The BEACON of Airport Seven by Harold S. Sykes "The plane at the last moment climbed upward and to the right as the watchers breathlessly waited for it to clear the upper corner of the tower. There was a collision and the mass settled to the ground and burst into flames." In the present story, our versatile author has given us quite a treat. One of the most important and quite indispensable necessities for night flying is, of course, the aerial beacon. The aviator's life and the safety of property, depends on such beacons. The author in the present story has woven a very clever adventure around this theme, which is as interesting as it is notable, from a scientific viewpoint. We are accustomed to think that light rays travel only in straight lines. This is, of course, not the case. Light rays are refracted, when, for instance, they pass through the atmosphere of the earth. Thus we see the sun rise actually before it does, due to this refraction. On the other hand, Einstein in his theory, which has been proven, has shown us that light waves are bent when they pass the gravitational field of a star. You will find the scientific part of this story particularly interesting. CHAPTER I A Close Shave AS Royce picked up the flash of the huge revolving beacon at Wayside he breathed a sigh of satisfaction, and slowed his motors fifty revolutions. It had been a tiresome climb to the divide all the way from Airport Six, with gusty headwinds threatening to put him behind schedule. But now the grind of another trip was over. There remained but forty miles from the summit to Airport Seven almost under the light, and a relief crew there would take charge to set the plane down at San Francisco long before daylight. A passenger in the saloon leaned back in his leather-covered chair and yawned. "We must be getting close to Seven. I wish I had taken a berth this trip, instead of trying to sit up most of the night. There's a hard day ahead of me in 'Frisco." "Yes, we know all about the hard days you traveling men have," a cattle buyer answered from across the big cabin. "Hopping from one city to another on these liners is a joke. Now when I hired a little dilapidated taxi-plane at Ogden one time to inspect a herd over in the Hidden Valley country, that was a ride to write home about." "Let's finish the rubber; I want to get out and stretch my legs at Seven," spoke up a man at one of the card tables. "Here, give me the cards; is that a pun or . . ." "Say, just listen to those motors; I thought we were over the divide." The score of saloon passengers grasped tables or the arms of their chairs as the huge plane banked and swerved upward at an ever increasing angle. The five motors, after responding madly to wide-open throttles, now were laboring terribly under a heavy load. Bluish wing lights flashed on, reflecting upon the faces of the forward passengers peering from the long windows. Shades were being flicked up far aft of the huge wings as those in the sleeping compartments were roused by the sudden deviation. A blinding flash drove the portside passengers back from the windows to their places and the motors eased to their customary monotonous undertone. "What was that?" Someone asked. "Just the big beacon light, but man, we were right on top of it!" They looked at one another in alarm. Explanations "MR. McCrea will see you now," said the secretary. Tommy Royce, chief pilot, quickly arose nervously and weary from his chair in the waiting room and strode into the division traffic manager's office with the air of one anxious to get through an ordeal as quickly as possible. McCrea was standing at an east window, gazing out in the direction of the beacon tower on Sentinel Hill, half a mile away. He whirled as the young man entered, and fixed him with a glowering look. "Well, Royce, out with it. Let's see what excuse you have for trying to come in under the beacon last night with the west bound passenger plane. Jameston, in the watch tower last night, told me you were flying fully fifty feet below the light until you almost reached it. The field crew thought you were going to land in the houses over there, but they heard your motors, so that won't do for an excuse." Finally given an opportunity to speak, the pilot answered, "I don't know what the matter was." "You don't? Well, why not? Were some of your motors going bad, or did you want to land on Sentinel Hill?" "No sir, I picked up the beacon at the pass, and followed it in. Relief Pilot Tillotson was in the forward cockpit with me. You can ask him about it." "Yes," barked McCrea, "I most certainly can ask Tillotson about it, and I will. But first I want an explanation from you, and it had better be a good one." Royce stood in the center of the big room, nervously twisting the ring he wore on his left hand. "After I picked up the beacon at the pass--" "Yes, yes, I heard that, go on." "Well, coming toward Seven here, I looked at the altimeter and it seemed to read about right, perhaps a trifle low, but I saw the light well ahead of and below me, so I knew I had plenty of altitude. I cut the motors to sixteen-fifty at the summit, and closed the throttles a trifle more when we were near the beacon in order to lose enough altitude to make a landing here." "Yes, yes, but why did you lose so much altitude? Jameston says you were flying low all the way from the point where he first picked up your flying lights. Why, why?" "I wasn't flying low, for I had the beacon well below me until I was almost over it. Then--then I glanced at the instrument board for a moment, and when I looked back the light on its next swing around was almost above me! I saw it as soon as Tillotson did, and by opening the throttles wide we just managed to scrape over the top of the hill." "Well, of all the--. Royce, I'm going to put you on as second relief pilot for a month, under 'Ace' Howard, and we'll see if your eyes get any better. If Tillotson swears you were not asleep last night, that will be letting you down easy. If you were asleep, then you are through, understand?" and McCrea pounded the mahogany top of his desk to emphasize his words. "Good gravy! Don't you realize the plane carried more than fifty passengers and a ton of valuable express?" "Yes, sir." Tommy Royce turned to leave but stopped when McCrea called, "Wait, just one thing more." The manager reached into his desk for a blank form. "Take this to the company doctor and let him test you again. I want a full report from A to Z. Tell him to test your eyes particularly." The tests were entirely favorable, although Tommy had begun to have some doubts regarding his ability as a crack pilot, after so nearly wrecking the giant air liner. The Two Confer TILLOTSON came back to the barracks from