Cylindrical tube and altazimuth mount for the objective called Amici II. Giovanni Battista Amici would test the quality of the objectives he produced by using them for observations of double stars or other objects that were particularly difficult to separate. He therefore built this mount, which allowed him to observe a selected star for a brief period. The mount is a wooden frame resting on castors, with mechanisms for adjusting the height of the tube of the astronomical telescope in the vertical plane. To avoid losing sight of the observed object because of the apparent motion of the celestial sphere, the mount is equipped with limited azimuth movements. This system made it possible to observe astronomical objects for a reasonable interval of time (5 minutes) around their meridian passage. As well as a means of testing the quality of objectives, the Amici II telescope was an effective comet-seeking instrument. For this purpose, the observer set the altitude angle and let the sky's motion bring successively into view the sectors of the sky where the search was conducted. The instrument seems to have been the private property of Amici before its transfer to the Arcetri Observatory, where it was used by Ernst Tempel and other astronomers.