“As a particle of the atmosphere is never lost, so sound is never lost. A strain of music or a simple tone will vibrate in the air forever and ever, decreasing according to a fixed ratio. The diffusion of the agitation extends in all directions, like the waves in a pool, but the ear is unable to detect it beyond a certain point. It is well known that some individuals can distinguish sounds which to others under precisely similar circumstances are wholly lost. Thus the fault is not in the sound itself, but in our organ of hearing, and a tone once in existence is always in existence.” This was nothing new to me. I had read it before, though I had never thought of it particularly; but while I listened to the robin, it seemed singular to know that all the sounds ever uttered, ever born, were floating in the air _now_—all music, every tone, every bird-song—and we, alas! could not hear them. Suddenly a strange idea shot through my brain—Why not? Ay, _why not hear_? Men had constructed instruments which could magnify to the eye and—was it possible?—Why not? I looked up and down the river, but saw neither it, nor the sky, nor the moss that I touched. Did the woodpecker still tap secreted among the leaves, and the robin sing, and the hum of insects run along the bank as before? I can not recollect, I can not recollect anything, only Mother Flinse, the deaf and dumb old crone that occasionally came to beg, and sell nuts to the students, was standing in the gateway. I nodded to her as I passed, and walked up her long, slim shadow that lay on the path. It was a strange idea that had come so suddenly into my head and startled me. I hardly dared to think of it, but I could think of nothing else. It could not be possible, and yet—why not? Over and over in the restless hours of the night I asked myself, I said aloud, Why not? Then I laughed at my folly, and wondered what I was thinking of and tried to sleep—but if it _could_ be done? The idea clung to me. It forced itself up in class hours and made confusion in the lessons. Some said the professor was ill those two or three days before the vacation; perhaps I was. I scarcely slept; only the one thought grew stronger—Men had done more wonderful things; it certainly was possible, and I would accomplish this grand invention. I would construct the king of all instruments—I would construct an instrument which could catch these faint tones vibrating in the air and render them audible. Yes, and I would labor quietly until it was perfected, or the world might laugh. The session closed and the college was deserted, save by the few musty students whom, even in imagination, one could hardly separate or distinguish from the old books on the library shelves. I could wish for no better opportunity to begin my great work. The first thing would be to prepare for it by a careful study of acoustics, and I buried myself among volumes on the philosophy of sound.