Contents: The Pythagorean Triangle Explained, with a Dissertation on the Peculiarities of Masonic Number; The Monad or Point Discussed as the Origin of All Calculation; The Duad or Line Exemplified; Illustration of the Triad or Superfice; (The Superfice, or Equilateral Triangle, Triad, Ternary, or the Number Three); Progressive Generation of the Tetrad or Solid, Representing Fire; Geometrical Application of the Pentad or Pyramid, Representing Water; Infinite Divisibility of the Hexad or Double Triangle, Representing Earth; Remarkable Properties of the Heptad; Mysterious References of the Ogdoad or Cube, Representing Air; Ancient Superstitions Attached to the Ennead or Triple Triangle; Perfect Nature of the Decad or Circle, and the Application of the Dodecaedron as a Representation of the System of the Universe.