English: Replica of Agusto Righi's 1894 experimental Hertzian wave apparatus built in 1984 for display purposes consists of a metal pedestal that supports a parabolic mirror of brass sheet. At the focus of this parabola there is a spark oscillator consisting of 4 brass spheres, with a wooden and wax paper container surrounding the spark gaps containing vaseline oil. The mirror and the oscillator attached to it are free to rotate around the coupling pin with the pedestal.

English: Replica of experimental microwave spark oscillator invented by Augusto Righi around 1894. These oscillators, connected to an induction coil, radiated radio waves with wavelengths less than 10 centimeters in the microwave band. The parabolic reflector focused the radiation into a beam. This type of spark oscillator, invented by Righi (which was based on previous studies by the scientists of Ginevra De la Rive and Sarazin) consisted of 4 brass spheres. The outer 2 were connected to the induction coil which applied a high voltage causing sparks between the spheres. The two inner spheres acted as resonators radiating the microwaves. The spark gaps were surrounded by a vaseline oil bath which decreased the energy losses. These oscillators were used with a receiver also equipped with a parabolic reflector (see attached photographic documentation and object number 8758). Righi used them to duplicate classical optics experiments with radio waves, using quasioptical components such as lenses and prisms of paraffin and sulfur and wire diffraction gratings to refract and diffract radio waves like light waves, to confirm the historic 1887 experiments of Heinrich Hertz, that radio waves and light waves were both forms of electromagnetic waves, differing only in frequency. Righi's oscillators also had great importance for the development of radio communications; in fact fellow Bolognese Guglielmo Marconi the inventor of practical radio in his first experiments in wireless telegraphy used a Righi type oscillator.