Mark ventured a question. "Frequency Tuner? Is that what gave you the acceleration? I knew it wasn't rocket power!"
Brownell turned piercing black eyes upon him. "Eh? Janus, who is this?"
Janus vouched for Mark, explained his presence aboard. He added: "The Bureau's after an invention of his, too. A camera."
The Professor was startled. "Did you say a camera? Since when do they—"
"Ah, but Mark's is a very special camera." Janus smiled maddeningly, but in the next instant was clapping a friendly hand on Mark's shoulder. "Don't worry, Travers, your secret's safe with us. We don't ask questions. You've a right to know our destination, though; come on, I'll show you."
They repaired to the chart room, where Janus indicated a moving red line on a glass-encased chart of the solar system. Other lines were being traced, too, at various angles to their trajectory.
"The red line is our present trajectory. The others are the orbits of the planets. See, there's Jupiter behind us; notice how close we came."
Mark nodded. Already in his mind's eye he was extending their present parabola. Distances between these outer planets were vast beyond imagining! Saturn was just in sight, but at their present speed they would probably cross its orbit far in advance of the planet. Then came Uranus, and next Neptune. The space between Neptune and Pluto was vaster than all.
Mark felt just a little staggered. There was no known record of men having come this far! Not beyond Jupiter, in fact.
He turned to Janus. "How far do we go?"