A perfect example of his compositional daring and eye for the unregarded is One of the Small Towers of Frederiksborg Castle, c. 1834. From high on the castle roof, Købke shows a cluster of chimneys and a massive ogee dome with its lantern and spire. Behind it is a gentle landscape peopled with tiny walking figures. A stork perches on one chimney while its mate circles in the warm air. It is a scene of quiet that is both static and subtly moving. It shows a bourgeois Eden in which Denmark's greatest national monument and the land it represents are bathed in a light that, fanciful though it may seem, has the beneficence of grace. It is architecturally accurate and simultaneously poetic. And it shows that Købke, at his best, was a quite magical painter.

Another artist who captured the spirit of his country at a formative moment in its history was Paul Sandby (1731-1809). Often referred to as "the father of English watercolour", Sandby was the precursor to Turner, Girtin et al and the man who showed not only the potential of watercolour as an artistic — rather than documentary — medium but showed too that the British Isles were as fit a subject for the brush as anything Italy had to offer. It is primarily to Sandby that we owe our mental image of the appearance of Georgian Britain.

The bicentenary exhibition at the Royal Academy (Sandby was one of the Academy's founding members) is an attempt to rehabilitate this superseded painter. It is not an easy task mainly because Sandby himself was not entirely clear whether he was primarily an artist — in the sense of having a transforming eye — or, more prosaically, a simple view-taker. He was not alone in this, George III astutely noting, somewhat equivocally, that the painter could turn his "hand to anything, like a fox".

Sandby's career started in the topographical drawing room at the Board of Ordnance and in 1747, in the wake of the Forty-Five rebellion, he was appointed chief draughtsman for the Army's project to make a "complete and accurate survey of Scotland". Although he was later to shake off some of this cartographical literalness the observational accuracy it instilled in him was evident throughout his career. It is there in the sun-infused views of Windsor Castle and its deer park he painted in the early 1760s and there, too, in the not-quite-picturesque landscapes of Wales he made while touring with Sir Joseph Banks a decade later. A lifelong lack of money further constrained his artistic ambition.

Perhaps the greatest pleasure in Sandby's pictures is to be found in his depiction of people. Small figures enliven every image — soldiers, carters, women both fashionable and common — as they do in Canaletto's scenes. They bring sense and scale to the settings, they bring life too and little snatches of humour. Above all, it is through them that his prelapsarian world of bustling streets, horse fairs, military encampments, ruined abbeys and country estates is shown to be not just a living entity but an irrepressibly hale and hearty realm.