Principia

The Principia, or Principals of Mathematics, is an item in the SNES version of Mario's Time Machine. It is the rough draft of Isaac Newton's Philosophiæ Naturalis Principia Mathematica, his masterwork on physics containing his famous three laws of motion and the rudiments of modern calculus. Mario receives the only copy in existence at the time from Edmund Halley, who financed the book's publication, and gives it to another Royal Society member in exchange for more information on Newton.