Percival Lowell detail in mid-1896 soon after the Alvan Clark & Sons refracting telescope was installed at his new Flagstaff, Arizona observatory. Lowell observed the planet high in the daytime sky with the telescope's lens stopped down to 3 inches in diameter to reduce the effect of the turbulent daytime atmosphere. Lowell observed spoke-like surface features including a central dark spot, contrary to what was suspected then (and known now): that Venus has no surface features visible from Earth, being covered in an atmosphere that is opaque. It has been noted in a 2003 "Journal for the History of Astronomy" paper and
Mannheim Observatory collection of the old library, the oldest of which dates back 1476, was transferred to the Manuscript Department of the University Library. Mannheim Observatory The Mannheim Observatory was a tower observatory built between 1772 and 1774 in Mannheim, Germany, which remained in operation until 1880. The observatory was transferred to Karlsruhe and finally in 1898, was established on the Königstuhl near Heidelberg where today’s successor institution the State Observatory Heidelberg-Königstuhl is located. The observatory tower is now owned by the city and was restored in 1905-1906, and after the Second World War. Since 1958, the tower houses studio flats. The