At one of those meetings, which took place toward the end of 1887, many scientific giants of the university were present and Helmholtz presided. There was an atmosphere of expectancy as if something unusual was going to happen. Helmholtz rose and looked more solemn than ever, but I noticed a light of triumph in his eyes; he looked like a Wotan gazing upon the completed form of heavenly Walhalla, and I felt intuitively that he was about to disclose an unusual announcement, and he did. Referring to Doctor Heinrich Hertz, a former pupil of his and at that time professor of physics at the Technical High School in Karlsruhe, Helmholtz solemnly announced that he would describe some remarkable experimental results which Hertz had obtained by means of very rapid electrical oscillations. He then described in his inimitable way a preliminary report which Hertz had sent him, pointing out, in a most lucid manner, the bearing of these experiments upon the Faraday-Maxwell electromagnetic theory, and affirming that these experiments furnished a complete experimental verification of that remarkable theory. Everybody present was thrilled, particularly when Helmholtz closed with a eulogy of his beloved pupil, Hertz, and with a congratulation to German science upon the good fortune of adding another “beautiful leaf to its laurel wreath.” That thrill soon reached the physicists in every physical laboratory in the world; and for a number of years after that memorable announcement most investigators in physics were busy repeating the beautiful Hertzian experiments. The radio of to-day is an offshoot of those experiments. This is no place to go into a detailed description of what Hertz did. The fundamental idea underlying his beautiful research and its relation to the Faraday-Maxwell far-reaching electromagnetic theory can be described in very simple terms. The wonderful achievements of radio broadcasting alone, to say nothing of other much more important achievements, demand this description. That idea, like the tiny seed hidden in a beautiful flower, lay hidden in Faraday’s visions and in Maxwell’s wonderful, but, to most ordinary mortals, enigmatic interpretation of them. Hertz, guided by his great teacher, Helmholtz, caught the hidden seed and out of it grew a physical embodiment of the Faraday-Maxwell theory, represented by ideally simple apparatus, operating in an ideally simple way. The apparatus and its operation are now the heart and soul of a new art, the radio art, a beautiful daughter of the beautiful mother, the Faraday-Maxwell electromagnetic science. The following description of Hertz’s apparatus and of its operation was the theme of popular lectures and of many conversations which I had with my friends who were not physicists by profession. It represents quite closely the simple picture which I carried away in my mind from that memorable meeting of the Berlin Physical Society thirty-six years ago. [Illustration: THE HERTZIAN OSCILLATOR]