his interview with McCrea, wearing a very serious and thoughtful expression on his face. He hunted up Tommy and the two talked during the rest of the afternoon without arriving at any definite reason for the contretemps. "I was watching the light out of the corner of my eye at the time it changed, old man, and I swear it suddenly blurred and then shot into the sky." "Did you tell McCrea that?" Royce asked, as they sat on his cot in his room. "No, I knew he wouldn't believe me; would insist we were both asleep, but I did tell him the old beacon changed her position. Little good it did. He gave me an awful raking over, and said he couldn't promote me to your place--I didn't want him to--but would leave me on as second man, and to see that some stray mountain didn't jump up and hit me in the face some day. He claimed the passengers had received the scare of their lives and that it was bad for the company, considering the new competition from the True Course line over the northern route. He expects a wigging from the 'Frisco offices." "Probably he will get it too," Tommy answered somberly. "I wish I could understand it." Then after a pause he looked at his wrist watch. "Let's hunt up Jameston at Number One hangar and try to get him to tell us just where we were flying last night. We just have time before the west bound freight comes in." Boundary and hangar lights at the field were flashing on as the two men made their way from the barracks past the transcontinental offices to the southwest corner of the huge landing area. A crew of ground men was making preparations for servicing the huge twenty-ton freight plane, while the two pilots who would fly it on to Field Eight were seated on the bench before the communications building, smoking and talking. One of the freight pilots called through the open window to the clerk on duty. "Phone up and ask Jameston if he's picked up the old wagon." "We're too late to see Jameston tonight; he must be on duty now," Tommy said to his companion as they stopped before the building. The gathering dusk was suddenly broken by the dip and swoop of the Sentinel Hill beacon as it started on its nocturnal swing around the sky at the rate of nine revolutions per minute. The far-reaching beam dropped low to the east and west, with an upward swing of thirty degrees as it traversed the north and south, describing two giant arcs on the furthermost confines of the sky. The men watched it in silence. The communications clerk leaned out of the open window above the pilot's bench. "Jameston phoned down that he has picked up a plane way to the south, but no sign of the freighter yet. Says this ship is headed about west and will miss the field by three miles." George Boyer, the larger of the two freight pilots, regarded Royce and Tillotson severely as they stood in front of the bench, waiting. "What's this I hear about you guys? The Field 'Supe tells me that you swiped the beacon when you came in this morning and tried to tow it home on your landing gear." "Aw, go fly a kite." Tillotson answered. "I hope it don't fool you the way it did us, that's all." "Boy, no ten million candle-power torch is going to fool me. When it starts jumping around off its tower I'll quit flying." Another Mystery THE low drone of a multi-motored plane was heard, steadily increasing in volume. As all eyes were turned to the now dark sky, Tommy perceived the red and green wing lights of a huge monoplane. The clerk called to the ground crew. "That's the freighter, boys, she's nine minutes late, and Jameston says she almost missed us." The outline of the wings was now clearly visible to those at the field as the ship came onward at its one hundred mile an hour cruising speed and passed over the hangers. Cutting the western boundary of the airport, the craft settled in a graceful circle into the gentle evening breeze. It was once illumined sharply by the swinging beam from the beacon. A brilliant blue-white radiance had flashed over the field as the battery of landing lights were switched on and the plane settled into it with throttled motors. "There's another good pilot gone batty," Boyer remarked plaintively, as he picked up his helmet and moved toward the craft, now coming to a stop beside the fuel hoses. "Here he comes staggering in from due south like he's been out on a scouting expedition or a picnic. How we can make up the time he lost without a tail-wind is more than I can see." His last words were lost as he approached the plane. "Come on, Tommy," Tillotson invited. "Let's see if he had trouble with the beacon too." It was a bewildered chief pilot who stepped out into the radiance of work lights turned on by the ground crew. He was followed down the ship ladder by his relief and mechanic a moment later. "Boys, I'll swear I followed the beacon true as an arrow, but when I got close it suddenly switched around to my right and I found I was way to the south." "You re not the only one," Boyer answered with heavy sarcasm. "Last night Royce had it jumping up and down and now you've got it wiggling side-ways. Of all the dizzy ideas! Here, climb in," he continued to his relief man. "I'll have to make up ten minutes that was lost by somebody playing tag with a fire-fly. Snap in to it, you ground men." "All set." "Fuel and oil O.K." "Condition and controls O.K." As the men gave their reports the Service Chief called, "Clear the props!" and then gave the starting signal to Boyer who was peering down from his high seat in the nose of the craft. The whine of the starters gave place to increasing roars of sound as each additional motor took hold. Locking his starboard wheel brake, the pilot gave full throttle to the port wing motors and whirled on the concrete service area. Under the response of wide throttles the plane moved forward with increasing momentum, showing Boyer's intention of taking off with the wind in order to save time. After a quick run the lumbering craft left the ground in a gradual upward curve, quickly banking to the west in an effort to save precious minutes. The burden of sound lessened to a hum and then died away in the star-lit sky. CHAPTER II of The BEACON of Airport Seven The Curse of the Airport DURING the following ten days passenger, sealed express and freight planes came and went with all the regularity of clock-work. Superintendent McCrea, who had been more than a little worried by a report from Alroyd, the freight plane pilot, that the beacon had apparently shifted, finally was able to convince himself that it was nothing more than a case of over work and eye-strain with three of his flyers. The relief pilot of the freighter had been unable to confirm or to deny Alroyd's report, having been busy at the time with a refractory fuel