There is a specific kind of hubris inherent to the Victorian scientific enterprise, a conviction that the physical world could be catalogued, quantified, and conquered simply through the application of sufficient empirical rigour. This era of rampant intellectual expansion saw men in tweed and worsted wool setting out to map the most hostile environments on Earth, armed with little more than brass instruments and an unwavering belief in their own invulnerability. Yet few expeditions encapsulate this lethal intersection of bravery and naivety quite like the mammoth balloon ascent of 5 September 1862.
On that late summer afternoon, meteorologist James Glaisher and professional aeronaut Henry Coxwell climbed into the wicker basket of a colossal gas balloon and ordered it released into the sky above Wolverhampton. Their objective was ostensibly straightforward: to carry out meteorological observations at unprecedented altitudes, measuring temperature, humidity, and atmospheric pressure on behalf of the British Association for the Advancement of Science. What actually transpired was a harrowing journey to the very edge of the stratosphere, an altitude where human physiology catastrophically fails.
Reaching an estimated 37,000 feet - significantly higher than the cruising altitude of a modern commercial airliner and far above the summit of Mount Everest - Glaisher and Coxwell inadvertently subjected themselves to the brutal realities of hypoxia and sub-zero temperatures. Their survival hinged on a single, desperate act of physical endurance, transforming a scientific errand into one of the most remarkable tales of survival in the history of human flight.
The Mandate from the British Association
By the mid-nineteenth century, the lower atmosphere was a familiar playground for entertainers and thrill-seekers, but the upper atmosphere remained a vast, intimidating unknown. The British Association for the Advancement of Science, eager to elevate meteorology from a speculative pursuit into a rigorous empirical discipline, commissioned a series of high-altitude balloon flights. The British Empire relied fundamentally upon maritime supremacy, which in turn relied upon understanding the weather. The Association required an observer of unimpeachable scientific credentials to chart these invisible currents, and they found one in James Glaisher.
Glaisher was the quintessential man of the establishment. Born in 1809, he had served as the Superintendent of the Meteorological and Magnetic Department at the Royal Observatory, Greenwich. He was accustomed to the predictable, grounded routine of reading thermometers and barometers within the manicured confines of the observatory. However, Glaisher understood that the weather patterns dictating the fortunes of the empire were born in the inaccessible atmospheric layers far above the smog-choked streets of London. To understand the weather, one had to physically enter it.
For the piloting of the vessel, Glaisher relied on Henry Coxwell, a former dentist who had abandoned his terrestrial practice for the theatrical, highly dangerous life of a professional aeronaut. Coxwell was a pragmatic, deeply experienced balloonist who understood the temperamental physics of lighter-than-air flight better than almost any man alive. The pairing was a classic duality of the Victorian era: the cerebral, data-obsessed academic paired with the rugged, practical operator.
They selected the Stafford Road Gasworks in Wolverhampton as their launch site. While recent cinematic adaptations have romantically relocated the ascent to the picturesque, manicured parks of London, the grim reality of 19th-century ballooning required immense quantities of heavy coal gas. The Wolverhampton site offered a direct, high-volume supply, and crucially, its central inland location minimised the terrifying risk of the balloon being swept out over the North Sea - a fatal prospect for any aeronaut unable to control their descent.
Ascending Beyond the Reach of Breath
At exactly 1:03 PM on the 5th of September, the heavy ropes were slipped. The balloon, a colossal sphere of silk swelling with 90,000 cubic feet of coal gas, shot upward into the overcast Staffordshire sky. Glaisher immediately set to work. The basket was heavily burdened with delicate scientific apparatus: wet and dry bulb thermometers, an electrometer, Daniel’s hygrometer, chronometers, evacuated glass tubes for collecting air samples, and a formidable array of barometers.
For the first hour, the ascent was a triumph of systematic observation. As they passed through the thick, grey layers of cloud, emerging into the blinding, unfiltered sunlight of the upper troposphere, Glaisher continuously recorded the plunging temperatures and shifting atmospheric pressures. He worked with the frantic speed of a man who knew his time in this alien environment was severely limited. By the time they surpassed 20,000 feet, the temperature had dropped well below freezing. The men, dressed merely in the heavy outdoor clothing typical of a Victorian gentleman, began to suffer intensely from the cold.
What neither Glaisher nor Coxwell fully understood was the insidious, invisible nature of high-altitude hypoxia. The human body, evolved strictly for the oxygen-rich environment of sea level, begins to systematically shut down when atmospheric pressure drops to extreme lows. The deterioration is cognitive as well as physical; it induces confusion, severe lethargy, and a fatal sense of euphoric detachment.
As the balloon crossed the 29,000-foot mark - the official altitude of Mount Everest, an environment modern climbers refer to as the "Death Zone" - the situation inside the cramped wicker basket became genuinely dire. Glaisher’s meticulous, previously flawless handwritten notes began to sprawl and stagger incoherently across the page. The temperature was registered at minus 20 degrees Celsius. Ice rapidly coated the delicate brass instruments, and the extreme cold began to dangerously numb their extremities.
The Paralysis of the Stratosphere
It was at an altitude approaching 30,000 feet that Glaisher’s body began to entirely betray him. He later documented the terrifying progression of his physical collapse in his 1871 book, Travels in the Air. The account remains one of the most vivid, clinical descriptions of extreme hypoxia ever recorded in the English language.
Attempting to read a barometer, Glaisher found his arm entirely unresponsive. "I struggled and shook my body again, but could not move my arms," he wrote, noting with a sense of detached horror the creeping paralysis ascending his limbs. "It seemed like I had no limbs."
