""The Geometry And Astronomy Of The Royal Arch"" is a book written by F. de P. Castells that explores the history, symbolism, and significance of the Royal Arch in Freemasonry. The book delves into the geometry and astronomy behind the construction of the Royal Arch, examining the symbolism of the sun, moon, and stars in Masonic ritual and philosophy. Castells also provides a detailed analysis of the various degrees of the Royal Arch, including their...