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National Museum of Nuclear Science & History

Harrison S. Brown

Geochemist, Assistant Director of Chemistry, ProfessorOak Ridge, TN

California Institute of TechnologyChicago, IL
Manhattan Project VeteranProject Worker/StaffScientist
Harrison Scott Brown

Harrison Brown (1917-1986) was an American geochemist. He worked at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) and Oak Ridge sites during the Manhattan Project.

In 1942, Brown was invited to join the staff of the Met Lab by Glenn Seaborg because they wanted his help in using the chemistry of plutonium to separate it from uranium generated in fuel rods of the atomic reactors. Brown and his co-worker, Orville Hill, discovered that plutonium could be separated from uranium using gaseous evaporation of fluorides prepared from dry fluoridation.

Later, Brown was transferred to Oak Ridge’s Clinton Engineering Works (X-10) site. At Oak Ridge, Brown worked to develop procedures for isolating gram quantities of plutonium from its trace occurrences in metallic uranium fuel rods. His group’s work was the backup plan for the liquid chemical separation methods being developed at the same time. While at Oak Ridge, Brown also became the assistant director of chemistry. He signed a petition at Oak Ridge similar to the Szilard Petition that called for the atomic bomb to be demonstrated publicly before being used against Japan.

After the atomic bombs were dropped on Hiroshima and Nagasaki, Brown became a strong advocate for regulating nuclear weapons. In 1946, Brown published Must Destruction Be Our Destiny?, a book that warned readers about the extreme dangers posed by atomic weapons. To maximize his political impact, he held 102 lectures about his book and work within three months of publication.

He also used his book sale royalties to support the work of an organization for atomic scientists that eventually became a part of the Federation of American Scientists. The Federation’s goal was to promote proper regulation of nuclear power and weapons. 


Early Years

Harrison Scott Brown was born on September 26, 1917 in Sheridan, Wyoming. After his father died, he moved with his mother to San Francisco in 1927. Brown learned how to play the piano from his mother, who worked as a dental assistant, music teacher, and piano player for silent movies.

Brown attended Galileo High School, where he apparently built his own chemistry laboratory. After graduating from high school, he attended the University of California at Berkeley. In 1938, Brown graduated with a B.S. degree in chemistry.

Following in his mentor, Professor Robert D. Fowler, across the country, he decided to pursue graduate studies at Johns Hopkins University. Before moving to Baltimore, he married Adele Scrimger and had a son, Eric. As a graduate student, Brown developed mass spectrometric techniques to study cobalt’s isotopic composition. 

After the discovery of nuclear fission in 1939, Brown and Fowler began to focus on the diffusion properties of uranium hexafluoride. By 1940, the two had the largest gaseous uranium fluoride generating capacity in the United States. They became major suppliers of uranium tetrafluoride and hexafluoride to the atomic fission projects at the Manhattan Project’s Columbia University and University of Chicago sites.

Brown received his Ph.D. in chemistry from Johns Hopkins University in 1941.

Later Years

In 1946, Brown returned to the University of Chicago to work as an assistant professor in the Department of Chemistry and the Institute for Nuclear Studies. Working with former Manhattan Project colleagues, Brown helped develop the new scientific field of nuclear geochemistry. The research and studies in this field greatly impacted understandings in Earth and planetary sciences.

Nuclear mass abundance data from Brown’s research helped Maria G. Mayer develop the concept of the nuclear shell model. At this point in time, Brown was focused on three fields:

  1. Estimating relative elemental abundances in the solar system by determining the composition of meteorites.
  2. Determining the temporal progress of magmatic evolution of the Earth’s crust by measuring uranium/lead ages of common igneous rock.
  3. Determining the age of the Earth by measuring the isotopic composition of lead in iron meteorites.

Beginning in 1949, Brown began traveling to Jamaica, where he first observed the problems of rapid population growth and technology struggles in developing countries. Brown’s travels led him to write, The Challenge of Man’s Future, a book about the structure and fate of human society.

In 1951, Brown moved from the University of Chicago to teach at the California Institute of Technology as a geochemistry professor. In 1955, Brown was elected to the National Academy of Sciences at the rather early age of thirty-seven years old. By now, Brown had also remarried to Rudd Owen, his colleague and fellow humanitarian advocate.


Foreign Affairs and Global Impact

Working with Bertrand Russell and Albert Einstein in the 1950s, he helped organize and direct the Pugwash Conferences, which were aimed at discussing the dangers of nuclear weapons and the need for regulation. 

In 1957, Brown was asked to organize a new committee on oceanography for the National Academy of Sciences by its president, Detlev Bronk. Known as NASCO, the committee published its first report, “Oceanography 1960,” which described the future of oceanographic research and proposed a ten-year plan for large-scale expansion of the field.

From 1962-1974, he served as the foreign secretary of the National Academy of Sciences. During his tenure, he helped transform the office into a development agency for fostering science and technology in developing nations from Africa, Asia, and Latin America. He also worked to facilitate East-West exchanges and collaborations.

Brown was served as the president of the International Council of Scientific Unions from 1974-1976. At the same time, Brown chaired a large-scale study of world food and nutrition and was asked to recommend what the United States could do to help.

Finishing in 1977, the study concluded that adequate food and nutrition levels could be sustainably achieved for ten billion people if research was done and used in developing countries to increase yields per hectare. It also stressed the focus on nitrogen fixation by leguminous and cereal plants. In 1977, he also became director of the Resource System Institute at the East-West Center in Hawaii. 

After retiring from the East-West Center in 1983, he moved to Albuquerque with his third wife, Theresa Tellez. Despite his age and progressive paralysis in his spine, Brown became the editor-in-chief of the Bulletin of the Atomic Scientists. He continued to work at the Bulletin until he died on December 8, 1986 at the age of sixty-nine.


For more information about Harrison Scott Brown’s life achievements, please see this resource:


Harrison S. Brown's Timeline
1917 Sep 26th Born in Sheridan, Wyoming.
1927 After his father died, moved to San Francisco with his mother.
1938 Graduated from the University of California, Berkeley with a Chemistry degree.
1938 Left California for Johns Hopkins University with Professor Robert Fowler.
1940 Developed the largest gaseous uranium fluoride generating capacity in the U.S. at Johns Hopkins.
1940 Became major suppliers of uranium tetrafluoride and hexafluoride for the Manhattan Project.
1941 Received his Ph.D. in chemistry from Johns Hopkins University.
1942 Joined the Met Lab staff.
19431946 Transferred to Oak Ridge.
1946 Published his book, Must Destruction Be Our Destiny?.
1946 Returned to the University of Chicago to be an assistant professor in the Department of Chemistry and the Institute of Nuclear Studies.
1949 Traveled to Jamaica for the first time and observed problems of population and industrial growth.
1951 Became a geochemistry professor at the California Institute of Technology.
1954 Published his most famous book, The Challenge of Man's Future.
1955 Elected to the National Academy of Sciences at thirty-seven years old.
1957 Organized the National Academy of Sciences' Committee on Oceanography (NASCO).
19621974 Served as foreign secretary of the National Academy of Sciences.
19741976 Served as president of the International Council of Scientific Unions (ICSU).
19741977 Chaired a large-scale study of world food and nutrition.
1977 Became the director of the Resource System Institute at the East-West Center in Hawaii.
1983 Retired from the East-West Center and moved to Albuquerque, New Mexico.
19831986 Served as the editor-in-chief of the Bulletin of the Atomic Scientists.
1986 Dec 8th Died in Albuquerque, New Mexico at the age of sixty-nine.

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