Einstein letter warning FDR of threat of Nazi nuclear bomb set to fetch $4m

A two-page letter written by Albert Einstein warning Franklin D Roosevelt - then the president of the US - that Nazi Germany might harness nuclear research to invent an atomic bomb is going up for sale at Christie's auctioneers in September with an estimate value of $4m. Einstein's letter - one of two the theoretical physicist drafted in a cabin on the north shore of New York's Long Island with a fellow scientist, Leo Szilard - warned that the German government was actively supporting nuclear research and could make "extremely powerful bombs" like the kind that were eventually deployed by…