"Do you mean to burn the prairie ahead of us?" panted Pratt. "Yes. We'll have to. I hope nobody will be hurt. But the way that fire is coming back there," said Frances, firmly, "the flames will be ten feet high when they get here." "You don't mean it!" "Yes. You'll see. Pray we may get a burned-over area before us in time to escape. The flames will leap a couple of hundred feet or more before the supply of gas--or whatever it is that burns so high above the ground--expires. The breath of that flame will scorch us to cinders if it reaches us. It will kill and char a big steer in a few seconds. Oh, it is a serious situation we're in, Pratt!" "Can't we keep ahead of it?" demanded the young man, anxiously. "Not for long," replied Frances, with conviction. "I've seen more than one such fire, as I tell you. There! Take this rawhide." The ranchman's daughter was not idle while she talked. She showed him how to knot the length of rawhide which she had produced from under the wagon-seat to one end of his share of the blanket. Her own fingers were busy with the other half meanwhile. "Into your saddle now, Pratt. Take the right-hand side of the trail. Ride as fast as you can toward the river when I give the word. Go a mile, at least." The ponies were urged close to the campfire and he followed Frances' example when she flung the tail of her piece of blanket into the blaze. The blankets caught fire and began to smoulder and smoke. There was enough cotton mixed with the wool to cause it to catch fire quickly. "All right! We're off!" shouted Frances, and spurred her pinto in the opposite direction. Immediately the smouldering blanket-stuff was blown into a live flame. Wherever it touched the dry grass and clumps of low brush fire started like magic. Immediately Pratt reproduced her work on the other side of the trail. At right angles with the beaten path, they fled across the prairie, leaving little fires in their wake that spread and spread, rising higher and higher, and soon roaring into quenchless conflagrations. These patches of fire soon joined and increased to a wider and wider swath of flame. The fire traveled slowly westward, but rushed eastward, propelled by the wind. Wider and wider grew the sea of flame set by the burning blankets. Like Frances, Pratt kept his mount at a fast lope--the speediest pace of the trained cow-pony--nor did he stop until the blanket was consumed to the rawhide knot. Then he wheeled his mount to look back. He could see nothing but flames and smoke at first. He did not know how far Frances had succeeded in traveling with her "flare"; but he was quite sure that he had come more than a mile from the wagon-trail.