Air-breathing

“ When you stand on the ground and turn your eyes upward all the sky looks alike. But it's far from it. It's full of all kinds of winds, currents and strata, pockets, of which all aviators stand in deadly fear, mists, vapors, clouds of every degree of thickness and complexion, and then you have thunder and lightning, just as you do on land and sea. It's these shifting elements that make the navigation of the air so dangerous, John. The whole question would be solved, if there was nothing but stationary air, growing thinner in exact proportion as we rise. ”

“ Far ahead of the actual fire itself ran its fatal forerunner, the sheet of gases and superheated air, sometimes level, sometimes high lifted at the whim of the breeze, but always fierce, always southward, always with annihilation in its grip. ”

“ As it approaches, the atmosphere assumes a yellowish hue, tinged with red; the sun appears of a deep blood colour, and gradually becomes quite concealed before the hot blast is felt in its full violence. The sand and dust raised by the wind add to the gloom, and increase the painful effects of the heat and rarity of the air. Respiration becomes uneasy, perspiration seems to be entirely stopped ”

“ With the mass of fire between us and the ground directly below, blinded by the smoke and half suffocated by the heat, we were not conscious of the good fortune that awaited us, until, with a swoop and a plunge, we found ourselves submerged, and, with an equal velocity, immediately thrown back again by the buoyant force of the balloon into the open air. The flood of fire in which we had descended was instantly extinguished; and we awoke to a sense of our possible safety in darkness rendered doubly profound by the contrast. ”

“ The flames still continued raging in the vessel, and as the yawl was still endangered by being within half a league of her, she stood a little to windward. Not long subsequent to this, the fire reached the magazine; and then to describe the thundering explosion which ensued is impossible. A thick cloud intercepted the light of the sun, and amidst the terrific darkness nothing but pieces of flaming timber, projected aloft into the air, could be seen, threatening to crush to atoms in their fall, numbers of miserable wretches still struggling with the agonies of death. ”

“ When, for example, they assault a house, the horizontal blasts push and wrench it on the foundation, the cellar air suddenly expanding puffs it aloft, the internal air bursts its walls or windows, the uprush carries its members on high and scatters them wantonly to the four winds. ”

“ Through the heavy air, in which one can scarcely breathe for dust and smoke, there is all the time an invisible gliding to and fro, a frightful whistling, roaring, and crackling, and a spurting of flames that seems endless. ”

“ A quarter of an hour of terrible anxiety and intense expectation ensued.
By degrees the flames became less fierce, the air more pure; the smoke dispersed, the roarings of the conflagration diminished. ”

“ You have no doubt, already guessed what had happened. The facts were simply these: In the night, the cold had increased, and several of the Wind Eaters, half asleep, and half stupefied by the deep draughts of the boisterous north-west wind, had approached closer and closer to the fire, when suddenly the vast quantity of cold air which they had swallowed began to expand and four of them exploded with a terrific noise.
In quicker time than it takes to tell it, my dwelling was surrounded by a screaming, shrieking, howling mob of Wind Eaters, demanding my instant death. ”

“ Their attention was now fully occupied with beating off the infuriated mates of the dead birds, who beat the air about the aeroplane with their huge wings until the air-storm created threatened to overbalance it. ”

“ As our globe sweeps through it, the lower stratum of air naturally sinks down into the valleys and like depressions. This action pulls down the upper stretches of air, thus creating what are termed 'air-pockets' or 'air-holes.' Very dangerous they are, too."
"That is plain enough," declared Bob. "Now, dad, let Paul go on explaining this 'automatic pilot.'"
"If the aviator is enshrouded in fog or tries to sail through a heavy bank of clouds, he is quite likely to lose all sense of direction," continued Paul. "He will not know whether he is banking or traveling on an even keel. ”

“ This advice, coming from a man with such wide experience of the theory and practice of flying, should surely be heeded by all those who engage in deadly combat with the demons of the air. In the early days of aviation, pilots were unacquainted with the nature and method of approach of treacherous wind gusts; often when they were flying along in a steady, regular wind, one of these gusts would strike their craft on one side, and either overturn it or cause it to over-bank, so that it crashed to earth with a swift side-slip through the air. ”

“ Rush comes the rain, and the gas-lamps are dimmed; whoo-oo comes the wind like a smack; cold drops get in the ears and eyes; clean wristbands are splotched; greasy mud splashed over shining boots; some one knocks the umbrella round, and the blast all but turns it. ”

“ If, on the other hand, the plane is almost overhead, the next act in the drama is a sibilant rushing sound rapidly increasing in volume, when all in a position to do so throw themselves prone on the ground, or rush for the nearest shelter, however meagre. Then follows an ear-splitting crashing roar, and a furious tornado of air, with or without splinters of bomb, hurls to the ground everything in its immediate neighbourhood. ”

“ When a calm succeeds a storm, the pressure is unusually low, consequently the foul air imprisoned in the mineral of coal pits escapes more readily into the air, accompanied by a buzzing sound, which miners regard as prognosticating a storm or heavy rain. Accordingly, it is when the barometer is low that explosions of fire-damp are most common. ”

“ But over the land, and for thousands of feet up into the sky, the air is more irregular than a torrent among rocks; it is—if only we could see it—a waving, whirling, eddying, flamboyant confusion. A slight hill, a ploughed field, the streets of a town, create riotous, rolling, invisible streams and cataracts of air that catch the airman unawares, make him drop disconcertingly, try his nerves. ”

“ The loss of men’s lives from the foul air of the well is a common accident in ships, and I have been myself witness to several instances of it. Where there is the least suspicion of this, a candle should previously be let down, and if it should be extinguished, it may be concluded that the air is deadly. It becomes safe for men to breathe in it by leaving it open for some time, or, more expeditiously, by letting down fire in a pot or grate, which soon changes the air, by producing a draught of it upwards. ”

