PLANISPHERE

"Giovanni Domenico Cassini's monumental 24 foot diameter hand-drawn map of the world was originally drawn by Cassini on the floor of the Paris Observatory between 1679 and circa 1690. Cassini's work was the final chapter of the centuries old quest to map the world based upon Astronomical Observations, dating back to the ancient geographers of Greece.

As noted by Alexander Vietor: This rather self-evident observation [that the world could be measured and mapped based upon astronomical observations] was completely understood by the ancients who struggled with their limited technology to try to form from terrestrial and celestial data an accurate picture of the globe they inhabited. The closest to a modern calculation of the earth's size was achieved by the Greek philosopher Eratosthenes, who came within 14 percent of the correct circumference of the earth by measurements made in the Nile Valley and the relative angles of the sun's shadow at widely separated points alone