Furnished with more than a hundred figures, maps and tables, this book was first published in 1878 by Simon Newcomb (1835–1909), a noted mathematician and professor at the United States Naval Observatory. A meticulous work, originally intended to be of use to the general reader as well as the student, it provides a view of astronomy as it stood on the eve of General Relativity, and inevitably includes some theories which have since been disproved. Newcomb outlines a brief history of astronomy, from ancient Greece (when the planets were thought to be fixed in crystal spheres), to the application of the new laws of thermodynamics and the latest observations of the solar system. Included are a rejection of the then prevalent theory that the sun has a cool interior and its own inhabitants, details of the anomaly of Mercury's orbit according to Newtonian theory, and thorough observational guides.