Once a week, in late eighteenth-century London, writers of contrasting politics and personalities gathered around a dining table. The host was Joseph Johnson, publisher and bookseller: a man at the heart of literary life. He was joined at dinner by a shifting constellation of extraordinary people who remade the literary world, including the Swiss artist Henry Fuseli, his chief engraver William Blake and scientists Joseph Priestley and Benjamin Franklin. William Wordsworth and Samuel Taylor Coleridge were among the attendees, as…