Universal "Avometer", manufactured by the Automatic Coil Winder and Electrical Equipment Co. Ltd. Universal "Avometer"
Battery of 18 Leyden jars, housed in a wooden box, about 1775, made and used by Henry Cavendish for electrical experiments in his private laboratory at Clapham Common, London. Battery of Leyden jars made by Henry Cavendish circa 1775
One lemon shaped vacuum tube with anode in small extension chamber and three thin circular screens near cathode