Part 4 (1/2)

And lo! the Aeroplane has alust, and down sinks one wing and up goes the other ”Oh, ly call the Planes; ”it's eloping with the Lift, and what in the nah scandal in the Factory without this, too!” For the lift varies with the horizontal equivalent of the planes, so that if the aeroplane tilts sideways beyond a certain angle, the lift becoht of the machine, which must then fall A fall in such a position is known as a ”side-slip”

But the ever-watchful Pilot instantly depresses one aileron, elevating the other, with just a touch of the rudder to keep on the course, and the Planes welcome back their precious Lift as the Aeroplane flicks back to its normal position

”Bit bumpy here under these clouds,” is all the Pilot says as he heads for a gap between them, and the next minute the Aeroplane shoots up into a neorld of space

”My eye!” ejaculates the Wind-screen, ”talk about a view!” And indeed mere words will always fail to express the wonder of it Six thousand feet up now, and look! The sun is rising quicker than ever mortal on earth witnessed its ascent Far below is Mother Earth, wrapt in ht, filed with pink And all about greatin space The sun rises and they take on all colours, blending one with the other, fro white to crimson and deep violet-blue Lakes and rivers here and there in the enormous expanse of country below refract the level rays of the sun and, like so ht far upwards The tops of the hills now laugh to the light of the sun, but the valleys are still mysterious dark blue caverns, crohite fil sense with altitude of vast, clean, silent solitudes of space

Lives there the man who can adequately describe this Wonder? ”Never,”

says the Pilot, who has seen it many times, but to whom it is ever new and ly speeds the Pilot and his ine and steady the Thrust as the Propeller exultingly battles with the Drift

And look! What is that bright silver streak all along the horizon? It puzzled the Pilot when first he saw it, but now he knows it for the Sea, full fifty htness of theitself to the ardent rays of the Sun; and on his left, so high is he, there is yet black night, hiding innues, and all those places where soon tee toil and the spirit within theer

And the Pilot's soul is refreshed, and his vision, now exalted, sees the Earth a very garden, even as it appears at that height, with discord banished and a happy tiner shall have at last captured Efficiency, and the Man-who-takes-the-credit is he who has earned it, and when kisses are the only things that go by favour

Now the Pilot anxiously scans the Barograph, which is an instrument much the same as the Altimeter; but in this case the expansion of the vacuum box causes a pen to trace a line upon a roll of paper This paper is made by clockwork to pass over the point of the pen, and so a curved line is isters the speed of the ascent in feet per er is the ascent at the rate of a thousand feet amy Revs

and the Thrust Buck up with the Power, for the Lift is decreasing, though the Weight rele for Air A certain proportion, and that of right density, I ive me full power and compression, and here at an altitude of ten thousand feet the Air is only two-thirds as dense as at sea-level Oh, where is he ill invent a contrivance to keep ht density and quality? It should not be iree,” said the dying Power and Thrust ”Only maintain Us and you shall be surprised at the result For our enemy Drift _decreases in respect of distance with the increase of altitude and rarity of air_, and there is no lith reers and a steeper pitch[11]

for the Propeller we may then circle the Earth in a day!”

Ah, Reader, sly, as you sreater wonders yet Consider that as the speed increases, so does the momentum or stored-up force in thethat in ravity decreases_ There may yet be literally other worlds to conquer[12]

Now at fifteen thousand feet the conditions are chilly and rare, and the Pilot, with thoughts of breakfast far below, exclaiet on with the Test” And then, as he depresses the Elevator, the Aeroplane with relief assu the Throttle, the Thrust dies away Now, the nose of the Aeroplane should sink of its own volition, and the craft glide doard at flying speed, which is in this case a hundred ner has carefully calculated the weight of every part and arranged for the centre of gravity to be just the right distance in front of the centre of lift

Thus is the Aeroplane ”nose-heavy” as a glider, and just so to a degree ensuring a speed of glide equal to its flying speed And the Air Speed Indicator is steady at one hundred ht!” exclai or a cloud,”

he reflects, for then he can safely leave the angle of the glide to itself, and give all his attention, and he will need it all, to keeping the Aeroplane horizontal froht on its course The latter he will e with the rudder, controlled by his feet, and the Coht course is kept The fored to the tips of the planes, and the bubble in the Inclinometer in front of hi only hus at once, but three is a tall order, so was this pilot relieved to find the Design not at fault and his craft a ”natural glider” To correct this nose-heavy tendency when the Engine is running, and descent not required, the centre of Thrust is arranged to be a little below the centre of Drift or Resistance, and thus acts as a counter-balance

But what is this streaouts of s at no more than one-tenth its normal speed, has upset the proportion of petrol to air, and co place intermittently or in the Exhaust Pipe, where it has no business to be ”Crash, Bang, Rattle----!----!----!” and worse than that, yells the Exhaust, and the Aeroplane, who is a gentleman and not a box kite,[13] remonstrates with the severity of a Senior Officer ”See the Medical Officer, you young Hun Go and see a doctor Vocal diarrhoea, that's your complaint, and a very nasty one too Bad form, bad for discipline, and a nuisance in the Mess What's your Regiment? Special Reserve, you say? Humph! Sounds like Secondhand Bicycle Trade to liding descent to a spiral one, and, obedient to the Rudder, the Aeroplane turns to the left But the Momentum (two tons at 100 e of direction, and tries its level best to prevent it and to pull the machine sideways and outwards from its spiral course--that is, to make it ”side-skid” outwards But the Pilot deflects the Ailerons and ”banks” up the planes to the correct angle, and, the Aeroplane skidding sideways and outwards, the lower surfaces of the planes press up against the air until the pressure equals the centrifugal force of the Momentum, and the Aeroplane spirals steadily doards

Down, down, down, and the air grows denser, and the Pilot gulps largely, filling his lungs with the heavier air to counteract the increasing pressure froap in the clouds, and the Aerodroer than a saucer, and the Pilot, having by now got the ”feel” of the Controls, proceeds to put the Aeroplane through its paces First at its Maxi horizontal flight; then a dive at far over flying speed, finishi+ng with a perfect loop; then sharp turns with attendant vertical ”banks,” and then a wonderful switchback flight, speeding down at a hundred and fiftyascents at the rate of two thousand feet a ether Such wires as were before in undue tension have secured relief by slightly elongating their loops, and each one is now doing its bit, and all are sharing the burden of work together

The Struts and the Spars, which felt so aard at first, have bedded the the coly

The Control Cables of twisted wire, a bit tight before, have slightly lengthened by perhaps the eighth of an inch, and, the Controls instantly responding to the delicate touch of the Pilot, the Aeroplane, at the will of its Master, darts this way and that way, dives, loops, spirals, and at last, in one long, ently in front of its shed