“Thunder!” exclaimed Billy; “if that isn’t tough luck.”
“Thunder!” echoed Bart incredulously; “not much. Why, the sky’s as clear as a mirror.”
“Well, it’s queer, certainly,” agreed the others, looking about, but as they saw no cause for the queer noise the auto party got aboard and Frank and Harry mounted in the aeroplane.
The desert in this part of Arizona is full of little dips and rises, and from the dip on a river bank where grew a sparse collection of trees, by which the boys had camped, they had not been able to see far across the plain. As soon as Frank and Harry rose in the air, however, they perceived at once what had been the cause of the rumbling sound they had heard.
Not more than a mile away, and coming toward them like the wind, was one of the deadliest perils of the plains.
They shouted warnings to the boys in the auto below.
“What’s the matter?” yelled back Lathrop, who was at the wheel.
“Matter?” shouted back Frank. “There’s a herd of stampeded cattle coming straight for you.”
The effect of these words on Bart Witherbee was electrical.
“Great guns, boys!” he exclaimed; “that’s the worst news we could have. If we can’t escape them we are as good as dead. Put on all the speed you can.”