Royal Greenwich Observatory

The Royal Observatory, designed by Christopher Wren,  opened in 1675	Prime Meridian	Quadrant used by Flamsteed's staff to prepare star maps	Small refractor circa 1700

The Royal Observatory at Greenwich (today an area in London) was commissioned by Charles II in 1675.  It was designed by England's best known architect, Christopher Wren.  The original purpose was to apply the new knowledge of astronomy to problems of maritime navigation. The first Astronomer Royal was John Flamsteed who organized the staff and prepared very accurate star maps using the instruments shown here (two photographs on the right).  Flamsteed's successor was Edmond Halley, a contemporary of Isaac Newton. Halley used Newton's laws to predict the return of the comet which now bears his name.  The line of longitude running thorough the observatory is still used as the prime meridian (when its midnight here, the day officially begins).