The early history of radio is the history of technology that produces and uses radio instruments that use radio waves. Within the timeline of radio, many people contributed theory and inventions in what became radio. Radio development began as "wireless telegraphy". Later radio history increasingly involves matters of broadcasting. Discovery In an 1864 presentation, published in 1865, James Clerk Maxwell proposed theories of electromagnetism, with mathematical proofs, that showed that light and predicted that radio and x-rays were all types of electromagnetic waves propagating through free space. Between 1886 and 1888 Heinrich Rudolf Hertz published the results of experiments wherein he was able to transmit electromagnetic waves (radio waves) through the air, proving Maxwell's electromagnetic theory. Exploration of optical qualities After their discovery many scientists and inventors experimented with transmitting and detecting "Hertzian waves" (it would take almost 20 years for the term "radio" to be universally adopted for this type of electromagnetic radiation). Maxwell's theory showing that light and Hertzian electromagnetic waves were the same phenomenon at different wavelengths led "Maxwellian" scientists such as John Perry, Frederick Thomas Trouton and Alexander Trotter to assume they would be analogous to optical light. Following Hertz' untimely death in 1894, British physicist and writer Oliver Lodge presented a widely covered lecture on Hertzian waves at the Royal Institution on June 1 of the same year. Lodge focused on the optical qualities of the waves and demonstrated how to transmit and detect them (using an improved variation of French physicist Édouard Branly's detector Lodge named the "coherer"). Lodge further expanded on Hertz' experiments showing how these new waves exhibited like light refraction, diffraction, polarization, interference and standing waves, confirming that Hertz' waves and light waves were both forms of Maxwell's electromagnetic waves. During part of the demonstration the waves were sent from the neighboring Clarendon Laboratory building, and received by apparatus in the lecture theater. After Lodges demonstrations researchers pushed their experiments further down the electromagnetic spectrum towards visible light to further explore the quasioptical nature at these wavelengths. Oliver Lodge and Augusto Righi experimented with 1.5 and 12 GHz microwaves respectively, generated by small metal ball spark resonators.. Russian physicist Pyotr Lebedev in 1895 conducted experiments in the 50 GHz 50 (6 millimeter) range. Bengali Indian physicist Jagadish Chandra Bose conducted experiments at wavelengths of 60 GHz (5 millimeter) and invented waveguides, horn antennas, and semiconductor crystal detectors for use in his