American astronomer. Boston English High School; L.L.D., DePauw University, 1891. After attending high school, he became a personal astronomical assistant, 1863-1869, to Benjamin A. Gould; from 1870 to 1885 he worked as a life insurance actuary. Also during this time, between 1880 and 1885, he continued his astronomical studies at Harvard College Observatory. Between 1886 and 1904, Chandler conducted private astronomical investigations in Cambridge, Massachusetts. His research advanced the knowledge of variable stars and comets. He classified approximately 500 variables in his catalogues. From 1896 to 1912, he was editor of the 'Astronomical Journal'.