The Radio Boys Rescue the Lost Alaska Expedition Part 9

The boys had been listening with interest. Now Frank nudged Jack, with whom he was standing by the fire, and whispered in his ear. Jack's face brightened and he nodded.

"I'll bet they have," he whispered. "Ask MacDonald."

Frank turned to the ranger.

"Mr. MacDonald, how far away is your Post?" he inquired.

MacDonald looked up puzzled, but answered readily enough.

"A good four hundred miles to the South."

"Why do you ask, Frank?" Mr. Hampton wanted to know.

"Just a minute, sir, please," begged Frank, once more turning to MacDonald. "And how many men are at the Post?"

"Captain and five men."

"Oh, is that all?"

Frank's tone was one of disappointment. MacDonald smiled slightly.

"People think the 'Mounties' must be as many as an army," he said.

"Well, we keep this wilderness clean with a handful. O' course, when necessary, too, we can swear in deputies."

"Have you got wireless at the Post?" asked Frank.

MacDonald nodded.

"Captain equipped us some time back," he said. "All posts or forts, as we call them sometimes, have wireless now."

"Good for you, Frank. I see what you're driving at now," said Mr.

Hampton. "You-"

Frank nodded.

"Yes, sir. I thought if we helped Mr. MacDonald capture Lupo and his gang, we could call his Post by wireless and have them send men to help him take his prisoners in."

CHAPTER IX.-A CALL TO THE FORT.

"Now," said Jack, "is the time that I wish I had my 20-kilowatt radio tube that I have been working on so long."

Mr. Hampton, Bob and Frank nodded sympathetically. An enthusiast on radio, Jack had developed a number of new appliances. The latest of these was not yet completed. He had worked on it in the laboratories at Yale during the Winter and Spring. The lateness of his return to his cla.s.ses, however, inasmuch as he did not arrive at college until after Christmas, due to the delay occasioned by his adventures in South America in search of "The Enchanted City of the Incas," compelled him to devote most his time to catching up in his studies. He did not, therefore, have as much time to devote to laboratory experiments as he desired. As a consequence, the 20-kilowatt tube had not yet been perfected, when time came for him to depart for Alaska with his father.

Jack's 20-kilowatt tube, when completed, would be the most powerful in the world, and he expected, moreover, to construct others of greater kilo-wattage. A 75-kilowatt tube had been produced in England, it is true, but it had not been found practicable. Jack's tube was to be steel-jacketed and equipped with a water-cooling device, due to the heat produced when in operation. His big dream was that this tube, when used as an amplifier in conjunction with an alternator, would make trans-atlantic telephonic communication as common as cabling or wireless telegraphing.

"If I only had one of my 20-kilowatt tubes now," he mourned, "we would be able to talk not only with Mr. MacDonald's Post but with Dawson or even Nome."

"Well, Jack," said Frank, "it's too bad. Just the same, let's get busy.

For, with our 50-watt oscillator tube set we will be able to communicate by telegraph up to 500 miles. And, as the Post is only 400 miles away, we can reach it easily."

For sending up to 500 miles, the boys knew they could use either three or four 5-watt oscillator tubes in parallel, or one 50-watt oscillator tube. They had decided on the latter method, in making their preparations for departure in faraway Seattle. For one thing, and the biggest, transportation was the most important item. And the 50-watt tube set was the more compact. Quickly, then, with Mr. Hampton helping, they got out the various parts from their baggage and made the connections.

Farnum, the Northwest policeman, MacDonald, and d.i.c.k and Art, watched with puzzled interest and even awe as the four, working in unison, put together the aerial series condenser, the blocking condenser, the grid condenser, the telegraph key, the chopper, the choke coil in the key circuit, the filament volt-meter, the protective condenser in the power circuit, the storage battery and the motor generator.

Farnum and MacDonald asked questions, although d.i.c.k and Art were content to sit silent and watch, keen-eyed, as the construction work progressed.

Several times, too, d.i.c.k arose and went to the water's edge to keep watch against surprise. That any would be attempted for the time being, n.o.body believed, as they figured the enemy would consider them on guard.

As they worked, Jack explained for the benefit of the others. His description of how the low voltage current from the storage battery flowed into one of the windings of the generator and drives it as a motor thus generating higher voltage in the other winding both puzzled and interested them. By the time, the set was ready for use, Farnum, who was something of a mechanic by inclination, had a fair understanding of the set, but MacDonald, though interested, was bewildered.

"I'm fair beat," he confessed. "Anyhow, just so you boys can make it work!"

"Oh, we'll make it work, all right," Frank a.s.sured him. "Well, now, to try to call the Post. What's its call, Mr. MacDonald?"

"I happen to remember," said MacDonald. "We were all so interested when wireless was put in that Captain Jameson gave us a little lecture on it.

He said our call would be JSN, abbreviation for his name. We were to remember it, in case of need, when we were able to get to a wireless station. Well, this is a case of need."

"I'll say it is," said big Bob. "Well, come on, fellows, who's going to call?"

It was an honor or distinction that each was eager to have, yet each wanted to force it on the others. A friendly argument developed, to which Mr. Hampton, smiling, put an end.

"Look here, boys, we are wasting time. Suppose you draw straws for the privilege. You all know the Morse and Continental codes, so there is no question of ability involved. Here-" breaking three matchsticks into varying lengths and offering them-"take your choice. Longest wins."

Frank drew the winning stick. The others laughed, clapped him on the back, and without more ado he began pressing the key and sending out the signal.

"Is somebody on duty at the Post wireless station, do you think, MacDonald?" asked Mr. Hampton.

"Somebody there all the time," the latter replied. "Captain Jameson has found wireless so useful in policing his vast district that he wonders how he ever got along without it."

"Hurray," shouted Frank, "listen. They're answering."

To those who understood the code, the answer was plain:

"JSN answering. Who are you?"

"MacDonald," tapped off Frank, grinning mischievously.

The receptor sounded almost angry.

"Quit your kidding."

"No, I mean it," replied Frank. "This is MacDonald of the Mounted."

"Prove it."

"That'll stump old Frank," chuckled Bob, in an aside. But he was mistaken.