 What main motivation did Antler Park have to leave the lens in the barracks?
What with red-spot fever, talking cockatoos and flagpole trees, I was running in circles—especially since Grannie became twins every now and then. 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. Blood-and-thunder as these books are, however, they have one redeeming feature—authenticity of background. Grannie Annie was the original research digger-upper, and when she laid the setting of a yarn on a star of the sixth magnitude, only a transportation-velocity of less than light could prevent her from visiting her "stage" in person. He was an old prospector Grannie had met, and he had become so attached to the authoress he now followed her wherever she went. As for Xartal, he was a Martian and was slated to do the illustrations for Grannie's new book. And then I was shaking hands with Antlers Park, the manager of I. V. himself. Antlers Park flicked the ash from his cheroot and shrugged. It's no use to the people of Earth but of untold value on Mars. Then it was found that this ore, Acoustix, revitalized their sounding apparatus, and the rush was on." "But up until now this moon is the only place where it can be found. So now here we were at the outer reaches of the Baldric, four travelers on foot with only the barest necessities in the way of equipment and supplies. Xartal, the Martian illustrator, already had a notebook in his hands and was sketching a likeness of the creature. Attached to its hood was a taut wire which slanted up into the sky to connect with the kite. Occasionally he touched a stud on an electric windlass to which the kite wire was attached. Apparently these adjustments moved planes or fins on the kite and accounted for the car's ability to move in any direction. "They walk out into the Baldric," he continued, "and nothing can stop them. "There's all kinds of rumors," he replied, "but none of them will hold water. Fully two hundred cockatoos were perched upon it. After that we were rolling up the driveway that led to the offices of Larynx Incorporated .
 He knew the value of this spot for Acoustix, and wanted to run the Jimmy Baker out.
 He didn't fully understand the effects of the infra-red rays and wanted to see what it was capable of.  He knew the value of this spot for Acoustix, and wanted to run the Jimmy Baker out.  He was afraid of Grannie Annie discovering his plot and tried to get rid of her.  He had struck a large load of Acoustix and wanted to hide the evidence.