When he reached the top of Beacon Hill, he usually stopped and looked down. The perspective before him still engendered in him a faint sense of wonder. He saw, laid before him, the orderliness of the city, which had grown with time, as new streets and squares were laid out. Noting how Bath had redefined itself as the years passed, and didn’t remain petrified in the past, he began to wonder whether he, a citizen of this tranquil place, could also achieve some alteration in himself. But he feared that the emptiness of his mind, this void of non-thinking, would prevent it.

One morning in late November, Ross was walking from the Hill towards Charlcombe across the fields. There was a thin crusting of last night’s frost on the grass. The sun, now risen in a blue sky, gave to the meadow a sudden jewelled splendour. Ross paused and stared at this, letting it dazzle his vision. Then, at the corner of his eye, he saw an extraordinary bird, shining black and green against the whitened field. It was, like him, standing quite still, seeming to regard the silent scene with close attention.

It was a capercaillie, the large wood grouse, tetrao urogallus, a bird of exceptional rarity, hardly ever glimpsed in England, but which, years before, on a visit to Scotland, had so beguiled Ross’s younger brother Edmund by its colouring and its display that from that day, Edmund had been determined to dedicate his life to becoming a naturalist. At once, Ross was transported to other fields, lanes and hedgerows where he and Edmund, as growing boys in Wiltshire and, always under Edmund’s instruction, had given all their hours to collecting plants and insects and to trapping small animals and birds.

What chiefly came to his mind, as he and the capercaillie remained motionless in the sunrise, was the sound of Edmund’s laughter, his inevitable way of communicating pure joy when his eyes alighted on something – a rare orchid flower, an adder coiled into a circle on a warm stone, a golden eagle flying above the trees – which few people ever saw, but which, to him, seemed as magnificent as the December fireworks in Sydney Gardens, as moving as a phrase of music by Mozart.

Edmund had so longed to possess and preserve all that he and his brother found that soon their shared room was hung with great squares of cork, set with meticulously pinned samples of beetles, spiders, moths and butterflies and the pages of every book he owned were interleaved with pressed ferns, grasses and meadow flowers.

In his father’s wine cellar, Edmund had set up a dissecting table, where he had studied the anatomy of the weasels, stoats, toads, lizards and birds he and Valentine had managed to trap or shoot with their father’s rifle. He had made drawings of wings and tails, mouths, internal organs, feet and eyes and taught himself the difficult art of taxidermy, so that he could continue to study the anatomy of the animals long after they were dead.