Photo of Newton's Principia (IMAGE) California Institute of Technology Caption Caltech's own copy of the first edition of the Principia is part of the Institute's Archives and Special Collections. In the 18th century, it belonged to French mathematician and natural philosopher Jean-Jacques d'Ortous de Mairan, whose signature can be seen in the left margin of the title page. More recently, it was in the collection of Caltech physicist Earnest Watson. The white "snake" seen at left helps hold the pages down. Credit Caltech Archives Usage Restrictions Please use credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.