Thank you for checking out this book by Theophania Publishing. We appreciate your business and look forward to serving you soon. We have thousands of titles available, and we invite you to search for us by name, contact us via our website, or download our most recent catalogues. Bacon made many discoveries while coming near to many others, despite many disadvantages and discouragements. His Opus Majus contains treatments of mathematics and optics, alchemy and the manufacture of gunpowder, the positions and sizes of the celestial bodies, and anticipates later inventions such as microscopes, telescopes, spectacles, flying machines, hydraulics and steam ships. Bacon studied astrology and believed that the celestial bodies had an influence on the fate and mind of humans. The study of optics in part five of Opus Majus draws heavily on the works of both Claudius Ptolemy (his Optics in Arabic translation) and the Islamic scientists Alkindus (al-Kindi) and Alhazen (Ibn al-Haytham). He includes a discussion of the physiology of eyesight, the anatomy of the eye and the brain, and considers light, distance, position, and size, direct vision, reflected vision, and refraction, mirrors and lenses. His research in optics was primarily oriented by the legacy of Alhazen through a Latin translation of the latter's monumental Kitab al-manazir (De aspectibus; Perspectivae; The Optics), while the impact of the tradition of al-Kindi (Alkindus) was principally mediated through the influence that this Muslim scholar had on the optics of Robert Grosseteste. Moreover, Bacon's investigations of the properties of the magnifying glass partly rested on the handed down legacy of Islamic opticians, mainly Alhazen, who was in his turn influenced by Ibn Sahl's 10th century legacy in dioptrics. Drawing on the recently discovered Greco-Muslim astronomy and on the calendaric writings of Robert Grosseteste, Bacon criticized the Julian calendar, describing it as intolerable, horrible and laughable. He proposed to correct its errors by deleting a day from the calendar every 125 or 130 days. Bacon was an enthusiastic proponent and practitioner of the experimental method of acquiring knowledge about the world. He advocated the study of mathematics to facilitate the grounding of the scientific method in quantitative techniques. Further, Bacon predicted the invention of the submarine, automobile, and airplane. He planned to publish a comprehensive encyclopedia, but only fragments ever appeared. The American pragmatist philosopher Charles Sanders Peirce said of him that "To Roger Bacon, that remarkable mind who in the middle of the thirteenth century was almost a scientific man, the schoolmen's conception of reasoning appeared only an obstacle to truth. He saw that experience alone teaches anything.... Of all kinds of experience, the best, he thought, was interior illumination, which teaches many things about Nature which the external senses could never discover, such as the transubstantiation of bread."