three-dimensional versions of the arch. Beyond this, in medieval churches it meant that the arch's legs, helping to support the roof, could be spread much further apart than was possible with post-and-lintel construction, thus giving more open floor space for worshippers to gather inside the building.It was the pointed arch, together with the cross vault (or groined vault), which helped to produce the impressive elements of the Gothic structure. Gothic churches are high and lofty, rising internally a hundred feet or more to the ceiling over the nave, where the congregation sits. Moreover, since the arches and vaults, along with the outside flying buttresses, hold up the roof, the walls no longer serve a support function. Theoretically, there is no need, from a sound construction standpoint, for the walls to exist at all. Does this mean that Chartres should have been left open? That would have shown no concern for the environment; France gets quite cold in the winter, and open spaces would simply invite draftiness. Here, however, is a challenge which becomes an opportunity; instead of just building walls, the wall-space is filled to overflowing withglowing stained glass windows, allowing light to filter intothe interior space through multicolored patterns.This stained glass, artfully composed, served two functions: to enhance the mystery of the space and thus the sense of the presence of God, and to educate the congregation by presenting visual images of figures in the Bible and saints of the church. The windows, along with the sculptures crowding around the portals leading into the building, present a summary of the basic teachings of the church.The whole of the cathedral is held together by a central symbol of Christianity--the cross of Jesus Christ--which provides the shape of the building. This cruciform floor plan, particularly evident from an aerial view (something which medieval man would not have had, but which he would h...
