Priscilla Duffield wasn't quite what you'd call an average secretary.

You can't really be average when you're taking dictation, answering phones and conversing with some of the most famous names in physics on a daily basis.

And that's what Duffield did, first as secretary to E.O. Lawrence and later as secretary to Robert Oppenheimer during and after he led the top-secret Manhattan Project in creating the world's first atomic bomb.

Duffield, 91, died of natural causes July 21 at her home in Norwood, Colo.

She was "the perfect secretary and Oppenheimer's right hand," said her friend, Betty Lilienthal.

An admirer and loyal friend of Oppenheimer, Duffield, in a public lecture at Los Alamos National Laboratory in 2006, said of her former boss: "He knew exactly what he wanted to do but he always listened to what you had to say. He was a considerate and smart man."

She also said that the 1940s in Los Alamos — rubbing shoulders with people like Hans Bethe, Richard Feynman, Enrico Fermi and Robert Serber — "were the best years of my life."

Duffield, whose maiden name was Greene, was raised in California and got a degree in political science from the University of California at Berkeley.

After spending some time studying and traveling in New York City and Europe, Duffield returned to California and became secretary to Lawrence, who was then director of the Berkeley Radiation Laboratory.

In 1943, Oppenheimer began borrowing her from Lawrence for help with dictation and other secretarial work. And when Oppenheimer returned from his scouting trip to headquarter the Manhattan Project in Los Alamos, he offered Duffield the job as his full-time secretary.

"When Robert returned from travel and told me that he had just been to a beautiful place, all I could say is, 'take me too,' " Duffield said at her Los Alamos lecture.

In the early years at Los Alamos, "everything was put together amazingly fast ... (but) it was nothing spectacular. There were unfinished buildings, mud and trucks everywhere," she said in the lecture.

While there, Duffield met and married her husband of 57 years, Robert Duffield, who died in 2000.

After working for Oppenheimer, Duffield worked as secretary and executive assistant to Roger Revelle of the Scripps Institution of Oceanography in the 1960s and to Robert Wilson of Fermi National Accelerator Laboratory in the 1970s.

And while she was privy to some sensitive information during the course of her career, she always kept her mouth shut about it, Lilienthal said.

"She was a charming person," Lilienthal said. "She had lots of secrets in her head, of course, but she never said anything."

Duffield had a quiet but fast-paced conversational style and spent a lot of her free time reading, corresponding with friends and talking on the phone, Lilienthal said.

And Duffield was always very proud of her work, Lilienthal said.

"She was a perfect secretary — always took notes correctly, never spilled the beans to anybody and just really knew what she was doing," Lilienthal said.

Duffield is survived by her daughter Deborah and grandson Miles Duffield of Norwood and her daughter Libby Dietrich and husband David Boorkman of Sausalito, Calif.

Contact Sue Vorenberg at svorenberg@sfnewmexican.com.