gabled dormers, [1] with pierced tympanums, one on each of the four faces of the octagon that are even with the tower walls, and, above these dormers, the openings pierced through each face of the octagon. 
FIG. 63. There are probably few spires of earlier date; and from such simple types the progress was surprisingly rapid—each new construction showing some innovation, and generally some improvement, upon what had been accomplished before. There were difficulties to be overcome of no slight magnitude. To manage the transition from the square plan of the substructure to the octagonal plan of the spire, so as to secure both stability and beauty, was by no means an easy matter when there were no precedents to guide the constructor.
If we regard these early spires as experiments, which indeed they were, in a new form of structure, we may well wonder at their cleverness; but if we judge them by the subsequent achievements in the building of spires, we appreciate the points in which they fail.
The adjustment of the octagon to the square, as exhibited in this spire of Chamant, was but partially successful. The transition is too abrupt—the upper story of the tower is not happily connected with its substructure and superstructure by any continuity of members; but a great improvement was very soon made, and the typical Gothic spire was brought into existence almost at one stride, in the Cathedral of Chartres.
The south tower and spire of this cathedral (Fig. 64)
- ↑ Gabled dormers, though of a more primitive form, occur in the Norman pyramidal roof of St. Contest Calvados). If they occur elsewhere in Norman design they are certainly rare.
