Sotheby's is preparing the auction next week of what is believed to be the world's first personal organiser.
The item being put up for sale on 8 March is an extremely rare ecclesiastical volvelle calendar from Verona, Italy, and predates the invention of portable electronic machines by more than 500 years.
The device consists of three discs placed on top of each other and measures almost four feet in diameter. On its scales it carries the date in the Julian calendar, the date in the Roman calendar, a dominical letter, the position of the year relating to lunar aspects and letters and numbers of the solar cycle - the days and months relating to the eclipse of the sun. It also measures degrees for each sign of the zodiac, how many hours the night will last and the phase of the moon. The calendar has been traced back to the 15th-century Veronese bishops Procolo, Lupicino and Lucillo and the monastery of St Zeno because of the references on its dials. It is an exceptionally large calendar, and rare for its type, and is expected to fetch pounds 60-80,000.
The sale of 200 instruments of science and technology is at Sotheby's in New Bond Street, London, and also features the mould that led to the invention of penicillin by the Scots pioneer, Alexander Fleming, estimated at up to pounds 15,000.
Other items include war-time machines, made in Germany but smuggled into Britain to unscramble German codes, television sets from the Fifties, and a selection of 40 unusual pairs of spectacles, some of which date from the 1700s. The reading glasses alone are thought to be worth pounds 8,000.Reuse content