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Published on Jun 25, 2011
Invention and Study of Lissajous Figures Many believe, that the optical method of studying compositions of oscillations with the help of so-called "Lissajous figures" are associated with an oscilloscope. However, it appeared long before the invention of this device as a method for studying the properties of low-frequency oscillations. The method was developed in 1885 by the French physicist Jules Antoine Lissajous and demonstrated for the first time in 1857. The American mathematician and astronomer Nathaniel Bowditch then provided a mathematical description of the Lissajous figures. Structurally the device consisted of a source of light, two tuning forks - vertical and horizontal, and a telescope used to observe the changes in figures depending on the changing oscillation frequency in the tuning fork. To maintain oscillations in the tuning fork the enhanced model of the device was supplied with an electromagnetic drive. For the purpose of public demonstrations, George Hopkins then supplemented the Lissajous device with a projector and control styluses with pendulums for control. The screen was made of a blackened glass plate. The Lissajous figures method enabled comparison of the parameters of different signals between each other, and served as a precondition for invention of devices with graphic data display.