Description

Black and white photograph of Arthur C. Ruge operating a machine that reproduces the motions of earthquakes in order to design structures that will withstand earthquakes.

Original Caption: "The science of designing structures to withstand earthquakes is advancing as engineers learn more about the nature of terrestrial convulsions. Here the earthquake machine in the seismology laboratory of the Massachusetts Institute of Technology is reproducing the motions of an actual earthquake to test a strong motion earthquake recorder developed by the United States Coast and Geodetic Survey. Thus the behavior of the recording instrument during an earthquake may be carefully studied under laboratory conditions. Professor Arthur C. Ruge, in charge of the engineering seismology laboratory, is operating the machine. The white silhouette is a shadowgraph of an actual earthquake record and by means of an optical system and a narrow beam of light which follows the irregular form of the shadowgraph the machine faithfully reproduces the earthquake in miniature scale."