The Age of Wonder (62 page)

But perhaps George Ticknor was a rather earnest academic, for there are signs that Davy began to tease him over the teacups. ‘I was much more surprised when I found that the first Chemist of his time was a professed
angler
; and that he thinks, if he were obliged to renounce fishing or philosophy, that he would find the struggle of his choice pretty severe.’ Jane avoided this interview altogether, tactfully sending a message down that she was ‘unwell’. When Ticknor did eventually catch up with her, he was impressed by her dark good looks, and what he called ‘the choice and variety of her phraseology’.
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In a thoughtful mood Davy wrote a new kind of metaphysical poem, ‘The Massy Pillars of the Earth’. It reflects on the human condition, and suggests that since nothing is ever destroyed in the physical universe, only transformed (the First Law of Thermodynamics), then man himself must be immortal in some spiritual sense. It also returns in a new way to Davy’s early Cornish beliefs about starlight as the source of all energy in the universe:

Nothing is lost; the ethereal fire,
Which from the farthest star descends,
Through the immensity of space
Its course by worlds attracted bends,

To reach the earth; the eternal laws
Preserve one glorious wise design;
Order amidst confusion flows
And all the system is divine.

If matter cannot be destroyed,
Then living mind can never die;
If e’en creative when alloy’d,
How sure is immortality!
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Intriguingly, the first stanza appears to anticipate Einstein’s General Theory of Relativity (1915), in which light is ‘bent’ by gravity; and then Eddington’s observations of a solar eclipse in 1919, when he recorded starlight actually being bent by the sun. But apparent anticipations of this kind can be deceptive in science, often hiding a more significant contemporary meaning. Here Davy was really expressing a more traditional belief: the sudden confidence that ‘eternal laws’ govern the universe in a benign and ordered way. In fact this view was largely at odds with the scepticism of his private journals. Instead, it proposes that nothing in the world is lost, or wasted or destroyed. There is ‘one glorious wise design’ throughout the universe, and ultimately ‘all the system is divine’; a belief somewhere between Romantic pantheism and the old Enlightenment deism.

In truth Davy was never ‘sure’ of individual immortality, which he constantly questions in his laboratory notebooks. Nor was the idea of man’s being ‘creative’ normally any kind of guarantee of it, especially when ‘alloy’d’ in flesh. What is striking about this poem is its sudden tone of Evangelical self-confidence and its unusually hymn-like form. It could have been written by John Wesley or Isaac Watts, though Davy carefully avoids the words ‘God’ or ‘soul’. It is quite unlike his more private speculative poems, and seems like a deliberate performance. Perhaps he wanted to settle down theologically, as well as socially. But science would never quite allow him to do either.

4

In July 1815 Davy took Jane on another fishing holiday in the Highlands, perhaps in an attempt to revive the happy memories of their honeymoon. But in early August, while at Melrose in the Yarrow valley, they were interrupted by a series of increasingly urgent letters from Dr Robert Gray of the Coal Mines Safety Committee, begging for his assistance. The situation in the mines was becoming critical (another fifty-seven men had died at Success colliery, Newbottles, in June), and ‘of all men of science’ in England, Sir Humphry was the one who could best bring ‘his extensive stores of chemical knowledge to a practical bearing’.

Replying on 18 August, Davy immediately proposed to visit Walls End colliery outside Newcastle, so he could observe the problem of lethal fire-damp on the spot. He determined to apply his pure scientific method: observation, experiment, analogy. He cancelled a visit to Banks at his country house in Lincolnshire, and sent Jane back to London. ‘Travelling as a bachelor’, he rode down to Walls End, and on 24 August had a long discussion with John Buddle, the Chief Mining Engineer.
⁷¹

Buddle (1773-1843) was a hard and experienced Yorkshireman, a Unitarian and a teetotaller. Neither a miner himself, nor a proprietor, he stood between capital and labour, proud of his professional independence as ‘viewer’ or engineer. He said that he had once been chaired in triumph by the miners, and another time burnt in effigy. In fact he was dedicated to them. He never married, never drank, lived with his sister, and played the cello in the evenings. In his way, he was a man not unlike Tom Poole. But initially he had grave suspicions of ‘Sir Humphry’, the man of science from the South.

