There are ampler possibilities of beauty in the realm of the sea painter. At first sight it may seem that the change is merely a change from one region of inorganic nature to another, from rocks, torrents and glaciers, to the stormy and impetuous sea. But if we examine the substance of Turner’s marine pictures carefully, we find that they contain elements which lend themselves more readily to a systematic unity in sensuous form. In his mountainous pieces Turner found room for very little immediate human interest. Man and his everyday occupations are banished from the steep and rocky places he chooses to represent, as incompatible with the gloomy, awe-struck feeling he wishes to evoke. The only immediate link with the feelings and interests of those for whom he worked which these pictures contained, was the shattered masonry of a castle built in the recesses of the past by men long since dead, but whose purposes and fate still awoke echoes in the historical imagination of the present. In his marine subjects Turner entered more closely into relation with the substantive interests of his time. During the Napoleonic wars the sea had come to be recognised as the chief safeguard of the nation. The dangers of the sea, the courage and skill of her sailors, were England’s only bulwarks against the invincible legions of Napoleon. The gathering of the French armies of invasion along the shores of Brittany, the flotillas of gun-boats and flat-bottomed boats safely moored at Boulogne and Ambleteuse, focussed the attention of the nation upon a point outside the limited and varying interests of the individual citizen, and united them all in the same community of hopes and fears. The existence and welfare of the nation were at stake, the need of self-sacrifice was felt, and the individual became animated with the common sentiments of the nation. The stress of circumstance woke up what I may call the merely physical and material nation into a self-conscious spiritual unity, thinking the same thoughts and throbbing with the same emotions. At such a moment the poet’s and the artist’s task is made comparatively easy. Their individual experiences are charged with a universal import; their art rises to the dignity of a public function. They have only to be true to their own impulses to realise the absolute beauty of eternal life. And it was happily at such a moment in the life of the English nation that Turner wearied of his ruined castles and terrifying mountains--of the picturesque in general--and devoted himself to marine painting.