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 with 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."