Sec. 49. Features which have been touched upon in connexion with Raunds bring us to two new features in the plan--the rebuilding of aisles and the lengthening of churches westward. In most parish churches, aisles, when they were added at first, were extremely narrow. The west wall of Hallaton church in Leicestershire, for example, shows that, in the fourteenth century, originally narrow aisles were heightened and widened. The roof lines of the earlier aisles remain; they were clearly under the same roof as the nave of the church, and had very low side walls. This was not always the case. At Raunds the thirteenth century south aisle was always broad and lofty, and must have had its own roof from the first. And, as the principles of Gothic construction became more familiar, and the larger churches began to exercise a more wide-spread influence upon the parish church, aisles began to increase in breadth and elevation. The small and narrow windows of churches of the twelfth and early thirteenth centuries gave way to the broad mullioned and traceried windows of fully developed Gothic work. For these, with their advantage of increased light, more headway was necessary. Aisle walls were consequently heightened or altogether rebuilt. The acutely pointed roof of the nave could no longer be continued downwards to cover these higher aisles. The aisle was consequently covered with a lean-to roof, or with a separate gabled roof of its own. A free increase in width was thus possible. The church of Appleton-le-Street in Yorkshire has a short nave with north and south aisles. The north aisle, added in the early part of the thirteenth century, is narrow, and the roof of the nave was continued over it. The south aisle, which was probably rebuilt a little before 1300, is broader and has a separate lean-to roof. The wide east window of this aisle could not have been introduced, had the south aisle been built to match the scale of the north aisle. [Illustration: Fig. 11. Plan of Harringworth church, Northants.]