After the plates were developed, they had two successful spectrographs for comparison. One was taken from the metal of a failed-engine part. The other was from the atmospheric dust. In the comparator Vickers brought the corresponding standard comparison lines together. For a long time he peered through the eyepiece.
"A lot of lines match up," he said. "I can throw out most of them, though—carbon, oxygen, a faint sodium."
"The stuff that's giving us trouble might be a compound of one of these," said Ken.
"That's right. If so, we ought to find matching lines of other possible elements in the compounds concerned. I don't see any reasonable combination at all." He paused. "Hey, here's something I hadn't noticed."
He shifted the picture to the heavy end of the spectrum. There, a very sharp line matched on both pictures. The boys took a look at it through the viewer. "What is that one?" Ken asked.
"I don't know. I used a carbon standard. I should have used one farther toward the heavy end. This one looks like it would have to be a transuranic element, something entirely new, like plutonium."
"Then it could be from the hydrogen bomb tests," said Joe.
"It could be," said Vickers, "but somehow I've got a feeling it isn't."
"Isn't there a quick way to find out?" said Ken.
"How?"