Sectors
Italian Style

Galileo became so associated with the sector that many people incorrectly believed he was the instrument's only inventor. Even though the collection is small, the Museum's holdings suggest there was little consensus in seventeenth-century Italy about which arrangement of scales was most essential to mathematical practitioners' activities. Indeed, Galileo himself experimented with several different scales during the decade he spent working on the instrument before he formally published Operations of the Geometric and Military Compass. One reason for the variety is he started out thinking only about military applications but gradually decided to develop a general-purpose device. The Italian sectors in the collection might have been used for tasks ranging from positioning a cannon and designing fortifications to converting between systems of currency.