"I know," Morrow said. He sighed wearily. "We've got to do better than this. Take her higher—ram-jets are supposed to work better at high altitude."
"I don't want to go over twelve thousand without oxygen," Smitty replied. "Can't let this wind blow us down over Yosemite National Park, either—if we can help it."
"Take her up," Morrow said.
The ship continued to rise, steadily.
"Eleven thousand," Smitty chanted. "Eleven thousand five hundred, twelve thousand, twelve thousand five—she's flattening out!"
Their ascent slowed, gradually. The ship steadied at thirteen thousand feet above sea-level—7500 feet on the altimeter, which had been zeroed to the altitude of their sawmill workshop.
"Down!" Morrow barked. "She's losing speed!"
The indicator needle was creeping back past thirty-five, then thirty—their sideward shift to the south could be felt. Smitty shoved forward his control wheel. The ship dived.
They glided easily back across the mountain slope toward their sawmill. Judging their wind-drift accurately, Smitty set the ship down in the yard before the black, yawning doors of the building. As the runners scraped the ground, he switched off the gravitors and slumped back in his seat, dejectedly.
"We've got to rebuild that jet chamber," he muttered. "There's something wrong with it, Bill. All we've got is a big wind-blower, in spite of her weightlessness—the drag of the hull wouldn't slow us down that much!"