"It's better than being so raging hot," said Paul. "It makes my head ache to ride when it's so fearfully hot."
"If it only don't rain," returned Chet. "We need it bad enough, goodness knows, but it has held off so long it might as well hold off twenty-four hours longer."
"I doubt if we get rain just yet. It hasn't threatened long enough," replied his brother.
Before the two left the ranch they saw to it that every building was locked up tight, and an alarm, in the shape of a loaded gun, set to the doors and windows.
"That ought to scare would-be thieves away," said Chet. "They'll imagine somebody is firing at them."
The rest for a couple of days had done Rush much good, and he made no work of carrying the two boys along the trail that led to the second foothills.
Long before noon they reached the hills, and here stopped for lunch.
"And now for the wonderful mine!" cried Chet. Then, happening to glance across the plains below, he added: "Gracious, Paul! What is that?"
The attention of both young ranchmen was at once drawn to a round, black cloud on the horizon to the east. It was hardly a yard in diameter, apparently, when first seen, but it increased in size with great rapidity.
It was moving directly toward them, and in less than two minutes from the time Chet uttered his cry it had covered fully a third of the distance.