Laboratory of Division of Radiation and Organisms, SIB, by Unknown, c. 1929-1934, Smithsonian Archives - History Div, The Division of Radiation and Organisms was located in the basement of the Smithsonian Institution Building. Shown here is apparatus for studying phototropism (bending toward light) of seedlings, in connection with experiments to determine effects of wave lengths of light on growth. Photo shows Earl S. Johnston at work..