510 
DUTCH ARMOUR-PIERCING EXPERIMENTS. 
The following conclusions was arrived at as regards tlie calculated 
penetration, namely, that a projectile discharged from the cast-iron 
gun, with a velocity of 373 metres, or 1224 ft., would pierce the 6-in. 
plate at about 1800 metres (1969 yds.) range; and a heavier projectile 
from the steel gun, fired with a velocity of 472 metres (1549 ft.), would 
pierce an 8-in. target and backing at about 1800 metres (1969 yds.) 
As regards the projectiles, none of the Ekman (Finspong) chilled- 
iron projectiles were broken up on impact, except that the point of one 
was broken off to the length of 142 ram (5*6 in.). The remainder of 
the projectiles underwent no alteration in form beyond setting up to 
the extent of 6 mm (0*236 in.) in length. Of the eight Griison chilled- 
iron projectiles, seven broke up into a great many fragments, while 
one, which remained entire, showed a crack along the tapering portion 
about the shoulder of it, but was set up in length only 2 mm (0*079 in.) 
The Krupp steel projectiles all remained entire. They underwent a 
slight deformation, setting up longitudinally to the extent of from 
23 ram to 28 mm (0*866 in. to l*102-in.), while above the shoulder the 
diameter increased to the extent of from l*5 mm to 2*5 mm (0*059 in. to 
0*098in.); also all the points for a length of from 16*5 mm to 21*5 mm 
(0*64 in. to 0*84 in.) were deformed. The Swedish projectiles of 
Ekman were considered very superior to those of Griison. The com¬ 
mittee found it difficult from these experiments to say whether the steel 
showed a superiority sufficiently decided to justify their high price as 
compared with the chilled projectiles. 
With regard to this report, it may be remarked that the behavour 
of the Finspong projectiles to a certain extent agreed with the results 
obtained in our own English competitive trials, that is to say, the 
Griison* s projectile was harder than the Finspong. At Shoeburyness, 
in 1878, one Griison shot broke up badly, but another did remarkably 
well (vide "The Engineer/* April 12th, 1878.) The Finspong metal 
is, of course, remarkably excellent; but no observation is made in this 
report as to its price. The chilling of the body, still retained by 
Griison, has been abandoned long ago by most manufacturers. In the 
abstract, the unchilled metal having the advantage in tenacity and the 
chilled metal in hardness, it would seem sound to retain a little un¬ 
chilled in the centre, to hold the shot together, while the entire ring of 
chilled metal might prevent setting up. Practically it has been found 
better to leave the entire body mottled. The crushing strain must 
fall much less heavily there than in front, and tenacity throughout the 
body seems the desideratum. 
