CHAPTER 15 _THE DEMONSTRATION_
Penny was due to meet Salt Sommers in ten minutes, but if she were late,she knew he would not leave without her.
Entering the crowded hotel, she waited her turn at the desk and theninquired if any Navy officers had registered.
"Not to my knowledge," the clerk replied, consulting the register. "No,we've not had a Navy man in for at least a week."
"Any Army officers?"
"The last was a sergeant who checked out two weeks ago. Most of ourguests rent on a monthly basis. We have only a few rooms for transientguests."
"Can you tell me if a Professor Bettenridge has called here in the lastfew days?"
"Not while I've been at the desk."
The information convinced Penny she had not misjudged the professor. Shenow was satisfied he never had arranged with Navy officers to inspect hisray machine. Instead, he had misinformed Mr. Johnson, no doubt hoping toimpress him that others were interested in the invention.
Quickly leaving the hotel, Penny hastened on to the news office. As shepassed near the loading platform, Salt hailed her from a car parkedthere.
"Here I am," he called.
Penny slid into the front seat beside him, apologizing for being late.
"That's okay," returned Salt, shifting into gear. "But we haven't muchtime unless we hurry. You know the way, don't you?"
"I do by daylight. And I think I can find the farmhouse, even if itshould get dark before we reach there."
Salt was a fast and very skillful driver. He chose the less frequentedstreets and soon they were in the open. They made excellent time,reaching their destination just as it began to grow dark.
"How shall we explain to the professor?" Penny inquired dubiously as thephotographer parked the car under an oak tree along the highway. "He maythink it strange that I returned."
"Let him," said Salt, unconcerned. "I'm here to get my camera."
"Don't go at him too hard," Penny pleaded. "After all, there is a chanceI was mistaken about the license number. In my excitement the night ofthe explosion, I may have remembered a wrong figure."
"That's so," Salt acknowledged gloomily. "Well, we'll see."
"Why not pretend we're here to get a feature story for the _Star_?" Pennysuggested impulsively. "That way, I could ask him all the questions Ilike about the secret ray machine."
"Any way you want to do it," Salt agreed amiably.
He locked the car and they walked to the farmhouse. Learning that theprofessor and his wife were at the lake, they trudged down the lane.
"Wait!" Penny suddenly warned in a whisper.
Clutching Salt's arm, she drew him into the shadow of a tree. At first hecould not understand the need for caution. Then as Penny pointed, he sawa hunched figure with a lighted lantern, walking along the lake shoreaway from the cabin where Professor Bettenridge's ray machine was kept.
"There goes Webb now!" Penny whispered. "He's evidently going to theshack where the mines are stored."
"What's he carrying?" Salt inquired.
Although too far away to see plainly, they thought that he had a smallsatchel tucked under his arm. As he drew closer they discerned that itwas leather, and apparently used as a container for a longcylinder-shaped object.
Passing a short distance away, the man did not see Salt or Penny. Theywatched until they saw the red glow of his lantern vanish over a hillock.
"That's the foot-path to the shack where the mines are stored," Pennycommented. "I wonder what's inside the satchel?"
"Shall we try to find out?"
"Let's talk to Professor Bettenridge first," Penny proposed, going downthe lane.
The door of the cabin stood slightly ajar. Inside the lighted room werethe professor, his wife, Mr. Johnson, and several other persons Penny hadnever seen before. However, she took them to be town residents who hadheard of the test and were eager to see it.
"Well, professor," they heard Mr. Johnson say jovially. "We're all here,so why not go ahead? Show us what the machine will do."
"All in good time, all in good time," the professor rejoined. "You mustgive my assistant an opportunity to drop the mine into the lake. He willsignal us by lantern when he is ready."
Penny tapped on the door. The professor whirled around, decidedlystartled. Then, observing Salt and Penny, he abruptly came over to speakto them.
"Well?" he asked in a tone which was not friendly.
"We came to see the demonstration," Penny said brightly.
"Glad to have you," the professor replied, though without cordiality.
