Much of Mayhew’s previous writing life had prepared him for this extraordinary essay. He was one of the greatest journalists of the age, whose interests spanned everything from the fine arts to social reform. He also wrote poetry, plays, operas and would go on to produce hugely successful accounts of the early lives of two scientists: Young Humphry Davy (1855) and Young Benjamin Franklin (1861). His most famous work, London Labour and the London Poor, had been published in instalments throughout 1851, deliberately timed to coincide with the Great Exhibition, as a sobering correction to its Victorian triumphalism.

      After spending much of his twenties knocking about Paris, freelancing alongside his friends William Thackeray and Douglas Jerrold, Mayhew returned to London full of ideas for a new kind of streetwise journalism. He was much taken with the irreverent and satirical style of the French magazine Le Charivari, to which the pioneering French aerial photographer Félix Nadar and many others contributed. In 1841 he helped the journalist Mark Lemon launch a quite new kind of humorous British periodical. It became Punch, with its mixture of witty essays and clever but good-natured satirical cartoons. It had an immediate success, but Mayhew and Lemon soon parted company, though remaining on excellent terms. Lemon continued at Punch, becoming a comfortable fixture in London literary clubland, and eventually one of Dickens’s most trusted editors. Meanwhile Mayhew struck out on his own, gradually developing a new kind of investigative journalism. He went far beyond the gentle, sardonic scope of Punch, contributing edgy, groundbreaking pieces to the Morning Chronicle. His special subject was London, and the underside of city life. Mayhew’s London was the city that few middle-class readers ever glimpsed: London from beneath.

      For the next decade Mayhew produced hundreds of vivid, detailed reports of life in the backstreets and the rookeries, and especially on the marginal trades and skills that sustained the poorest men and women – and not least the children – of the capital. Among his celebrated and scandalous subjects were street vendors, costermongers, milkmaids, ratcatchers, mudlarks, crossing sweepers, fire eaters, prostitutes, pickpockets and dustmen. Each of his accounts was written with the clipped shape and high polish of a short story. They were buttressed by statistics, glinting with minute visual details, and brought to life with inimitable passages of dialogue.

      Often these develop into simple but disturbing sequences of question and answer. ‘I make all kinds of eyes,’ the eye-manufacturer says, ‘both dolls’ eyes and human eyes; birds’ eyes are mostly manufactured in Birmingham, and as you say, sir, bulls’ eyes at the confectioner’s … A great many eyes go abroad with the dolls … The annual increase in dolls goes on at an alarming rate. As you say, sir, the yearly rate of mortality must be very high, to be sure, but still that’s nothing to the rate in which they are brought into the world … I also make human eyes. Here are two cases, in the one I have black and hazel, in the other blue and grey. Here you see are the ladies’ eyes … There’s more sparkle and brilliance about them than the gentlemen’s … There is a lady customer of mine who has been married three years to her husband, and I believe he doesn’t know she has a false eye to this day.’¹ Such material, with its mixture of the mundane and the gothic, its small revelations of human eccentricity and affection, would clearly influence the later and darker novels of Dickens.

      When he had amassed about half a million words of material, Mayhew began to edit and reorganise the pieces into the form of his grim masterwork London Labour and the London Poor. Once the work was completed, he cast around for a suitable way to celebrate. It struck him that an airy overview of the great city, in whose backstreets and dark corners he had spent so many years almost buried, would be suitable. So he accepted an invitation to take a flight in one of Charles Green’s balloons.

      Officially this was to be one of Green’s frequently-advertised ‘Last Ascents’ from Vauxhall Gardens. For Mayhew, the flight was also to be, in a sense, the culmination and farewell to much of his previous journalism. But it was also a celebration and a release from it. Having seen London from the darkest and most labyrinthine street level, he now wished to sail into the clear air above it. He wanted to see his huge and ‘monstrous’ city at last in the grand perspective, or – as he put it with poignant irony – from ‘an angel’s view’. What’s more, he would write about it for the leading current-affairs weekly in Britain, the Illustrated London News.

      In case the ‘angel’ approach seemed rather presumptuous, he began by explaining that he was naturally ‘a coward – constitutionally and habitually timid’. As it did for most of his readers, the idea of flying in a balloon frankly