Notes

Abstract

PROMINENCE has been given in the daily papers to an interview with Dr. J. O. Arnold, who has recently resigned from the chair of metallurgy at the University of Sheffield, relating to a new alloy tool-steel, the cutting powers of which are claimed to be far in advance of those of any rapid-cutting tools at present in the market. The efement conferring this property is stated to be molybdenum. It was reported in the interview that Dr. Arnold had taken out British and American patents, but that, owing to the veto of the War Office, the Admiralty, and the Ministry of Munitions, he was not allowed to exploit his discovery, and that he was forbidden to communicate its details except under censorship to anyone in Greajf Britain. Meanwhile, representatives of the United States Government were said to be conducting inquiries in Sheffield. On December 19 it was announced, however, that Dr. Arnold had received notice from the Government that the restrictions had been removed. Until more information is forthcoming as to the precise chemical composition of the steel tools in question it will be well to suspend judgment on the matter. That rapid-cutting tools can be made with molybdenum as the alloy basis has been known for many vears. Such tools, however, have hitherto been regarded as peculiarly sensitive to heat conditions, and therefore liable to injury by improper treatment. This has stood in the way of their exploitation in practice.