Alexandro Malaspina (right) and José de Bustamante, performing an experiment with the simple pendulum. Drawing by Giovanni Ravenet (1794), Museo Naval, Madrid, ms. 1726-36 (see Carmen Sotos Serrano: Cat. no. 71).  From this version are derived many other drawings, oil paintings and engravings.

 Image courtesy of the Centro di Studi Malaspiniani, Mulazzo, Italy.