Johann Winkler made improvements in early electrostatic machines and used them to study electrical phenomena.
Johann Winkler, professor of Languages at Leipzig, improved on the Globe electrical machine by adding a cushion to rub the globe. In the 1740′s cylinder machines appeared and gradually replaced the globe machines. These machines had a prime conductor provided with several points. The points were directed to a rotating cylinder and speeded up the process of electrization.
Johann Winkler’s early electrostatic generator from his 1744
“Gedanken von den Eigenschaft, Wirkungen und Ursachen der Electricitaet …”
This generator uses a bottle or glass as the cylinder, with its base set into a cone with a pivot point on the end. It looks quite complicated – but the main part of the generator is a pole lathe, used by generations of wood-turners long before electricity was a gleam in Gilbert’s eye. Winkler merely added a few elements to an already existing tool.
In a pole lathe, a straight piece of wood has one end rounded, and little depressions made in the center of each end. The string of the lathe is wrapped several times about the rounded end, and the corresponding depression put over a pin on the side of the lathe framework. The adjustable pin p (see Fig. 2) is then moved until it settles into the other depression. When the turner steps on the treadle, the string is pulled down, turning the workpiece one way; when he releases the treadle the pole at top springs back and turns the workpiece the opposite way.
For a wood-turner, using a knife or chisel, the lathe is only useful on the downstroke. Used to make electricity, you want friction against the glass – and friction works well both ways. In earlier days the friction would have been provided by the user’s hand against the glass; but the friction cushion was more convenient. It can be seen as Fig. 3.
During much of the eighteenth century, England and France were the centers of electrical study and innovation; but during the early 1740s, there was a great burst of invention in Germany. Bose’ use of a suspended metal conductor and his early experiments with thread became the basis of the later collector, or charge comb, of the electrical machine. Winkler and Gordon, the two chief claimants for the invention of the cylinder generator, worked in Germany. And Winkler is probably the inventor of the friction cushion. He made electrical machines that worked on the back-and-forth principle of the pole lathe, and also machines that used Hauksbee’s multiplying wheel.