CHAPTER IX

GROUND WORK

Before Hal Dane lay the great unknown--the three thousand parts of a dissected D. C. engine.

"And I've got to get 'em together," he moaned. "Gosh, was it to assort engine-hash that I went through all I've stood lately?"

Hal Dane had been on a strain, of a sort.

As soon as he landed at the far-stretching, smooth acres of the Rand-Elwin Field, bounded by hangars, barracks, instruction halls, he had passed the inspection of Mr. Rand at the office, inspection of short, dark, imperturbable Major Weston, primary instructor, passed test-inspection for every ailment in the world--or so it had seemed.

Hal had to undergo examination for heart action, and short-sightedness, and color blindness, and sense of balance and equilibrium. He was thumped and spun and eye-tested till he began to imagine that he really must have some outlandish physical defects. It came as an exhilarating shock to him when the doctor thumped him in the back and grunted, "Umph,--prime condition,--fellow with a constitution like that could fly to the moon!"

So Hal was turned over to Major Weston for training in the elementary principles of flying.

In relief at his acceptance, Hal's hopes flew high.

But hopes were all that flew high. Hal Dane in person was kept pretty low, smudging at a lot of engine junk that didn't look like it was ever meant to fit together.

To Instructor Weston aviation was neither a sport nor an experiment. It was a business. Under him a student was taught an aerial groundwork as solid as a railroad rock bed.

Since the internal-combustion gasoline engine was the accepted, standardized motor power for aircraft flight, Major Weston saw to it that his pupils knew internal-combustion gasoline engines--else they didn't graduate into the next class.

For Hal, the lessons seemed to go on interminably about the valve, the piston, ignition, spark, carburetor. He endured all the miseries of a brilliant pianist given to performing by "ear" who is set down in a primer class to learn note reading and scales. He began to feel that the outside of the ship, wing beauty, pull of propeller, soaring power, were what had fascinated him--not greasy, grimy intricacies of engines. In fact, heretofore engines had not entered very much into his aerial plans. He had known how to crank them, and fly them, and that had seemed enough.

But at Rand-Elwin, engines loomed large.

He had been here for weeks, and so far had not been allowed even the feel of a ship--except the Puddle Duck, and one couldn't call that a ship.

The Puddle Duck was an atrocity. It was a stubby, short-winged boat with no more grace of movement than the land-waddle of that barnyard fowl for which it had been named. The chunky plane, for all its ridiculous wing effect, was merely a land ship. In it, pupils studying balance taxied madly across the turf, striving to keep its misshapen body at proper angle--an impossibility. How could one keep such an unbalanced blob balanced?

Hal could have shed buckets full of tears over his efforts at the joy stick of the Puddle Duck. He who had flown real ships tied to this thing!

A huge surprise to young Dane was the finding of Fuz McGinnis as an upper-classman here. There had been no chance for writing or receiving letters in the past months of Hal's track-hopping at various country fairs. Circumstances had forced him out of touch with Old Fuz and the rest of the home gang. And now here was McGinnis grades ahead of him, doing flights in a late model sky ship while he wrestled with the Puddle Duck.

He and Fuz eagerly fell back into the old jolly comradeship in the little time school duties allowed.

For Hal, time seemed forever filled with motors,--motors in sections, motors in mixed masses waiting for him to learn their functions and to reassemble their anatomies.

Only gritted teeth and the sputtering flicker of his river of the wind ambition held him to his bewildering task day after day. He thought he hated motors.

Then in a blinding flash of understanding, he began to "see" engines, to grasp their mechanical beauty.

It was the marvel of the piston that first got him. He began to sense something of the power of that driving force that man has learned to harness. It had taken man thousands of years to learn to explode a mixture of gasoline vapor and air in an engine's cylinder where a piston caught the force to hurl forward power in a four-stroke cycle. That four-stroke cycle could speed an automobile over the highway or a wind ship over the airways.

And he, Hal Dane, had fretted at giving a few weeks to study this master power! Realization came to him of how primitive were all his notions of aircraft as compared with the perfection man had already reached. Into the building of one airship had to go the knowledge of more than half a hundred crafts and trades.

Instead of mere rods and tubes of metal, Hal now saw pistons and cylinders as power-containers. To help his understanding, he visualized how a pinch of gunpowder can easily be put into a gun cartridge. But when the powder is exploded it expands into gases that would fill a house. It is the expansion that shoots the bullet. So it was that the air-gas mixture exploded in a cylinder rushed out to force the piston into unbelievable speed. This speed harnessed to gear and camshaft was the power that was hurling the motor world forward--first on wheels, now on wings.

Hal forgot grease and grime in the sheer wonder of mechanism. Those black engines of iron, steel, aluminum and alloy became beautiful--more beautiful than the spread wings that had once fascinated him entirely. For motors gave power to those wings.

Instead of hastening from ground work into flying, as he could have done, Hal went back into classes for a second course in engine work.

Because Hal showed promise, Major Weston laid the work on him, uncompromisingly made him dig for what he got. But after class hours, a friendship sprang up between the blond boy and the short, heavy-set pilot trainer. Engines were their meat!

Hal was beginning to master the intricacies of motors, from the old seven thousand part Spano Motor down through its more modern descendant, the three thousand part D. C. Motor.