pump. Tommy, Tillotson and Alroyd were driven together for mutual support in an effort to withstand the heavy barrage of witticisms from the other pilots during the first few days. Boyer was sure to take advantage of every opportunity of poking fun at the trio. As time went on they almost became convinced that the vagaries of the huge light had been hallucinations. Then without warning, and as if possessed by an evil spirit, Number Seven beacon suddenly became a curse to be known from one end of the Transcontinental lines to the other as a siren, malicious and malevolent. Pilots who at first scoffed at the recurrent report, were soon forced to admit that something was wrong, they knew not what. McCrea, appealing for more and saner pilots, for electrical experts to put the beacon in order and for scientists to make tests of the light, bombarded the Pacific office with a barrage of radiograms. It started again on a dark, moonless night when the west bound passenger plane landed thirty minutes late, after flying in a zig-zag course from the pass to Seven. The irate superintendent was waiting at the loading area when the pilot emerged from the cockpit. Tommy was there, having been placed upon the reserve board for two weeks, before resuming his disciplinary flights as second assistant under "Ace" Howard. Tillotson and Alroyd were handling their regular positions, as first relief and chief freight pilot, respectively. "What's the matter, are you drunk?" shouted McCrea above the muffled purr of idling motors. "No, sir, but the beacon would swing away to the north, and when I orientated the plane, it would turn back to the south, until I thought I had picked up the wrong light." "Good gravy! And here I thought you men were through with all that nonsense. Don't you realize that there is not another light like that beacon within a hundred miles?" "There's not one like it anywhere in the world," Tommy muttered from his position near the pair. McCrea, evidently having overheard the remark, whirled toward him opening his mouth to speak, then choked and grasped. After an inward struggle he sighed audibly, turned and strode toward his private hangar. The cry of "all aboard" sent a number of interested passengers back to the machine, with an absorbing topic of conversation and discussion for the rest of the journey. McCrea had broken one of the first rules of the company when he found fault with a pilot in the presence of passengers. Scarcely had the huge plane left the field on its westward journey, when it was followed in the air by a tiny ship bearing the superintendent aloft. Still frowning and red of face, McCrea flew with wide open throttle directly toward the source of the circling beam, which dipped and rose from its vantage point on Sentinel Hill. The Accident THREE times he circled the light while gaining altitude, then the watchers at the airport saw his wing lights moving rapidly toward the east in the direction of the pass, until the hill hid them from view. Jameston phoned down the progress of the flight, kept in view in the field of his telescope, and the communications clerk relayed the messages to Tommy and members of the field crew. "He headed east for several miles, and then came back toward the beacon--now he's flying toward the pass again, but very low--now he is coming back, climbing all the time--he's turning toward the south--now back to the other side." Then the tiny red and green flying lights appeared almost over the field, but swung away to the west as men were reaching for the switches to turn on the battery of flood lights. After half an hour more the plane landed and McCrea strode toward the radio office with the expressed intention, flung back over his shoulder, of filing a message to headquarters that a demented pilot had been the sole cause of throwing the passenger plane behind schedule. Scarcely had he reached for a pad of forms, however, when a muffled crash and the reflected glare of blazing gasoline brought him to the loading area on the run. The hill crest below and just to the left of the beacon was a mass of soaring flames. Madly jangling bells suddenly coming to life in the ambulance quarters were stilled again as the emergency squad roared away over the now brilliantly flooded airport, closely followed by a fire truck to which half clothed men were clinging. "It's the west bound sealed express," the communications clerk gasped. "Flying low and washed out right at the foot of the beacon!" The superintendent dashed toward his private plane, still standing on the concrete area way. Others were hurriedly turning to automobiles parked beside the enclosure, while several men caught the salvage trucks as they emerged from the garage. Tommy, nervous and pale, stood beside two waiting pilots, obeying, yet not giving a thought to the company rule which forbade flyers to visit the scene of a crash when other help was available. The ambulance and fire truck had crossed the wide expanse of the field, pursued by McCrea, ground hopping his plane like a monstrous grass-hopper, and tiny flashlights could be seen now as the rescue crews toiled up the steep incline. "Which crew was flying it, I wonder." Then remembering the bulletin board under the electric on the wall, Tommy read, aloud: "'Crew 37, Sealed Express, Jones and Hillard, vice Thomas and Abernathy, west bound, 10:20 p.m.' Gee! it was Vance Thomas; he and I went through the training school together. I don't know Abernathy; he must be a new man on this division." The two waiting pilots were watching the dying flames, fascinated by the calamity which so easily might have been their own. McCrea returned shortly to dispatch a radiogram to the western office, then following a telephone conversation with the lookout he approached the bench on which the three flyers now sat, each busy with his own thoughts. "Well, it's too bad, boys. Jameston tells me that the ship had been flying much too low, just as yours did, Royce, when you so nearly cracked up. Thomas or Abernathy, whichever one was piloting, tried to pull her up at the last moment, but was too close to the hill." "Yes," Tommy answered slowly, sitting forward on the bench with elbow on knee and chin in his hand. "It fooled poor old Vance Thomas just as it fooled me, but my plane can climb faster than one of these express crates. It just meant the difference between a miss and a wreck." "Well, don't let this scare you, boys. There must be some reason for that light acting the way it has. Good gravy! There has to be a reason! I thought you pilots were going crazy at first but now I'll admit I was mistaken. I don't see how it can be the beacon, but anyway I am having oil flares placed on the hill tonight for the planes due before morning. Some