Log in


Log in

Frank Exner: From ‘Rad Lab’ to Radburn

 By Rick Hampson and Stephen Taylor

It’s 1936. Beneath the streets of upper Manhattan, in the bowels of the Columbia-Presbyterian Medical Center, a physicist is working on a technological marvel: a three-story, million-volt X-ray machine. When it’s finished, one of his colleagues will call it “a monster.’’

The X-ray machine was designed in the famed Radiation Laboratory at the University of California at Berkeley headed by Ernest Lawrence, who in a few years will win the Nobel Prize and become one of the fathers of the atomic bomb.

The physicist assembling the machine is Frank Exner, who worked with Lawrence. Now, he will use it to treat cancer and do groundbreaking research into the nature of viruses, and thus lead to vaccines against the diseases they cause, up to and including COVID-19.
And each night, after working on the leviathan, he goes home -- to Radburn.

The Exners – Frank, his wife Faith, and their two young daughters — were among Radburn’s founding families. In 1933 they became the first to live at 5 Bristol Place, one of the last houses built by Radburn’s developer before it declared bankruptcy a year later.

But in less than a decade the family will suffer a tragedy that will change everything, including Frank’s promising career on the fast track of academic scientific research.

Ernest Lawrence (in tie, seated second from right) and his staff, circa 1932Exner stands second from left. 

A young man of promise

A photograph taken in 1932 at Ernest Lawrence’s ‘‘Rad Lab,’’ as it came to be known, suggests the potential of Frank Exner.
In the background of the photo is Lawrence’s most famous invention, the cyclotron. It was the first in a series of nuclear particle accelerators that would be used in the discovery of plutonium, a constituent of the first atomic bomb.

Alongside Lawrence in the photo are his acolytes. One is Exner. Another is David Sloan, designer of the X-ray machine. A third is Wesley Coates; more, sadly, about him later.

Exner was 33 when the photo was taken. He’d grown up in Northfield, Minnesota, where his father taught chemistry at Carleton College. Frank graduated from Carleton in 1919 and went to Yale to study physics.

In 1922 he took a break from graduate school to teach physics at the Peking Union Medical College, which had been founded by Protestant missionary organizations and funded by the Rockefeller Foundation. The school would play a key role in the development of physics in modern China.

Peking Union Medical College staff. Exner standing at far right. 

In 1925 Exner returned home. Aboard ship he met Faith Wiggin, a Bostonian and a graduate of Mount Holyoke College and Simmons College, from which she received a master’s degree in social work. Her father was treasurer of the national Congregational Church’s foreign mission board. The family had lived in China for a number of years.

Frank and Faith shared many interests, including music. She played the cello, he, the violin. 

Faith Exner

Exner resumed research at Yale for his Ph. D. dissertation, and Faith attended the university’s nursing school. They were married June 22, 1928; their daughters Polly and Betty were born in 1929 and 1930, respectively.

But Frank’s dissertation research was plagued by problems; by 1930 he was running out of time. “I took in a folding cot (to the office) and worked almost around the clock,’’ he later recalled, “as long as I could stay awake.’’ In the end, though, his data was inconclusive.

In need of a job to support his family, he joined Columbia-Presbyterian’s Crocker Institute for Cancer Research.

A powerful new machine 
Meanwhile, in California, Lawrence’s graduate student David Sloan had designed the X-ray machine, which would be useful for a range of experiments. Lawrence – always struggling for funds to support his research and the grad students who helped do it – next needed to finance construction of such a device.

He settled on a use that funders would support – cancer treatment. A prototype would be built for the University of California Medical School in San Francisco. The Crocker Institute in New York ordered another.

In 1932 Exner was dispatched to California to help Sloan on the prototype and learn how to assemble and operate the New York  machine. The months he spent in the Rad Lab, he later wrote, were among the most satisfying of his life.

Exner house, 5 Bristol Place, Radburn, circa 1933

When he returned east in spring, 1933, the Exners bought a new house in Radburn, which called itself “The New Town for the Motor Age.’’ But the five-year-old community was  feeling the impact of the Depression. Many early buyers had lost their homes, and had to move or stay on as renters. Faith’s widowed mother, who’d been wiped out financially in the stock market crash in 1929, moved into the unfinished attic at 5 Bristol.
To appeal to higher-income buyers – the only ones still in the new home market – Radburn’s developer offered custom touches. At 5 Bristol, these included an open-air, second-story porch off a bedroom, and a door between the two largest bedrooms.

