By the 19th century, death masks weren't just tools for artists anymore. The pseudoscience of phrenology exploded, and phrenologists eagerly collected death masks to study the skull shapes of the royal and the famous [source: Gibson].
The masks had also become mementos of the dead. It's the last likeness of a loved one a family can own, and a death mask preserves what some consider to be the very essence of a person -- their face. The plaster negative could be used to make multiple positives out of stone, metal or wax that could then be shared to commemorate the dead. Royal and wealthy families proudly displayed their macabre reminders of the recently deceased.
Today you can see the death masks of Beethoven, Chopin, Audobon and many others. Chances are, if they were famous or royal, they had a death mask.
Even with the advent of photography, death masks were still being made well into the 20th century. A photograph can capture the likeness of the recently deceased, but only in two dimensions. A plaster mold and mask is true to scale. It's a three-dimensional impression that responds to the light and shadows of a room, copied from the very face it represents. The most famous examples include Nikola Tesla and Max Reinhardt. A bronze death mask was cast for Arthur H. Compton, the physicist and Nobel laureate -- he died in 1962! [source: Delaney].
So do you want to learn how one is made?