extra lights can do no harm." An eastbound passenger and a freight plane landed safely at number Seven within the next two hours, during all of which time the worried superintendent was engaged in writing out a two thousand word report to the Pacific coast office. He signed his name with a sigh and handed the last page to the radio operator on duty. "There. I have asked for experts out on the first passenger ship in the morning. That is, if there are experts able to figure out this blankety blanked double dashed beacon." Another Victim OF the two remaining westbound planes due to arrive before daylight, the first was a regular express at 4:10 a.m., followed thirty minutes later by a freighter. The first missed the beacon by three miles to the north and came on to the airport from almost due west, twenty minutes late. The salvage crew watched it from the top of Sentinel Hill where the express was being sorted from the wreckage. The lookout picked up the wing lights of the freight plane to the southeast. The field was flooded with lights in an effort to attract the attention of the pilot, and the emergency spot lamp on the lookout tower was flashed skyward, throwing a bright pencil of light up until it touched scudding clouds thousands of feet overhead. In response the plane quickly veered to the north, then headed directly toward the beacon, as a moth is drawn by a candle. Ground crew men and electricians worked frantically flashing field lights and whirling the beam of the spot. The freighter, unconscious of danger, dipped lower and lower as it drove onward. The starboard wing light was hidden by the large fuselage of the craft as it drew abreast of the landing area, heading almost directly north. The tiny red port light on the tip of the left wing and the amber tail light on the stabilizer were all that could be seen in the dark. The score of watchers on the ground grew silent and tense as the machine held lower and lower, now heading for the base of the beacon tower. The motors diminished their song, telling those below that the pilot had partly closed thethrottles, believing himself well above the beacon. Light from the oil flares on the hill crest now began to be reflected from the swiftly whirling propellers and polished metal nose cap. Flashlights were waved madly by members of the salvage crew on the hill top and then flicked off as the men sprang behind the concrete shoulder of the tower foundation, waiting for the inevitable crash. Just when it seemed the hurtling mass was on the point of striking the outmost flare on the southern crest of the hill, the now dimly outlined shape swerved upward. The heavy craft had gained many feet in altitude at the expense of its momentum before the startling roar of wide open motors reached those waiting impotently at the service area. Closer and closer it came to the beacon, climbing ever steeper in a parabolic curve. "He's hung her on her props!" Someone exclaimed. Almost over the beacon and not twenty feet from it, the craft hung for a long moment in a perfect stall, nose pointed almost straight skyward. Motors and pilot had done their best but it was not enough. Slowly a green light appeared, rising at one wing tip while the red one sank lower and lower, telling the agonized onlookers that the plane, having lost all flying speed, was falling off toward the landing area. The pilot was doing everything possible now to save his ship, settling ever faster down the slope of the hill under full power in an effort to gain his minimum flying speed of sixty miles an hour and level off before striking the ground. The distance allowed him was frightfully short. With left wing still a trifle low the craft touched the ground at a point just within the lighted boundary, bounced into the air with crumpled landing gear, then settled forward and slowly nosed over in a fog of illuminated dust particles. A Promise From Boyer THE ambulance and fire truck raced over the field for the second time that night, shrieking their way through the running spectators already midway to the wreck. The fateful beacon serenely traced its bright path around the horizon, content now with dipping its beam low over the second catastrophe of the night, then turning onward to the east as if beckoning new victims to a like fate. Eager hands tore open the emergency doors on each side of the pilots' section. A groan was heard from within as flashlights were directed into the small control cabin. The large figure of George Boyer, head down, hung limp against the instrument board. One foot was caught in the rudder bar stirrup and held him suspended. He was tenderly lifted down and placed upon an ambulance cot made ready beside the stricken craft, just as the superintendent arrived on foot, gasping for breath. "Boyer is the only pilot in here, Mr. McCrea," one of the men announced, emerging from the inverted doorway. "Nonsense, there must be others. An express wouldn't be allowed to leave Airport Six without two pilots and a mechanic; keep looking until you find them." Tommy was already entering a wing door, opening from the control cabin into the interior of the huge wing. The cat walk was overhead and it was with difficulty that he made his way along the narrow forward spar and over themetal ribs. An electric lamp still burned at the first wing motor, twenty feet from the fuselage, but beyond that all was dark. After reaching a position beyond the projecting portion of the engine housed within the wing, Royce discerned, by the aid of his flashlight, the forms of the relief pilot and mechanic crumpled beside the out-board motor. A height of only four feet through the long thick wing would make it difficult to carry the men all the way back to the cabin, so Tommy found an inspection manhole and quickly unfastened it. Then he lifted the men up through the opening. With the crew out of the machine, cables were quickly hooked to the tail wheels from powerful salvage trucks in an effort to right the plane and move it from the landing area before others arrived. "The men are suffering from severe contusions, but apparently no bones are broken," the field doctor declared after a hurried examination. "Take them to the hospital, boys." "Wait a minute," said a husky voice from a cot and burly George Boyer hoisted himself to one elbow. "Where's Tommy Royce; is he here?" "Here, George." "Well, all I gotta say, Royce, is that I take it all back about the d . . . old beacon--what I said to you. And when they let me out of the hospital we'll see what is the matter with it if it takes all summer." He eased himself back with a sigh, saying, "all right boys, load me in." CHAPTER III Why Airport Seven? "WHY should there be an Airport Seven," was the question