Betty Exner was 3 when the family moved to Radburn. In an interview in July 2021, she recalled the sense of safety and freedom that Radburn -- which marketed itself as “Safe for Children’’ -- offered her and her sister: “We loved Radburn! It was such a nice little cocoon. We thought it was wonderful, how you could just go from here to there, to the Plaza Building. We could be free.’’

Faith threw herself into community life. She gave welcoming teas for newcomers and sat on the Recreation Advisory Council. She sang in the choir at the inter-denominational Church in Radburn, played in a chamber music trio, and directed a boys band.

When the daughter of a Radburn couple was discharged from the hospital after an asthma attack, the Exners put her up in what The Hackensack Evening Record described as “a special sealed dust proof room’’ in their home.

They also, at another point, took in a border. This was Oscar Ameringer, a Socialist activist from Oklahoma who was finishing work on his autobiography.

In the book’s introduction, the poet Carl Sandburg described Ameringer as “a man on fire over the injustice between man and man, over the chaos and darkness of so many human fates where he cannot be a silent witness,..." Yet also a speaker who could make a crowd of tired, tough working men laugh.

Ameringer mailed the Exners a copy of the book when it was published in 1940. Faith replied: “It is almost like having you in the house again to share our pumpernickel bread and to share your delightful stories. We still call you Our Roomer and watch the reviews of your book with as much pride as if we had a share in its writing. All Radburn is proud of you, too.’’

Sometimes the Exner family would go into New York, descend to the basement of the building at West 168th Street, and, standing on a sort of balcony, look down at the machine that consumed so much of Frank’s time.
“New York’s newest weapon’

 New York Times coverage of the X-ray machine’s dedication 

He still did important work, and received patents for several wartime inventions. One (below), filed in 1944 but not officially announced until 1951 for security reasons, was a  kind of mechanical computer to calculate an aircraft’s drift angle and ground speed. It’s unclear when, if or how it was used in warfare.

In 1937, Columbia-Presbyterian’s X-ray machine was dedicated. A photo accompanying a story in The New York Times showed a shirt sleeved Exner posing with the machine alongside Francis Carter Wood, director of the cancer institute.

The Times hailed the machine as “New York’s newest weapon in the fight against cancer.’’ (Its virtues also were trumpeted by Popular Science and Popular Mechanics.)


Popular Mechanics depicts Exner in article that incorrectly calls him “inventor” of the X-ray machine

The Times article included  a safety claim: “There is no glass to be broken, nor is there any danger of accidental contact with high voltage conductors.’’

But two months after the dedication, Wesley Coates -- one of those with Exner in the 1932 Rad Lab photo -- was electrocuted when he touched some wires while trying to fix a problem.

Exner was there. He gave first aid and called for help. But within an hour, Coates was pronounced dead. He was 29.
Wood, the cancer center director, chose to blame the victim rather than the machine, telling the Times that Coates “must have slipped, and thus have brought his body into contact with the conductor. … I cannot explain how (else) he came to touch one of the conductors.’’

Frank Exner apparently did not dismiss the incident so easily. In a 2021 interview, his granddaughter, Gretchen Kuhn, said Coates’ death “always bothered him a lot. He felt that there weren’t proper safety protocols.’’

The giant X-ray machine’s problems continued. Despite the glowing predictions at its dedication, it proved “capricious’’ and was “frequently under repair,’’ a Columbia scientist would later report.

There were other problems: conflicts between basic research and patient treatment; the retirement of Wood, Exner’s patron; and a new cancer institute in the city, Memorial Sloan Kettering, that purchased an X-ray machine of its own.

Soon, medical school administrators wanted to redirect the project’s funds.

The time Exner spent at the Rad Lab earlier in the decade came to seem to him like a golden age. “I wish I could come out and see the lab now,’’ he wrote in a letter to Lawrence in 1938. “I think of my years at Berkeley as the pleasantest and best laboratory experience I ever had.’’

Exner, seated at right, with Max Delbruck (left) and S.E. Luria at Cold Spring Harbor Laboratory,
1941. Luria and Delbruck would later share a Nobel Prize.

