Lansing Lamont, Journalist and Historian of Atomic Bomb, Dies at 82

Lansing Lamont, a journalist who was credited with writing the first popular account of the building and testing of the atomic bombs used in the attacks on Hiroshima and Nagasaki, died on Sept. 3 in Manhattan. He was 82. The cause was cancer, his wife, Ada Jung Lamont, said.

Lansing Lamont

Mr. Lamont, the author or editor of several books, was a Washington correspondent for Time magazine when he conducted the interviews and gathered the information he used in his book “Day of Trinity,” published in 1965, 20 years after the bombings, in August 1945, that brought about the end of World War II.

It described the personalities and sometimes conflicting emotions of the scientists involved in the American program to build the bomb, known as the Manhattan Project; the rudiments of the mineralogy, physics and chemistry required in engineering the device; and the first atomic bomb test at Alamogordo, N.M., conducted on July 16, 1945, three weeks before Hiroshima.

“A pinprick of brilliant light punctured the darkness, spurted upward in a flaming jet, then spilled into a dazzling cloche of fire that bleached the desert to a ghastly white,” Mr. Lamont wrote. “For a fraction of a second the light in that bell-shaped fire mass was greater than any ever before produced on earth. Its intensity was such that it could have been seen on another planet. The temperature at its center was four times that at the center of the sun, and more than 10,000 times that at the sun’s surface. The pressure, caving in the ground beneath, was over 100 billion atmospheres.”

An international best seller, the book included the first publicly available illustration of the interior of an atomic bomb.

Writing in The New York Times Book Review, William Laurence, a former Times science editor, praised Mr. Lamont for preserving the recollections of the aging “principal protagonists” of the Manhattan Project.

“In a few years these facts would no longer have been available as firsthand material,” he wrote. “The contemporary world, as well as the historian of the future, are, and will be, deeply indebted to Mr. Lamont.”

Most government documents relating to the project were not declassified until a decade after Mr. Lamont’s book was published.

Mr. Lamont wrote or edited seven other books, including works on national affairs and Canadian-American relations as well as a memoir, “You Must Remember This: A Reporter’s Odyssey From Camelot to Glasnost,” published in 2008.

After his stint in Washington, during which he covered the assassinations of President John F. Kennedy and Senator Robert F. Kennedy, Mr. Lamont was Time’s deputy bureau chief in London, its chief correspondent in Canada and its United Nations bureau chief.

Lance Lamont, as he was known, was born in Manhattan on March 13, 1931, to Thomas and Elinor Miner Lamont. His father was a banker.

After graduating from Milton Academy in Massachusetts, Harvard College and the Columbia School of Journalism, Mr. Lamont served in the Army from 1954 to 1957. He worked for The Washington Star and was the Congressional correspondent for The Worcester Gazette in Massachusetts before joining Time in 1960.

Besides his wife, he is survived by two sons, Douglas and Thomas; two daughters, Elisabeth Wolcott and Virginia Cazedessus; a brother, Edward; a sister, Elinor Hallowell; and 12 grandchildren.

A version of this article appears in print on September 16, 2013, on page B11 of the New York edition with the headline: Lansing Lamont, 82, Journalist And Historian of Atomic Bomb.