I’ve always been really interested in Ireland’s sacred wells. They’re pre-Christian, but when the Christian monks arrived, they decided that they couldn’t fight [the paganism], so they had to co-opt them into Christianity. People still enact what they call devotions, where they walk around wells a certain number of times and leave offerings. An academic did a scientific analysis of some sacred wells that are still operational. There’s one that is said to cure madness, and when they analyzed the water, they found it has a really high level of lithium. Amazing, isn’t it? For thousands of years, people have known that if you have mental health problems, you go and you drink from this well, and you feel better.
It seems like this is like a particularly personal novel, at least in terms of the research you’d already done, and what you knew about your family history.
I think it is. I’ve always been interested in the story of my great-great-grandfather, who was a mapper [and the inspiration for Tomás], and his son, who was initially a Jesuit, and then came back to his same job as a farmer. That strange character arc is so fascinating, because nobody becomes a Jesuit by accident; it’s really not something that you just fall into. So I was very into that, and I was always clear that I wanted to find out as much as I possibly could, which wasn’t that easy, because records—particularly in the middle of the 19th century, where there’s huge political and social upheaval in Ireland—are a bit vague. But I took the little particles that I could find, and built the novel around those.
Where did you find those particles?
The archives in Dublin are excellent—they hold all the records for the Ordnance Survey in Ireland—but it was quite difficult to find my great-great grandfather, because if you were working for the British in the mid-19th century, you were not allowed to sign your own work. It had to be signed by a British officer. I could see his names on wage slips and memos, but it was quite hard to actually work out which maps were his.
There was something mentioned in the archive in Ireland, though, which suggested that some personnel had been sent to Scotland, so I thought, “I live in Edinburgh, I’ll just go see, you never know.” They came out wheeling this trolley with stacks of field notebooks and draft maps and sketches that were all his—because in Scotland, he was allowed to sign his own name. It was like striking gold. I’d been looking for this man for 15 years, and it turns out I could find him about a mile from my house.
I also visited Grosse Île [an island in Canada’s St. Lawrence River that served as the processing station for an estimated 500,000 Irish immigrants between 1832 and 1932], which made a massive impression on me, and Ellis Island in New York. It was fascinating. I took about 3 million photographs of all these [records of] immigrants and their stories.