Great progress in the scientific analysis of light will be made possible through a delicate new machine for defraction grading just completed by Prof. A. A. Michelson. With this new apparatus, scientists will be enabled to take an analysis of light on a ruled paper showing from 10,000 to 20,000 lines to the inch. Heretofore it has been possible to get only about 1,000 lines to the inch. That Professor Michelson's work is to be of great value to astronomers in the study of the planets is acknowledged by scientists who have been following his experiments.