enemy, now charging rapidly through the dry, inflammable low growth, now creeping stealthily in the needles and among the rocks; always making way, always gathering itself for one of its wild leaps which should lay an entire new province under its ravaging. Somewhere on the other side of that ring of fire were four men. They were trying to cut a lane over which the fire could not leap.

Bob gazed at the wall of flame with some dismay. "How we going to get through?" he asked.

"We got to find a rock outcrop somewheres up the ridge," explained Jack, "where there'll be a break in the fire."

He turned up the side of the mountain again, leading the way. After a time they came to an outcrop of the sort described, which, with some difficulty and stumbling, they succeeded in crossing.

Ahead, in the darkness, showed a tiny licking little fire, only a few inches high.

"The fire has jumped!" cried Bob.

"No, that's their backfire," Pollock corrected him. They found this to be true. The rangers had hastily hoed and raked out a narrow path. Over this a very small fire could not pass; but there could be no doubt that the larger conflagration would take the slight obstacle in its stride. Therefore the rangers had themselves ignited the small fire. This would eat away the fuel, and automatically widen the path. Between the main fire and the back fire were still several hundred yards of good, unburned country. To Bob's expression of surprise Amy added to the two principles of fire-fighting he had learned from Pollock.

"It doesn't do to try to stop a fire anywhere and everywhere," said she. "A good man knows his country, and he takes advantage of it. This fire line probably runs along the line of natural defence."

They followed it down the mountain for a long distance through the eddying smoke. The flames to their right shot up and died and crept. The shadows to their left

their own among the number-leaped and fell. After a while, down through the mists, they made out a small figure, very busy at something. When they approached, they found this to be Charley Morton. The fire had leaped the cleared path and was greedily eating in all directions through the short, pitchy growth of tarweed. It was as yet only a tiny leak, but once let it get started, the whole forest beyond the fire line would be ablaze. The ranger had started to cut around this a half-circle connected at both ends with the main fire line. With short, quick jabs of his hoe, he was tearing away at the tough tarweed.

"Hullo!" said he without looking up. "You'll find camp on the bald ridge north the fire line. There's a little feed there."

Having completed his defence, he straightened his back to look at them. His face was grimed a dingy black through which rivulets of sweat had made streaks.

"Had it pretty hot all afternoon," he proffered. "Got the fire line done, though. How're those canteens-full? I'll trade you my empty one." He took a long draught. "That tastes good. Went dry about three o'clock, and haven't had a drop since."

They left him there, leaning on the handle of his hoe. Jack Pollock seemed to know where the place described as the camp-site was located, for after various détours and false starts, he led them over the brow of a knoll to a tiny flat among the pine needles where they were greeted by whinnies from unseen animals. It was here very dark. Jack scraped together and lit some of the pine needles. By the flickering light they saw the four saddles dumped down in a heap.

"There's a side hill over yander with a few bunches of grass and some of these blue lupins," said Jack. "It ain't much in the way of hoss-feed, but it'll have to do."

He gathered fuel and soon had enough of a fire to furnish light.

"It certainly does seem plumb foolish to be lightin' more fires!" he remarked.

In the meantime Amy had unsaddled her own horse and was busy unpacking one of the pack animals. Bob followed her example.

"There," she said; "now here are the canteens, all full; and here's six lunches already tied together that I put up before we started. You can get them to the other boys. Take your tools and run along. I'll straighten up, and be ready for you when you can come back."

"What if the fire gets over to you?" asked Bob.

"I'll turn the horses loose and ride away," she said gaily. "It won't get clost to there," put in Jack. "This little ridge is rock all round it. That's why they put the camp here."

"Where's water?" asked Amy.

"I don't rightly remember," confessed Pollock. "I've only been in here once."

"I'll find out in the morning. Good luck!"

Jack handed Bob three of the canteens, a hoe and rake and one of the flat files.

"What's this for?" asked Bob.

"To keep the edge of your hoe sharp," replied Jack. They shouldered their implements and felt their way in the darkness over the tumbled rock outcrop. As they surmounted the shoulder of the hill, they saw once more flickering before them the fire line.

C

V

HARLEY MORTON received the lunch with joy. "Ain't had time to get together grub since we came," said he, "and didn't know when I would." "What do you want us to do?" asked Bob.

"The fire line's drawn right across from Granite Creek down there in the cañon over to a bald dome. We got her done an hour ago, and pretty well back-fired. All we got to do now is to keep her from crossing anywheres; and if she does cross, to corral her before she can get away from us." "I wish we could have got here sooner!" cried Bob, disappointed that the little adventure seemed to be flattening out.

"So?" commented Charley drily. "Well, there's plenty yet. If she gets out in one single, lonesome place, this fire line of ours won't be worth a cent. She's inside now if we can hold her there." He gazed contemplatively aloft at a big dead pine blazing merrily to its very top. Every once in a while a chunk of bark or a piece of limb came flaring down to hit the ground with a thump. "There's the trouble," said he. "What's to keep a spark or a coal from that old coon from falling or rolling on the wrong side of the line? If it happens when none of us are around, why the fire gets a start. And maybe a coal will roll down hill from somewhere; or a breeze come up and carry sparks. One spark over here," he stamped his foot on the brushed line, "and it's all to do over again. There's six of us," added the ranger, "and a hundred of these trees near the line. By rights there ought to be a man camped down near every one of them."

"Give us our orders," repeated Bob.

"The orders are to patrol the fire line," said Morton. "If you find the fire has broken across, corral it. If it gets too strong for you, shoot your six-shooter twice. Keep a-moving, but take it easy and save yourself for to-morrow. About two o'clock, or so, I'll shoot three times. Then you can come to camp and get a little sleep. You got to be in shape for to-morrow."

"Why especially to-morrow?" asked Bob.

"Fire dies in the cool of night; it comes up in the middle of the day," explained Morton succinctly.

Bob took to the right, while Jack went in the opposite direction. His way led down hill. He crossed a ravine, surmounted a little ridge. Now he was in the worse than total darkness of the almost extinct area. Embers and coals burned all over the side hill like so many evil winking eyes. Far ahead, down the mountain, the rising smoke glowed incandescent with the light of an invisible fire beneath. Bob, blinded by this glow, had great difficulty in making his way. Once he found that he had somehow crept out on the great bald roundness of a granite dome, and had to retrace his steps. Twice he lost his footing utterly, but fortunately fell but a short distance. At last he found himself in the V of a narrow ravine.

All this time he had, with one exception, kept close track of the fire line. The exception was when he strayed out over the dome; but that was natural, for the dome had been adopted bodily as part of the system of defence. Everywhere the edge of the path proved to be black and dead. No living fire glowed within striking distance of the inflammable material on the hither side the path.

But here, in the bottom of the ravine, a single coal had lodged, and had already started into flame the dry small brush. It had fallen originally from an oak fully a hundred feet away; and in some mysterious manner had found a path to this hidden pocket. The circumstances some