Henry Bumstead became an instructor at the Sheffield Scientific School of
Yale University in 1893, working with
Charles S. Hastings. At the same time he became a student of
Willard Gibbs, learning
vector analysis and continuing the study of thermodynamics and the electromagnetic theory of light. He was awarded the Ph.D. in 1897, composing a thesis
A Comparison of Electrodynamic Theories. Bumstead became an
assistant professor in 1900. In 1905 Bumstead spent a sabbatical year at the
Cavendish Laboratory. Performing an experiment suggested by
J. J. Thomson, Bumstead examined the effect of
X-rays (then called
Röntgen rays) when applied to
lead and
zinc, finding that "twice as much heat is produced in lead compared to zinc". When
Arthur Williams Wright retired in 1906, Bumstead became
professor of physics at Yale College and Director of the Sloan Physics Laboratory. In
World War I Bumstead was selected to serve as the head of the Scientific Section in London under Admiral
William Sims, Commander of the American Forces countering the U-boat campaign in the North Atlantic: :The American headquarters in London comprised many separate departments, each one of which was responsible to me as the Force Commander, through the Chief of Staff, they included such indispensable branches as...the Scientific Section, Professor H. A. Bumstead, Ph.D. In 1920 Bumstead was elected Chairman of the
National Research Council. He was a member of the
Connecticut Academy of Arts and Sciences, the United States
National Academy of Sciences, the
American Academy of Arts and Sciences, and the
American Philosophical Society. ==Personal life==