saaco Newton, Philosophiæ Naturalis Principia Mathematica, Tomus Secundus, 1740, (Tomus Secundus only) was first published on 5 July 1687 with a second edition (1731), and a "corrected" reprint of the second edition in 1740, whihc this copy is. full calf armorial binding of Trinity College Dublin impressed with the seal which reads 'Coll. Sanctae Individuae Trinitatis Rec Elizab Juxta Dublin', board seperate, leather scruffy, pages generally good, book plate

The book called "Philosophiæ Naturalis Principia Mathematica" (English: The Mathematical Principles of Natural Philosophy) is often referred to as the Principia. It was written by Isaac Newton and talks about Newton's laws of motion and his law of universal gravitation. The Principia was written in Latin and was first published on 5 July 1687.

The Principia is considered one of the most important works in the history of science. In 1747, the French mathematical physicist Alexis Clairaut described it as a book that brought about a significant revolution in physics. Sir Newton, the esteemed author, used a method that shed light on physics using mathematics. Prior to this, the field had been largely based on conjectures and hypotheses.

The Principia serves as the foundation for classical mechanics. It explains Johannes Kepler's laws of planetary motion, which Kepler had discovered through observation. Newton formulated his physical laws using mathematical techniques that are now part of calculus. He expressed them in the form of geometric ideas about very small shapes that disappear or become insignificant.