In a moment he had his shoes on and was racing down the stairs. "What"s happened, Art? Anything gone wrong?"
The mechanic looked downcast. "Everything! We got the Norton elevator motor and hooked it up with the gas engine. It ran fine for a couple of days, and we got a lot of batteries charged up."
"Then it quit," said Ken.
"Yeah--how did you know?"
"I"ve been afraid we had missed one bet. It just isn"t enough to supply filtered air to the engines built of new parts. The parts themselves are already contaminated with the dust. As soon as they go into operation, we have the same old business, all over again.
"Unless some means of decontamination can be found these new parts are no better than the old ones."
"Some of these parts were wrapped in tissue paper and sealed in cardboard boxes!" Art protested. "How could enough dust get to them to ruin them?"
"The dust has a way of getting into almost any corner it wants to," said Ken. "Dad and the others have found it has a tremendous affinity for metals, so it seeps through cracks and sticks. It never moves off once it hits a piece of metal. What parts of the engine froze?"
"Pistons, bearings--just like all the rest."
"The generator shaft, too?"
Art nodded. "It might have gone a few more revolutions. It seemed loose when we started work, but as soon as we broke the bearings apart they seemed to fasten onto the shaft like they were alive. How do you account for that? The bearings were new; I just cast them yesterday."
"They were contaminated by dust between casting and installation in the protected room. We"ve got to dig a lot deeper before we"ve got the right answer. It might be worthwhile setting up another rig just like the one we have in order to get some more juice in our batteries. Do you think you could do it again, or even several times? That engine lasted about 90 hours, didn"t it?"
"Eighty-eight, altogether. I suppose I could do it again if you think it"s worth it. The trouble is getting generators. Maybe we could machine the shaft of this one and cast a new set of bearings to fit. I"ll try if you think it"s worth it."
"Get it ready to run," said Ken. "The battery power for our radio isn"t going to last forever. We"ll be in a real jam if we lose touch with the outside."
Chapter 11. _The Animals Are Sick_
That night, Ken reported to his father the fate of the engine a.s.sembled by Art.
"It did seem too good to be true," said Professor Maddox. He stretched wearily in the large chair by the feeble heat of the fireplace. "It bears out our observation of the affinity of the dust for metals."
"How is that?"
"It attaches itself almost like a horde of microscopic magnets. It literally burrows into the surface of the metal."
"You don"t mean that!"
"I do. Its presence breaks down the surface tension, as we had supposed.
The substance actually then works its way into the interstices of the molecules. As the colloid increases in quant.i.ty, its molecules loosen the bond between the molecules of the metal, giving them increased freedom of motion.
"This can be aggravated by frictional contacts, and finally we have the molecular interchange that binds the two pieces into one."
"The only metal that would be clean would be that which had been hermetically sealed since before the appearance of the comet," said Ken.
"Look--wouldn"t this affinity of the dust for metal provide a means of purifying the atmosphere? If we could run the air through large filters of metal wool, the dust would be removed!"
"Yes, I"m very sure we could do it that way. It would merely require that we run the atmosphere of the whole Earth through such a filter. Do you have any idea how that could be done?"
"It would work in the laboratory, but would be wholly impractical on a worldwide scale," Ken admitted. "How will we ever rid the atmosphere of the dust! A colloid will float forever in the air, even after the comet is gone."
"Exactly," Professor Maddox said, "and, as far as we are concerned, the whole atmosphere of the Earth is permanently poisoned. Our problem is to process it in some manner to remove that poison.
"During the past few days we have come to the conclusion that there are only two alternatives: One is to process the whole atmosphere by pa.s.sing it through some device, such as the filter you have suggested. The second is to put some substance into the air which will counteract and destroy the dust, precipitate it out of the atmosphere."
"Since the first method is impractical what can be used in carrying out the second?"
"We"ve set ourselves the goal of discovering that. We"re hoping to synthesize the necessary chemical compound to accomplish it."
"It would have to be a colloid, too, capable of suspension in the atmosphere," said Ken.
"Correct."
"If we do find such a substance we still have the problem of decontaminating existing metals. We couldn"t build a moving piece of machinery out of any metal now in existence without first cleaning the dust out of its surface."
"That"s part of the problem, too," said his father.
Ken resumed his duties in the laboratory the following morning. Dr.
Adams had warned him not to walk up College Hill, so he had borrowed the horse Dave Whitaker still had on loan from his uncle. He felt self-conscious about being the only one enjoying such luxury, but he promised himself he would go back to walking as soon as Dr. Adams gave permission.
On the third day, the horse slipped and fell as it picked its way carefully down the hill. Ken was thrown clear, into the deep snow, but the horse lay where it had fallen, as if unable to move. Ken feared the animal had broken a leg. He felt cautiously but could find no evidence of injury.
Gently, he tugged at the reins and urged the horse to its feet. The animal finally rose, but it stood uncertainly and trembled when it tried to walk again.
Ken walked rather than rode the rest of the way home. He took the horse to the improvised stable beside the science shack. There he got out the ration of hay and water, and put a small amount of oats in the trough.
The animal ignored the food and drink.
After dinner, Ken went out again to check. The horse was lying down in the stall and the food remained untouched.
Ken returned to the house and said to his father, "Dave"s horse slipped today, and I"m afraid something serious is wrong with him. He doesn"t seem to have any broken bones, but he won"t eat or get up. I think I should go for the vet."
His father agreed. "We can"t afford to risk a single horse, considering how precious they are now. You stay in the house and I"ll go to Dr.
Smithers" place myself."
Ken protested. He hated to see his father go out again on such a cold night.
Dr. Smithers grumbled when Professor Maddox reached his house and explained what he wanted. As one of the town"s two veterinarians, he had been heavily overworked since the disaster struck. The slightest sign of injury or illness in an animal caused the Mayor"s livestock committee to call for help.
"Probably nothing but a strained ligament," Smithers said. "You could have taken care of it by wrapping it yourself."
"We think you ought to come."