Sound and light being associated in my young mind of fifty years ago with divine operations by means of which man communicates with man, beast with beast, stars with stars, and man with his Creator, it is obvious that I meditated much about the nature of sound and of light. I still believe that these modes of communication are the fundamental operations in the physical universe and I am still meditating about their nature. My teachers in Panchevo rendered some assistance in solving many of the puzzles which I met in the course of these meditations. Kos, my Slovenian teacher, who was the first to tell me the story of Franklin and his kite, was a great help. He soon convinced me that sound was a vibration of bodies. This explanation agreed with the Serbian figure of speech which says: “My heart quivers like the melodious string under the guslar’s bow.” I also felt the quivering air whenever during my term of service as guardian of the oxen I tried my skill at the Serbian flute. Few things excited my interest more than the operations of the Serbian bagpiper as he forced the air from his sheepskin bellows and made it sing by regulating its passage through the pipes. The operations which the bagpiper called adjustment and tuning of the bagpipes commanded my closest attention. I never dreamed then that a score of years later I should do a similar operation with an electrical circuit. I called it “electrical tuning,” a term which has been generally adopted in wireless telegraphy. But nobody knows that the operation as well as the name were first suggested to me by the Serbian bagpiper, some twenty years before I made the invention in 1892. Skipping over several sections of my story, I will say now that twenty years after my invention of electrical tuning a pupil of mine, Major Armstrong, discovered the electrical vacuum-tube oscillator, which promises to revolutionize wireless telegraphy and telephony. A similar invention, but a little earlier, was made by another pupil of mine, Mr. Vreeland. Both these inventions in their mode of operation remind me much of the operation of Serbian bagpipes. Perhaps some of those thrills which the Serbian bagpiper stirred up in me in my early youth were transferred to my pupils, Armstrong and Vreeland. * * * * * I was less successful in solving my puzzles concerning the nature of light. Kos, the Slovenian, my first guide and teacher in the study of physical phenomena, told me the story that a wise man of Greece with the name of Aristotle believed that light originates in the eye, which throws out feelers to the surrounding objects, and that through these feelers we see the objects, just as we feel them by our sense of touch. This view did not agree with the popular saying often heard in Idvor: “Pick your grapes before sunrise, before the thirsty sunbeams have drunk up their cooling dew.” Nor did it agree with Bishop Nyegosh, the greatest of Serbian poets, who says: