Joseph Henry's Letter to Spencer Fullerton Baird (August 12, 1866), August 12, 1866, Smithsonian Archives - History Div, Letter from Joseph Henry, first Secretary of the Smithsonian Institution, to Spencer Fullerton Baird, then Assistant Secretary and later second Secretary of the Smithsonian Institution, August 12, 1866. In the letter, Henry discusses a recent meeting of the National Academy of Sciences, and his feelings about the election of a president for the group..