 What gives away the location of the lens?
We had left the offices of Interstellar Voice three days ago, Earth time, and now as the immense disc of Jupiter flamed across the sky, entered the outer limits of the Baldric. If my calculations are right, we've hit it at its narrowest spot." He could be excused this time, however, for this was only our third day on Jupiter's Eighth Moon, and the country was still strange to us. Apparently these adjustments moved planes or fins on the kite and accounted for the car's ability to move in any direction. A pontocated glass lens, three or four Wellington radite bulbs, each with a spectroscopic filament, a small dynamo that would operate on a kite windlass, and a quantity of wire and other items.
 Workers were showing their first symptoms after being in the barracks.
 When Billy enters the barracks, he realizes he's being hit by Red Fever.  Workers were showing their first symptoms from working in the mines.  The location was written in the Fever Victims file.  Workers were showing their first symptoms after being in the barracks.