To erect the main structure of his cathedral, Thibaut had called in a traveling fraternity of workmen, the Lodging-House Keepers of the Good God, who obeyed the Master of the Work--_i.e._, an architect. They would stay for years in one place, recruiting new members as old ones died, then moving elsewhere when no longer needed. This fraternity erected the main structure of the building; then Thibaut passed away, money failed, and enthusiasm somewhat lapsed. However, twenty years later, a new fraternity were put to work on the façade and towers. This was more delicate work, involving a great deal of skillful carving. They were obliged to stop again before completion had been attained. Probably a score of years hence, still another such fraternity will raise the second tower. Meantime, every year, a few skillful craftsmen, sustained by donations, add a statue here and a gargoyle yonder, put richly painted glass into another window, or complete the intricate carving around the railing to the pulpit stairs. Now and then there is a special exhibition of relics to attract worshipers and their alms.[129] One of the results is that the style of the different parts of the cathedral differs subtly according to the respective periods of their construction. There is not a contradiction, but only a pleasing variety. One feels that _the cathedral is something living_. It has come into being, not by arbitrary creation, but by a natural growth; like a mighty, comfort-spreading tree. [Illustration: THIRTEENTH-CENTURY WINDOW IN THE CATHEDRAL OF CHARTRES, REPRESENTING SAINT CHRISTOPHER CARRYING CHRIST]