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   Chapter 13 SOME NOTEWORTHY ASCENTS.

The Dominion of the Air: The Story of Aerial Navigation By John M. Bacon Characters: 18017

Updated: 2017-12-01 00:02


It was the year 1862, and the scientific world in England determined once again on attempting observational work in connection with balloons. There had been a meeting of the British Association at Wolverhampton, and, under their auspices, and with the professional services of Thomas Lythgoe, Mr. Creswick, of Greenwich Observatory, was commissioned to make a lofty scientific ascent with a Cremorne balloon. The attempt, however, was unsatisfactory; and the balloon being condemned, an application was made to Mr. Coxwell to provide a suitable craft, and to undertake its management. The principals of the working committee were Colonel Sykes, M.P., Dr. Lee, and Mr. James Glaisher, F.R.S., and a short conference between these gentlemen and the experienced aeronaut soon made it clear that a mammoth balloon far larger than any in existence was needed for the work in hand. But here a fatal obstacle presented itself in lack of funds, for it transpired that the grant voted was only to be devoted to trial ascents.

It was then that Mr. Coxwell, with characteristic enterprise, undertook, at his own cost, to build a suitable balloon, and, moreover, to have it ready by Midsummer Day. It was a bold, as well as a generous, offer; for it was now March, and, according to Mr. Coxwell's statement, if silk were employed, the preparation and manufacture would occupy six months and cost not less than L2,000. The fabric chosen was a sort of American cloth, and by unremitting efforts the task was performed to time, and the balloon forwarded to Wolverhampton, its dimensions being 55 feet in diameter, 80 feet in height from the ground, with a capacity of 93,000 cubic feet. But the best feature in connection with it was the fact that Mr. Glaisher himself was to make the ascents as scientific observer.

No time was lost in getting to work, but twice over the chosen days were unsuitable, and it was not till July 17th that the two colleagues, of whom so much is to be told, got away at 9.30 a.m. with their balloon only two-thirds full, to allow of expansion to take place in such a lofty ascent as was contemplated. And, when it is considered that an altitude of five miles was reached, it will be granted that the scientific gentleman who was making his maiden ascent that day showed remarkable endurance and tenacity of purpose-the all-important essential for the onerous and trying work before him. At 9.56 the balloon had disappeared from sight, climbing far into the sky in the E.N.E. The story of the voyage we must leave in Mr. Glaisher's hands. Certain events, however, associated with other aeronauts, which had already happened, and which should be considered in connection with the new drama now to be introduced, may fittingly here meet with brief mention.

The trouble arising from the coasting across country of a fallen and still half-inflated balloon has already been sufficiently illustrated, and needs little further discussion. It is common enough to see a balloon, when full and round, struggling restively under a moderate breeze with a score of men, and dragging them, and near a ton of sand-bags as well, about the starting ground. But, as has already been pointed out, the power of the wind on the globe is vastly increased when the silk becomes slack and forms a hollow to hold the wind, like a bellying sail. Various means to deal with this difficulty have been devised, one of these being an emergency, or ripping valve, in addition to the ordinary valve, consisting of an arrangement for tearing a large opening in the upper part of one of the gores, so that on reaching earth the balloon may be immediately crippled and emptied of so large a quantity of gas as to render dragging impossible. Such a method is not altogether without drawbacks, one of these being the confusion liable to arise from there being more than one valve line to reckon with. To obviate this, it has been suggested that the emergency line should be of a distinctive colour.

But an experiment with a safeguard to somewhat of this nature was attended with fatal consequence in the year 1824. A Mr. Harris, a lieutenant in the British Navy, ascended from the Eagle Tavern, City Road, with a balloon fitted with a contrivance of his own invention, consisting of a large hinged upper valve, having within it a smaller valve of the same description, the idea being that, should the operation of the smaller outlet not suffice for any occasion, then the shutter of the larger opening might be resorted to, to effect a more liberal discharge of gas.

Mr. Harris took with him a young lady, Miss Stocks by name, and apparently the afternoon-it being late May-was favourable for an aerial voyage; for, with full reliance on his apparatus, he left his grapnel behind, and was content with such assistance as the girl might be able to render him. It was not long before the balloon was found descending, and with a rapidity that seemed somewhat to disturb the aeronaut; and when, after a re-ascent, effected by a discharge of ballast, another decided downward tendency ensued, Mr. Harris clearly realised that something was wrong, without, however, divining the cause. The story subsequently told by the girl was to the effect that when the balloon was descending the second time she was spoken to by her unfortunate companion in an anxious manner. "I then heard the balloon go 'Clap! clap!' and Mr. Harris said he was afraid it was bursting, at which I fainted, and knew no more until I found myself in bed." A gamekeeper tells the sequel, relating that he observed the balloon, which was descending with great velocity, strike and break the head of an oak tree, after which it also struck the ground. Hurrying up, he found the girl insensible, and Mr. Harris already dead, with his breast bone and several ribs broken. The explanation of the accident given by Mr. Edward Spencer is alike convincing and instructive. This eminently practical authority points out that the valve lines must have been made taut to the hoop at the time that the balloon was full and globular. Thus, subsequently, when from diminution of gas the balloon's shape elongated, the valve line would become strained and begin to open the valve, but in such a gradual manner as to escape the notice of the aeronaut. Miss Stocks, far from being unnerved by the terrible experience, actually made three subsequent ascents in company with Mr. Green.

