A Thousand Degrees Below Zero

  CHAPTER VIII.

  New York lay below them. The long, straight lines of lights shining upthrough the semidarkness of the moonlit night made a strange appearanceto the two in the swift machine. Davis had mounted to a great height,some ten thousand feet, and the pin points of light outlined more thana dozen cities and towns. The Hudson was a faintly silvery ribbonflowing down placidly from a far-distant source. Because of the icecake in the Narrows its level had risen two or three feet, but now itflowed smoothly over that great obstacle, melting and carrying it awaytoward the sea.

  The fighting plane roared around in huge circles, seeming strangelyalone in the vast expanse of air. One searchlight from below movedrestlessly about the sky. A second joined it, then a third. One byone a dozen or more of long, pencil-like beams of light shot up intothe sky and moved here and there in seeming confusion, but actuallyaccording to a carefully prearranged plan. A hooded red light showedbelow the biplane in which Teddy and Davis were awaiting some sign ofthe black flyer. That had been agreed upon, and none of the searchlightbeams flashed upon the circling machine. From time to time Davis shutoff the motors, and the two of them lifted the ear flaps of theirhelmets to listen eagerly for the musical humming that would heraldVarrhus' approach.

  Far to the east they could see where the faintly luminous waters ofthe ocean came up to and stopped at the darker masses of the land. Theharbor below them glittered in the moonlight. The only peculiarity inthe scene was the absence of the little harbor craft that ply aboutbusily by day and night upon their multifarious errands. They wereall securely docked. The wharves, too, were dark and silent. All themaritime industry of New York was at a standstill.

  A wide spiral to twelve thousand feet. The motors were hushedduring a two-thousand-feet glide, while the two men in the machinelistened intently. For two hours this maneuver had been repeated andre-repeated. No sound save the rush of the wind through the guy wiresand past the struts had broken the chilly stillness of the heights.The sky was a blue dome of a myriad winking lights. A pale silver moonshone down.

  The nose of the machine pointed down and the motors ceased to roar.Faintly but unmistakably above the whistling and rushing of the windabout the surfaces of the biplane a deep, musical humming could beheard. Abruptly the motors burst into life again. The exhausts began tobellow out their reassuring thunder. The machine began to climb again,circling to every point of the compass, while Teddy and Davis scannedthe sky keenly for a sign of the black flyer with its cargo of menaceto New York.

  "I'm going to fifteen thousand."

  Davis' voice sounded with metallic clearness in Teddy's ear. Thetelephones between the two helmets were working perfectly.

  "That was Varrhus, all right?" said Teddy quietly. "Did you signal tothe people beneath?"

  Davis pushed a button, and a green light glowed beside the red one inthe hood below the machine. In a moment the receipt of this signal bythose below was evidenced. The searchlights took up their task withrenewed vigor, searching the sky frantically for a sign of the blackflying machine. The hood below the biplane allowed the signal to beseen by those on the ground, but made the light invisible to any one inthe air. The biplane swung in wide circles, Teddy and Davis with everynerve taut and every sense alert, aflame with eagerness to sight theirquarry. They saw it, outlined for an instant by the white beam of oneof the circling lights.

  It was dropping like a stone from the clouds. The searchlight raysglistened from polished black sides and were reflected from shimmeringpropeller blades above it.

  "Helicopter," said Davis crisply. "Now!"

  The black flyer was a thousand feet below them and still falling. Thenose of the biplane dipped sharply and it dived straight for the stillfalling machine. Teddy gripped the machine gun and sighted along thebarrel. Down, down, the biplane darted, all the power of its eighthundred horse power aiding in the speed of its fall. The glisteningblack machine checked in its drop and hung motionless in mid-air. Thepilot was evidently unconscious of the machine swooping down upon him.

  Five hundred feet down, six hundred----Teddy pulled hard on thetrigger, and his machine gun spurted fire. A stream of explosiveprojectiles sped toward the menacing black shape. Teddy saw them strikethe shining sides of the machine and explode with little bursts offlame. The biplane was rushing with incredible speed toward the otherflyer. Teddy played his machine gun upon it as he might have played ahose, and apparently with as little effect. The tiny explosive shellsstruck and flashed futilely. The black flyer seemed to be unharmed.After a second's hesitation, it dropped again abruptly. The biplaneshot toward the spot the other machine had occupied. The distance wastoo short to turn or swerve, quickly as it responded to the controls.

  "Flares," gasped Davis, but before he spoke Teddy was pressing thesmall button that would set them off.

  A burst of tiny lights shot out before the biplane, many-coloredballs of fire driven forward from a tube below the fusilage. Theyilluminated the air for a short distance, entering the space from whichthe black flyer had just dropped. Teddy and Davis saw a small cloud ofwhat seemed to be mist or fog hanging in the air. The tiny fire ballsdarted into it the fraction of a second before the biplane itself hadto traverse the same space. As the first of the lights struck thefringe of the whitish cloud it flared up. The fire ball had touched adroplet of liquified gas and set it flaming. It burned fiercely andwith incredible rapidity, setting fire to the remainder of the cloud.Teddy ducked his head as the a?roplane shot madly through a huge globeof blazing gas in mid-air.

  "Great God!" gasped Davis. "Now where's Varrhus?"

