But as masons grew more skilful, and designers more sophisticated, they found it pleasant to play with their material; to turn their single pillars into bundles of clustered shafts; to fill their windows with tracery, structural at first, but afterwards as free and fantastic as lacework. The result is often beautiful. The method gave the freest play to the artist's invention, but it had its dangers, and they are exemplified at York. There the designer has evidently regarded his west front as a large space of wall to be played with, to be decorated much as if it were a piece of embroidery, and, in his anxiety to decorate it richly, he has lost his sense of unity and proportion. He has forgotten to use his ornament merely to emphasise the main lines of the structure. Where this is done, where the ornament is massed on the porches, on the windows, and on the lines dividing the storeys, the rest of the facade may be left alone. The bare spaces of masonry only serve to give relief to the decoration. But at York the main lines are so neglected, they offer so little opportunity for decoration, that the designer was afraid to leave his walls plain, lest the whole should appear lean and cold. He has, therefore, spun his tracery and panelling over the whole surface. Nowhere can the eye rest on a plain piece of wall; everywhere it is fidgeted by monotonous rows of niches and mouldings. In fact, it may be compared to an etching so full of unnecessary details that composition, balance of mass, and beauty of line are all smothered in them. And yet there is much to be said on the other side. The mere size--the height and width--go far to make the front impressive; and the detail, even now when so much of it has been restored, is usually beautiful. If it is not great architecture, it is at least living architecture, and as such infinitely superior to the most scholarly works of the Gothic revival. It is only when we compare it to the magnificent west fronts of France that we are inclined to regret that it has not rivalled them.