Shortly after the second UFO-radiation episode the research group finished its work. It was at this time that the scientist had first become aware of the incidents he related to me. A friend of his, one of the men involved in the sightings, had sent the details in a letter.

As the story of the sightings spread it was widely discussed in scientific circles, with the result that the conclusion, an equipment malfunction, began to be more seriously questioned. Among the scientists who felt that further investigation of such phenomena was in order, were the man to whom I was talking and some of the people who had made the original sightings.

About a year later the scientist and these original investigators were working together. They decided to make a few more tests, on their own time, but with radiation- detection equipment so designed that the possibility of malfunction would be almost nil. They formed a group of people who were interested in the project, and on evenings and weekends assembled and set up their equipment in an abandoned building on a small mountain peak. To insure privacy and to avoid arousing undue interest among people not in on the project, the scientist and his colleagues told everyone that they had formed a mineral club. The "mineral club" deception covered their weekend expeditions because "rock hounds" are notorious for their addiction to scrambling around on mountains in search for specimens.

The equipment that the group had installed in the abandoned building was designed to be self-operating. Geiger tubes were arranged in a pattern so that some idea as to the direction of the radiation source could be obtained. During the original sightings the equipment- malfunction factor could not be definitely established or refuted because certain critical data had not been measured.

To get data on visual sightings, the "mineral club" had to rely on the flying saucer grapevine, which exists at every major scientific laboratory in the country.

By late summer of 1950 they were in business. For the next three months the scientist and his group kept their radiation equipment operating twenty-four hours a day, but the tapes showed nothing except the usual background activity. The saucer grapevine reported sightings in the general area of the tests, but none close to the instrumented mountaintop.

The trip to the instrument shack, which had to be made every two days to change tapes, began to get tiresome for the "rock hounds," and there was some talk of discontinuing the watch.

But persistence paid off. Early in December, about ten o'clock in the morning, the grapevine reported sightings of a silvery, circular- shaped object near the

When the "rock hounds" checked the recording tapes in the shack they found that several of the Geiger tubes had been triggered at 10:17A.M. The registered radiation increase was about 100 times greater than the normal background activity.

Three more times during the next two months the "mineral club's" equipment recorded abnormal radiation on occasions when the grapevine reported visual sightings of UFO's. One of the visual sightings was substantiated by radar.

After these incidents the "mineral club" kept its instruments in operation until June 1951, but nothing more was recorded. And, curiously enough, during this period while the radiation level remained normal, the visual sightings in the area dropped off too. The "mineral club" decided to concentrate on determining the significance of the data they had obtained.

Accordingly, the scientist and the group made a detailed study of their mountaintop findings. They had friends working on many research projects throughout the United States and managed to visit and confer with them while on business trips. They investigated the possibility of unusual sunspot activity, but sunspots had been normal during the brief periods of high radiation. To clinch the elimination of sunspots as a cause, their record tapes showed no burst of radiation when sunspot activity had been abnormal.

The "rock hounds" checked every possible research project that might have produced some stray radiation for their instruments to pick up. They found nothing. They checked and rechecked their instruments, but could find no factor that might have induced false readings. They let other scientists in on their findings, hoping that these outsiders might be able to put their fingers on errors that had been overlooked.

Now, more than a year after the occurrence of the mysterious incidents that they had recorded, a year spent in analyzing their data, the "rock hounds" had no answer.

By the best scientific tests that they had been able to apply, the visual sightings and the high radiation had taken place more or less simultaneously.

Intriguing ideas are hard to kill, and this one had more than one life, possibly because of the element of mystery which surrounds the subject of flying saucers. But the scientific mind thrives on taking the mystery out of unexplained events, so it is not surprising that the investigation went on.

According to my friend the scientist, a few people outside the laboratory where the "rock hounds" worked were told about the activities of the "mineral club," and they started radiation- detection groups of their own.