Davy was immediately put on his mettle. He knew that the Royal Institution was committed to helping science serve British industry, and this was an important part of Banks’s conception of humane progress: the appliance of science. But at Walls End he saw a peculiarly personal challenge, requiring all his experience and skill. In his youth he had explored Cornish tin mines with his lost friend Gregory Watt, and he had a feeling for mining communities and their intense local loyalties. He had never lacked physical courage in his experiments, and had been confidently handling dangerous gases since the Bristol days. He had already had a first encounter with fire-damp in the Apennines with Faraday. Above all, here was a chance for Davy to fulfil his greatest ambition: to show that a man of science could serve humanity-
and be a genius.

What an outsider like Davy had to encounter in the Northumberland mines was described by a local journalist: ‘It would require all the fortitude of nature to refrain from fear, and to examine everything with calmness and precision. The immense depth [sometimes 600 feet], the innumerable windings and the dark solitary wastes of a coalmine are truly astonishing, and create a sensation of horror in the imagination.’
^72
♣

Buddle later recalled: ‘After a great deal of conversation with Sir Humphry Davy, and he making himself perfectly acquainted with the nature of our mines, and what was wanted, just as we were parting he looked at me and said, “I think I can do something for you.” Thinking it was too much ever to be achieved, I gave him a look of incredulity; at that moment it was beyond my comprehension. However, smiling, he said, “Do not despair, I think I can do something for you in a very short time.” ’
⁷³

From the start, Davy approached each stage of his solution with great originality, and also hectic speed. The Accidents Committee had considered that the prevention of explosions was essentially a problem of designing better ventilation for the mineshafts, rather as Davy had already done in Newgate Prison. Buddle wondered if a different kind of gas could be pumped down to neutralise the fire-damp. But Davy quickly grasped that something far more fundamental was required: safe light.

All miners needed to carry lights (candles or oil lamps) to every part of a mine. How could this be done without exploding the lethal firedamp gas, and moreover without living in permanent fear of such an explosion? The solution must be simple, inexpensive, robust and absolutely reliable: a miner’s ‘safe lamp’. Here Davy took his first original step. Instead of starting with the lamp, as every other inventor had done, he started with the gas. The first step was not the technology of the lamp, but a complete scientific analysis of the gas and all its properties. Buddle undertook to send samples of the fire-damp to London as soon as it could be safely gathered and bottled.

Davy went to ground in Durham for over three weeks, and neither Jane nor any friend in London (except Faraday) knew where he was. He visited numerous mines, talked to miners and overseers, silently observing, analysing and reflecting. He borrowed Dr Clanny’s bellows lamp for a day, but was not impressed. Then he suddenly seems to have made up his mind. He hurried back to London, and precipitately took over the Royal Institution laboratory on 9 October 1815, which he was not really authorised to do. He ordered glass and metal apparatus, capable of ‘withstanding an explosion’, from the Institution’s instrument-maker, John Newman, and summoned Michael Faraday to his assistance.
⁷⁴

They remained closeted in the basement laboratory almost without interruption for three months, pursuing a feverish series of experiments and issuing ongoing reports to the Royal Society. Faraday said he was only let out to attend the weekly meetings of the City Philosophical Society. He later modestly recalled: ‘I was a witness in our laboratory to the gradual and beautiful development of the train of thought and experiments which produced the Safety Lamp.’
⁷⁵

Davy first began a minute analysis of the properties of fire-damp, quickly confirming that it was ‘light carburetted hydrogen’ (methane), with unusual combustion characteristics. He discovered that explosions would only occur when methane reached a critical ratio of gas to air (approximately one to eight parts). It then became true explosive firedamp. Once ignited-a mere lick of a candle flame would do this-it produced an accelerated reaction, spreading with an intense flame that rapidly reached a critical temperature and then exploded with extreme violence. He noted that this critical temperature at which the explosion occurred was surprisingly high: much higher, for example, than for that of the hydrogen used in Charlier balloons.

