Sleutel voor de prent van de zelfopoffering van Jan van Speijk, 1831 1831

This 1831 sketch by Jean-Baptiste Madou, titled "Sleutel van het schilderij van Van Speijk," provides a key to a larger painting. The work is a collection of small drawings, each labeled with a number and a corresponding description in Dutch. These drawings, likely portraits, serve as a guide to identifying the figures in the larger painting, which depicts the heroic act of Dutch naval officer Jan van Speijk. The sketch, now part of the Rijksmuseum collection, offers a glimpse into the process of creating historical art in the 19th century.