Florence boasts a long tradition of astronomical studies documented as early as the Middle Ages in the "solstice" marble slab of the Baptistry of San Giovanni. Other significant testimony is found in later periods: the large gnomon of Paolo Dal Pozzo Toscanelli in the dome of Santa Maria del Fiore, the Ptolemaic "planetarium" painted on the inside of the dome of the Sagrestia Vecchia of the Basilica of San Lorenzo, the astronomical instruments of Ignazio Danti in Santa Maria Novella, and the large armillary sphere of Antonio Santucci. Florence's first astronomical observatory was founded in 1756 by the Jesuit Leonardo Ximenes in the convent of San Giovannino, which also set up a teaching chair in astronomy that remained active until the mid-19th C. Between 1780 and 1789, at the behest of Grand Duke Peter Leopold, the Museo di Fisica e Storia Naturale opened an observation facility (Specola) that remained practically unused until 1824, when Jean-Louis Pons—already director of the small Observatory of Marlia, near Lucca—was appointed to head it. In 1831, the directorship of the Florentine observatory passed to Giovan Battista Amici, also known as a microscope- and telescope-maker. The transfer of the Specola from the tower of Via Romana to the Arcetri hill—a place better suited to astronomical observation and rich with Galilean memories—was carried out by Giovan Battista Donati. The new Observatory was inaugurated in 1872.