The Great Refractor of Potsdam (Große Refraktor), a double telescope of 1899 with a 80cm (31.5") and 50 cm (29.5") lenses, one of the world's largest telescopes of the time. it is now preserved for public visits inside the Leibniz Institute for Astrophysics Potsdam near Berlin, a successor of the Berlin Observatory founded in 1700 and of the Astrophysical Observatory Potsdam (AOP) founded in 1874. In the foreground is a picture of the 1919 solar eclipse by British astronomer Eddington which confirmed the General Relativity by finding the evidence for Einstein's prediction of gravitational deflection of starlight by the Sun.