Augusto Righi is an obscure and under-rated figure in radio history. He was an Italian physicist with a tremendous mustache. He also wrote what I believe is the first scientific treatise on wireless telegraphy.His paper The wireless Telegraphy was published in 1903 but it drew upon another two earlier works L'Ottica delle oscillazioni elettriche and Optice Elettrica which he published in 1887 and 1897 respectively. In these Righi discussed his experiments on Hertzian waves. Righi was not alone in trying to reproduce the work of Hertz, but he was uniquely successful, and documented. He tested short electric waves, and compared them to light. He built a small oscillator with a spark gap that jumped between two two spheres in oil as contact points.
In his experiments he found that the spark carbonized the oil which mean that successive sparks we not dampened and therefore more consistent. He also found that the diameter of the spheres changed the wavelength of the generated radio wave. He managed to propagate electric waves as short as 2.5 centimeters, Hertz had only tried them at 30 centimeters in length.This was a small step. Righi was methodical and developed the concept of wave frequency. His work was easy to follow and logical so others could build upon it. What makes him critical is that he passed it to Marconi. Guglielmo Marconi, who studied in Righi’s laboratory at the University of Bologna. Marconi was not actually a student though. Marconi was just auditing his classes as we say now. By 1903 Marconi was publicly thanking Righi for his role in the develpment of the wireless.