It was one of the most foolhardy flights in history, and only a stroke of luck at 37,000ft prevented them drifting up to their deaths at the edge of the atmosphere.

The dead pigeons should have been James Glaisher’s warning. On 5 September 1862, the scientist was taking one of his first balloon flights – and alongside the compass, thermometers and bottles of brandy, he had decided to bring along six birds. 

“One was thrown out at the height of three miles,” he later wrote. “When it extended its wings it dropped like a piece of paper; the second, at four miles, flew vigorously round and round, apparently taking a dip each time; a third was thrown out between four and five miles, and it fell downwards as a stone.”

No sooner had he noted these observations than he began to feel the “balloon sickness” himself. His arm had been resting on the table, but it failed to respond when he tried to lift it. Alarmed, he tried to call out to his aeronaut, Henry Coxwell, but the words froze in his mouth and his head lolled helplessly to one side.

Advertisement

Discover stunning Wales

Gethin Jones takes to the sky to explore his favourite landscape in the world

Inspired to visit stunning Snowdonia? Find out more here

Click here to find out more

Glaisher knew the end was nigh. “In an instance darkness overcame me… I believed I would experience nothing more as death would come unless we speedily descended.”

Amazingly, both Coxwell and Glaisher survived thanks to some last-minute luck – but had they not they would have drifted to their deaths at the edge of the Earth’s atmosphere. Their plight is one of the great daredevil stories in the history of aviation – and perhaps even a glimpse into the future of space travel.

The aerial ocean

Glaisher had first set his sights skyward as he surveyed Ireland, mapping the contours of its highest peaks. “I was often compelled to remain sometimes for long periods, above or enveloped in cloud,” he wrote. “I was thus led to study the colours of the sky, the delicate tints of the clouds, the motion of opaque masses, the forms of the crystals of snow.”  His interest only peaked as he moved to the great observatories of Cambridge and Greenwich. “Often when a barrier of cloud has suddenly concealed the stars from view, I have wished to know the cause of their rapid formation and the processes in action around them.”

Ballooning had progressed somewhat since “Les Freres Roberts” tried to guide their balloon flights with oars and umbrellas at the end of the 18th Century, and ballooning was now of increasing interest to scientists like Glaisher. In contrast to today’s hot air balloons, their vehicles were filled with a light gas, like hydrogen, allowing the aeronauts to rise “with the ease of an ascending vapour … carried by the imprisoned gas”, as Glaisher put it.  

To rise, they would have thrown sand out of the basket, and to descend they opened a valve to let some of the gas out of the balloon. Once they were close enough to Earth, they would then release an anchor “that would hook into a tree or hedges and stop them being dragged along the ground”, says John Baker, the archivist at the British Balloon Museum and Library. Whereas others had always kept within view of the ground below, however, Glaisher wanted to reach higher, to explore the “aerial ocean”, which offered a “boundless sea of inquiry”.

Persuading the British Association for the Advancement of Science to fund his trips, Glaisher teamed up with the expert balloonist Henry Coxwell to take these voyages into the unknown. Their quest was quintessentially British – to understand the atmospheric forces governing the weather down on Earth. “He spent lots of time manufacturing suitable apparatus,” says Baker.

After some initial hiccups, the pair took their first flight on 17 July 1862, taking off from Wolverhampton at 9:43 in the morning. Within 12 minutes they had passed through the clouds. Under the heat of the sun, the balloon – an enormous construction containing 90,000 cubic feet (2,500 cubic metres) of gas – filled out to assume an almost perfect sphere. The sky, he noted, had turned a “deep Prussian blue”.

With cheap and accessible air travel today, it is easy to forget the romance of travelling thousands of feet above the ground. In 1862, however, Glaisher was among a small handful of people who had seen the world this way, and his lyrical descriptions help us to see those sights with fresh eyes. He describes the “supreme beauty” of the clouds “presenting at times mountain scenes of endless variety and grandeur”. The shadow of the balloon on the clouds below was “surrounded by a kind of corona tinted with prismatic colours”.

The illuminated dials of Westminster clock were like two dull moons

His later flights departed from Crystal Palace in London, offering a unique view of the British capital. “The illuminated dials of Westminster clock were like two dull moons,” he wrote, while Commercial Road “appeared like a line of brilliant fire”. The closest comparison, he thought, was the Milky Way on a clear dark night. “The field of view appeared covered with gold-dust, to be possessed of the power to see those minute spots of light as brilliant stars.”

