Shadowgraphy (or Ombromanie) is the art of using hands to form figures onto a screen using shadows. It can be traced back to 18th Century, although the idea is probably much older. Shadow puppets of Indonesia were being performed around 850 AD and in China during the Tang Dynasty (618 - 907).
The art was introduced to Europe by travelers returning back from China, who had seen the Chinese puppet theater shows. The first "ombres chinoises" were presented in Paris in 1776 by Dominique Séraphin, but this was using two-dimensional cut-out "puppets" made from various materials.
In modern times, the art of "ombromanie" (using only the hands as a medium to create the shadow) was made popular by Félicien Trewey. At the age of fifteen Trewey ran away from home to become a magician and tight rope walker. Trewey popularized the art by making silhouettes of famous personalities with his hands. In 1889, he joined Alexander Herrmann.
Magicians performing shadowgraphy
It would appear that Alexander Herrmann learned Shadowgraphy from watching the performances of Trewey.
David Tobias Bamberg most likely learned it from Alexander who passed this down to his son Okito. Okito passed it down to his son Fu Manchu. "Okito" toured with the Thurston show as a shadowgrapher for many years. "Fu Manchu" likewise featured shadowgraphy in his act for many years.
Max Holden featured Shadowgraphy in his performances, with his assistant wife, as the duo "Holden and Graham". Holden was famous for his shadow "Monkey in the Bellfry".