It may not be amiss for the architect to take advantage _sometimes_ of that to which I am sure the painter ought always to have his eyes open, I mean the use of accidents; to follow when they lead, and to improve them, rather than always to trust to a regular plan. It often happens that additions have been made to houses, at various times, for use or pleasure. As such buildings depart from regularity, they now and then acquire something of scenery by this accident, which I should think might not unsuccessfully be adopted by an architect, in an original plan, if it does not too much interfere with convenience. Variety and intricacy is a beauty and excellence in every other of the arts which address the imagination; and why not in architecture?
The forms and turnings of the streets of London, and other old towns, are produced by accident, without any original plan or design; but they are not always the less pleasant to the walker or spectator, on that account. On the contrary, if the city had been built on the regular plan of Sir Christopher Wren, the effect might have been, as we know it is in some new parts of the town, rather unpleasing; the uniformity might have produced weariness, and a slight degree of disgust.
I can pretend to no skill in the detail of architecture. I judge now of the art, merely as a painter. When I speak of Vanbrugh, I mean to speak of him in the language of our art. To speak then of Vanbrugh in the language of a painter, he had originality of invention, he understood light and shadow, and had great skill in composition. To support his principal object he produced his second and third groups or masses; he perfectly understood in his art what is the most difficult in ours, the conduct of the background, by which the design and invention is set off to the greatest advantage. What the background is in painting, in architecture is the real ground on which the building is erected; and no architect took greater care than he that his work should not appear crude and hard: that is, it did not abruptly start out of the ground without expectation or preparation.
This is a tribute which a painter owes to an architect who composed like a painter; and was defrauded of the due reward of his merit by the wits of his time, who did not understand the principles of composition in poetry better than he; and who knew little or nothing of what he understood perfectly, the general ruling principles of architecture and painting. His fate was that of the great Perrault; both were the objects of the petulant sarcasms of factious men of letters; and both have left some of the fairest ornaments which to this day decorate their several countries; the façade of the Louvre, Blenheim, and Castle Howard.