But, in point of fact, an ascension being made to any given altitude, the ponderable quantity of air surmounted in any farther ascension, is by no means in proportion to the additional height ascended, (as may be plainly seen from what has been stated before,) but in a ratio constantly decreasing. It is therefore evident that, ascend as high as we may, we cannot, literally speaking, arrive at a limit beyond which no atmosphere is to be found. It must exist, I argued; although it may exist in a state of infinite rarefaction.
On the other hand, I was aware that arguments have not been wanting to prove the existence of a real and definite limit to the atmosphere, beyond which there is absolutely no air whatsoever. But a circumstance which has been left out of view by those who contend for such a limit, seemed to me, although no positive refutation of their creed, still a point worthy very serious investigation. On comparing the intervals between the successive arrivals of Encke’s comet at its perihelion, after giving credit, in the most exact manner, for all the disturbances due to the attractions of the planets, it appears that the periods are gradually diminishing; that is to say, the major axis of the comet’s ellipse is growing shorter, in a slow but perfectly regular decrease. Now, this is precisely what ought to be the case, if we suppose a resistance experienced from the comet from an extremely rare ethereal medium pervading the regions of its orbit. For it is evident that such a medium must, in retarding the comet’s velocity, increase its centripetal, by weakening its centrifugal force. In other words, the sun’s attraction would be constantly attaining greater power, and the comet would be drawn nearer at every revolution. Indeed, there is no other way of accounting for the variation in question. But again : – The real diameter of the same comet’s nebulosity, is observed to contract rapidly as it approaches the sun, and dilate with equal rapidity in its departure toward its aphelion. Was I not justifiable in supposing, with M. Valz, that this apparent condensation of volume has its origin in the compression of the same ethereal medium I have spoken of before, and which is dense in proportion to its vicinity to the sun? The lenticular-shaped phenomenon,20 also, called the zodiacal light, was a matter worthy of attention. This radiance, so apparent in the tropics, and which cannot be mistaken for any meteoric lustre, extends from the horizon obliquely upwards, and follows generally the direction of the sun’s equator. It appeared to me evidently in the nature of a rare atmosphere extending from the sun outwards, beyond the orbit of Venus at least, and I believed indefinitely farther.* Indeed, this medium I could not suppose confined to the path of the comet’s ellipse, or to the immediate neighborhood of the sun. It was easy, on the contrary, to imagine it pervading the entire regions of our planetary system, condensed into what we call atmosphere at the planets themselves, and perhaps at some of them modified by considerations purely geological; that is to say, modified, or varied in its proportions (or absolute nature) by matters volatilized from the respective orbs.
Having adopted this view of the subject, I had little farther hesitation. Granting that on my passage I should meet with atmosphere essentially the same as at the surface of the earth, I conceived that, by means of the very ingenious apparatus of M. Grimm, I should readily be enabled to condense it in sufficient quantity for the purposes of respiration. This would remove the chief obstacle in a journey to the moon. I had indeed spent some money and great labor in adapting the apparatus to the object intended, and confidently looked forward to its successful application, if I could manage to complete the voyage within any reasonable period. – This brings me back to the rate at which it would be possible to travel.
It is true that balloons, in the first stage of their ascensions from the earth, are known to rise with a velocity comparatively moderate. Now, the power of elevation lies altogether in the superior gravity of the atmospheric air compared with the gas in the balloon; and, at first sight, it does not appear probable that, as the balloon acquires altitude, and consequently arrives successively in atmospheric strata of densities rapidly diminishing – I say, it does not appear at all reasonable that, in this its progress upward, the original velocity should be accelerated. On the other hand, I was not aware that, in any recorded ascension, a diminution had been proved to be apparent in the absolute rate of ascent; although such should have been the case, if on account of nothing else, on account of the escape of gas through balloons ill-constructed, and varnished with no better material than the ordinary varnish. It seemed, therefore, that the effect of such escape was only sufficient to counterbalance the effect of the acceleration attained in the diminishing of the balloon’s distance from the gravitating centre. I now considered that, provided in my passage I found the medium I had imagined, and provided it should prove to be essentially what we denominate atmospheric air, it could make comparatively little difference at what extreme state of rarefaction I should discover it – that is to say, in regard to my power of ascending – for the gas in the balloon would not only be itself subject to similar rarefaction, (in proportion to the occurrence of which, I could suffer an escape of so much as would be requisite to prevent explosion,) but, being what it was, would, at all events, continue specifically lighter than any compound whatever of mere nitrogen and oxygen. Thus there was a chance – in fact, there was a strong possibility – that, at no epoch of my ascent, I should reach a point where the united weights of my immense balloon, the inconceivably rare gas within it, the car, and its contents, should equal the weight of the mass of the surrounding atmosphere displaced; and this will be readily understood as the sole condition upon which my upward flight would be arrested. But, if this point were even attained, I could dispense with ballast and other weight to the amount of nearly 300 pounds. In the meantime, the force of gravitation would be constantly diminishing, in proportion to the squares of the distances, and so, with a velocity prodigiously accelerating, I should at length arrive in those distant regions where the force of the earth’s attraction would be superseded by that of the moon.
