MICHELSON, Albert Abraham, physicist, born in Strelno, Poland. 19 December, 1852. He was graduated at San Francisco high-school in 1869, and at the United States naval academy in 1873, and held the rank of ensign until 1877, when he was pro-meted master. In September, 1881, he resigned from the navy to become professor of physics at the Case school of applied science in Cleveland. Ohio. Professor Michelson's reputation depends largely upon his series of investigations on the velocity of light. His researches at the United States naval academy during 1878-'80 resulted in his experimental determination of that velocity as 186,305 miles a second. His later investigations have been published as "The Relative Motion of the Earth and Luminiferous Ether" (1881) ; "A New Sensitive Thermometer" (1882): "Interference Phenomena in a New Form of Refractometer" (1882); "A Method for Determining the Rate of Tuning-Forks" (1883) ; "Velocity of Light in Carbon Disulphide and of Red and Blue Light in Same" (1885) ; "Influence of Motion of this Medium on the Velocity of Light" (1886) ; "On a Method for making the Wave Lengths of Sodium Light the Absolute and Practical Standard of Length" (1887). The degree of Ph. D. was conferred on him by Western Reserve university in 1885, and by Stevens institute of technology in 1886. He is a member of various scientific societies, was elected vice-president of the American association for the advancement of science in 1887, and will have charge of the section on physics at the Cleveland meeting in 1888.