The clock which Bertolla made for the Baron of Cles is a tall, narrow, case clock of ebony or ebonized pearwood which is approximately 91/2 feet in height. The decoration of the case is considerably more conservative than the one made for Di Noris, but the black wood is decorated with silver trim and carved designs in the wood itself. The dial is decorated with silver scrollwork and spandrels within and around a raised chapter ring. The clock operates for one month at each winding, has an alarm, indicates and strikes the hours, and will repeat the quarters. This handsome timepiece is still in the possession of the descendants of the Baron of Cles.
According to Pippa, [19] certain characteristics become apparent in a study of the surviving clocks by Bertolla. The tall-case clocks are narrow and range in height from 73/4 feet to 101/2 feet. The cases had this excessive height in order to obtain the greatest fall for the month and year movements which Bertolla constructed. For the weight assembly, he substituted a drum wound with a key at the point of the driving wheel in place of the customary pulley. The addition of an intermediate wheel augmented the drop of the weight.
Figure 22.—Interior of Bertolla's workshop, showing detail of ceiling. (Courtesy Museo Nazionale della Scienza e della Tecnica, Milan.)
Figure 23.—Interior of Bertolla's workshop, showing the main workbench and the collection of clockmakers' tools. (Courtesy of Museo Nazionale della Scienza e della Tecnica, Milan.)