For a year he taught mathematics at a high school in Beloit, Wisconsin. It was a year in which he was able to put his many talents other than mathematics to good use for he :-
... coached the track team, led the school orchestra, and trained the debating club.Mason then went to Germany in the autumn of 1900 where studied for his doctorate at the University of Göttingen, working under Hilbert's supervision. The first problem which Hilbert suggested to him for a thesis topic was rapidly solved and he wrote up an elegant solution in two pages. Hilbert was impressed, but said this was not sufficient to submit for his doctorate. He then gave Mason a second problem which led to a substantial and impressive thesis. His received his doctorate in 1903 for his dissertation entitled Randwertaufgaben bei gewöhnlichen Differentialgleichungen which was awarded the highest distinction. Mason then returned to the United States, accepting a post of instructor in mathematics at the Massachusetts Institute of Technology.
After spending the academic year 1903-4 at MIT, Mason spent the next four years as assistant professor of mathematics at Yale. He married Mary Louise Freeman in 1904; they had three children. In 1908 he was appointed as an associate professor of mathematics at the University of Wisconsin but after one year a vacancy arose in the physics department for a full professor. Mason was appointed and transferred to the physics department. Weaver, who studied at Wisconsin, said that Mason :-
... had a great and lasting influence on a large number of graduate students. The mediocre ones found him pretty tough, but the really good ones almost worshiped him.Mason remained at Wisconsin until 1925 but during World War I, between 1917 and 1919, he took leave of absence and worked as a member of the submarine committee of the National Research Council. During this period of war work he invented a submarine detection device known as the "M-V tube". The idea for this type of detector was due to the French Navy, and Mason learned of the French device at a meeting at the National Research Council in July 1917. Mason worked with colleagues to produce a prototype which was first tested on a raft in Lake Mendota, then tested on a ship off the east coast of the United States. Hunter writes in :-
These tubes consisted of sets of sound receivers, which were mounted on the outside of a ship below the water line, and transmitters that focussed the sound inside the ship. The device allowed the crew to determine the location of a submarine or other ship producing the noise.Weaver writes that Mason's :-
... contributions were critical in all aspects of these problems, in acoustical theory, and in mechanical and naval engineering. the short time required to bring this detector into service is almost complete evidence of the energy and ability which Mason concentrated upon this problem.Mason left Wisconsin in 1925 to become president of the University of Chicago. Up until that time the presidency had been filled by one of the founding faculty members but on the death of Ernest Burton in 1925 it was realised that the university would have to make an outside appointment. Although Mason had little experience of university administration, it was his experience in managing the large research team developing the submarine detectors which convinced the Board that he was the right man for the job. It appears that his abilities on the golf course also played a part! The chairman of the Board, Harold Swift, later wrote:-
... here was a president who was a well-known scientist, who might do things differently! The leaders of the city became excited, and the University became very excited. He handled himself well. He met the public well. The idea that a university president might beat almost any member of the Commercial Club in a golf game was something new.One might have expected that Mason would have stayed in his post as president of the University of Chicago for a long spell; certainly many around the university expected that he would. However he was only there for three years before, in June 1928, he resigned to become the natural sciences director of the Rockefeller Foundation in New York. Whether the move was related to the death of his wife in 1928 it is hard to say, but he certainly left Chicago after her death.
The father and son philanthropists both named John D Rockefeller had founded the Rockefeller Foundation in 1913. Mason was the director of Natural Sciences Division of the Rockefeller Foundation for one year and then became president of the foundation in 1929 after George E Vincent retired. After becoming president, Mason approached Weaver to take up the post of director of the Natural Sciences Division. Mason held the position of president until 1936 when he moved to California to join the team directing the construction of the Palomar Observatory. George Ellery Hale, the original designer of the 200-inch telescope, died shortly after Mason joined the team and he took over as chairman. There were many problems to solve with the 200-inch telescope, in particular the mirror deformed under gravity as it was moved. Mason used his engineering skills to solve these problems with the telescope which was completed in 1948.
We noted above that Mason's wife Mary died in 1928. He married for a second time and then, in 1938, he married Helen Schermerhorn Young but she died in 1944. One year later Mason married Daphne Crane Drake who became his fourth wife.
Mason's mathematical research interests lay in differential equations, the calculus of variations and electromagnetic theory. He developed the relation between the algebra of matrices and integral equations as well as studying boundary value problems. Other topics in the large range of applied mathematics topics which he studied were existence theorems and asymptotic expansions. He published seven papers in the Transactions of the American Mathematical Society between 1904 and 1910: Green's theorem and Green's functions for certain systems of differential equations (1904), The doubly periodic solutions of Poisson's equation in two independent variables (1905), A problem of the calculus of variations in which the integrand is discontinuous (1906), On the boundary value problems of linear ordinary differential equations of second order (1906), The expansion of a function in terms of normal functions (1907); The properties of curves in space which minimize a definite integral (1908) and Fields of extremals in space (1910). He also published Curves of minimum moment of inertia with respect to a point in the Annals of Mathematics in 1906, and he invented acoustical compensators.
He wrote a number of books, in particular The New Haven Mathematical Colloquium (1910) and he co-authored The Electromagnetic Field with Warren Weaver which was first published in 1929 and reprinted in 1952.
A strong supporter of the American Mathematical Society, he was an associate editor of the Transactions of the American Mathematical Society between 1911 and 1917. He was elected a member of the National Academy of Sciences (United States), the German Mathematical Society, and the Mathematical Circle of Palermo.
After he retired in 1949, Mason moved to Claremont, California, and taught at Claremont College for a year. Let us end our biography with a quotation from Mason which he wrote in the preface to Edward Price Bell's Europe's Economic Sunrise (1927):-
Unless man can set his social house in order ... all his knowledge of natural law, so dearly bought, will but serve to bring him the quicker to disaster.
Article by: J J O'Connor and E F Robertson