The Astronomical Observatories of Jai Singh c15.s3.2

c15.s3.2

But, about the thirteenth century, sounder opinions began to prevail, and in the early part of the sixteenth century Copernicus wrote his *De Revolutionibus Orbium Cœlestium*. Tycho Brahe, Kepler, and Galilei preceded Jai Singh by about a century. Greenwich observatory was founded some forty years before that at Delhi. Newton's *Principia* was written at the time of Jai Singh's birth; Huygens died a few years later; Flamsteed's catalogue of stars was first printed in 1688; Halley, in 1705, predicted the return of the comet named after him; the aberration of light was discovered in 1727. Jai Singh succeeded to the Amber territory in 1699, and the Delhi observatory was built about 1724.