The transition from the Early English, or Lancet style, to the Decorated was much more gradual than from Norman to Early English, so gradual that it is impossible to draw a line where one style ceases and another begins. There can be no doubt that in some parts of the kingdom, Early English was in use at the same time that, in other districts, the Decorated style was becoming general, and thus the terms adopted to denote the different periods must not be taken as definite or as commencing or closing at any particular date, but merely as indicating the broad classification of the styles and details, and for associating them with particular reigns for convenience of study. The divisions are arbitrary, but very convenient in practice. Structurally, there was not a great change in the buildings, but there was a more harmonious relation and development of all the architectural features in walls, piers, buttresses, windows, etc., both with regard to their size and their enrichment, and it was because of this general use of ornament or enrichment that it is called the Decorated Period. “It rivals the preceding style in chasteness and elegance, while it surpasses it in richness.” Great progress was made in the reign of Edward I., and the Decorated work exhibits the most complete and perfect development of the Gothic arch, which in the Early English was not fully matured, and in the Perpendicular began to decline. It is remarkable for its geometric tracery, its natural types of foliage, and the undulating character of line and form in its ornamental details. _Windows._--The most distinctive features of the Decorated style are its large windows and its mouldings. The windows are the chief glory of the 14th century Gothic. They vary very considerably in size, in form and in intricacy. As the window arches became broader, mullions or vertical bars of masonry were required for their support, dividing the windows into lights, and the upper portions of these mullions were developed into tracery, forming circles, trefoils, or other geometric figures, and, afterwards, flowing lines.