‘They had the fire going,’ he said. ‘And we had to stand here, hard up against the fireplace. It was that blessed hot, the seat of me pants was just about on fire.’

But Harold got through, and Solomon Wiseman must have, too.

Would Wiseman have been bound here, or in some earlier version of the Watermen’s Hall? According to Harold, it would have been in this same room. Wiseman would have come up that staircase. His hand would have added its share to the patina of age on the handrail.

Harold was a warm, clever and generous man, bemused that I was taking notes about the day his trousers nearly caught fire. Harold’s father and his father’s father had been watermen. His family had lived in Bermondsey as long as anyone could remember. He was proud of his skills and knowledge, of the hard work he’d done, of getting through those tough apprentice years. Harold knew who he was, where he’d come from, and what part of the world he could claim as his own.

It was from Harold that I learned how to find out exactly when and where Solomon Wiseman was born. Since he had served an apprenticeship, his binding—including his date of birth—would be in the registers up the road at the Guildhall.

The Guildhall Library turned out to contain every kind of document, picture, map and book relating to the City of London and its guilds.

It didn’t take long to find him: bound 17/12/1795, place of birth Southwark Christ Church, April 27, 1777, master Thomas Evans Gash, freed 06/01/1803.

And in the margin, a single word in a coarse script: DEAD.

One glance had taught me more than all that time on the internet and at the Society of Genealogists. Of the many Solomon Wisemans who’d flirted with me behind the gauze of dates, churches, and parents’ names, not one was my great-great-great grandfather. I could take the piece of paper which I’d so proudly propped up on the bed at the hotel, make it into a small ball, and throw it away.

Now that I knew about the Guildhall Library, I’d mine it for all it could tell me.

From the many dense volumes of Henry Humpherus’ History of the Origin and Progress of the Company of Watermen and Lightermen of the River Thames, first published in 1869, I learned the difference between ‘watermen’ (they transported people) and ‘lightermen’ (they transported goods). I learned how Old London Bridge (still standing in Wiseman’s day) choked the river so much that at low tide it created a fall of water like rapids. I read Boswell’s account of choosing to get out of the boat and walk around, rather than dangerously ‘shoot the Bridge’. I learned that the watermen were famous for thievery and ‘foul oaths’. Unfortunately Mr Humpherus was too delicate to write down the exact words that constituted a ‘foul oath’.

In the Guildhall’s collection of pictures was an engraving of a waterman standing up to his knees in the river steadying his boat and watching his customers board. The gentleman— a puny slip of a fellow with dark curls—was saying to his lady, ‘Be cautious my Love, don’t expose your leg!’ but her white-shod leg, with its dainty green high-heeled slipper, seemed displayed for the boatman’s pleasure, and from the look on his face he was getting a good eyeful.