"But a deadly corrosive acid," finished the speaker, "yes! Happily, the 'seas' of Titan do not cover such a share of the planet's surface as do those of Earth; if they did, no life—either flora or fauna—would ever have developed upon the little world."
His heavy shoulders shivered.
"Still ... imagine frothing, tide-swept lakes as large as Lake Erie or Victoria Nyanza splashing endlessly at shores until inch by inch and foot by foot those beaches are eroded, rotted, eaten away by the action of the fluid they contain! These are the 'oceans' of Titan. There are four of them, fed by subterranean sources we have not yet discovered. One day they will have completely devoured the parent planet, and Titan will cease to be."
"But that day, of course," interposed the girl, "is a long way off. Is this the only physiological danger?"
"There is one even more dreadful. The T-radiation."
"T-radiation? What is that?"
Grossman smiled mirthlessly.
"Were I able to tell you, I should be a greater physicist than any who have so far visited Titan. Dozens of the wisest have come, probed, pondered, analyzed ... and left Titan none the wiser for their efforts. Frankly, they do not know! The very name 'T-radiation' is an admission of their failure. It is simply an abbreviation for 'Titan-radiation.' It is an electro-magnetic or radioactive emanation lethal to humans ... that is all they know about it."
Young Dr. Roswell wiped his spectacles carefully and interrupted, "But ... er ... but surely, Factor, these physicists were able to determine the wave-length of the radiation? Did that not tell them—?"
Grossman said bluntly, almost rudely, "The radiation lies in the Hertzian range, Doctor Roswell. Does that knowledge help you any? Perhaps now you can tell us why these rays are deadly?"