Mural quadrant

This type of quadrant has its base fixed to a wall. By moving the telescope vertically, the observer can measure a star’s maximum height over the horizon and the instant at which this occurs. The large size and excellent workmanship of this quadrant, produced by one of the most famous craftsmen of the 18th century, allow great precision in measuring. It was one of the first instruments to be purchased, in 1971, by the Osservatorio Astronomico di Brera, and was for many years one of the most frequently used by its astronomers.