This accession includes the outgoing correspondence of George B. Field, director and senior research fellow (as well as an applied astronomy professor) at Harvard University. Materials also include some incoming correspondence as well as attachments. A small amount of correspondence belonged to George B. Rybicki, L. M. Ozerno , Alan P. Lightman, and others. Together, the Smithsonian Astrophysical Observatory and the Harvard College Observatory administer the Harvard-Smithsonian Center for Astrophysics which was also directed by Field. Subject matter within the correspondence relates to all of these organizations.