Lot Essay
The Universal Joints were invented by Robert Hook (1605-1703) and adapted for medical and scientific instruments long before they were needed by the motor car.
Details
A very rare gilt-brass and blued steel mechanical trephine, signed Evans, London, with ivory handles, the centre pin in the crown, saw moved in and out by a rack-and-pinion mechanism with locking screw, the winding handle incorporating two miniature universal joints, the body containing a gear-box reducing the drive by 2 to 1: circa 1850-55 - length 7ins. (18cms.)