“ The plane must have entered a torrential downpour of rain at the time of, or immediately following, the flash of lightning in its vicinity, and if the cockpit windows had been smashed in, the pilots might have been subjected not only to the violent impact of flying pieces of glass but also to a withering stream of water striking them with all the force of the airplane's speed through the air of 150 miles an hour and upwards. ”

“ The air indeed was very sharp and cold, and we had strong gales, but they were steady and uniform, and we had at the same time sunshine and a clear sky: whereas in the lower latitudes, the wind every now and then intermitted, as it were, to recover new strength, and then returned suddenly in the most violent gusts, threatening at every blast to blow away our masts, which must have proved our inevitable destruction. ”

“ The danger to which firemen are most exposed is catching [Pg 78] cold, from their being so frequently drenched with water, and from their exposure to the sudden alternations of heat and cold. A man is turned out of bed at midnight, and in a few minutes after quitting it he is exposed to the sharp air, perhaps, of a frosty winter night; running to the fire as fast as he can, he is, from the exercise, joined to the oppressive heat inside the place on fire, in a few minutes in a state of the most profuse perspiration ”

“ The wind still appeared to be rushing up past us at a fearful rate, and, to add to the horror, we came among the still expiring discharge of the fireworks which floated in the air, so that little bits of exploded cases and touch-paper, still incandescent, attached themselves to the cordage of the balloon and were blown into sparks.... I presume we must have been upwards of a mile from the earth.... ”

“ Another cause of fire, which is of recent date, is the use of naphtha in lamps—a most ignitable fluid when mixed in certain proportions with common air. "A delightful novel" figures as a proximate, if not an immediate, cause of twenty-two fires. This might be expected, but what can be the meaning of a fire caused by a high tide? When we asked Mr. Braidwood the question, he answered, "Oh! we always look out for fires when there is a high tide. They arise from the heating of lime upon the addition of water." Thus rain, we see, has caused four conflagrations, and simple overheating forty-four. ”

“ The hot air rises and the cool air rushes down to take its place. An aeroplane striking one of these descending currents drops as if the entire atmospheric support had been suddenly removed, and if it be not high enough, may strike the ground with fatal results to the aviator. Every experienced airman has met these conditions. They are especially noticeable over water, streaks of calm water showing where the up-currents are just starting, and waves or ripples where the down-currents strike the surface. ”

“ However, it happens sometimes, though but seldom, that the clouds floating with great rapidity open currents of air so violent, as suddenly to chill the atmosphere and produce the most destructive hail storms. ”

“ It cannot be denied, that fire proceeding from the stars which are above the clouds, may fall on them, as we frequently observe on serene evenings, and that the air is agitated by the impulse, as darts, when they are hurled, whiz through the air. And when it arrives at the cloud, a discordant kind of vapor is produced, as when hot iron is plunged into water, and a wreath of smoke is evolved. Hence arise squalls. And if wind or vapor be struggling in the cloud, thunder is discharged; if it bursts out with a flame, there is a thunderbolt ”

“ It is also constantly happening that two winds arise from different quarters, one against the other, and if they meet in the air there is a hard shock, and this shock gives off a great fire, which spreads far in the air,” etc. ”

“ Together they reached the sea, where, after the splash, the fish-like hull could be seen floating. And, however the combat may have been continued and determined in the water by possible survivors, it was certain that these two had ceased to be air-ships; and the lesson was conclusively borne home to the interested watchers that ramming is as suicidal in mid-air as upon the surface of the sea. ”

“ In the same manner, Fire, when mixed with Earth, produced sometimes a fiery exhalation, whose qualities 390 were heat and dryness, which being elevated by the levity of the first into the Air condensed by the cold, so as to take fire, and being at the same time surrounded by watery vapours, burst forth into thunder and lightning, and other fiery meteors. ”

“ The upper strata of air in the room, charged with the heated products of respiration and combustion, is drawn downwards towards the fire and inhaled by the occupants, who are thus compelled to continuously rebreathe exhausted and impure air. ”

“ In going from convectionally still air into an updraught, he gets a “bump.” The same result is apparent if, while traversing a downdraught, he strikes still air.
It has been noted that the air ranges itself in layers differing in density, temperature, and moisture content. In many cases an acquired sense born of experience enables the airman to discern these layers and to adjust the wings of his plane in encountering them. Frequently a sheet of smoke or dust separates two cloud layers and experience has taught how to avoid or how to penetrate it.
Air is either going up or coming down. ”

“ Air, when rendered impure by the combustion of a candle, but in which the candle will still burn, will not explode the gas from the mines; and when a lamp or candle is made to burn in a close vessel having apertures only above and below, an explosive mixture of gas admitted merely enlarges the light, and then gradually extinguishes it without explosion. ”

“ The mass of vapor becomes incandescent; the hail-stones which strike the metal of our boots and our weapons, are actually luminous; the waves as they rise appear to be fire-eating monsters, beneath which seethes an intense fire, their crests surmounted by combs of flame. My eyes are dazzled, blinded by the intensity of light, my ears are deafened by the awful roar of the elements. I am compelled to hold on to the mast, which bends like a reed beneath the violence of the storm, to which none ever before seen by mariners bore any resemblance. ”

“ The effects of torrential rains in high winds of the storm are simulated in this manner. After every flight, the plane needs very thorough examination. One of the troubles is that salt air at high speed causes rapid corrosion. Salt may accumulate around the engines. Also, severe turbulence causes damage to the plane.
After the take-off, the pilot and co-pilot can see what is ahead most of the time, but for considerable intervals they are on instruments, or, as they say in the Navy, “on the gauges.” ”