Figure 32.—Striking clock sketch found in Bertolla's manuscripts. (Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan.)
Figure 33.—Fifteen-day striking clock sketch, inscribed "Design No. 3," found in Bertolla's workshop. (Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan.)
Figure 34.—Dial plate of a brass lantern clock made by Bertolla at the age of 80. (Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan.)
Figure 35.—Movement of brass lantern clock produced by Bertolla at the age of 80, showing details of movement and double bell. (Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan.)