Nickel steel has become famous the world over for its capacity to form an impenetrable ship armor.
It is an alloy of steel with about 3.2 per cent. of nickel. Its color and appearance are those of ordinary steel, but its qualities are remarkable. Its tensile strength is raised by the addition of the nickel to about 200,000 pounds per square inch, which is nearly as great as that of the best hardened steel, without any of its brittleness. On the contrary, it has extraordinary toughness, and resists cannon shot to a degree far beyond any armor plating before known.
The commander of the United States Arsenal in Springfield, Mass., informs me that he has tried to make rifle barrels of it, but he finds it almost impossible to turn it or bore it.
It seemed likely that qualities like this might be of use in certain surgical instruments. Having