An Introduction to the True Astronomy: Or, Astronomical Lectures Read in the Astronomical School of the University of Oxford

An Introduction To The True Astronomy: Or, Astronomical Lectures Read In The Astronomical School Of The University Of Oxford by John Keill is an 18th?century translation of lectures from the Oxford Astronomical School (1739). It presents true astronomy as a rational, theistic science and defends a heliocentric system grounded in geometry and gravity, while training readers in observation and computation. The volume surveys astronomical knowledge across cultures—from ancient Egypt, Babylon, and Greece to Islamic scholars and later European observers—and then unfolds a program of demonstrations, measurements, and problems. It covers vision and optics, the Earth–Sun–planet system, and the transition from epicycles to a true theory of motion; discusses planetary appearances, retrograde motion, lunar and solar phenomena, eclipses, comets, and calendars. Instruments (quadrants, sextants, octants, telescopes) and geometric methods are used to determine positions, longitudes, and the relation between apparent solar time and mean time. The work reflects empirical, mathematical inquiry within the Oxford tradition.