Tom flung some iron filings into the tank of water, then switched on the console. Instantly three out of eight lights flashed on, labeled “Fe” for iron.
Several other lights also came on.
“You see, this shows us that three different isotopes of iron are present in the water,” Tom explained, pointing to the lights, “as well as a certain amount of chlorine and some minerals.”
“Brand my boiler scale, that’s plumb wonderful, Tom!” Chow exclaimed.
“Could you cut sign on an enemy sub with them lights?”
“Well, let’s say they’d help clue us in. If we found the right indications, like certain metallic or oil traces, we could guess a submarine had 90 AQUATOMIC TRACKER
passed that way. But to follow a trail, it will take lots more gadgetry than this.”
For the next forty-eight hours Tom worked at a furious pace. Then he flew to Fearing and began installing his tracker on the Sea Hound with the help of Bud, Hank Sterling, and Arv Hanson.
“Sure wish I could help you run that pilot test,” Bud said regretfully, “but I’d hate to miss seeing Mom and Dad in New York.”
Bud’s parents had called from San Francisco saying they would arrive at International Airport at noon and be in New York City for a few hours before embarking on a West Indies cruise.
“You go right ahead and meet your parents-and please give them my regards,” Tom replied. “Hank says he’ll be ‘it’ for our underwater hide-and-seek game.”
The seacopter had been brought to an airfield hangar for the installation job.
Nine long, bell-flared horns projected around the nose of the craft. These, Tom explained, were his repello-spectrograph detectors, or RSG units, with built-in driltometers.