(eich PROCEEDINGS OF SECTION H. 
CONCLUSIONS ON THE RESULTS OF TESTING NICKEL STE&uL.. 
Elasticity, Strength, and Ductility.—It will be seen by 
referring to Tables X., XI., and XVI. that the elastic limit, 
tensile strength, also the ratio of the elastic limit to the 
tensile strength, and the ductility are much greater in 
nickel steel than in ordinary carbon steel. This is shown 
in the results recorded in the paper for all nickel steel. 
Comparing the results of testing Vicker’s axle-steel, which is. 
well-known for its excellent qualities, with Krupp’s nickel 
steel, it is clear that the latter is much superior to the for-- 
mer. The results of the impact tests recorded in Tables 
XVII. and XVIII., although not as complete as the other 
tests made by the author, show that nickel steel possesses. 
an enormous resistance to shocks and suddenly-applied 
loads. : 
The experiment in the oil bath at 505° F. proves that 
there is no practical diminution in the essential qualities 
of the material due to this temperature. 
Again the experiments on repeated stresses alternating” 
between tension and an equal compression clearly demon- 
strate the enormous endurance of nickel steel, even with a 
fibre stress of 54,085 lbs. per square inch, which was con- 
siderably above the elastic limit of the material in the mild 
quality, and about equal to it in the medium quality. The 
effect of repeated stresses in the rotating machine was 
clearly shown in the mild variety, but is very slight in the 
harder variety of nickel steel. 
The results of testing Krupp railway axles by a Commis- 
sion of Engineers in Germany show the superiority of nickel 
over the best crucible carbon steel. The axles were first 
cut in the middle by means of a sharp turning-tool to a 
certain depth, thus artificially damaging them, and then 
subjected to the drop test. The crucible steel axle was- 
fractured with the first blow of approximately 1 ton falling 
3°3 feet; the fracture being dense, finely granulated, and 
serrated. The nickel steel axle required thirteen blows 
from heights varying from 3-3 to 21:3 feet to produce 
fracture, the axle deflecting 7:3 inches, and gradually 
tearing away on the underside of the nick. A hollow nickel 
steel axle damaged and tested in a similar manner sustained 
fifty-four blows, of which thirty took place from a height. 
of 36 feet (that is, with a momentum drop of 80,000 foot-. 
pounds). 
Uses oF NICKEL STEEL. 
Armour Plates.—-It appears that the first application of 
nickel steel for armour plates is due to Messrs. Schneider 
