§ XI. But this superimposition of lightness on weight is still more distinctly the system of many buildings of the kind which I have above called Architecture of Position, that is to say, architecture of which the greater part is intended merely to keep something in a peculiar position; as in light-houses, and many towers and belfries. The subject of spire and tower architecture, however, is so interesting and extensive, that I have thoughts of writing a detached essay upon it, and, at all events, cannot enter upon it here: but this much is enough for the reader to note for our present purpose, that, although many towers do in reality stand on piers or shafts, as the central towers of cathedrals, yet the expression of all of them, and the real structure of the best and strongest, are the elevation of gradually diminishing weight on massy or even solid foundation. Nevertheless, since the tower is in its origin a building for strength of defence, and faithfulness of watch, rather than splendor of aspect, its true expression is of just so much diminution of weight upwards as may be necessary to its fully balanced strength, not a jot more. There must be no light-headedness in your noble tower: impregnable foundation, wrathful crest, with the vizor down, and the dark vigilance seen through the clefts of it; not the filigree crown or embroidered cap. No towers are so grand as the square-browed ones, with massy cornices and rent battlements: next to these come the fantastic towers, with their various forms of steep roof; the best, not the cone, but the plain gable thrown very high; last of all in my mind (of good towers), those with spires or crowns, though these, of course, are fittest for ecclesiastical purposes, and capable of the richest ornament. The paltry four or eight pinnacled things we call towers in England (as in York Minster), are mere confectioner's Gothic, and not worth classing.