Zircon took the skin and ran his finger tips over the lining. He held it up so that it caught the light, then looked at Rick curiously. "That's odd," he muttered. "This is certainly a goatskin. And almost surely, this is a plastic lining. I can't be sure, of course, but I've never seen anything like this in nature."
"It's a goatskin water bag," Rick said excitedly. He pointed to Ko. "He had a dozen of them."
Zircon bellowed, "So! Then if this is plastic...."
"It was a clever stunt," Rick finished. "No one would suspect coolies toting goatskin water bags. And even if anyone did suspect, he wouldn't be able to tell anything by a casual examination."
Sing scratched his head. "Forgive my stupidity," he said. "The suspicious one wouldn't be able to tell what? If this lining is plastic, it is a senseless waste. Water keeps cool in a goatskin bag because of evaporation through the pores. It certainly couldn't evaporate through plastic."
"No," Zircon agreed. "That is the idea. They don't want evaporation. Also, the plastic guarantees the water's purity."
Sing said no more, but he was obviously puzzled. Nor could the Americans tell him what had excited them, that they had found the means by which the substance they sought was carried to the coast.
Rick had a quick vision of Chinese coolies making their slow way through the countryside, unnoticed because water-bearers were so commonplace. But the coolies in this case carried bags lined with plastic, and the stuff that made the legs thrust out stiffly and that swelled the bag was not ordinary water! It was the stuff which had brought them halfway across the world.