J.Y. Simpson’s original pattern employed a cross-over button and groove pivot joint and smooth ebony handles as in his long forceps.  The larger blade is fenestrated and serrated and was applied to the external surface of the head, while the smaller one was applied inside the cranium.  After perforation and application, a twisting motion was used to wrench off portions of the cranium. A fine example of his earlier form by “ARNOLD & SONS LONDON”, constructed of nickel plated steel and with shaped smooth ebony handles.