range of such velocities as could be attained 
at the time. Analysis shows that while English, French, and German 
formulae give nearly the same results at about 1G00 f.s., they gradually 
diverge as the velocity increases. No very serious discrepancy arises 
at such velocities as have been obtained with heavy guns, although 
even with these the differences at the muzzle are hardly such as ought 
to be ; when, however, such velocities as 2500 feet are reached the 
formulae give grossly divergent results, and at 3000 feet such as are a 
disgrace to science. 1 So that the experiments hereafter given on this 
question were urgently needed. 
The experiments will be given with a little divergence from their 
historical sequence in order to group them better according to their 
character. Under any circumstances they are suited rather for refer¬ 
ence than for reading in the ordinary sense of the word. 
Opiate 661 On O c t°k er 23rd, 1888, 2 a “ through steel plate,” made by Messrs. 
Schneider for the Swedish armour-clad coast service turret-ship, Gota, 
was tested. The plate was 6'5 feet x 6‘86 feet x 9*56 inches. It 
weighed 12,676 lbs., or about 5’6 tons. It was attacked by chilled- 
iron 6-inch projectiles, each weighing 99’2 lbs., with a velocity of about 
1835 f.s., having a calculated perforation of 11*4 inches of iron or 9*1 
inches of steel. The plate was cracked through for fully half its 
length. The projectiles broke up witli a penetration of about 3*6 
inches. This trial is unimportant because chilled projectiles were 
employed. 
o^steeUnd 1889, 3 Messrs. Schneider communicated to the “ Engineer” 
compound paper accounts of trials of plates of his own, and of projectiles made 
plates * by Krupp fired at CammelFs plates at Shoeburyness. In the latter 
trials the face of the plate had stripped off, exhibiting a total failure 
in the attachment, which was most damaging to the compound prin¬ 
ciple. The plate which Schneider instanced in comparison was one 
made by him for the Nordeuskjold, and tested in 1880, anterior to the 
1 On September 20th, 1892, M. Canet fired a projectile from a 10 cm (d‘9-inch) gun, with a 
muzzle velocity of 10-'6 metres (-1366 feet). The perforation through wrought-iron would be, by 
the formulae of De Marre, 20 inches, and by English formulae under 14*5 inches. 
2 See “Engineer/* February 1st, 1889, and “ Brassey’s Annual,” 1888-89. 
9 See “ Engineer,” July 12th, 1889, and “ Brassey’s Annual,” 1890. 