mentally asked by the humdrum business man later that morning as he propped a paper against the sugar bowl and munched his toast. The first editions carried scare-heads of the mysterious happenings, featuring the isolated airport and the beacon as the most interesting news of the day, but with only meager details. Later editions carried histories not only of the beacon and Airport Seven, but of the Transcontinental company, hurriedly prepared by feature writers for news agencies and the larger dailies. The evening papers explained to the business man upon his return from work that same day that the Transcontinental interests had founded the New York-San Francisco line primarily for transcontinental traffic, and for that reason had located service airports at evenly spaced intervals along a great circle route between the coastal points. Short feeder lines connected some of these airports with the larger population centers along the way, offering an expeditious means of reaching either the Atlantic or Pacific coast. Passenger traffic over the line however, was only an adjunct of the last freight and express service. The "sealed" express planes, carrying sealed compartments from coast to coast, were a link in the rapidly expanding World Corporation belt-line, inaugurated in 1932, and connecting all continents in the northern hemisphere. A subsidiary of the Transcontinental operated a fleet of amphibians on regular schedule between San Francisco and Manila, while associated European interests controlled the Transatlantic and Eurasianroutes. With seven intermediate airports between the two coastal cities, Airport Seven was arbitrarily located in north central Nevada, at a point east of Reno and south of Elko, the most desolate of all the stops along the route. Wayside had been a small western frontier town, practically deserted following the ebb of the mining tide which had washed over the west. Water was available, pumped from deep wells. Transcontinental by preemption and purchase rescued the place from ultimate decay, installed a power plant, erected hangars and other necessary buildings and placed a beacon upon Sentinel Hill. Still given on the older maps as Wayside, all pilots knew the place only as Airport Seven, where planes were refueled and crews changed. Contrary to forecasts made several years earlier that planes would make non- stop flights from coast to coast on schedule, the rapid progress of aviation with large planes had demonstrated the advantage of operating with a system of division points, as used by railroads. In place of carrying useless weight by loading on sufficient fuel for a non-stop flight, the fuel tanks merely served from one airport to the next, allowing the maximum of payload. Plane crews were changed at each stop for additional safety in operating the huge multimotored crafts, as tests had shown the superiority of using an air liner pilot at his point of best efficiency, relieving him before he became aware of fatigue. Experts Take A Hand MCCREA's urgent appeals for aid brought not only a corps of electrical and airport illumination experts from San Francisco during the morning, but also brought a number of officials, several major stock holders in the corporation, moving picture news reel cameramen, and a horde of newspaper reporters and photographers. By ten o'clock the two sides of the field were lined with visiting aircrafts, in sizes ranging from the dilapidated single seater of a free- lance photographer to the palatial four thousand horse-power private ship of the executive vice-president, with a wing spread of more than two hundred feet. Royce, Tillotson and Alroyd were called upon to testify as to what they had seen, and were requested to remain for the subsequent conference which took place in the drawing room of the air yacht. Electricians busied themselves meanwhile in inspecting the tower and beacon, although without finding anything at all unusual or out of the ordinary. McCrea made a plea for a cessation of night flying over divisions seven and eight until the mysterious trouble could be located, but was immediately over- ruled by his superiors. "No, McCrea, that's impossible," the chief ex-executive replied. "Our two strongest competitors are looking for just such an opportunity as that would offer them. We can't afford to delay a single freight or express ship." "But something must be done, Mr. Clark. The beacon may be alright tonight and again it may be the cause of several more wrecks before daylight tomorrow. It has cost the lives of two pilots and a mechanic already, to say nothing of three men now in the hospital, one ship totally destroyed and another damaged." "Surely some of these operatives here today can think of some suitable safety measures. We can turn off the beacon if necessary and instruct all pilots to fly by compass until they pick up the field lights." "No, Mr. Clark, you are subject to a heavy fine if your company deliberately turns off a beacon," declared a man at the foot of the long table. All eyes turned to regard the new speaker, John Cavanaugh, a Federal Bureau of Aeronautics inspector, who had that morning arrived to investigate the accidents for the Department of Commerce. He continued: "Until we are positive that your Number Seven beacon, which is listed upon government maps as 'type A, 62,' is at fault it must continue to burn." "That's right," Clark replied, then added reflectively, "the Interstate Commerce Commission has been after us to install a short-wave directional radio system over our whole line, but as this is primarily a freight and express route the board of directors has been unwilling to vote such an expenditure, at least until next year. Perhaps it may be necessary to install such a system temporarily for a guide over this district. Can it be done immediately?" He turned to a radio executive beside him. "Yes, the communications equipment at each airport can easily be supplemented with directional beam apparatus, but we shall need at least two weeks to install receivers in all company planes." "All right, I shall remain here tonight and will know more definitely by tomorrow; see me then. There is one angle of this business that has struck me as very peculiar, McCrea--do you know what I mean?" "It must be, sir, that no east-bound pilots have been bothered by the light; it is always the westbound planes that get into trouble." "Exactly. Now let's draft a set of instructions for all pilots leaving Airport Six tonight, telling them what to guard against and telling them for heaven sake to watch their altimeters!" The afternoon was spent in placing several flares at intervals on the desert between Sentinel Hill and the pass. Half a dozen men were placed at vantage points