Obviously this solution does not identify the particular beacon, searchlight, or other ground light that produced the Chesapeake Bay disks. But it does offer a highly probable explanation that is consistent with all the observations and does not depend on the presence of an extraterrestrial spacecraft. _Other UFOs in “Stack” Formation_ A correspondent has reported a UFO sighting very similar to the Norfolk case, almost certainly produced by the mechanism just described. In the late spring of 1955 a physicist, Mr. Z, was driving west on the highway between Dayton and Yakima, Washington, in a region of low-lying hills. The time was shortly after dark; the sun had set but there was still a suggestion of light in the west. Suddenly a line of five glowing UFOs appeared in the western sky, apparently three to five miles away, traveling east at high speed, and accelerating as they approached. Flying in a “stack” with the leading saucer on top, the individual saucers were oriented in horizontal planes, but each follower was lower than and somewhat behind its predecessor so that the entire formation was “like a stack of pancakes” leaning at about a 45-degree angle toward the direction of flight. (Note that this arrangement is the reverse analogue of that of the Chesapeake Bay UFOs.) The top saucer advanced more rapidly than the bottom one, so that as they flashed through the sky at the left of the observer they appeared to be in single file. Startled, he stopped his car and got out to scan the sky, but the saucers had disappeared. Some fifteen to twenty seconds later a similar formation appeared in the west. As they approached he could see that they were thin, flat disks, glowing with a white light, sharply defined and circular in shape, and apparently fifty to a hundred feet in diameter. As they passed, the stack again spread out into single file. When they were apparently about ten miles east, the three lead saucers suddenly disappeared, while the two that had been on the bottom made a sharp turn to the north, as abruptly as balls bouncing off a wall. Concluding that the saucers might be images produced by an airfield beacon shining upward through very thin horizontal clouds, the observer continued to watch. They reappeared again and again, sometimes at the correct interval for an airfield beacon, but sometimes delaying for two or three minutes. To explain their occasional failure to appear on schedule, he reasoned that some very dense, fast-moving, low-lying clouds must lie in the west between him and the beacon, so that sometimes the light could penetrate to shine on the assumed stratified layers overhead, and sometimes not. After twenty minutes or so, the appearance of the phenomenon changed. The top three saucers merged gradually into an indistinct blur, while the bottom two remained sharp and distinct and continued to dart abruptly to the north just before disappearing.