This male skull within a "craniostat" forms part of the Samuel George Morton Cranial Collection, now held by the University of Pennsylvania Museum of Archaeology and Anthropology.
Morton (1799-1851) was a successful doctor who went on to become a professor of anatomy at the Pennsylvania Medical College. While preparing a lecture on skull types and racial groups in 1830, it seems, he realised that he did not have enough examples to hand. He soon remedied this by starting his celebrated collection, which became known as the "American Golgotha".
Army surgeons sent Morton craniums from all over the world, sometimes even robbing graves to do so. At the time of his death, Morton had prepared and labelled 867 in all, which friends purchased and presented to the Philadelphia Academy of Natural Sciences. They were loaned and then given to the museum in the 1960s.
There are still controversies about whether Morton's racial views had an impact on his scientific work. Yet he is widely regarded as a key figure in the development of physical anthropology, using more than 12 separate measurements to compare skulls from different continents.