to the east, equipped with surveyors' levels, small telescopes, or binoculars, to watch the beacon and make notes on their observations. A Night of Terror THE first plane to be sighted from the watch tower after dark was the west bound passenger. A radiogram had reported its departure from Airport Six on time to the minute, with the crew fully informed as to all the precautionary measures to be observed. A new moon was just dropping behind the low range of hills to the west, scarcely an hour behind the sun, when the communications clerk reported to the large crowd that flying lights had been picked up, high above the pass. The beacon swung monotonously around the sky, rising in its passage from east to south, descending as it veered to the west then up in a grand arc over the northern horizon. The brilliant beam showed bright and steady at all times. Clark stood within the passenger area, hands clasped behind his back and occasionally addressed a remark to McCrea as he waited. Suddenly a light was seen at the foot of the beacon tower. It waved up and down, then began flashing on and off in the dot-dash of a code message relayed from the observers to the east. "All observers report beacon light O.K." the message ran. The drone of the passenger plane was soon heard flying overhead. It landed several minutes later after gradually circling down. Following a hurried refueling and change of crew it took to the air again, fifteen minutes late. At the same time another plane was reported from the east, thoughtby Jameston to be a tourist ship, as the sealed express was not due for almost an hour. The pilots who had brought in the passenger craft were being interrogated by Clark and McCrea at the landing area. "Well, I am glad that you report the light as O.K., at least for this evening, "the executive said. "I am inclined to the belief that the other pilots may have been at fault. Perhaps--" "Just a moment, Mr. Clark, the observer on the hill is flashing a message. Write it down Royce, as I spell it out." The group fell silent as McCrea announced the message letter by letter and all were dimly aware of its significance even before Tommy read it aloud. "Observer No. 1,--Peculiar refraction or parallax noted at 8:21, when beacon apparently moved down several hundred feet to angle of seven degrees below my level. Relay man at tower also apparently lower with his light in answering my message." "McCrea, that seems impossible; its all right from here!" Clark exclaimed. "What about that other plane that was just sighted? Where is it now?" No answer was necessary, for the throb of approaching motors could be heard distinctly in the still evening air. Royce was the first to pick up the winglights, showing just above the hill top and almost directly behind the beacon tower. The relay man was waving his tiny flashlight wildly, for it could be seen at times by those tensely silent at the airport. "He is going to crash!" "No, he will clear if only he won't try to fly directly over the beacon; why doesn't he turn!" The plane, at the last moment climbed upward and to the right but as the watcher breathlessly waited for the red wing light to flash clear from the upper corner of the tower, there was an apparent collision, followed by the swerve of the free wing tip, when the mass settled to the ground half way down the dark hill side and burst into flames. For a single dazzling instant the brilliant beam on its westward swing outlined a tiny figure high in the air. The sound of the crash was not heard at the service area until the light had swung away to the north. In that instant Tommy was reminded of the first crude talking pictures he had seen as a boy in which the action on the screen at times preceded the sound sequence. The rest of the night was a nightmare to those at the airport. The flyer who had collided with the tower miraculously escaped with only a broken ankle, owing to a new type instantaneous self-opening parachute he had been wearing. It was he the others had seen outlined in the beacon's glare, just as he was catapulted from his plane. The parachute had in a measure checked the speed of his fall before he landed dangerously close to the blazing wreckage. He was a tourist with a penchant for night flying, traveling in a small monoplane. An emergency radio sent by the now frightened executive to Airport Six to hold all planes landing there that night, was too late to stop the freighter, already on its way toward the fateful light. After an agony of suspense the watchers breathed a sigh of relief when the plane was finally reported with five thousand feet elevation and several miles to the south. Prepared for and fully expecting a severe reprimand for bringing his ship in forty minutes late, the chief pilot was complimented by the chief executive for his excellent work; so surprising him that he later said in an aside to Tommy that it was "almost as bad a shock as if I had washed out on Sentinel Hill." The beacon was not satiated until it had wrecked one more ship, a private touring plane, shortly after midnight. Flying too low, under the delusion that the beacon was still below him, the pilot with his family as passengers, was barely able to clear the hill, to land awkwardly at the edge of the airport and nose over. From their cots in the now crowded hospital, they reported later that they had passed Airport Six without stopping, intending to buy fuel at Number Seven to take them on to San Francisco before morning. Chapter IV of The BEACON of Airport Seven The Three Investigate A HUGE bandaged figure was seated beside the door of Tommy's room at the barracks upon his return from the company breakfast hall the following morning. "Hello, Tommy." "Why, hello, George, how are you?" It looks as though you ought to stay in bed for a few days longer." "No, I'm alright," Boyer replied. "This dizzy beacon business has been on my mind until I can't rest in the hospital, so I came over to see if you and Tillotson wouldn't come with me to scout around and see what we can find." "Yes, we shall be glad to go; wait until I call him." "I borrowed a car from one of the boys; I'll be waiting with it in front here. " The huge pilot moved away with a pronounced limp. Tillotson was waiting with Tommy when Boyer returned with the machine. A short drive skirting the edge of the fenced landing area brought them to the northern tip of the low hill on which the beacon was located. "Can we drive around to the east side, Tommy?" Boyer asked. "I believe so; take this road to the left. There is a dim road to that house on the east slope of the hill--here it is. I remember seeing it from the air." The road led around the point of Sentinel Hill toward a long low adobe house lying directly