So--as it seems to me--they sought among vegetable forms for what they needed: and they found it at once in the pine, or rather the fir--the spruce and silver firs of their own forests. They are not, of course, indigenous to England. But they are so common through all the rest of Europe, that not only would the form suggest itself to a continental architect, but to any English clerk who travelled, as all did who could, across the Alps to Rome. The fir-tree, not growing on level ground, like the oaks of Fontainebleau, into one flat roof of foliage, but clinging to the hillside and the crag, old above young, spire above spire, whorl above whorl--for the young shoots of each whorl of boughs point upward in the spring; and now and then a whole bough breaking away, as it were, into free space, turns upward altogether, and forms a secondary spire on the same tree--this surely was the form which the medieval architect seized, to clothe with it the sides and roof of the stone mountain which he had built; piling up pinnacles and spires, each crocketed at the angles; that, like a group of firs upon an isolated rock, every point of the building might seem in act to grow toward heaven, till his idea culminated in that glorious Minster of Cologne, which, if it ever be completed, will be the likeness of one forest-clothed group of cliffs, surrounded by three enormous pines. One feature of the Norman temple he could keep; for it was copied from the same Nature which he was trying to copy--namely, the high- pitched roof and gables. Mr. Ruskin lays it down as a law, that the acute angle in roofs, gables, spires, is the distinguishing mark of northern Gothic. It was adopted, most probably, at first from domestic buildings. A northern house or barn must have a high- pitched roof, or the snow will not slip off it. But that fact was not discovered by man; it was copied by him from the rocks around. He saw the mountain-peak jut black and bare above the snows of winter; he saw those snows slip down in sheets, rush down in torrents under the sun, from the steep slabs of rock which coped the hillside; and he copied, in his roofs, the rocks above his town. But as the love for decorations arose, he would deck his roofs as nature had decked hers, till the gray sheets of the cathedral slates should stand out amid pinnacles and turrets rich with foliage, as the gray mountain-sides stood out amid knolls of feathery birch and towering pine. He failed, though he failed nobly. He never succeeded in attaining a perfectly natural style.