This remarkable manuscript is almost 500 years old and was hand-written in Italian by Leonardo da Vinci in his characteristic "mirror writing" and supported by copious sketches. It covers a wide range of his observations and theories on astronomy, the properties of water, rocks, fossils, air, and celestial light. The Codex Leicester provides a rare insight into the inquiring mind of the definitive Renaissance artist, scientist, and thinker as well as an exceptional illustration of the link between art and science and the creativity of the scientific process. Each delicate page is faithfully reproduced and accompanied by an insightful interpretation of the original Italian texts by the foremost Leonardo scholar, Professor Carlo Pedretti. There is also an introductory essay by Michael Desmond.