east of the beacon. They came to an abrupt stop at a barb-wire fence surrounding the place. A weathered wooden gate was before them. "The gate is locked, George. There's a big padlock on that chain around the post." "Say, Tommy, who lives here?" Boyer, turning off the motor, reached in his shirt pocket for a cigarette. "I've heard he is a doctor of some sort. Let's see--his name is Lawson or Larson as I remember it. He has lived here for years--was here when Transcontinental installed this airport and beacon." "He must be a radio amateur," spoke up Tillotson, from the rear seat. "See that erection of wires between those masts? That is just the kind of rig my brother is always experimenting with on some of the short wave bands." Boyer was deliberately climbing out of the machine. "I'm going over and talk to him if he's home; maybe he has noticed something funny about the light." Doctor Lawson HIS companions followed, helping each other through the fence by holding the strands of wire apart. The place appeared to be deserted as they approached, but Boyer crossed the low porch and knocked loudly upon the door. The impatient pilot rapped again, more insistently, when he was startled by a voice behind him. "What do you wish, please?" The three turned and beheld a grey haired old man, of less than medium height. He was wearing a chemist's apron over nondescript clothing and his feet were encased in frayed carpet slippers. Sparkling blue eyes regarded them from under bushy brows. "Are you Dr. Larson ?" asked Tommy. "Lawson, Lawson, not Larson." "Pardon me Doctor. We saw your radio towers and thought we would drop in to see your station, if you don't mind. We are from the Transcontinental airport over the hill." "I have no radio station. I am engaged at all times in very intricate and important scientific research and so do not make friends." The finality of the statement caused an uncomfortable pause. Tommy decided to try a new angle. "We are having trouble with the beacon on the hill, Doctor Lawson. It has caused a number of bad crack-ups lately." Tommy turned and pointed to the tower as he spoke. Dr. Lawson looked at it for a moment, then shrugged his shoulders. "Have you noticed anything peculiar about the light from your house here?" "Peculiar? What do you mean?" Tommy felt uncomfortable under the fixed stare of the old man but replied, "the beacon has appeared to move as we flew toward it." "Ah!" "What did you say?" "Nothing, nothing,--go on." "Sometimes the light seems to swing to the right or the left as a pilot comes close to it. Several planes have been wrecked and a number of men killed because the beacon seemed to shoot suddenly into the air. I suppose you have heard of the trouble it has caused us however?" "No." "Have you any suggestions to offer, Doctor? Don't you think that it may be caused by refraction, as light rays are bent when they pass at an angle through water? I have even thought of what little I've read of the Einstein theory, in connection with the bending of light rays from a star as they pass near the sun," Royce finished with a smile. "What do you know of relativity? And as for theories--bah! Why don't these theorists prove their statements? I'll tell you why--because they do not know how." Lawson's eyes glittered as he became animated. "These men, Newton, Leverrier, Michelson, Einstein, they thought they knew what to look for but they go at it wrong. They try to prove these things from the stars and by trying to measure the velocity of the ether! I can show in my researches how man can bend light in degrees, many degrees mind you, where others observe a bending of star light during an eclipse of less than two seconds! I have done it in my laboratory. As for your beacon light--I am not interested." The three pilots were momentarily bewildered under the tirade and before any of them could think of a suitable reply the man was gone shuffling around the corner of the adobe building. The slam of a door was followed by silence. "That guy spoke over my head, but I bet he knows more about the beacon than he told us," growled Boyer. "I'm going in the house." He gave an experimental yank at the door knob, as if testing its strength. "Wait, George, let's find out something about him first. This is his property and we are trespassing. I think he is crazy but he would have a right to shoot us for housebreaking if you tear down the door. Let's go back to headquarters and find someone who knows what he was talking about." Tillotson seconded Tommy's suggestion that they wait until the matter was reported to McCrea, and Boyer reluctantly abandoned the idea of forcing an immediate entry. The division traffic manager was more than interested in the report of the meeting with Dr. Lawson, and called in Mr. Clark, the chief radio operator and the Bureau of Aeronautics inspector, to hear the story. "How does it happen that the man is living so close to the beacon," inquired Cavanaugh. "It's this way," the San Francisco executive replied. "I remember at the time we located this airport, we tried to buy Sentinel Hill and found out that it was part of the land owned by this doctor or scientist. However, we finally reached an agreement with him to lease a site for our beacon tower, in return for the privilege of electricity from our power plant. The underground cables were extended past the beacon to a point he designated near his house. I remember we had to put in an extra wire to switch the beacon on and off from the field without cutting off his supply of current." "Yes," added McCrea, "he insisted upon having the meter for his extension located at the beacon tower. We send a monthly statement through the local post office and it is always paid promptly by check." "Obviously the thing to do is investigate this man's laboratory or whatever it is he has in the house." Clark regarded the group thoughtfully for a moment before he continued, "Royce, Tillotson and Boyer, you three having found this lead ought to be the ones to return tonight I think." The men nodded eager assent. "I should like to be a member of the party," said Cavanaugh. "Yes, I think you should go, as you have authority as a representative of the Department of Commerce to enforce any orders for the safety of the company's planes. But I can't for the life of me see how this Lawson is able to throw our planes off their course. It is becoming ridiculous; only this morning a man asked for permission to install a portable television station on Sentinel Hill, to transmit close-ups of the next crash over a nation-wide chain of stations! So you men go as far as you like tonight. Anything to stop this nonsense." Determined Action THE beacon awoke with an unwinking glare and started its continuous