The feted flight on the 5 September (again from Wolverhampton) began sanguinely enough. “A flood of strong sunlight burst upon us with a beautiful blue sky without a cloud, and beneath us lay a magnificent sea of clouds, its surface varied with endless hills, hillocks, and mountain chains, and with many snow-white tufts rising from it.”

While Coxwell was dangerously clambering among the rigging, Glaisher was slowly losing consciousness

As they rose beyond five miles, however, the temperature dropped below -20C, and he began to notice difficulties with his vision. “I could not see the fine column of the mercury in the wet-bulb thermometer; nor the hands of the watch, nor the fine divisions on any instrument.” Clearly, they needed to descend – yet the balloon’s valve-line had become entangled in the other ropes. Coxwell had to climb out of the basket to release it, but while he was dangerously clambering among the rigging, Glaisher was slowly losing consciousness.

Up on the ring, Coxwell felt that he too was losing control of his limbs. Realising that his life was at risk, he grabbed hold of the valve-line with his teeth and yanked his head several times. To his immense relief, it opened and they began their descent.

Glaisher awoke to hear Coxwell muttering vaguely above him. “I have been insensible,” he said – but wasted no time in returning to his experiments. “I then drew up my legs and took a pencil to begin observations,” he recorded in the book Travels in the Air. Of the pigeons, only one remained with them by the time they had reached the ground. It seemed so traumatised by the experience that it clung to Glaisher’s hand for 15 minutes before taking flight.

The pair estimated that they had risen to 37,000 feet – 7 miles (11km) – the highest altitude that a manned flight had reached at that point.

Neither Glaisher nor Coxwell could have fully understood the cause of their “balloon illness”. The cold, and the lack of oxygen will have certainly contributed, but a recent paper in Neurology journal suggests they may also have been suffering the “bends” that divers experience if they rise too quickly; thanks to falling pressure during the rapid ascent, gases like nitrogen and oxygen are released in the blood, forming bubbles in the neural tissue. The result is nausea, paralysis and loss of consciousness.

Glaisher reported, somewhat stoically, that he had been unscathed by the incident. “No inconvenience followed my insensibility.” He went on to make another 21 flights, recording observations that were crucial for our understanding of weather – discovering, for instance, the way raindrops form and gather moisture as they hurtle towards Earth, and noting that the winds change speed as you rise or fall through the atmosphere. “On one flight they took off with no wind on the surface, but flew 120 miles (190km), which proved that the wind was different at different altitudes,” says Baker.

Today, these kinds of measurements are made in unmanned, meteorological balloons – although some daredevils are still using balloons for equally intrepid journeys. Felix Baumgartner, for instance, rose 24 miles (39km) in a helium balloon for his famous “skydive” from space – and according to some, ballooning may even become the preferred means of space tourism. Advised by Nasa astronaut Michael Lopez-Alegria, the Spanish company Zero2Infinity plans to use a massive helium balloon to float into near-space, reaching around 21 miles (34km) above the Earth – a point beyond 99% of the atmosphere.

Although this is nowhere near the altitudes planned by the likes of Virgin Galactic, it should be far enough to view the serene orb of the Earth curving below you, surrounded by blackness – the source of the profoundly moving “overview effect” that so many astronauts have described. The advantage is that a balloon journey should be much more serene than a ride on a rocket-powered spaceplane.

Glaisher (who now has a crater on the Moon named in his honour) would surely approve. “We seem to be citizens of the sky, separated from the Earth by a barrier which seems impassable,” he wrote of his ballooning experiences. “In the upper world, to which we seem now to belong, the silence and quiet are so intense that peace and calm seem to reign alone.”

--

David Robson is BBC Future’s feature writer. He is @d_a_robson on Twitter.

Join 500,000+ Future fans by liking us on Facebook, or follow us on Twitter, Google+, LinkedIn and Instagram. This story is a part of BBC Britain – a series focused on exploring this extraordinary island, one story at a time. Readers outside of the UK can see every BBC Britain story by heading to the Britain homepage; you also can see our latest stories by following us on Facebook and Twitter.

If you liked this story, sign up for the weekly bbc.com features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital, Travel and Autos, delivered to your inbox every Friday.