His vision began to fail next. He could not read the intricate dials; the bold black numbers blurred into the white porcelain faces of the instruments. He attempted to speak to Coxwell, to warn his pilot of his condition, but found his vocal cords utterly paralysed. Complete, terrifying blindness followed shortly after. Yet, bizarrely, his consciousness remained entirely lucid. He was a passenger trapped within his own dying body, fully aware that his life was slipping away in the freezing silence of the stratosphere.
"In an instant, darkness came over me," Glaisher recalled of his final moments of awareness. "I believed I would experience nothing more as death would come unless we speedily descended." Shortly after this horrifying realisation, Glaisher lost consciousness entirely, slumping backward into the bottom of the basket, his head resting against the freezing wicker.
Coxwell’s situation was scarcely better. The balloon was still ascending rapidly, accelerating into thinner, deadlier air. To arrest the climb and initiate a descent, Coxwell needed to open the primary release valve at the apex of the balloon, venting the lifting gas. However, the vital valve line had become violently twisted in the rigging during the turbulent, spinning ascent through the cloud layer.
When Coxwell reached for the cord, he found that the extreme cold had entirely deadened his hands. His fingers were blackened by severe frostbite, immobile, and utterly useless.
A Desperate Act in the Ropes
The balloon was now estimated to be hovering around 37,000 feet. The air pressure was so low that water would boil at blood temperature. If the ascent was not halted immediately, the balloon envelope would eventually burst from the expanding gas, or both men would die of simple asphyxiation.
Summoning the absolute last reserves of his waning strength, Coxwell climbed out of the relative safety of the basket and into the freezing, ice-coated rigging. With his hands completely paralysed, he was forced to rely solely on his forearms to haul his entire body weight upward. The physical exertion in the oxygen-starved environment must have been excruciating, every muscle burning desperately for air that simply was not there.
Reaching the tangled valve line, Coxwell found he could not grip it. In a final, desperate act of primal survival, he leaned forward, caught the heavy cord between his teeth, and violently threw his head back. He pulled with the muscles of his neck and jaw, feeling the heavy mechanical valve eventually yield.
Gas hissed from the apex of the balloon. The colossal silk envelope finally stopped its deadly upward rush and began to sink back toward the earth. Coxwell dropped back down into the basket, utterly exhausted, his mouth bleeding, hovering on the very edge of unconsciousness himself.
As the balloon dropped rapidly back into the thicker, oxygen-rich layers of the lower atmosphere, Glaisher’s body began to slowly revive. The paralysis retreated from his limbs, and his vision swam painfully back into focus. He found Coxwell slumped over in the basket, his hands blackened and frozen.
With characteristic Victorian understatement, the first words Glaisher spoke upon regaining his senses were a simple, clinical observation of fact.
"I have been insensible," he noted.
Coxwell, recovering his own breath in the freezing air, replied, "You have, and I too very nearly."
Cinematic Erasure and Historical Memory
The reams of scientific data harvested from the 5 September flight fundamentally altered the contemporary understanding of the atmosphere. Glaisher proved that temperature drops continuously with altitude, completely disproving the prevalent theory that the atmosphere was divided into neat, stratified temperature layers. Yet the sheer human drama of the flight has always threatened to overshadow the data.
In recent years, the story was thrust back into the global public consciousness by the 2019 feature film The Aeronauts. Directed by Tom Harper, the film is a visually spectacular, dizzying recreation of the flight, capturing the terrifying verticality of 19th-century ballooning. However, it made a highly controversial historical revision: while Eddie Redmayne played James Glaisher, the hero of the hour, Henry Coxwell, was entirely erased from the narrative.
In Coxwell’s place, the filmmakers inserted a fictional female aeronaut named Amelia Wren, played by Felicity Jones. While the character was a composite intended to honour early female ballooning pioneers like Sophie Blanchard and Margaret Graham, the decision to overwrite Coxwell’s verifiable, factual act of heroism sparked intense criticism from historians and meteorologists alike.
In the intersection of art and science, cinematic adaptations are expected to take creative liberties. But removing Coxwell fundamentally alters the historical and social truth of the flight. It was a working-class aeronaut - a man who had learned his dangerous trade through years of practical, often brutal experience - who saved the life of the elite establishment scientist. The teeth that pulled the frozen valve line belonged to Henry Coxwell, and his erasure from his own survival story highlights the frequent, uncomfortable friction between modern cinematic storytelling and historical reality.
The Enduring Reality of the Ascent
The great balloon eventually touched down roughly seven miles from Ludlow. The two men were battered, severely frozen, and utterly exhausted, but they were entirely alive. They had survived an excursion into a hostile realm that human biology was never designed to enter.
Glaisher and Coxwell’s 1862 ascent remains a towering achievement of nineteenth-century empirical science. It was not merely a daredevil stunt, but a calculated, if recklessly ambitious, push into the absolute unknown. They lacked supplemental oxygen, pressurised cabins, thermal suits, or any means of communication with the ground. They faced the freezing, breathless vacuum of the stratosphere armed only with their fragile glass instruments and a profound, distinctly Victorian refusal to yield to the elements.
When James Glaisher lost his sight and motor functions at 30,000 feet, he was experiencing the absolute limits of human biology. When Henry Coxwell climbed the rigging with frozen hands and pulled a rope with his teeth, he was redefining the absolute limits of human willpower. Together, they proved that the sky was not a mere ceiling above the Empire, but a vast ocean of shifting currents and deadly extremes - an ocean they had briefly, terrifyingly, conquered.