round of the sky as the three pilots made their way with Cavanaugh along the dim road to the gate. No light showed from the adobe house as the sky grew dark and the only sound was an even undertone coming from the airport where a liner warmed its motors beyond the hill. The men approached the house in silence, making their way to the side door which Dr. Lawson had used. Shades were tightly drawn over the window, but sounds of someone moving within the building came to their ears. "I'll try this door," Boyer whispered and turned the knob. It was not locked, so he pushed the door back and cautiously entered followed by his companions. They found themselves in a small room, with a half-opened door ahead showing a glimpse of a large well-lighted laboratory. The burly pilot again took the lead moving toward the light. "Stop!" The command came from the next room, and as Boyer paused Lawson appeared before them. "Those wires across the door mean death if you touch them. You cannot enter--go away. I am busy with important experiments." The intruders now saw that wires had been laced back and forth across the opening. Boyer kicked the door back against the wall as the others came forward to stare into the laboratory. A long table occupied the center of the room, with benches, book cases and a heterogeneous collection of scientific apparatus lining the walls. Upon the central table were row on row of radio tubes, large coils, condensers, and switches, scattered "breadboard fashion," and connected with wires to other instruments, unfamiliar in design. Dr. Lawson was bent over a meter as he slowly turned the knob of a large rheostat, paying no attention to those watching him. "He's a radio nut after all," Tillotson said in an undertone. "If I ever saw a 'ham' station, this is it." "No, it's more than that," Cavanaugh answered. "The first plane is due in a few minutes; we must find some way to break in. I think he has found some method of bending light rays by means of this apparatus and the antenna system outside." "I'll go pull the switch at the meter on the beacon tower," Tillotson whispered. The scientist whirled from the table and sprang to a large wall switch which he closed. "I heard you, my friend and I have electrified the wire fence around the house so you cannot leave. It is your own fault for coming here." The little man, grey hair disheveled, glared at them from under his shaggy brows, then deliberately turned his back and continued his work at the table. "Doctor Lawson, we must know whether this apparatus of yours is responsible for bending the rays of the beacon light." Tommy stood as close as he dared to the wires as he addressed the man. "Yes, it is!" the scientist shouted, turning again to stare at them unwinkingly with his sparkling blue eyes. "Fly your planes somewhere else. Day and night those infernal mechanisms roar over my head, interfering with my research. If your light is rendered useless, I am glad of it! I installed my laboratory here long before the air field was opened. I chose this location to be alone. If your planes are wrecked I am glad! Glad! Glad!" His voice rose to the shriek of a maniac with the last words. A sudden spasm shook his meager frame, then growing quiet he slowly shuffled toward the doorway, stopping within bare inches of the wires. "But Doctor!" Cavanaugh exclaimed, "are you trying deliberately to wreck the air liners and murder the pilots?" Lawson Confesses THE scientist stood regarding them with a cunning leer for a moment then spoke. "Are you trying to kill a moth when you light a candle? Because the fool flys into the flame is that any concern of yours? That is just what your planes are--moths, blind, foolish moths. I throw on the current from my generators, tune my apparatus to a point in resonance with the wave-length of the light from the beacon, and bend it as I will! It's not radio--it's magnetism. Ordinary magnetism attracts metals; the magnetism I have discovered attracts light, because it is of a frequency in resonance with the wave-length of light. That is why the sun bends the light of stars passing near it. Astronomers have discovered the parallax but they have been too blind to know that it is because the sun is discharging wave-lengths of all frequencies. One particular frequency bends the star light while all the others do not affect it. I have found that frequency and control it as I will." The old man paused for breath, though his eyes continued to regard his audience malevolently. "But the light is not affected to the west." "Of course not," Lawson answered testily, "All my apparatus is on this side of the beacon--to the east." Tommy, resolving to be agreeable in an effort to win the further confidence of the madman, asked, "how do you make the light move to either side as well as down, Doctor?" "How, you ask? How does the revolving magnetic field in the coils of an electric motor induce a revolving pull or torque on the armature? I merely send the power through my outside wiring system from the north to the south, and the beacon's beam is bent sharply as it passes overhead. Then I bend the light to the north merely by throwing a switch. I switch the power to other wires and bend the light down. I hear a plane approaching--I'll do it now, I'll drive it into the hill top!" Steadily growing louder came the sound of a speeding air liner from the direction of the pass. While the others pleaded with the man, now feverishly adjusting his instruments, Boyer whirled to the outside door and with one tremendous yank wrenched it from its hinges. "Out of the way," he shouted as he lunged toward the inner opening holding the door before him as a huge battering ram. The wires snapped under the impact, falling harmlessly aside and Boyer lurched into the laboratory. A reverberating pulsation announced the proximity of the multi-motored plane, driving onward toward the beacon. The others were in the room now, led by Cavanaugh who sprang to a large switch at the end of the long table. At the instant he reached the handle a sudden piercing scream turned all eyes to the scientist who lay sprawled in an attitude of reaching across the apparatus, hand outstretched toward the inspector. As the switch was opened the little man's tense muscles relaxed and his body slumped from the table edge to the floor, inert. "Electrocuted!" gasped Tommy, pointing to a livid scar showing plainly on an outflung arm. A sudden quickening roar over the house top reached a higher pitch then abruptly fell again to the departing drone of a plane which has passed. Coming plainly through the still night air those in the laboratory heard the song change to an even low-voiced murmur, as throttles were closed for a safe landing. THE END