One of the first practical principles aimed at throughout the whole range of Mediæval architecture was so to arrange their designs as to facilitate the use of small materials, and to render themselves independent of the accident of having quarries at command which would supply vast blocks of stone. It happened that in the great seats of early art this was of less consequence, for Egypt, Syria, Greece, and Italy contain such quarries in tolerable abundance, though even the Romans resorted to concealed arches for the security of their architraves; but in Northern Europe, though building-stone in most parts abounds, it is quite exceptional to find it at once in blocks of great dimensions and of strength which would render it a trustworthy covering to openings of any considerable bearing. With all our increased facilities at the present day, we never find the trabeated system carried out in its integrity when on a large scale; either the middle stones of architraves are suspended by concealed arched joints, as is the custom here, or are visibly arched-jointed, as in France, or the entire architraves consist of brick arches plastered over, to mimic the construction they affect but cannot follow. Even in our Gothic buildings, where every facility exists for the use of moderate-sized stone, it is often with much difficulty that blocks of a size suited to all purposes can be obtained. Thus with the Houses of Parliament, after the whole kingdom had been ransacked by a geological commission, not only was the quarry they recommended summarily rejected as incapable of furnishing stone of any reasonable size, but the second quarry, which was adopted in its place, and which produced an admirable material, was, after a time, abandoned, and a third selected, the productions of which have, in other respects than size, proved so lamentably inferior. The fact is that it is only here and there that we find quarries uniting _quality_ and _size_ which suit even our moderate requirements; and if such is the case now, with all our mechanical advantages and facilities of transit, how much more must it have been felt in days when the mechanical appliances of the ancients had been in a great measure lost, and the Roman roads broken up, while the means which were to supply these deficiencies were yet in their infancy. While, then, _at all times_ and _everywhere_, it is a desideratum to a rational system of construction that it should offer every facility for the use of ordinary and easily-obtained material, such was the case in a more than usual degree in those early ages of modern art. Though the universal use of the arch by the Romanesque builders obviously promoted this object, it would not of necessity lead to its fullest attainment. Arches may be, and often are, constructed of enormous blocks of stone; and it had to be studied how to make good construction with small materials.