This installation, made by R J Reynolds, is one of the oldest in the world. It consists of a thirteen inch spark coil mounted on glas pillars with a mercury dipper break (motor control) and commutator, all mounted on a wooden stand. There is a condenser mounted in a mahogany case, a three-legged wooden tube stand and a chromic acid battery. Wilhelm Roentgen (1845-1923) discovered X-rays when he encountered emisions from a Crookes' discharge tube. Experiments revealed that these rays penetrated some substances more easily than others, and also fogged photographic plates. The fact that X-rays could produce images differentiating between the densities of body tisues, was a discovery which the medical profesion was keen to exploit.
© Science Museum / Science & Society Picture Library