History of the McCormick Observatory

Samuel Alfred Mitchell




Samuel Alfred Mitchell

Samuel Alfred Mitchell was born in Kingston, Ontario on April 29, 1874. This son of John Cook and Sarah Chown Mitchell was the sixth of ten children to grow up in the Mitchell home. At age twelve, undoubtedly to get away from his many siblings, he went off to Kingston Collegiate Institute. From there, he went on to Queen's University where he received his Masters of Arts in mathematics in 1894. While at Queen's University, he was introduced to Reverend James Williamson, known as Uncle Billy, who at eighty years of age found it pleasant to delegate the care of the astronomical instruments to Mitchell which is how he acquired knowledge of the techniques of an astronomical observatory.

Upon encouragement from his math professor, Nathan F. Dupuis, he left in 1895 for The Johns Hopkins University to study math under Simon Newcomb, only to find Newcomb retired. Thomas Craig was the new head of mathematics and Mitchell also began study under Charles Lane Poor, the head of astronomy. Poor was an excellent teacher and Mitchell was inclined to follow astronomy from that point on. Mitchell was awarded an astronomy assistantship for his second year at JHU and continued until he received his PhD in 1898 with his thesis published in the Astrophysical Journal, which included a discussion of the amount of astigmatism of concave grating. While at Hopkins, his astronomy duties consisted of caring for the transit instrument and the clocks in the little observatory behind the physics laboratory, and the 9.5-inch refractor in the dome of the laboratory roof.

Following receipt of his doctoral degree, Mitchell set out for the brand new Yerkes Observatory in Wisconsin where he began work as a research student in 1898. Though he enjoyed his work at Yerkes, he was enticed to move away and became an instructor in astronomy at Columbia University in June 1899. The following December he married the daughter of Professor E. T. Dumble who was then the State Geologist of Texas. Over the fourteen years he was at Columbia, Mitchell taught undergraduate courses in descriptive astronomy both at Columbia and later for girls from Barnard College, a year long course in geodesy for third year students, which continued into a first semester fourth year course, and a six week summer camp for civil engineers.

In 1900 he took what would be for him the first of ten eclipse expeditions. The May 28, 1900 eclipse took him to Griffin, Georgia with the United States Naval Observatory. Mitchell became a world-renowned authority on solar eclipses through his numerous expeditions, including trips to: Sumatra in the Dutch West Indies (1901), Spain (1905), Oregon (1918), San Diego (1923), Connecticut (1925), Norway (1927), "Tin-Can Island" in the South Pacific Ocean (1930) and Magog in Canada (1932), with one final expedition taking place in 1937. These ten expeditions allowed him to write Eclipses of the Sun, summarizing his work on solar flash spectra, first published in 1923 and produced through five editions.

Mitchell at the 26-inch
refractor, 1935
Mitchell went back to Yerkes for the summers of 1909, 1910 and 1911 and then returned for a fifteen month sabbatical in 1912 and 1913. Frank Schlesinger first demonstrated the technique of determing stellar parallaxes photographically at Yerkes in 1905, and Mitchell (along with Frederick Slocum) carried out research applying the technique, publishing their results in 1913. At that point, he was offered the directorship at the Leander J. McCormick Observatory at the University of Virginia. Mitchell spent much of his time and energy as director coming up with funds for running the observatory and paying staff and graduate students. Mitchell started the use of photographic plates with the visual 26-inch refractor shortly after his arrival at the University of Virginia. He became well known for his work on stellar parallaxes and photometry. Dr. Mitchell was liked by faculty and students alike, known for helping to bring prestige to the University. "Corks and Curls", the yearbook at the University of Virginia, honored Dr. Mitchell by dedicating its 1938 volume to him, saying "Dr. Mitchell typifies the intellectual ideal of the University."
Award Ceremony
Mitchell was elected Director Emeritus in 1945 with a wealth of academic and scientific honors attributed to him.  The following year, the McCormick family recognized him for his service to the Observatory. He was presented a silver plate by two of Leander J. McCormick's grandsons. (Mitchell is shown at the ceremony: l-r Robert H. McCormick, Mrs. Warren Buckley Jr., Harold L. Alden, Mitchell and Leander McCormick-Goodhart). He was a member of the following societies: National Academy of Sciences (elected in 1933), American Association for the Advancement of Science (Vice-President in 1921), American Astronomical Society (V-P 1925-27), American Philosophical Society, and the American Academy of Arts and Sciences. Dr. Samuel Mitchell died in Bloomington, Indiana on February 22, 1960.