It deserves mention that another disaster, equally instructive, but happily not attended with loss of life, occurred in Dublin in 1844 to Mr. Hampton, who about this time made several public and enterprising voyages. He evidently was possessed of admirable nerve and decision, and did not hesitate to make an ascent from the Porto-Bello Gardens in face of strong wind blowing sea-wards, and in spite of many protestations from the onlookers that he was placing himself in danger. This danger he fully realised, more particularly when he recognised that the headland on which he hoped to alight was not in the direction of the wind's course. Resolved, however, on gratifying the crowd, Mr. Hampton ascended rapidly, and then with equal expedition commenced a precipitate descent, which he accomplished with skill and without mishap. But the wind was still boisterous, and the balloon sped onward along the ground towards fresh danger unforeseen, and perhaps not duly reckoned with. Ahead was a cottage, the chimney of which was on fire. A balloonist in these circumstances is apt to think little of a single small object in his way, knowing how many are the chances of missing or of successfully negotiating any such obstacle. The writer on one occasion was, in the judgment of onlookers below, drifting in dangerous proximity to the awful Cwmavon stack in Glamorganshire, then in full blast; yet it was a fact that that vast vent of flame and smoke passed almost unheeded by the party in the descending car. It may have been thus, also, with Mr. Hampton, who only fully realised his danger when his balloon blew up "with an awfully grand explosion," and he was reduced to the extremity of jumping for his life, happily escaping the mass of burning silk and ropes.

The awful predicament of falling into the sea, which has been illustrated already, and which will recur again in these pages, was ably and successfully met by Mr. Cunningham, who made an afternoon ascent from the Artillery Barracks at Clevedon, reaching Snake Island at nightfall, where, owing to the gathering darkness, he felt constrained to open his valve. He quickly commenced descending into the sea, and when within ten feet of the water, turned the "detaching screw" which connected the car with the balloon. The effect of this was at once to launch him on the waves, but, being still able to keep control over the valve, he allowed just enough gas to remain within the silk to hold the balloon above water. He then betook himself to the paddles with which his craft was provided, and reached Snake Island w

ith the balloon in tow. Here he seems to have found good use for a further portion of his very complete equipment; for, lighting a signal rocket, he presently brought a four-oared gig to his succour from Portsmouth Harbour.

The teaching of the above incident is manifest enough. If it should be contemplated to use the balloon for serious or lengthened travel anywhere within possible reach of the sea-board-and this must apply to all parts of the British Isles-it must become a wise precaution, if not an absolute necessity, to adopt some form of car that would be of avail in the event of a fall taking place in the sea. Sufficient confirmation of this statement will be shortly afforded by a memorable voyage accomplished during the partnership of Messrs. Glaisher and Coxwell, one which would certainly have found the travellers in far less jeopardy had their car been convertible into a boat. We have already seen how essential Wise considered this expedient in his own bolder schemes, and it may further be mentioned here that modern air ships have been designed with the intention of making the water a perfectly safe landing.

The ballooning exploits which, however, we have now to recount had quite another and more special object consistently in view-that of scientific investigation; and we would here premise that the proper appreciation of these investigations will depend on a due understanding of the attendant circumstances, as also of the constant characteristic behaviour of balloons, whether despatched for mere travel or research.

First let us regard the actual path of a balloon in space when being manoeuvred in the way we read of in Mr. Glaisher's own accounts. This part is in most cases approximately indicated in that most attractive volume of his entitled, "Travels in the Air," by diagrams giving a sectional presentment of his more important voyages; but a little commonplace consideration may take the place of diagrams.

It has been common to assert that a balloon poised in space is the most delicate balance conceivable. Its intrinsic weight must be exactly equal to the weight of the air it displaces, and since the density of the air decreases according to a fixed law, amounting, approximately, to a difference in barometric reading of 0.1 inch for every 90 feet, it follows, theoretically, that if a balloon is poised at 1,000 feet above sea level, then it would not be in equilibrium at any other height, so long as its weight and volume remain the same. If it were 50 feet higher it must commence descending, and, if lower, then it must ascend till it reaches its true level; and, more than that, in the event of either such excursion mere impetus would carry it beyond this level, about which it would oscillate for a short time, after the manner of the pendulum. This is substantially true, but it must be taken in connection with other facts which have a far greater influence on a balloon's position or motion.

