Donald F Hornig, who died on 21 January at the age of 92, was a scientist who worked on the atomic bomb and was a scientific adviser to three US presidents. He was the president of Brown University from 1970 to 1976 and also taught at Princeton and Harvard.
Hornig was a Harvard-trained physical chemist and one of the youngest group leaders on the Manhattan Project that developed the atomic bomb during the Second World War. He designed the firing unit that triggered the simultaneous implosion of the bomb's plutonium device.
He advised presidents Eisenhower, Kennedy and Johnson, then became president at Brown, where he restored the university to financial health.