Solon Irving Bailey (1854-1931), Phillips Professor of Astronomy at Harvard, spent forty four years with the Harvard College Observatory. Bailey was largely responsible for the successful establishment of Harvard’s Boyden Station observatory in Arequipa, Peru. Bailey’s pioneering photographic studies of globular clusters, variable stars, nebulae, and galactic clusters provided the basis from which other astronomers were able to determine the size of the Milky Way and other galaxies.