An early 18th century circular list of monarchs and popes, with a moving arm

A chronological disc with 14 rings listing the Roman Emperors (original and Holy), popes, Eastern emperors and sultans, and monarchs of Spain, France, Britain, Denmark, Sweden, Poland, Bohemia, Hungary, Russia, Portugal and Prussia. It starts ad AD 1 and, although the disk marks 1800, the last printed date is the accession of Ulrika Eleonora as Queen of Sweden, but not her abdication in 1720. The names of three Roman emperors of the House of Habsburg-Lorraine have been added in the same hand: Joseph II, (acceded 1765), Leopold II (1790) and Francis II (1792). The previous two emperors have been ignored. The arm is tethered at the centre of the disc and is printed with the titles of each circle. The title is on a banner held aloft by two putti.