The illustration is from L.A. Vaught’s Practical Character Reader, a volume on the peculiar and sometimes racially sinister subject of phrenology published in 1902. The author maintains that human character is made up of a combination of 42 elements that can be observed from the shape of the head. The theory was originated by Viennese physician Franz Joseph Gall in the late 18th century. It introduced, importantly, the neurological concept of cerebral localisation. The subject later became irredeemably tainted and discredited when racial anthropologists used it to justify a brutal and oppressive imperial agenda.