There was another difficulty, however, which occasioned me some little disquietude. It has been observed that, in balloon ascensions to any considerable height, besides the pain attending respiration, great uneasiness is experienced about the head and body, often accompanied with bleeding at the nose, and other symptoms of an alarming kind, and growing more and more inconvenient in proportion to the altitude attained.* This was a reflection of a nature somewhat startling. Was it not probable that these symptoms would increase until terminated by death itself? I finally thought not. Their origin was to be looked for in the progressive removal of the customary atmospheric pressure upon the surface of the body, and consequent distention of the superficial blood-vessels – not in any positive disorganization of the animal system, as in the case of difficulty in breathing, where the atmospheric density is chemically insufficient for the due renovation of blood in a ventricle of the heart. Unless for default of this renovation, I could see no reason, therefore, why life could not be sustained even in a vacuum; for the expansion and compression of chest, commonly called breathing, is action purely muscular, and the cause, not the effect, of respiration. In a word, I conceived that, as the body should become habituated to the want of atmospheric pressure, these sensations of pain would gradually diminish – and to endure them while they continued, I relied with confidence upon the iron hardihood of my constitution.
Thus, may it please your Excellencies, I have detailed some, though by no means all, the considerations which led me to form the project of a lunar voyage. I shall now proceed to lay before you the result of an attempt so apparently audacious in conception, and, at all events, so utterly unparelleled in the annals of mankind.
Having attained the altitude before mentioned – that is to say, three miles and three quarters – I threw out from the car a quantity of feathers, and found that I still ascended with sufficient rapidity; there was, therefore, no necessity for discharging any ballast. I was glad of this, for I wished to retain with me as much weight as I could carry, for the obvious reason tha
t I could not be positive either about the gravitation or the atmospheric density of the moon. I as yet suffered no bodily inconvenience, breathing with great freedom, and feeling no pain whatever in the head. The cat was lying very demurely upon my coat, which I had taken off, and eyeing the pigeons with an air of nonchalance. These latter being tied by the leg, to prevent their escape, were busily employed in picking up some grains of rice scattered for them in the bottom of the car.
At twenty minutes past six o’clock, the barometer showed an elevation of 26,400 feet, or five miles to a fraction. The prospect seemed unbounded. Indeed, it is very easily calculated by means of spherical geometry, how great an extent of the earth’s area I beheld. The convex surface of any segment of a sphere is, to the entire surface of the sphere itself, as the versed sine of the segment to the diameter of the sphere. Now, in my case, the versed sine – that is to say, the thickness of the segment beneath me – was about equal to my elevation, or the elevation of the point of sight above the surface. ‘As five miles, then, to eight thousand’, would express the proportion of the earth’s area seen by me. In other words, I beheld as much as a sixteen-hundredth part of the whole surface of the globe.23 The sea appeared unruffled as a mirror, although, by means of the telescope, I could perceive it to be in a state of violent agitation. The ship was no longer visible, having drifted away, apparently, to the eastward. I now began to experience, at intervals, severe pain in the head, especially about the ears – still, however, breathing with tolerable freedom. The cat and pigeons seemed to suffer no inconvenience whatsoever.
At twenty minutes before seven, the balloon entered a long series of dense cloud, which put me to great trouble, by damaging my condensing apparatus, and wetting me to the skin. This was, to be sure, a singular rencontre, for I had not believed it possible that a cloud of this nature could be sustained at so great an elevation. I thought it best, however, to throw out two five-pound pieces of ballast, reserving still a weight of one hundred and sixty-five pounds. Upon so doing, I soon rose above the difficulty, and perceived immediately, that I had obtained a great increase in my rate of ascent. In a few seconds after my leaving the cloud, a flash of vivid lightning shot from one end of it to the other, and caused it to kindle up, throughout its vast extent, like a mass of ignited charcoal. This, it must be remembered, was in the broad light of day. No fancy may picture the sublimity which might have been exhibited by a similar phenomenon taking place amid the darkness of the night. Hell itself might then have found a fitting image. Even as it was, my hair stood on end, while I gazed afar down within the yawning abysses, letting imagination descend, and stalk about in the strange vaulted halls, and ruddy gulfs, and red ghastly chasms of the hideous and unfathomable fire. I had indeed made a narrow escape. Had the balloon remained a very short while longer within the cloud – that is to say had not the inconvenience of getting wet, determined me to discharge the ballast – my destruction might, and probably would, have been the consequence. Such perils, although little considered, are perhaps the greatest which must be encountered in balloons. I had by this time, however, attained too great an elevation to be any longer uneasy on this head.
