Irving Kahn, the Manhattan money manager whose astounding longevity enabled him to carry firsthand lessons from the Great Depression well into the 21st century, has died. He was 109. He died on Feb. 24 at his apartment in Manhattan, his grandson, Andrew Kahn, said Thursday. A studious, patient investor from a family whose durability drew the attention of scientists, Kahn was co-founder and chairman of Kahn Brothers Group Inc., a broker-dealer and investment adviser with about $1 billion under management. Last year, at 108, he was still working three days a week, commuting one mile from his Upper East Side apartment ... (full story)