A definitive treatment of the phenomenology of galaxies - this volume takes account of advances in the field. The text draws on observations of both our own galaxy, the Milky Way, and of external galaxies. The two sources are complementary, since the former tend to be highly detailed but difficult to interpret, while the latter are typically poorer in quality but conceptually simpler to understand. Binney and Merrifield introduce all astronomical concepts necessary to understand the properties of galaxies, including co-ordinate systems, magnitudes and colours, the phenomenology of stars, the theory of stellar and chemical evolution, and the measurement of astronomical distances. The book's core covers the phenomenology of external galaxies, star clusters in the Milky Way, the interstellar media of external galaxies, gas in the Milky Way, the structure and kinematics of stellar components of the Milky Way, and the kinematics of external galaxies. Throughout, the book emphasizes the observational basis for current understanding of galactic astronomy.