Paradoxically, fire-damp was also capable, under certain conditions, of burning with a cool flame which did not explode. Accordingly, Davy next tried igniting it in various closed containers. If a glass tube was used, it instantly exploded. But when confined to a narrow metal tube, it would only burn with the cool, slow blue flame he had observed in the Apennines. He established that the reason for this was that the surface of the metal tube, if sufficiently narrow (’less than an eighth of an inch’), had the peculiar property of conducting away the heat and continuously cooling the methane flame, thus keeping it below the critical explosion temperature.

With his analysis of the gas complete, Davy turned his attention to the lamp. He began designing the first model of an enclosed, airtight safety lamp, using a sealed glass chimney round the wick, with a system of narrow metal tubes to let in the air at its base. Methane mixed with air would not explode in these tubes. Davy’s hasty sketches were transformed into neat technical drawings by Faraday. The prototypes were then constructed overnight by the Institution’s temperamental engineer, John Newman, at nearby Lisle Street, so that Davy could immediately try them out the next morning in large glass containers filled with fire-damp. ‘After many disappointments from the instrument-maker’, and some spectacular rows, several possible models began to emerge. This trial-and-error process was a new type of teamwork for Davy, which caused some friction. But crucially it allowed him and Faraday to work very rapidly, and on several concepts at once.
⁷⁶

Despite some fearful explosions, Davy already had at least three working prototypes of a ‘Safe Lantern’ ready by the end of October. All of these were sealed lamps, using various forms of metal tubes or ‘fire sieves’ as air inlets. He summarised his researches in a letter to Banks on 27 October, and a week later sent the lamps to the Royal Society, with a detailed scientific paper which was officially read on 9 November. He also copied his summary in a ‘private communication’, not to be released, to Dr Gray at the Safety Committee.
⁷⁷
Not surprisingly, news of at least one prototype was soon leaked to the Newcastle newspapers, which would later lead to confusion about the exact mechanism Davy had discovered, and a bitter priority dispute.

Banks was triumphant. On 30 October he wrote one of his most flamboyant missives to Davy, bubbling with emphatic capital letters, from Revesby Abbey in Lincolnshire. Davy’s ‘brilliant’ discoveries had given him ‘unspeakable Pleasure’, and would exalt the reputation of the Royal Society throughout the ‘Scientific world’. His personal achievement was nothing less than heroic: ‘To have come forward when called upon, because no one else could discover the means of defending Society from a Tremendous Scourge of Humanity; and to have by the application of Enlightened Philosophy found a means of providing a Certain Precautionary Measure [the lamp] effectual to guard Mankind for the future against this alarming & increasing Evil, cannot fail to recommend the Discoverer to much Public Gratitude, & to place the Royal Society in a more Popular Point of View than all the abstruse discoveries beyond the understanding of unlearned People could do. I shall most certainly direct your paper to be read at the very first day of our meeting.’
⁷⁸

But Banks’s congratulations were premature. The lamps with tubes were only
relatively
safe, as Davy discovered after further trials. Here his true genius as a man of science-his impetuosity, his imagination, his ambition and his seething energy-were demonstrated. Davy would not rest, nor would he let Faraday rest. Obsessively pursuing his researches into December, and largely ignoring Christmas, to Jane’s evident dismay, he remained closeted with his assistant. In late December or early January he made a further technical breakthrough, which he reported to the Royal Society in a hurried but triumphant paper of 11 January 1816.
⁷⁹

What he had discovered was this.
Fine-gauge iron mesh
would work even better than thin metal tubes in preventing an explosion. Indeed, it replaced the need for an airtight glass chimney (easily broken) entirely. The fine apertures in the mesh or ‘gauze’ provided the equivalent of hundreds of tiny metal cooling tubes (‘784 apertures to the inch’). The function of tubes and gauze was ‘analogous’. This application of metal gauze or ‘tissue’ was the key discovery that no other researcher had hit upon.