## Section 2.7 Profile: Howard Hawks Mitchell (1885-1943)

Howard Hawks Mitchell was one of the most accomplished members of our section. He first came to the area to attend graduate school, and after leaving for a year he joined the faculty at the University of Pennsylvania. He lived in Merion and remained at Penn for the rest of his life. During that time he was one of the three founders of the Philadelphia Section of the MAA

^{ 1 }.H. H. Mitchell was born in Marietta, OH, on January 14, 1885, the son of Oscar Howard and Mary Hoadley (Hawks). His father was a well-known mathematics professor at Marietta College. Oscar Mitchell had been one of the first fellows at Johns Hopkins 1879-1882; he received his Ph.D. in 1882 for a dissertation in number theory. Oscar’s son’s middle name was his wife’s maiden name, a custom at that time for the naming of both boys and girls. The younger Mitchell attended local schools in Marietta and received a Ph.B. degree from Marietta College in 1906. (No longer in use, the notation Ph.B. is the abbreviation of the Latin expression for the Bachelor of Philosophy degree.) In 1935 Marietta College conferred upon him the honorary degree of Doctor of Science.

Mitchell enrolled in the graduate program at Princeton in the fall of 1906, holding a university fellowship from 1908 to 1910. [On a related note, Carl E. Stromquist, the brother of the grandfather of former section president Walter Stromquist, was a faculty member in Princeton’s mathematics department 1903- 1909. More famous mathematicians included Gilbert Bliss, G. D. Birkhoff, J. H. M. Wedderburn, and Luther Eisenhart.] Mitchell was the first doctoral student of Oswald Veblen, completing his dissertation on linear groups in 1910, the very year that fellow EPADEL founder Albert Bennett entered the graduate program. Bennett too would receive his Ph.D. degree under Veblen, five years later. Although the periods of their matriculation at Princeton had nonempty intersection, the lives of Mitchell and Bennett overlapped long enough to establish the Philadelphia Section of the MAA

^{ 2 }in 1926.Upon graduation from Princeton, Mitchell was appointed an instructor in mathematics at the famous Sheffield Scientific School at Yale University. However, he remained at Yale only one year before accepting the same position at the University of Pennsylvania, where he taught for the rest of his life. Altogether he supervised five Ph.D. dissertations with topics ranging from finite group theory to Galois fields and cyclotomic field extensions. His most well known student was probably Leonard Carlitz (Ph.D. 1930), who spent a very productive career at Duke University.

In addition to Veblen, Mitchell had another link to an important figure in American mathematics. In 1911, when he began teaching at Penn, another new faculty member was R. L. Moore. Today R. L. Moore is widely known for his method of teaching and for his contributions to topology. Up to that point, however, Moore had not published very much. Yet Penn offered both instructors a stable and supportive environment, and they prospered in Philadelphia. Moore’s manner of teaching exerted a dominant influence on his students. Mitchell’s case shows that Moore played a similar role with some of his colleagues too. Moore’s second Ph.D. student, G. H. Hallett, Jr., took courses from both Moore and Mitchell. In discussing the Moore Method fifty years later, Hallett recalled:

One other course I took at the same time was somewhat similar. It was taught by Professor Mitchell, whom I liked very much. He took a book, I think it was by Dr. Pierpont, in the area of functions of a real variable. I guess Professor Mitchell had found on inspection that not all of Professor Pierpont’s proofs held up, so the way he taught this course in that subject, he gave us this book, but asked us to go through all the proofs that were given and find out whether they were watertight proofs or not and if not, why not. This course had many elements of the other course.

Mitchell married Emma Vestine White on September 18, 1912, shortly before the start of classes for his second year at Penn. The couple resided in the Philadelphia area thereafter. Like his friend Albert Bennett, Mitchell applied his knowledge of mathematics in World War I, serving as a ballistician with Bennett under their dissertation supervisor, Oswald Veblen, at the Aberdeen Proving Ground near Washington, D.C., in 1918.

Mitchell held office in both the AMS

^{ 3 }and the AAAS. He was on the Board of Trustees (now the Council) of the AMS^{ 4 }from 1921 through 1923. In 1926 he was appointed chair of the first Committee on the Cole Prize, which was given for the most meritorious paper on linear algebra. He also was elected Vice President of the AMS^{ 5 }in 1932 and 1933, and Vice President of AAAS in 1932. In addition, he served a six-year stint as editor of the prestigious journal, the Transactions of the American Mathematical Society, from 1925 through 1930. In 1923 he was one of four authors of the book Algebraic Numbers, written with L. E. Dickson, H. S. Vandiver, and G. E. Wahlin for the National Research Council.Mitchell’s publication record was not prodigious; we have been able to locate only 11 items, including his dissertation and his printed solution to a Monthly problem. Between 1913 and 1918 he published seven important papers in three of the country’s leading journals: two in the American Journal of Mathematics, one in the Annals of Mathematics, and four in the Transactions of the American Mathematical Society. Two appeared after that, an article on ideals in quadratic fields from 1926, and his final paper, which appeared in 1935 and hearkened back to his initial investigations on group theory and projective geometry. Overall, he published papers in four of the five journals that were available in America at the time.

Howard H. Mitchell died of coronary thrombosis on March 13, 1943, at his home in Merion, PA, at the age of 58. He was survived only by his wife. Overall, he was known as an inspiring teacher of both graduate and undergraduate students, and an accomplished researcher in linear groups and algebraic numbers.

`www.maa.org`

`www.maa.org`

`www.ams.org`

`www.ams.org`

`www.ams.org`