For instance, in the volume just referred to it is stated by M. Gaston Tissandier that on one occasion when aloft he threw overboard a chicken bone, and, immediately consulting a barometer, had to admit on "clearest evidence that the bone had caused a rise of from twenty to thirty yards, so delicately is a balloon equipoised in the air." Here, without pausing to calculate whether the discharge of an ounce or so would suffice to cause a large balloon to ascend through ninety feet, it may be pointed out that the record cannot be trustworthy, from the mere fact that a free balloon is from moment to moment being subjected to other potent influences, which necessarily affect its position in space. In daytime the sun's influence is an all-important factor, and whether shining brightly or partially hidden by clouds, a slight difference in obscuration will have a ready and marked effect on the balloon's altitude. Again, a balloon in transit may pass almost momentarily from a warmer layer of air to a colder, or vice versa, the plane of demarcation between the two being very definite and abrupt, and in this case altitude is at once affected; or, yet again, there are the descending and ascending currents, met with constantly and unexpectedly, which have to be reckoned with.

Thus it becomes a fact that a balloon's vertical course is subjected to constant checks and vicissitudes from a variety of causes, and these will have to be duly borne in mind when we are confronted with the often surprising results and readings which are supplied by scientific observers. With regard to the close proximity, without appreciable intermingling, of widely differing currents, it should be mentioned that explorers have found in regions where winds of different directions pass each other that one air stream appears actually to drag against the surface of the other, as though admitting no interspace where the streams might mingle. Indeed, trustworthy observers have stated that even a hurricane can rage over a tranquil atmosphere with a sharply defined surface of demarcation between calm and storm. Thus, to quote the actual words of Charles Darwin, than whom it is impossible to adduce a more careful witness, we find him recording how on mountain heights he met with winds turbulent and unconfined, yet holding courses "like rivers within their beds."

It is in tracing the trend of upper air streams, to whose wayward courses and ever varying conditions we are now to be introduced, that much of our most valuable information has come, affecting the possibility of forecasting British wind and weather. It should need no insisting on that the data required by meteorologists are not sufficiently supplied by the readings of instruments placed on or near the ground, or by the set of the wind as determined by a vane planted on the top of a pole or roof of a building. The chief factors in our meteorology are rather those broader and deeper conditions which obtain in higher regions necessarily beyond our ken, until those regions are duly and diligently explored.

Mr. Glaisher's estimate of the utility of the balloon as an instrument of research, formed at the conclusion of his aeronautical labours, has a special value and significance. Speaking with all the weight attaching to so trained and eminent an observer, he declares, "The balloon, considered as an instrument for vertical exploration, presents itself to us under a variety of aspects, each of which is fertile in suggestions. Regarding the atmosphere as the great laboratory of changes which contain the germ of future dis discoveries, to belong respectively, as they unfold, to the chemist and meteorologist, the physical relation to animal life of different heights, the form of death which at certain elevations waits to accomplish its destruction, the effect of diminished pressure upon individuals similarly placed, the comparison of mountain ascents with the experiences of aeronauts, are some of the questions which suggest themselves and faintly indicate enquiries which naturally ally themselves to the course of balloon experiments. Sufficiently varied and important, they will be seen to rank the balloon as a valuable aid to the uses of philosophy, and rescue it from the impending degradation of continuing a toy fit only to be exhibited or to administer to the pleasures of the curious and lovers of adventure."

The words of the same authority as to the possible practical development of the balloon as an aerial machine should likewise be quoted, and will appear almost prophetic. "In England the subject of aero-station has made but little progress, and no valuable invention has arisen to facilitate travelling in the air. In all my ascents I used the balloon as I found it. The desire which influenced me was to ascend to the higher regions and travel by its means in furtherance of a better knowledge of atmospheric phenomena. Neither its management nor its improvement formed a part of my plan. I soon found that balloon travelling was at the mercy of the wind, and I saw no probability of any method of steering balloons being obtained. It even appeared to me that the balloon itself, admirable for vertical ascents, was not necessarily a first step in aerial navigation, and might possibly have no share in the solution of the problem. It was this conviction that led to the formation of the Aeronautical Society a few years since under the presidency of the Duke of Argyll. In the number of communications made to this society it is evident that many minds are taxing their ingenuity to discover a mode of navigating the air; all kinds of imaginary projects have been suggested, some showing great mechanical ingenuity, but all indicating the want of more knowledge of the atmosphere itself. The first great aim of this society is the connecting the velocity of the air with its pressure on plane surfaces at various inclinations.

"There seems no prospect of obtaining this relation otherwise than by a careful series of experiments."

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