This paper presents a 2' × 2' map of 60 μm polarization from the core of the massive molecular cloud Sagittarius B2, located near the center of the Galaxy. The measurements were obtained from the Kuiper Airborne Observatory with the array polarimeter Stokes. The polarization (up to 8%) is large compared to the polarization at 115 μm and, in contrast to other molecular clouds, is greatest toward the peaks in the dust column density. We argue that the far-infrared polarization is due to absorption by aligned dust grains. The magnetic field in the absorbing cloud, as projected onto the plane of the sky, is roughly north-south, making an agle of 54° with the Galactic plane.Dissertation submitted to the Department of Astronomy and Astrophysics, University of Chicago, in partial fulfillment of the requirements for the Ph.D degree.