Glass Harmonica in mahogany case, E. Pohl, Czech Republic, 1862.
Invented by Benjamin Franklin in 1761 to refine the idea behind ‘singing glasses’, the glass harmonica consists of a series of glass bells (bowls) which are affixed in regular order with an iron rod running horizontally through them. The performer rotated the bells through a simple foot pedal mechanism and played the harmonica by moistening their fingers and pressing them against the rotating bells. The harmonica produced different tones which were determined by the size and thickness of the glass bowl (rather than the amount of water inside them). This example of a glass harmonica was made by E. Pohl, a member of one of the most well-known glass harmonica manufacturers in Europe.