Gothic architecture differs from all previous forms in the economical use of material, and the small size of the stones used. Whereas in both Roman and Norman buildings the arrangement of the materials depended upon their strength in masses, the Gothic masons employed stones of small size in the construction of edifices of equal strength and of far greater magnificence; while in constructive properties the Gothic style was a great advance on anything that had gone before, as the buildings in this style did not depend for their stability on the vertical pressure of columns, but on the correct adjustment of the bearings and thrusts of different arches operating in various directions. Owing to the fact, then, that each portion of a Gothic Church helps to support something besides itself, it is obvious that such buildings could be erected with a far smaller quantity of material than was previously necessary. The various little shafts or columns are so disposed as to distribute the weight of the superstructure and thus relieve the greater columns or piers of some portion of the superincumbent weight; the aisles help to support the nave; the walls of the side chapels act as abutments against the walls of the aisles, while the towers are generally placed so as to resist the accumulated thrust of all the arches along the sides of the nave. [Illustration: An Early English Doorway. Huntingdon.] The enrichments and little ornaments attached to mouldings, and particularly those placed in the hollows, are most characteristic of the various styles of Gothic architecture. The zig-zag is peculiar to the Norman, the nail head to the Transitional or semi-Norman, and the dog tooth to the Early English. [Side note: Early English Ornament.] This last ornament represents a flower, looking like four sweet almonds arranged pyramidically, and there is no other ornament so distinctive of this period. Early English foliage is known by reason of the stalks always being shown as growing upwards from the lower ring of the capital, called the astrigal. These stalks are generally grouped together and curve forward in a very graceful manner. The plants mostly represented are the wild parsley, seakale and celery, and this foliage, called stiff-leaved foliage, is found at no other period than the end of the 12th century. [Side note: Early English Mouldings.] Early English mouldings are very complicated and yet very beautiful, and consist of beads, keel and scroll patterns, separated by deep hollows giving a rich effect of light and shade round the arch. These deeply-cut hollows are also a distinctive mark of the style. [Side note: Early English Windows.]