Despite his struggles, Exner remained well-connected and well regarded.

In addition to his link to Lawrence, who won the Nobel for physics in 1939, he co-authored several important academic papers, including three with S. E. Luria, a Columbia colleague who would win his own Nobel two decades later for work on viruses.

In 1941, one of their papers appeared in Science, and another in the equally prestigious Journal of the American Medical Association. At a time when no one knew what viruses actually were -- what they looked like, how they reproduced, why they caused diseases -- Luria and Exner did foundational research into their basic nature.

Exner also had contact at Columbia with Enrico Fermi, who would become a chief architect of the atomic bomb, and Leo Szilard, who in 1939 wrote the letter to President Roosevelt (for Albert Einstein’s signature) that resulted in the decision to build the bomb.

So Exner’s lack of a Ph. D. was no bar to a successful career in physics -- especially at a time when the government’s Manhattan Project would need physicists for its crash program to develop the atomic bomb.

‘A special kind of relationship’
Then, in the summer of 1941, Faith Exner was diagnosed with breast cancer. A year later, at age 43, she died. Her memorial service was held at the house on Bristol Place. The two surviving members of her chamber trio played several of Faith’s favorite pieces.
Frank was crushed; he and Faith “had a special kind of relationship,’’ their daughter Betty would recall.

It was a turning point for everyone in the family. Changes at Columbia already had clouded Frank’s future there; in 1941 he’d told Lawrence he was worried that the X-ray machine would be “scrapped.’’ Now, he decided to move to Minnesota, where his father still lived, and take a job with the Minneapolis-Honeywell Company. 

Minneapolis-Honeywell headquarters 

The company had received many important war contracts. One would produce the C-1 autopilot control used by the B-29s that dropped atomic bombs on Hiroshima and Nagasaki in 1945. 

Polly and Betty, who’d spent the summer on Fire Island as their mother’s health worsened, had only a few days in Radburn before moving west. “Oh, it was a shock to have to leave,’’ Betty recalled. “It felt like my life ended.’’

Frank never finished his Ph. D. or joined the Manhattan Project. Luria, in an autobiography written years after their work together, cited Exner’s “lack of aggressiveness’’ for the end of his academic career. Regardless, the widower probably felt that taking a secure private sector job close to family was best for his daughters.

He still did important work, and received patents for several wartime inventions. One (below), filed in 1944 but not officially announced until 1951 for security reasons, was a  kind of mechanical computer to calculate an aircraft’s drift angle and ground speed. It’s unclear when, if or how it was used in warfare.

Exner remarried in 1945 to Marjorie Joslyn, a friend of Faith’s. He retired in 1970 and died 20 years later, at 91. (Lawrence, in contrast, died in 1958, 19 days after his 57th birthday.)

His granddaughter, Gretchen Kuhn, said Exner always regretted not finishing his dissertation. He even wrote a three-page explanation entitled, “Why Frank didn’t get his Ph.D.’’

But unlike Lawrence, a lifelong advocate of nuclear weapons development, Exner may have been glad he never worked on the Manhattan Project. During the Cold War he joined two prominent anti-nuclear groups, the Committee for a SANE Nuclear Policy and the Union of Concerned Scientists. He also was active in the Minnesota chapter of the Nature Conservancy and became an advocate of world government. 
He kept busy in other ways, too. He liked to take his grandchildren down into his basement shop and work on an amusing project. It wasn’t the world’s largest X-ray machine, but Frank Exner seemed perfectly content.

His career had embraced physics and virology (at Berkeley and Columbia); mechanical engineering (at Honeywell); and even astronomy (at Carlton, where as an undergraduate he published a paper on astronomical observations at the college’s nationally-known Goodsell Observatory).
He was also a good man. S.E. Luria, with whom Exner did the virus research, came to Columbia as an Italian Jewish refugee from European facism. He said he’d never met anyone like his new colleague.

In his memoirs, he praised “Frank’s serenity, candor and lack of conceit.’’ His colleague, he wrote, seemed to personify certain American traits: “Personal responsibility, respect for privacy and concern for social welfare.’’

This is one in a series of profiles of eminent early Radburnians.
Rick Hampson and Steve Taylor lead free walking tours of historic Radburn. For information, contact them at

Upcoming events

Powered by Wild Apricot Membership Software