It was a tall thin building and, being so tall and thin, inside it seemed to be mostly narrow, lino-covered stairs that strained and popped as people went up and down, pressing themselves into the corner of the landing to let each other pass. The Births, Deaths and Marriages Room on the second floor was busy. Behind the counter, elderly gentlemen in tweed—volunteer genealogists, I discovered—were helping the customers.

Someone had unfolded a long scroll of sticky-taped paper with an endless family tree tracking down page after page and was poring over it with one of the tweedy gentlemen. A woman like me, with too many coats and bags over her arm, kept saying, ‘No, it’s the distaff line I want, d’you see? The distaff line.’ A tremulous old man was trying to use the equally ancient photocopier in the corner. A volunteer was explaining, ‘It costs 20p, but you put 10p in and give me 10p, cos it doesn’t take 20p.’ The old man turned over the coins in his palm, first one way, then the other.

When it was my turn, I thought it would be plain sailing. I had brought my seven Solomon Wisemans with me to London. The most likely seemed to be the one born in 1776 and baptised at St Mary Mounthaw. My plan was to ask for the registers of the church.

But my gentleman—a scholarly fellow with leather elbow-patches— frowned as if at news of a death. ‘St Mary Who?’

I repeated the name.

‘Never heard of it,’ he announced, and that was going to be that, but I was able to bring forth from my shabby bag the printout from the Mormon website.

He frowned over it for some time, even turning it over to see the back, which wasn’t much help as I’d been recycling my paper and the back announced Ms Ford’s Year Six Farewell Please Bring A Plate. Finally he consulted another, sterner man.

In front of me across the counter they compared abstruse names. ‘Have you looked in so-and-so?’ ‘Yes, and I tried the Register of such-and-such too.’ At last in a small shabby book, they found it.

No one had ever heard of St Mary Mounthaw because the church was destroyed in the Great Fire of London. Its parish was later joined with St Mary Somerset—another name from the Mormon records. Where were the parish records for St Mary Somerset? More consulting obscure books, more riffling through indices and cross-references.

St Mary Somerset, it turned out, was also destroyed in the Great Fire. It was rebuilt by Wren soon after, but was demolished in 1872 and the parish united with St Nicholas Cole Abbey.

I seemed to be getting a long way from Solomon Wiseman.

St Nicholas Cole Abbey was gutted by a firebomb in May 1941. Uh oh, I thought, there go the parish registers.

The search was no longer mine, however. There were now no fewer than four gentlemen activated by my enquiry. Between them all, they performed some little bit of genealogical legerdemain and directed me to the proceedings of the Harleian Society, Volume 58, Shelf MX/R58.