THE DEVELOPMENT OP AKMOUR. 
481 
with a velocity of 1,960 f.s. Also it was decided to subject thick 
plates to regular firing tests to govern supply. 
The following experiments with plates and projectiles took place 
during 1896 in the United States. 
In the beginning of the year an 8-inch curved plate of Carnegie 
Harveyed nickel steel armour was rejected for fracture when attacked 
by 6-in. projectiles, with perforations equal to 10*8 in. and 12*3 in. of 
iron, so that the plates resistance established a "figure of merit ” of 
1*4 and 1*5. Each shots weight was 100 lbs. and their velocities were 
1,689 and 1,846 f.s. The plate resisted perforation but not fracture 
by the first blow. A curved Carnegie Harveyed plate, 7 in. thick, on 
February 12th, defeated and broke up Carpenter and Wheeler 
Sterling 6-in. projectiles, with 1,620 and 1,821*5 f.s. striking velocity 
and 1,820 and 2,287 foot tons energy. One fine surface crack was 
made. The figures of merit thus established are 1*4 and 1*7 and the 
energies per ton was 151*8 and 190*8 foot tons, which are very low, 
probably the projectiles were very good but the test as a pass is mild. 
Figs. 14 and 15 show a 15-in. Harveyed nickel Carnegie plate under 
Fig • 