I was now rising rapidly, and by seven o’clock the barometer indicated an altitude of no less than nine miles and a half. I began to find great difficulty in drawing my breath. My head, too, was excessively painful; and, having felt for some time a moisture about my cheeks, I at length discovered it to be blood, which was oozing quite fast from the drums of my ears. My eyes, also, gave me great uneasiness. Upon passing the hand over them they seemed to have protruded from their sockets in no inconsiderable degree; and all objects in the car, and even the balloon itself, appeared distorted to my vision. These symptoms were more than I had expected, and occasioned me some alarm. At this juncture, very imprudently, and without consideration, I threw out from the car three five-pound pieces of ballast. The accelerated rate of ascent thus obtained, carried me too rapidly, and without sufficient gradation, into a highly rarefied stratum of the atmosphere, and the result had nearly proved fatal to my expedition and to myself. I was suddenly seized with a spasm which lasted for more than five minutes, and even when this, in a measure, ceased, I could catch my breath only at long intervals, and in a gasping manner, – bleeding all the while copiously at the nose and ears, and even slightly at the eyes. The pigeons appeared distressed in the extreme, and struggled to escape; while the cat mewed piteously, and, with her tongue hanging out of her mouth, staggered to and fro in the car as if under the influence of poison. I now too late discovered the great rashness of which I had been guilty in discharging the ballast, and my agitation was excessive. I anticipated nothing less than death, and death in a few minutes. The physical suffering I underwent contributed also to render me nearly incapable of making any exertion for the preservation of my life. I had, indeed, little power of reflection left, and the violence of the pain in my head seemed to be greatly on the increase. Thus I found that my senses would shortly give way altogether, and I had already clutched one of the valve ropes with the view of attempting a descent, when the recollection of the trick I had played the three creditors, and the possible consequences to myself, should I return, operated to deter me for the moment. I lay down in the bottom of the car, and endeavored to collect my faculties. In this I so far succeeded as to determine upon the experiment of losing blood. Having no lancet, however, I was constrained to perform the operation in the best manner I was able, and finally succeeded in opening a vein in my left arm, with the blade of my penknife. The blood had hardly commenced flowing when I experienced a sensible relief, and by the time I had lost about half a moderate basin-full, most of the worst symptoms had abandoned me entirely. I nevertheless did not think it expedient to attempt getting on my feet immediately; but, having tied up my arm as well as I could, I lay still for about a quarter of an hour. At the end of this time I arose, and found myself freer from absolute pain of any kind than I had been during the last hour and a quarter of my ascension. The difficulty of breathing, however, was diminished in a very slight degree, and I found that it would soon be positively necessary to make use of my condenser. In the meantime, looking towards the cat, who was again snugly stowed away upon my coat, I discovered, to my infinite surprise, that she had taken the opportunity of my indisposition to bring into light a litter of three little kittens. This was an addition to the number of passengers on my part altogether unexpected; but I was pleased at the occurrence. It would afford me a chance of bringing to a kind of test the truth of a surmise, which, more than any thing else, had influenced me in attempting this ascension. I had imagined that the habitual endurance of the atmospheric pressure at the surface of the earth was the cause, or nearly so, of the pain attending animal existence at a distance above the surface. Should the kittens be found to suffer uneasiness in an equal degree with their mother, I must consider my theory in fault, but a failure to do so I should look upon as a strong confirmation of my idea.
By eight o’clock I had actually attained an elevation of seventeen miles above the surface of the earth. Thus it seemed to me evident that my rate of ascent was not only on the increase, but that the progression would have been apparent in a slight degree even had I not discharged the ballast which I did. The pains in my head and ears returned, at intervals, with violence, and I still continued to bleed occasionally at the nose: but, upon the whole, I suffered much less than might have been expected. I breathed, however, at every moment, with more and more difficulty, and each inhalation was attended with a troublesome spasmodic action of the chest. I now unpacked the condensing apparatus, and got it ready for immediate use.
The view of the earth, at this period of my ascension, was beautiful indeed.24 To the westward, the northward, and the southward, as far as I could see, lay a boundless sheet of apparently unruffled ocean, which every moment gained a deeper and deeper tint of blue. At a vast distance to the eastward, although perfectly discernible, extended the islands of Great Britain, the entire
Atlantic coasts of France and Spain, with a small portion of the northern part of the continent of Africa. Of individual edifices not a trace could be discovered, and the proudest cities of mankind had utterly faded away from the face of the earth.
What mainly astonished me, in the appearance of things below, was the seeming concavity of the surface of the globe.25 I had, thoughtlessly enough, expected to see its real convexity become evident as I ascended; but a very little reflection sufficed to explain the discrepancy. A line, dropped from my position perpendicularly to the earth, would have formed the perpendicular of a right-angled triangle, of which the base would have extended from the right-angle to the horizon, and the hypothenuse from the horizon to my position. But my height was little or nothing in comparison with my prospect. In other words, the base and hypothenuse of the supposed triangle would, in my case, have been so long, when compared to the perpendicular, that the two former might have been regarded as nearly parallel. In this manner the horizon of the æronaut appears always to be upon a level with the car. But as the point immediately beneath him seems, and is, at a great distance below him, it seems, of course, also at a great distance below the horizon. Hence the impression of concavity; and this impression must remain, until the elevation shall bear so great a proportion to the prospect, that the apparent parallelism of the base and hypothenuse, disappears.
The Science Fiction of Edgar Allan Poe (Penguin Classics) Page 6