"I'm glad you think it's pretty good," Bob said modestly. "We fellows have surely worked hard enough over it."

"This gentleman here," said Mr. Layton to the boys, "ought to know quite a bit about radio. He operates an airplane in the service of our Government Forestry."

"In the United States Forest Service?" cried Bob, breathlessly, eyeing the stranger with increasing interest. "And is your airplane equipped with radio?"

"Very much so," replied Mr. Bentley. "It seems almost a fairy tale--what radio has done for the Forest Service."

"I've read a lot about the fighting of forest fires," broke in Joe eagerly. "But I didn't know radio had anything to do with it."

"It hadn't until the last few years," the visitor answered, adding, with a laugh: "But now it's pretty near the whole service!"

"Won't you tell us something about what you do?" asked Bob.

Mr. Bentley waved a deprecating hand while Mr. Layton leaned back in his chair with the air of one who is enjoying himself.

"It isn't so much what I do," protested this interesting newcomer, while the boys hung upon his every word. "It is what radio has done in the fighting of forest fires that is the marvelous, the almost unbelievable, thing. The man who first conceived the idea of bringing radio into the wilderness had to meet and overcome the same discouragements that fall to the lot of every pioneer.

"The government declared that the cost of carrying and setting up the radio apparatus would be greater than the loss occasioned every season by the terribly destructive forest fires. But there was a fellow named Adams who thought he knew better."

"Adams!" repeated Bob breathlessly. "Wasn't he the fellow who had charge of the Mud Creek ranger station at Montana?"

The visitor nodded and gazed at Bob with interest. "How did you know?"

he asked.

"Oh, I read something about him a while ago," answered Bob vaguely. He was chiefly interested in having Mr. Bentley go on.

"I should think," said Herb, "that it would be pretty hard work carrying delicate radio apparatus into the lumber country."

"You bet your life it is," replied Mr. Bentley. "The only way the apparatus can be carried is by means of pack horses, and as each horse can't carry more than a hundred and fifty pounds you see it takes quite a few of the animals to lug even an ordinary amount of apparatus.

"The hardest part of the whole thing," he went on, warming to his recital as the boys were so evidently interested, "was packing the c.u.mbersome storage batteries. These batteries were often lost in transit, too. If a pack horse happened to slip from the trail, its pack became loosened and went tumbling down the mountain side----"

"That's the life!" interrupted Jimmy gleefully, and the visitor smiled at him.

"You might not think so if you happened to be the one detailed to travel back over the almost impa.s.sable trails for the missing apparatus,"

observed Mr. Bentley ruefully. "It wasn't all fun, that pioneer installation of radio. Not by any means."

"But radio turned the trick just the same," said Bob slangily. "I've read that a message that used to take two days to pa.s.s between ranger stations can be sent now in a few seconds."

"Right!" exclaimed Mr. Bentley, his eyes glinting. "In a little while the saving in the cost of forest fires will more than pay for the installation of radio. We nose out a fire and send word by wireless to the nearest station, before the fire fairly knows it's started."

"But just what is it that you do?" asked Joe, with flattering eagerness.

"I do scout work," was the reply. "I help patrol the fire line in cases of bad fires. The men fighting the fire generally carry a portable receiving apparatus along with them, and by that means, I, in my airplane, can report the progress of a fire and direct the distribution of the men."

"It must be exciting work," said Herb enviously. "That's just the kind of life I'd like--plenty of adventure, something doing every minute."

"There's usually plenty doing," agreed Mr. Bentley, with a likable grin.

"We can't complain that our life is slow."

"I should think," said Bob slowly, "that it might be dangerous, installing sets right there in the heavy timber."

"That's what lots of radio engineers thought also," agreed Mr. Bentley.

"But no such trouble has developed so far, and I guess it isn't likely to now."

"Didn't they have some trouble in getting power enough for their sets?"

asked Joe, with interest.

"Yes, that was a serious drawback in the beginning," came the answer.

"They had to design a special equipment--a sort of gasoline charging plant. In this way they were able to secure enough power for the charging of the storage batteries."

Bob drew a long breath.

"Wouldn't I have liked to be the one to fit up that first wireless station!" he cried enthusiastically. "Just think how that Mr. Adams must have felt when he received his first message through the air."

"It wasn't all fun," the interesting visitor reminded the boys. "The station was of the crudest sort, you know. The first operator had a box to sit on and another box served as the support for his apparatus."

"So much the better," retorted Bob stoutly. "A radio fan doesn't know or care, half the time, what he's sitting on."

"Which proves," said Mr. Bentley, laughing, "that you are a real one!"

And at this all the lads grinned.

"But say," interrupted Joe, going back to the problem of power, "weren't the engineers able to think up something to take the place of the gasoline charging stations?"

"Oh, yes. But not without a good deal of experimenting. Now they are using two hundred and seventy number two Burgess dry batteries. These, connecting in series, secure the required three hundred and fifty-volt plate current."

CHAPTER VII

RADIO AND THE FIRE FIEND

"Well, I hope that the boys know what you're talking about," interrupted Mr. Layton at this point, his eyes twinkling, "for I'm sure I don't."

"They know what I'm talking about all right," returned his guest, admiration in his laughing eyes as he looked at the boys. "Unless I miss my guess, these fellows are the stuff of which radio experts are made. I bet they'll do great things yet."

"Won't you tell us more about your experiences?" begged Herb, while the other boys tried not to look too pleased at the praise. "It isn't often we have a chance to hear of adventures like yours first hand."

"Well," said Mr. Bentley, modestly, "I don't know that there's much to tell. All we scouts do is to patrol the country and watch for fires. Of course, in case of a big fire, our duties are more exciting. I remember one fire," he leaned back in his chair reminiscently and the boys listened eagerly, hanging on every word. "It was a beauty of its kind, covering pretty nearly fourteen miles. Thousands of dollars' worth of valuable timber was menaced. It looked for a time as if it would get the better of us, at that.

"Men were scarce and there was a high wind to urge the fire on. A receiving set was rushed to the fire line, some of the apparatus in a truck and some carried by truck horses. My plane was detailed to patrol the fire line and give directions to the men who were fighting the fire."

He paused, and the boys waited impatiently for him to go on.

"The good old plane was equipped for both sending and receiving, and I tell you we patrolled that fourteen miles of flaming forest, sometimes coming so close to the tree tops that we almost seemed to brush them.

"My duty, of course, was to report the progress of the fire. Controlled at one point, it broke out at another, and it was through the messages from my 'plane to the ground set stationed just behind the fire line that the men were moved from one danger point to the next.