Mr. Clarke was married to Mary P. Olmsted, September 9, 1874. They have had three children, all of whom are (1905) living. His mother died when he was an infant. In childhood and in youth his time was divided between city and country, his health was fair, and he had no serious difficulties in obtaining an education. His first strong impulse to make a career for himself he traces to the collection of minerals in his boyhood and the reading about chemical experiments in "The Boy's Own Book"; and he regards "private study " as the most important of the various influences which have helped him to succeed. His own preference determined the choice of his profession. He is fond of good literature, both prose and poetry. Aside from reading, he finds his principal relaxation in attending the theater. In politics he is independent. His religious sympathies are with the Unitarian denomination. While he has accomplished much, he says that his "ideals have always been beyond his attainment." In scientific research his specialties have been the study of atomic weights, and investigations upon the chemical constitution of the silicates.
