We do not need to imagine what the tunnels of the Metropolitan Railway were like as a growing number of steam locomotives poured through them from every direction since, once the initial enthusiasm for underground railway travel had waned, a number of contemporaries recorded their experiences of travelling through the dark, steaming, smoking tunnels. A letter to The Times described a journey in 1879:

The condition of the atmosphere was so poisonous that, although a mining engineer, I was almost suffocated and was obliged to be assisted from the train at an intermediate station. On reaching the open air I requested to be taken to a chemist close at hand&helli[; Without a moment’s hesitation he said “Oh, I see, Metropolitan Railway”, and at once poured out a wine glass full of what I conclude he designated Metropolitan Mixture. I was induced to ask him whether he often had such cases, to which he rejoined, “Why, bless you sir, we often have twenty cases a day.”

Even a supposedly flattering account of a journey in the 1890s in the English Illustrated Magazine conjures up a vision of a dentist from Hell, comparing the noise of the train with the “shrieking of ten thousand demons above the thunder of the wheels. The sensation was altogether like the inhalation of gas preparatory to having a tooth drawn”. In October 1884 a leading article in The Times, celebrating the completion of the Inner Circle Line, reminded its readers that early promises by the Metropolitan Railway to use locomotives which “consume their own smoke and condense their own steam” had quickly been forgotten, and added:

A journey from King’s Cross to Baker Street is a form of mild torture which no person would undergo if he could conveniently help it. Passengers have been consoled by the assurance that semi-asphyxiation by sulphurous fumes is not an injurious thing even for the asthmatic but this is a point on which coughing sufferers cannot be expected to agree with railway directors.

The reference to railway directors reflected the often-expressed conviction of these gentlemen that smoke-filled tunnels were not only harmless to humans but positively beneficial. In 1898 a Board of Trade Committee on Ventilation of Tunnels on the Metropolitan Railway was told that almost 550 passenger and goods trains were passing through the system each day, all, of course, drawn by steam locomotives. In his evidence to the committee, the Metropolitan Railway’s general manager, Colonel John Bell, assured his questioners that the company’s employees were the healthiest railwaymen in the country, that the fumes were health-giving and that Great Portland Street station was “actually used as a sanatorium for men who had been afflicted with asthma and bronchial complaints”. Indeed, Bell attributed his own recovery from decades of tonsillitis to the ‘acid gas’ in the tunnels and claimed that another employee’s bronchitis cure was due to the company’s thoughtfulness in transferring him from a quiet, well-ventilated station at Bayswater to the fuming chasm of Euston Square. These strange assurances received some support from an independent quarter. In his book The Soul of London, published in 1895, F M Hueffer (better known as Ford Madox Ford) wrote:

I have known a man, dying a long way from London, sigh queerly for a sight of the gush of smoke that, on a platform of the Underground, one may see escaping in great woolly clots.”

However, the Board of Trade Committee heard some more unsettling evidence from a Metropolitan Railway train driver, Mr A Langford. Having told the committee of his excellent health despite 34 years’ subterranean service, he added, rather alarmingly, that “very seldom” was the smoke so thick as to prevent him seeing the railway signals. The committee’s reaction to this disconcerting news is not recorded but their deliberations achieved little since, two years later, the journalist R D Blumenfeld, a reliable chronicler of London at the turn of the century, recorded in his diary his experience of a journey from Baker Street to Moorgate:

I had my first experience of Hades to-day, and if the real thing is to be like that I shall never again do anything wrong. I got into the Underground railway at Baker Street… The compartment in which I sat was filled with passengers who were smoking pipes, as is the English habit… the smoke and the sulphur fill the tunnel, all the windows have to be closed. The atmosphere was a mixture of sulphur, coal dust and foul fumes from the gas lamps above; so that by the time we reached Moorgate Street I was near dead of asphyxiation and heat. I should think these underground railways must soon be discontinued, for they are a menace to health.

Fortunately for Blumenfeld’s own son this gloomy prognosis was wrong since the son in question, Sir John Elliot, went on to become chairman of London Transport in the 1950s.

The problem of the fumes was eventually solved, after much hesitation and acrimony, in the early 1900s through the adoption of electric traction, though steam locomotives continued to be used for many years to haul engineers’ trains for track maintenance. The last working steam train ran on 4 June 1967.