“This,” said Karn smugly, “will interest you. Just take a look at it!”

He pushed across the file he had been reading, and for the nth time I decided to ask for his transfer, or failing that, my own.

“What’s it about?” I said wearily.

“It’s a long report from a Dr Matthews to the Minister of Science.” He waved it in front of me. “Just read it!”

Without much enthusiasm, I began to go through the file. A few minutes later I looked up and admitted grudgingly: “Maybe you’re right—this time.” I didn’t speak again until I’d finished…

My dear Minister [the letter began]. As you requested, here is my special report on Professor Hancock’s experiments, which have had such unexpected and extraordinary results. I have not had time to cast it into a more orthodox form, but am sending you the dictation just as it stands.

Since you have many matters engaging your attention, perhaps I should briefly summarize our dealings with Professor Hancock. Until 1955, the Professor held the Kelvin which he was granted indefinite leave of absence to carry out Chair of Electrical Engineering at Brendon University, from which he was granted indefinite leave of absence to carry out his researches. In these he was joined by the late Dr Clayton, sometime Chief Geologist to the Ministry of Fuel and Power. Their joint research was financed by grants from the Paul Fund and the Royal Society.

The Professor hoped to develop sonar as a means of precise geological surveying. Sonar, as you will know, is the acoustic equivalent of radar, and although less familiar is older by some millions of years, since bats use it very effectively to detect insects and obstacles at night. Professor Hancock intended to send high-powered supersonic pulses into the ground and to build up from the returning echoes an image of what lay beneath. The picture would be displayed on a cathode-ray tube and the whole system would be exactly analogous to the type of radar used in aircraft to show the ground through cloud.