"We want to write a feature story about your machine too," Pennycontinued. "For the newspaper."
The request displeased the professor. Scowling, he said curtly:
"I am sorry, but there must be no publicity at this time--orders of theNavy, you know."
"The Navy is interested in buying your machine?" Penny asked, hoping tolead him on.
"The deal is concluded except for my signature," the professor said,darting a quick glance at Mr. Johnson. "I should have signed at once, butI promised Mr. Johnson first chance to buy the machine."
"I suppose the Navy men are in town now?" Penny inquired.
"In Riverview."
"At the Gables Hotel?" Penny pursued the subject.
The professor looked at her sharply, for the first time suspecting thatshe was inducing him to reveal far too much.
Without answering, he turned his back, and began to talk to Mr. Johnsonabout technical details of the machine.
"I am convinced it is a wonderful invention," the latter declared. "Butbefore I invest $200,000, I must be absolutely certain that it will doeverything you claim."
"You shall not be disappointed," reassured the professor. "Only bepatient for a few minutes, and you will witness a demonstration that willconvince you beyond a shadow of a doubt."
Ignored by the professor and his wife, Penny and Salt did not enter thecabin. Instead, they walked a short distance away to discuss their nextmove.
"The demonstration won't start for a few minutes," the photographer said."Suppose we ankle down to the lake and find out what Webb is doing."
Proceeding down the path which led around the lake shore, they soonsighted the man's glowing lantern. He had set it down on the ground whilehe trundled out one of the heavy mines from the shack. As they watchedfrom a distance, he loaded it into a boat, picked up the lantern, andslowly rowed out into the lake.
"Apparently he's going to drop it overboard for the test," Salt said."While he's out there, let's take a look in the shack."
He tried the door. It was locked.
"I don't know how it's done, but I'm sure those mines are doctored insome way," Penny declared. "Louise and I saw Webb working on one when wewere here yesterday, but what he did I couldn't guess."
"We'll learn nothing here," Salt said. "Let's go back to the cabin andsee how the professor pulls off the demonstration. Apparently he has Mr.Johnson two-thirds convinced already."
"Whatever you do, don't get into an argument with the professor aboutyour camera until after the test," Penny pleaded as they started up theslope again. "I want to watch the demonstration. If you accuse him ofdeliberately keeping the camera, he may throw us out."
"Okay, I'll wait," Salt promised.
Reaching the cabin, the pair became instantly aware of a tenseness in theattitude of the professor and his wife. Although they did not tell thenewcomers they were unwelcome, it was evident by their expressions thatthey distrusted Penny and Salt.
Professor Bettenridge stood behind his machine, explaining its many partsto the awed spectators. Penny could make nothing of the technical jargon.
"The demonstration will soon start," the professor declared, looking athis watch. "I will turn on the motors now, as they must heat for severalminutes."
He turned several switches and the room was filled with a low hummingsound. Two ti
ny lights buried deep in the complicated mechanism began toglow a cherry red. The professor bent low over the machine, frowningthoughtfully. He adjusted three of the concave mirrors, and switched onanother motor.
Despite a dubious attitude, Penny found herself becoming deeplyimpressed. Was it possible, she wondered, that she had misjudged theprofessor and his machine? She dismissed the thought. The mine neverwould explode unless it had been tampered with--she was certain of that.
"Watch closely now," the professor directed. "At any moment my assistantwill signal with his lantern that he has dropped the mine and is safelyaway from the area."
The professor's wife had gone to the doorway. Tensely she watched thelake. Minutes passed. Then from out on the water, there came a movingcircle of red--the signal from Webb.
"Now!" exclaimed the professor's wife.
Everyone in the little cabin held his breath. Dramatically, ProfessorBettenridge took a metal tuning fork and struck it sharply against thecrystal ball in the center of his machine.
"It will take a moment for the sound to reach the lake," he said softly."But only a moment. Watch closely."
All persons in the room crowded to the door and the windows. Suddenly ahuge burst of flame appeared on the lake, fanning out on the surface ofthe water. A moment later came the dull boom of a terrific explosion.