Engine mechanism was marvelous, was complicated--too complicated. Even after he understood the wondrous power and pull in unison of the D. C., Hal's brain rebelled somewhat at the involvement of even this latest build of motors. Man was smart to have made so complicated a thing--but man would have been more of a marvel to have made a simple thing that would perform the same work.

"But," questioned Hal of his instructor-friend, "for the air motor, every ounce of weight removed means power saved; now what--what could be taken from such an engine, and still leave efficiency?"

"But what? But why?"

In their after-school confabs, Weston's experience and Hal's theory and hopes fought many an acrimonious friendly battle. Raynor, who as advanced-flying pilot was for the present out of Hal's school sector, sometimes of a night joined in these air battles fought out on the ground. All manner of past and modern experiments came under the fire of their discussions. Aeronautical engine builders seemed to have tried out many varieties of motors. There were the long ago experiments with steam engines for airplanes. The engine itself could be made much lighter than the gasoline engine, but the fuel and water added so much weight that the whole combination was far too heavy for air purposes. Mercury and other liquids were tried out without much success. Then came gasoline and mercury-vapor turbines, fine in principle but somehow unsuccessful. There was a flaw that needed some genius to find it.

"The turbine principle is the coming change," argued Weston. "If the turbine principle could be applied to an aeronautical engine, it would eradicate many of the present troubles."

"But engine makers can't seem to apply it," contended Hal. "Seems to me," he hazarded his next thought gingerly, "that the engine without batteries is going to be the thing. Batteries weigh an awful lot. How about this high-degree compressed fuel and the way it explodes under pressure in the cylinder--without the ordinary explosion by electric spark? That would cut out batteries and save weight--"

"Save battery weight, yes!" countered Weston out of his deeper knowledge, "but how about the five hundred pound pressure to the square inch needed to explode such engine fuel?"

And so the arguments ran on. But for all the seeming impracticability, Hal's mind was focused on the experiments with the new type engine with which certain inventors were struggling. It appeared to the boy so much simpler and safer an engine, with its few parts, its more flying hours per given weight of fuel. Not now, but some day--perhaps.

Fuz McGinnis was specializing in wings, not engines. Engines as they were suited him well enough. Quite often though he came in to take silent part in these nightly symposiums held over the ills and blessings of motors. He sat in the discussion for love of the companionship of this oddly assorted trio of thinkers.

As spring came on, Hal went from ground work back again into air flight. He found the routine of flying tests easy, because the inner workings of engine mechanics seemed etched on his very brain. The feel of wings stirred him, roused all the old wild exhilaration of flight. And yet he was more critical of air machinery than in the past. Where before he had been vastly satisfied with the mechanisms of man-flight, he now caught himself wondering continually why man had not made his machines the better to withstand certain shocks that were bound to come in any flying routine. Flying gear had made progress, but landing gear was still crude, still based on land-moving machinery, instead of machinery of the air.

Pondering these things, Hal found his mind working back to the piston-and-cylinder that gave engines their power, their thrust. Why couldn't this same piston-and-cylinder principle be used to lessen power for a landing gear? His thoughts hung to this strange idea, revolved the thing continually in his mind.

Then one night he set before Weston and Raynor his ponderings and plans.

"It's the crack and crash of quick landings that break up so many planes." The boy spread his ideas gingerly before these two experienced old heads, fearing the laugh over some ridiculous flaw that his reasoning might have passed up. "Seems to me man hasn't got so far in what he lands on! Oh, of course he's gone a little way, passed from a sled base to wheels, then made the wheels larger and put pneumatic tires on 'em! But at that, any kind of speed landing bangs a fellow with a recoil like a rammed cannon. Now suppose between the ship and the landing gear we had a new kind of shock absorbers--sort of buffers made up of long cylinders with pistons in them, containing oil or glycerine, or some fluid like that, wouldn't they--"

"Hum--say--yes--"

Raynor and Weston were leaning forward, all absorbed in following this young fellow's reasoning, this radical plunge into something far out of the ordinary rounds of mechanisms. One piston-and-cylinder principle had been harnessed to a gasoline vapor explosion to hurl a motor forward. Now here was this fellow's futuristic brain seeing another piston-and-cylinder principle harnessed in oil or glycerin to gentle power and ease a speed plane to the ground in a shockless landing!

Long into the night the three of them discussed the idea from all angles. It was his friends' advice that he keep his plans to himself--for a while anyway. Then if the right backing ever came along, something worth while might be developed out of the thing. Any dabblings in invention needed money to back them.

Out on the field, Hal went from week to week through the different grades of flying. Although he had done a deal of actual flying before he ever entered the school, the precise, thorough routine training of the Rand-Elwin took no account of this. With flight, as with engine study, he was made to start at the bottom and was then given the "whole works." He had to begin with learning the controls, pass from that to their application, then to straight and even flying, climbs, banks.

One day out on the flying field, Hal stood, neck cracked back, eyes glued to the sky, watching a plane that seemed to have gone mad in the heights. He was sure it was Raynor. He had seen Raynor take off just before. Must be his ship. Yet he had never seen Raynor double-daring death like that before.