The Expanding Universe
Despite the claim that the expansion of the universe made the cosmological constant redundant, Eddington was a strong supporter of a positive cosmological constant, which enabled the universe to start from a static model and gradually expand (no big bang here), but most of all Eddington wanted the universe to be finite. The book introduces the popular 'expanding balloon' model of the universe. Some of Eddington's ideas haven't stood the test of time so well though. In the last chapter he gives a long calculation based on all sorts of numbers such as 137 and the mass of the electron to show why the Hubble constant must be around 600 km/s/Mpc. It is now accepted that it is an order of magnitude less than that.