From the founding of this department until 1942, there were five professors of physics: Crawford, Rosa, Cady, Van Dyke, and Eaton.
Morris B. Crawford (Wesleyan ’74) has left us invaluable lecture notes on the early history of this department and of its later development up until the time of his retirement in 1921. Like the elder Van Vleck, Crawford spent most of his productive years here at a time when the administrative and other demands made by the college gave scant time for individual work. Perhaps his most interesting contribution was in constructing here at Wesleyan an X-ray machine similar to the one he had observed while studying in Germany, and it was used for the first medical X-rays ever taken in Middletown. The occasion was a student’s broken leg. A local doctor had set it but was not sure that he had done it very well. Fortunately, Crawford already had the machine and could take the pictures. Unfortunately, the bone setting had not been well done, and so the doctor broke the leg and tried again. The second set was not too good either, but a third trial was not attempted.
Edward B. Rosa, an 1886 graduate of Wesleyan and for twelve years a member of its Faculty, collaborated with Atwater in the construction of the respiration calorimeter. His individual research was chiefly in electricity and magnetism. Ingenious and scholarly, he worked with wholly inadequate laboratory space and instruments. In 1903 he resigned to become Chief Physicist of the National Bureau of Standards. His published papers fill four stout volumes in the Wesleyan Collection in the Olin Library.
Rosa was followed at Wesleyan by Walter G. Cady, who became famous in the piezoelectric field. Cady served on the Faculty for forty- four years, from 1902 to 1946. Early in the first World War, he was using piezoelectricity and underwater sound to make devices that would locate enemy submarines. This work led to more important discoveries out of which he evolved the crystal resonator and oscillator. Before the first World War, Cady’s work had been chiefly in the investigation of electric arc and glow discharges in gases, and before that, during his earliest years here, he had designed for the Carnegie Institute a magnetic storm detector that would sound an alarm when such a storm was just beginning.
For his work in piezoelectricity, Cady received the Dudell Medal from the Physics Society of Great Britain in 1936. He was awarded the Morris Liebermann Memorial Prize by the Institute of Radio Engineers in 1928 and became the president of this organization in 1932. He was an Editor of the Physical Review (1924-26), was a member of the National Research Committee (1935-38), and became a Fellow of the American Academy of Arts and Sciences. “One night when I was getting ready for bed,” said Cady, “it suddenly flashed on me that the resonance (in crystals) was so sharp that such a rod could serve as a standard of frequency. It could be used to standardize or calibrate a frequency meter. It was in this way the piezo-resonator came to be invented. The next thing was to see whether a crystal could be made to control the frequency of an oscillating current instead of merely checking it.” This was done in 1919-21. The quartz crystal has a vibration frequency which is constant except for a possible error of one part in a billion. In 1924 Cady was made a Lieutenant Commander, United States Navy. In 1929 he wrote for the International Critical Tables the section on electro-elastic and pyro-electric phenomena, a formidable job, which he said took ten years. Cady’s bibliography is very impressive, containing as it does many articles that reported primary discoveries and inventions, good examples of what we have called scientific research in the strictest sense.
As soon as Karl S. Van Dyke (Wesleyan ’16) joined the department, in 1921, he began to work along with Cady on piezoelectricity and the essential phenomena involved. He soon contributed a valuable addition to the theory. He continued research in this field until his retirement in 1960. At the beginning of the second World War, because of Cady’s work on resonators, what was specially needed then by the Defense Department was a very large number of quartz crystals properly cut. In general, this was the job Van Dyke was given at the beginning of the war, and it was helpful that there was in the country a number of young men who had already learned about this in Scott Hall. The Physics Department has been actively engaged in supervising research of many graduate assistants, some of whom have become well known as physicists.
Vernet E. Eaton attained national eminence as a teacher and lecturer. Somewhat later (1954) he was to be awarded the Oersted Medal for Teaching of Physics by the American Association of Physics Teachers, and was president of this association in 1957. Upon his retirement in 1964 he was succeeded in the chairmanship of the department by Professor John McIntosh, who had come to Wesleyan a year earlier after service on the Yale faculty.