Mr. Smith says: “At the beginning of the twelfth century many local peculiarities—some due to accident, some to the quality of the building materials, and some to other causes, began to make their appearance in the buildings in various parts of Europe; and through the whole Gothic period they were met with; still the points of similarity were greater and more numerous than the differences. So, when we have gone through the course which the style ran in one country where it prevailed, we have a general outline of the whole, and may omit to speak particularly of them all without serious loss. On some grounds France would be the most suitable to select for the purpose, as the new order appeared earlier and had a more brilliant course in that country than in any other. But the balance of advantage lies in selection of Great Britain. The various phases the art has passed through in that country are well marked; and even the American student, who can not visit the country, may acquire some helpful information through engravings and photographs, that are happily quite common.” By far the most important specimens of Gothic architecture are the cathedrals and large churches. They are more complete as works of art than any other structures, and in all respects fit examples of pointed architecture. The ground plan of the Peterborough Cathedral is especially simple; give a competent builder the order he is to follow, and he will need no picture, the plan tells him the whole. Cathedrals are all similarly located as to the points of compass, and the principal entrance is in the west end. The one mentioned is about five times as long as it is wide. The wall is relieved by a large transept, the east wall of which begins about one third the distance from the east end. This gives the building the form of a cross. The part from the west end to the crossing of the transept is called the nave. The ends of the transept extend about one-third of the width of the building. The nave is flanked by avenues on each side, narrower and lower than itself, called aisles. They are separated from it by a row of columns or piers, connected by arches. Thus the nave has an arcade on each side, and each aisle has an arcade on one side, and the outer wall pierced by windows on the other. The strong arches of the arcade carry the walls that rise above the roofs of the aisles. These walls are usually divided internally into two stories. The lower story consists of a series of smaller arches, forming a second arcade, called the triforium, that opens into the dark space above the ceiling of the aisles, and is hence called the blind story.