ILLUSTRATIONS

[ "Right off there! Look! Look!" The lanky cow puncher pointed out
beyond the shadow of the solitary mesa . . . . . . Frontispiece ]

[ As it flared up, all three recoiled with expressions of dismay.
At their very feet was a deep chasm. ]

[ A tempest of lead rattled about the engine. Almost before they
realized it, they had swung around the curve. ]