Well here you have it - proof that your average late 19th century amputee was about as cuddly as the Terminator. Let's have a closer look at those fingers, shall we?
AHH! The London Science Museum, the reluctant owners of the steel and brass nightmare arm, explain:
The elbow joint can be moved by releasing a spring, whereas the top joint of the wrist allows a degree of rotation and an up-and-down motion. The fingers can also curl up and straighten out. The leather upper arm piece is used to fix the prosthesis to the remaining upper arm.
They then admit that the hand in particular looks "rather sinister", and when the museum finds whatever you're looking at creepy you know you're dealing with one seriously frightening historical artefact. [London Science Museum via BoingBoing]