The University of Cambridge, where Newton studied, digitized and put online a handwritten and annotated draft of Principia, the main work of this British physicist.
The British physicist Isaac Newton published a major work entitled Philosophiae naturalis principia mathematica. He lays on the paper a scientific explanation to the movements of the planets as well as to the fall of the bodies. In his Principia Newton formulates his law of universal gravitation. The Law that explains the elliptical orbits and movements of celestial bodies previously described by Kepler and Galileo. These laws explain why the Earth revolves around the Sun and the Moon around the Earth, but also the phenomena of tide on Earth. Published for the first time in 1687, this book will undergo several updates and will be translated all over the world. Now you can consult a digital version of the last edition, that of 1726.
The Cambridge site states that the handwriting of this collection is not that of Isaac Newton but that of his assistant and copyist Humphrey Newton. However, some pages are annotated by the author as well as his contemporary British astronomer Edmond Halley, the first to have calculated and predicted the return of a comet named after him. You can read the entire document by visiting this address.