Great works: Sir Robert and Lady Buxton with Their Daughter Anne, Castle Museum and Art Gallery, Norwich

Not longer after this delightfully restrained, 18th- century conversation piece was painted by a landowner from Norfolk called Henry Walton, its spidery-legged male sitter, Sir Robert Buxton – he in the green, buttoned-just-north-of-the-knee breeches and smooth white hose, was elected to Parliament as a Tory. In this painting, however, he looks relatively benign, if not protective of all that he surveys – which is not much, but it is more than enough, we feel.

In fact, the entire atmosphere of the work is pleasingly low-key, and made more so by the passages devoted to nothing but nourishingly unemphatic colour – the blue wall behind the unjazzy chaise longue; that carpet, whose greenness seems to want to suggest the enduringly nourishing presence of the natural world, miraculously transported to an interior such as this one in order to do some good. Perhaps a good half of this painting is nothing but plain passages of colour.

We admire the unpretentious, unadorned nature of this domestic interior. Nothing is drawing undue attention to itself as evidence of the family's sense of innate superiority. There are no paintings on the walls, no coats of arms, nothing flourishingly heraldic. This is a modestly virtuous bubble of a place, a serene and relatively noiseless site of exemplary living.

The four-year-old child at the painting's centre is not about to throw a tantrum or vomit on to the carpet. In fact, she is beginning to emerge into her years of educated responsibility, such is the attention she seems to be giving to the book in her mother's hand. She looks, delicately touching the top of her own small chair with her left hand, as restrained and pleasantly dutiful as the broad pink sash at the level of her stomach might suggest.

It is not as though there is nothing happening here. In fact, the family is going about its proper family business. The mother has been working at her embroidery with the aid of the tambour frame that sits on the table beside her while, simultaneously perhaps, reading to the child from that book of hers. Sir Robert has a book of his own in his left hand, and he has evidently been reading it – he is halfway through it, the position of his finger seems to indicate.

The way the arms reach out, touching or intertwining and interlocking, seems to suggest a kind of circling, dance-like motion – and this in spite of the fact that only the child is on her feet. We are prompted into feeling that even more so by the extreme, near painful angle of Sir Robert's roguishly out-flung leg – although by the look on his face he does not seem to be paying much attention to what his leg is doing. It is as if he is just about to rise. The child is at the centre of this protective circle, this act of grave familial binding.

The entire scene puts us somewhat in mind of a great painting by Poussin called A Dance to the Music of Time, which was in England during these years because it was owned by an Englishman. It now hangs in the Wallace Collection in London. Poussin's figures – there are four of them – circle slightly awkwardly. His is a dance of the seasons, and the music is provided by a greybeard of a lyre-player. It is possible that Walton could have known this painting – after all, he was a dealer in Old Master paintings, too.

Perhaps, remembering Poussin, there is also a hint that this family encirclement, in addition to being a gesture protective of the fragility of childhood, exists to remind us of the serenely unstoppable cycle of the seasons (remember that promise of nature in the grassy-hued carpet), kept in motion by that unobtrusive Enlightenment deity (there are no visual hints of deity idolatry in this room) who always, year in, year out, managed the universe like the best of clock-makers.

About the artist: Henry Walton (1746-1813)

Henry Walton was a landowner from East Anglia, and spent the greater part of his life there. Between 1769 and 1770 he did some training with Johann Zoffany in London. He was widely exhibited in London during the 1770s but, by the end of that decade, he had retired to his rural fastness, where he painted, collected and dealt in Old Master paintings and drawings until the cows came home.