The picture has always been a national icon. I rather take the catalogue's point that the scene is not merely or mostly about the obsolescence of sail now that steam is around. It is just as much about the redundancy of glory now that England is at peace.
Turner, even in elegaic mood, was not gloomy in a Ruskinite way. It is one of the many virtues of Stephen Daniels' book, Fields of Vision, that its essay on Turner is determinedly irresolute on the matter of whether Turner liked or disliked progress. The NG's gloss agrees that we can share a sort of active ambivalence with Turner. It seems very likely that he meant us to feel both thrill and dread as we respond to the steam tug in The Fighting Temeraire, as we can when we view the steam train in Rain, Steam and Speed (also on show at Trafalgar Square).
The steam age of course swept away the age of sail, and the horse and cart. Just as surely, the machine age swept away a craft world, while secularism was giving religion a bashing.
But none of the unease people must have felt about these things seems to have dented the enthusiasm of many 19th-century sensibilities for the sheer drama and vigour of the industrial world. The power and size of machines and factories seem to have been almost as glamorous to artists and their customers as the power and size of the natural phenomena which had also become acceptable cynosures. Turner loved storms and his portrayal of steam ships surviving them are easily seen as essays on the matter of the resilience, impertinence or fragility of man-made contrivances. But one could also see them as simply the result of a painter seeing that portraying smoke is very nearly as exciting as portraying clouds. And the fires of smelters (say at Dudley in Worcestershire), just like the steam engine's, were simply visually irresistible.
We have had plenty of opportunity to dwell on these themes in the shows of Romantic painting in London over the past few years. They are just as evident in the Hayward's current "Landscapes of France", which has a heavenly Monet depicting a suburban steam train pulling double-decker carriages past a sunny park. The billows of white smoke (the sole evidence of the locomotive hidden behind trees) have dark underbellies of soot, but mirror the fluffy clouds, parasols and frocks of the people in the grassy foreground.
Another much less brilliant picture at the Hayward, by a salon painter, would have made a fine subject for one of Daniels's ruminations on landscape imagery and national identity. It shows a rustic valley, but there is a new bridge, and a train is heaving into view, perhaps bearing a companion for the tourist fisherman who is being gawped at by labourers resting from making hay. The point, again, is that we do not have to dislike the signs of progress.
I find this whole business fascinating because in a faltering sort of way, I'm allied with the progressives. Or rather, I am struck by how much natural beauty we have preserved alongside our man-made intrusions into the landscape we have inherited. I even find nuclear power stations and chemical works beautiful and exciting. But these modern contrivances are oddly too clean to be paintable: they are smoke-free, for a start. And we have learned to fear them. In place of charismatic smoke, we now have pollution which is not merely insidious and ubiquitous. It is invisible, and thus useless to painters.