From the November 28, 1931, issue

ACTION OF STEEL UNDER STRESS REVEALED IN WRITING ON SAND

How solid steel softens and flows like wax when compressed or stretched is being shown to the naked eye by Dr. A. Nadai at the Research Laboratories of the Westinghouse Electric and Manufacturing Company, at East Pittsburgh, Pa.

In his new apparatus, a beam of light is reflected from a highly polished surface of the metal specimen that is being compressed or twisted.