Presumably his agent--whoever or whatever it might be--was located in some sort of aircraft; for an extremely loud and steady buzzing, suggesting a powerful engine, filled the engineer's borrowed ears. Try as he might, however, he could not identify the sound exactly. It was more like an engine than anything else, except that the separate sounds which comprised the buzz occurred infinitely close together. Smith concluded that the machine was some highly developed rotary affair, working at perhaps six or eight thousand revolutions a minute--three or four times as fast as an ordinary engine. Meanwhile his agent continued to stare into the sky. Shortly something arrived in the field of vision; a blurred speck, far to one side. It approached leisurely, with the unknown agent watching steadfastly. It still remained blurred, however; for a long time the engineer knew as little about its actual form as he knew about his mysterious agent. Then, like a flash, the vision cleared. All the blurring disappeared instantly, and the form of a buzzard was disclosed. It was almost directly overhead, about a quarter of a mile distant, and soaring in a wide spiral. No sound whatever came from it. Smith's agent made no move of any kind, but continued to watch. Shortly the buzzard "banked" for a sharper turn; and the engineer saw, by the perspective of its apparent speed, that the aircraft whose use he was enjoying was likewise on the move. Apparently it was flying in a straight line, keeping the sun--an object vastly too brilliant to examine--on the right. The buzzard went out of sight. Once more the clear sky was all that could be seen; that, and the continual roar of the engine, were all that Smith actually knew. He became impatient for his agent to look elsewhere; it might be that the craft contained other specimens of the unknown creatures. But there was no change in the vigilant watch which was being kept upon the sky. Suddenly the engineer became exceedingly alert. He had noticed something new--something so highly different from anything he had expected to learn that it was some minutes before he could believe it true. His borrowed eyes had no eyelids! At least, if they did, they were never used. Not once did they flicker in the slightest; not once did they blink or wink, much less close themselves for a momentary rest from the sun's glare. They remained as stonily staring as the eyes of a marble statue. Then something startling happened. With the most sickening suddenness the aircraft came to an abrupt halt. Smith's senses swam with the jolt of it. All about him was a confused jumble of blurred figures and forms; it was infinitely worse than his first ride in a hoist. In a moment, however, he was able to examine things fairly well.