The book ""Theory of Parallels: The Proof of Euclid's Axiom Looked for in the Properties of the Equiangular Spiral"" by T. Perronet Thompson explores the concept of parallel lines in mathematics. The author seeks to prove Euclid's axiom, which states that parallel lines never meet, by examining the properties of the equiangular spiral. The book delves into the history of parallel lines and the various attempts made to prove this axiom, as well as...