Van de Graaff generator
Other electrostatic machines like the Wimshurst machine or Bonetti machine work similarly to the Van De Graaff; charge is transported by moving plates, disks, or cylinders to a high voltage electrode. For these generators, however, corona discharge from exposed metal parts at high potentials and poorer insulation result in smaller voltages. In an electrostatic generator, the rate of charge transported (current) to the high-voltage electrode is very small. After the machine is started, the voltage on the terminal electrode increases until the leakage current from the electrode equals the rate of charge transport. Therefore, leakage from the terminal determines the maximum voltage attainable. In the Van de Graaff generator, the belt allows the transport of charge into the interior of a large hollow spherical electrode. This is the ideal shape to minimize leakage and corona discharge, so the Van de Graaff generator can produce the greatest voltage. This is why the Van de Graaff design has been used for all electrostatic particle accelerators. In general, the larger the diameter and the smoother the sphere is, the higher the voltage that can be achieved.
Edward Nairne
Nairne patented several electrical machines, including an electrostatic generator consisting of a glass cylinder mounted on glass insulators; the device can supply either positive or negative electricity, and was intended for medicinal use. In the eighth edition of the instruction manual for this device he claimed that "electricity is almost a specific in some disorders, and deserves to be held in the highest estimation for its efficacy in many others". He recommended its use for nervous disorders, bruises, burns, scales, bloodshot eyes, toothache, sciatica, epilepsy, hysteria, agues and so on. He also made improvements to the Cuff microscope, building it into a portable case and calling it a chest microscope.