  The heavy masks the two aviators had worn had protected them from theflaming hydrogen, and their goggles had saved their eyes. Now Davis wasonly eager to make a second attempt upon the black machine. He swervedand circled. The searchlights below were waving frantically throughthe air. The flare aloft had been seen, and they concentrated uponthe space below the spot. In a second the black flyer was once moreoutlined by half a dozen beams. Davis banked sharply and darted towardit again.

  The pilot of the strange machine seemed to be quite confident that hehad disposed of his antagonist, and was apparently busy with somethinginside the cabin. He was probably preparing to release his cold bomb,but was again interrupted. The biplane approached. Teddy saw hisexplosive bullets strike and flash. He knew they struck, but theyseemed incapable of doing harm. The black flyer was clearly defined bythe searchlights, and Teddy could see it distinctly. It was a long,needlelike body with a glass-inclosed cabin near the center. Above itfour whirring disks of comparatively huge size showed the position ofthe vertical propellers that enabled it to rise and fall and to hangsuspended motionless in the air. A fifth propeller spun slowly at thebow. That was evidently not running at full speed. Below the needlelikebody hung a misshapen globe, like the bulging ovipositor of somestrange insect.

  Flash! Flash! The impact of the explosive bullets was marked byspiteful cracks as they burst. Teddy was aiming for the cabin of themachine.

  "Got him!" he exclaimed.

  The glass of the cabin windows had splintered into fragments. Thea?roplane shot toward the motionless black flyer.

  "Shall I ram?" asked Davis in a perfectly even voice. He was quiteprepared to sacrifice both his and Teddy's lives to make absolutelycertain of the destruction of the menacing helicopter with its morethan dangerous occupant.

  Teddy, with lips compressed, nodded. He had forgotten that in thedarkness Davis could not see his movement. As the biplane sped forwardthe black machine dropped again. Again the whitish cloud was leftbehind it, clearly defined in the searchlight rays. Teddy had barelytime to press the flare button before they reached the cloud. The mistof atomized liquid hydrogen seemed to burst into flame all about them.The a?roplane roared through hell-fire for a moment. Flame was beforeTeddy's aviator's goggles. He was in a veritable inferno. Then thea?roplane shot free again.

  "Ram him!" panted Teddy. "Smash him! Do anything, only we've got to gethim!"

  They circ
led swiftly, searching for the black flyer. The searchlightswere following him now, and they saw that he was rising straight up.He had not yet dropped his cold bomb. Davis put his machine at theascent at as steep an angle as he dared. They climbed almost asrapidly as the helicopter. The black machine made its first aggressivemove now. Davis was climbing in a jerky spiral, rising at an amazingspeed. Teddy was busily fitting a new belt of cartridges into hismachine gun. The pilot of the other machine darted to one side and ahuge cloud of mist sprang into being just below him, darting downwardlike some pale-gray snake, unfolding itself in the sky. Davis zoomedsharply. Another second and he would have run into the whitish cloud.The biplane recovered and swerved to one side. Twelve thousand feet.Thirteen thousand feet. Fourteen thousand feet. Three miles in theair! Then the black flyer began to drop. The biplane dived after him,Teddy's machine-gun spitting fire and explosive bullets in a furious,well-directed blast. Once, twice, bursts of the little flashes thatshowed his bullets were striking served to reassure Teddy, but thebiplane could not gain on the falling helicopter.

  Down, down----There were half a dozen quick bursts of flame in theair. Anti-aircraft guns were firing. The black flyer dropped unharmed.Barely a thousand feet above the waters of the bay, the propellerat the bow seemed to be put into motion, for the straight descentchanged into a graceful curve. The curve flattened out, and the blackmachine ceased to fall. It sped madly for the Narrows, with a bedlamof bursting shells all about it and the vengeful, spitting two-seaterdarting after it like an avenging Nemesis. Again and again spurts offlame against the body of the glistening helicopter showed that Teddy'sfire was well directed, but the machine shot onward in a furious rushfor the Narrows. Above the Narrows, without pausing, a black objectthat turned to white in the searchlight rays fell from the misshapenglobe below the center of the black flyer's body. The thing that fellseemed to leave a mist of fog behind it as it dropped. Then, itsmission accomplished, the dark machine fled toward the west.

  Teddy and Davis, in the biplane, sped after it at the topmost speed ofwhich their a?roplane was capable. Teddy was nearly insane with baffledrage and disappointment. He knew that he had failed. Another cold bombhad been dropped in the Narrows, and any attempt to destroy it wouldonly result in the death of those who made the attempt.

  "Faster, faster!" he pleaded to Davis. "If it gets far ahead of uswe'll lose it in the darkness."

  Davis pressed his lips together and used every artifice he knew of toincrease the speed of his machine, but the glistening black body aheadof them drew steadily farther away. At last it could barely be seen.Then, as if in derision, a light appeared in the cabin of the blackflyer. It winked oddly. Dot-dash, dot-dash----

  "He's signaling," said Davis.

  Dot-dash, dot-dash----

  "W-a-t-c-h," spelled Davis, "t-h-eM-i-s-s-i-s-s-i-p-p-i.--V-a-r-r-h-u-s."

  "Watch the Mississippi, Varrhus," repeated Teddy. "He's getting away!He's getting away!"

  The light ahead of them winked and disappeared. The sky was emptyexcept for the biplane roaring after a vanished enemy.

  "He's gotten away," half sobbed Davis. "Damn him! He killed Curtiss,and he's gotten away!"

  Teddy stared into the empty night with something of Davis'disappointment and despair.