At the beginning of the century the department of physics of Princeton University consisted of only four men - C F Brackett, W F Magie, E H Loomis, and H McClenahan - but the University must already have started to plan for a considerable expansion of the department. In 1903 those four were joined by P E Robinson and E P Adams, the latter having just completed 4 years of graduate work at Harvard, Berlin, Göttingen, and Trinity College, Cambridge, after taking his bachelor's degree at Beloit College in 1899.
In 1906 two further additions to the faculty in physics were made. These were 0 W Richardson from England and Augustus Trowbridge from Wisconsin, and with them the department took on a new activity in research in which Adams was an active participant. At this time he was very much interested in experimental research, and he directed the work of a number of graduate students. His interests were wide enough to encompass work in radioactivity, contact differences of potential, electromagnetic. wave propagation, electrostriction, dielectric constant, and the Hall and Corbino effects.
In 1905 Princeton had also brought to its mathematics department the already famous James H Jeans, who introduced new lecture courses in theoretical physics. When Jeans returned to England in 1909 this type of instruction had to be continued, and Adams was the individual who proved willing and able to step into the breach. In consequence, his research activities shifted gradually from experiment to theory. It was during this period, in 1913-14, that I first knew him, when I listened with great pleasure and profit to his senior course in electricity, using Jeans' Electricity and Magnetism as a textbook. Those lectures formed the strongest of my recollections of undergraduate days when I returned to graduate work, 5 years later.
World War I did not provide many outlets for physicists, but there was one very active field of work in sound-ranging. In 1917 Adams went on leave from Princeton University to join the Royal Engineers of the British Army for active service in France with a sound-ranging company, where he remained until his demobilization in March 1919. In recognition of his services he was made an Officer of the Order of the British Empire.
At the time that he returned from the war, Adams was considered one of the leaders in theoretical physics. He was, therefore, commissioned by the National Research Council to write a report on the existing state of the quantum theory, which had had a considerable development using classical ideas with superimposed quantum conditions, as in Bohr's atomic theory. Adams' report appeared in 1920, with a second edition in 1923, and was an authoritative textbook for a considerable number of years. He also at this time (1922) edited The Smithsonian Mathematical Formulae and Tables of Elliptic Functions. The most striking theoretical development of the period, the theory of relativity, also attracted Adams, and he was the translator for the lectures that Einstein gave in Princeton in 1921, which appeared as The Meaning of Relativity.
After these excursions into the new theories, Adams returned to his older loves and worked assiduously in the fields' of classical electricity and mechanics. His courses in these subjects, as well as in statistical mechanics, were models of clarity, simplicity, and completeness. They form for me, and I know for many other Princeton graduate students, the most vivid memories of our student days.
Adams succeeded K T Compton as chairman of the physics department when Compton was called to the presidency of Massachusetts Institute of Technology, and he served in that capacity from 1931 to 1935, when he was succeeded by H D Smyth.
In the 1920's Adams was an enthusiastic horseman; because of his great height, about 6 feet 6 inches, and the small size of the horse he rode, he became known to the students as the "professor who goes out walking with a horse under him." Unfortunately this pastime proved disastrous; he was thrown from his horse and severely injured. His recovery from the accident and from the subsequent complications was slow and left his health permanently impaired. In spite of this he continued to work very actively, and indeed even after his retirement in 1943 his chief occupation was mathematics and its application to physical problems. In a letter written in October 1956, he remarked about the teaching of physics: "I still think there must be a solid foundation of Newtonian and Maxwellian physics, but how to make the transition to quantum and relativistic physics is what puzzles me. It seems as if it were about time for some new revolutionary principle to be evolved to do away with the discovery of new elementary particles."
Professor Adams was a rather difficult person to know, but once one had broken through into his friendship one found him a genial host and a man of subtle humour. He was a great lover of classical music and had even taught himself to play the piano with sufficient skill to get great enjoyment from it. He was a gentleman in the truest sense and of a kind which is becoming more and more rare. His personality will not be easily forgotten by the many Princeton graduate students who came under his influence, nor by his friends and colleagues.
A G Shenstone.
Princeton, New Jersey