Jan and Petrus van Musschenbroek, Hieronymus van der Mij , 1715
Inv P00810

The two bewigged gentlemen in this painting are the Van Musschenbroek brothers. They were scions of a Leiden family that for several generations had run a workshop for 'philosophical instruments'. These were apparatuses like air pumps and collision equipment, but also thermometers and barometers; in fact everything which was required for the study of the natural sciences.
Jan van Musschenbroek (left) continued the family instrument-making workshop. His younger brother Petrus became a professor of physics, with a predilection for demonstrations and apparatuses. He could easily use the equipment from his brother’s workshop, some of which is depicted in the background of this painting.