Disarmament, and led the panel in urging that the United States postpone its planned first test of the hydrogen bomb and seek a test ban with the Soviet Union, on the grounds that avoiding a test might forestall development of a catastrophic new weapon and open the way for new arms agreements between the two nations. The panel lacked political allies in Washington, however, and the Ivy Mike shot went ahead as scheduled. Bush was outraged when a security hearing stripped Oppenheimer of his security clearance in 1954; he issued a strident attack on Oppenheimer's accusers in The New York Times. Alfred Friendly summed up the feeling of many scientists in declaring that Bush had become "the Grand Old Man of American science". Bush continued to serve on the NACA through 1948 and expressed annoyance with aircraft companies for delaying development of a turbojet engine because of the huge expense of research and development as well as retooling from older piston engines. He was similarly disappointed with the automobile industry, which showed no interest in his proposals for more fuel-efficient engines. General Motors told him that "even if it were a better engine, [General Motors] would not be interested in it." Bush likewise deplored trends in advertising. "Madison Avenue believes", he said, "that if you tell the public something absurd, but do it enough times, the public will ultimately register it in its stock of accepted verities." From 1947 to 1962, Bush was on the board of directors for American Telephone and Telegraph. He retired as president of the Carnegie Institution and returned to Massachusetts in 1955, but remained a director of Metals and Controls Corporation from 1952 to 1959, and of Merck & Co. 1949–1962. Bush became chairman of the board at Merck following the death of George W. Merck, serving until 1962. He worked closely with the company's president, Max Tishler, although Bush was concerned about Tishler's reluctance to delegate responsibility. Bush distrusted the company's sales organization, but supported Tishler's research and development efforts. He was a trustee of Tufts College 1943–1962, of Johns Hopkins University 1943–1955, of the Carnegie Corporation of New York 1939–1950, the Carnegie Institution of Washington 1958–1974, and the George Putnam Fund of Boston 1956–1972, and was a regent of the Smithsonian Institution 1943–1955. Final years and death After suffering a stroke, Bush died in Belmont, Massachusetts, at the age of 84 from pneumonia