With a wise look, Chow nodded approval.
Tom said that the job of setting up the listening posts would begin immediately. The necessary building material and equipment would be hauled to each location by dog team and snowmobile.
A short time later the first team of technicians set out from the base. In the lead was the snowmobile, plowing a trail through the crusted snow with its blunt nose and wide caterpillar treads. Behind came the dog-team freight sled, guided by Colonel Eagle Friend and loaded down with additional supplies and equipment.
Work went ahead rapidly on the three listening posts. In the one nearest the digging site, Voorhees installed special temperature recorders. These would pick up readings from delicate thermal-measuring devices inside the blaster, and thus show the earth’s temperature at every point as the blaster went down deeper and deeper.
Before launching the blaster, Tom double-checked his depth soundings. He wanted to make sure how soon he could expect to hit solid rock.
Just as the geophones were being connected, a si-160 TOM SWIFT AND HIS ATOMIC BLASTER
ten screeched. This was the alarm signal from the radarman.
“It’s another air raid!” Blake shouted, as all hands made a dash for their emergency stations.
A moment later the same jet bomber that had buzzed the camp before came roaring down out of the skies. But again it passed over harmlessly-this time without even dropping a message.
Puzzled and somewhat worried, Tom gave the all-clear signal for his aides to return to work. They had hardly resumed their tasks, however, when once again the siren shrieked.