Shortly thereafter I started for the Sahara in search of a rather rare species of antelope that is to be found only occasionally within a limited area at a certain season of the year. My chase led me far from the haunts of man. It was a fruitless search, however, in so far as antelope is concerned; but one night as I lay courting sleep at the edge of a little cluster of date-palms that surround an ancient well in the midst of the arid, shifting sands, I suddenly became conscious of a strange sound coming apparently from the earth beneath my head. It was an intermittent ticking! No reptile or insect with which I am familiar reproduces any such notes. I lay for an hour—listening intently. At last my curiosity got the better of me. I arose, lighted my lamp and commenced to investigate. My bedding lay upon a rug stretched directly upon the warm sand. The noise appeared to be coming from beneath the rug. I raised it, but found nothing—yet, at intervals, the sound continued. I dug into the sand with the point of my hunting-knife. A few inches below the surface of the sand I encountered a solid substance that had the feel of wood beneath the sharp steel. Excavating about it, I unearthed a small wooden box. From this receptacle issued the strange sound that I had heard. How had it come here? What did it contain? In attempting to lift it from its burying place I discovered that it seemed to be held fast by means of a very small insulated cable running farther into the sand beneath it. My first impulse was to drag the thing loose by main strength; but fortunately I thought better of this and fell to examining the box. I soon saw that it was covered by a hinged lid, which was held closed by a simple screwhook and eye. It took but a moment to loosen this and raise the cover, when, to my utter astonishment, I discovered an ordinary telegraph instrument clicking away within. “What in the world,” thought I, “is this thing doing here?” That it was a French military instrument was my first guess; but really there didn’t seem much likelihood that this was the correct explanation, when one took into account the loneliness and remoteness of the spot. As I sat gazing at my remarkable find, which was ticking and clicking away there in the silence of the desert night, trying to convey some message which I was unable to interpret, my eyes fell upon a bit of paper lying in the bottom of the box beside the instrument. I picked it up and examined it. Upon it were written but two letters: D. I. They meant nothing to me then. I was baffled. Once, in an interval of silence upon the part of the receiving instrument, I moved the sending-key up and down a few times. Instantly the receiving mechanism commenced to work frantically.