The edifice is prodigious and appears so; only St. Sophia, Cologne Cathedral, and St. Peter's at Rome cover larger areas. Now in St. Peter's each detail was enlarged in proportion to the giant scale chosen; thus, a cherub would have a thigh the size of an elephant's. The result is that the great church appears less than its real size. The method of the mediæval architect was precisely opposite. He saw no advantage in making his edifice appear smaller than it really was. He observed that no matter how big a tree might grow, its leaves were no larger than those on smaller trees. The mediæval architect took for his scale of measurement the height of man. His doorways were made for man to walk under. In the bases of his piers, in the triforium arches, in the normal size of his sculpted flora and fauna, he recalled to the eye the scale of a man, his chosen _échelle_: "And he measured the wall thereof ... the measure of a man, which is of an angel."[125] No matter how large a Gothic church might be, the statues decorating it did not increase in scale. To those who prefer a cathedral of the north there will always seem to be a touch of the artificial, of the _tour de force_ in St. Peter's. The name of the master mind who designed the cathedral of Picardy was Robert de Lusarches, recorded in a labyrinth formerly in the nave's pavement, as were his two successors, Thomas de Cormont and his son Renaud. The occasion for a new structure was the fire of 1218 which partly destroyed the Romanesque cathedral. As its old choir was preserved sufficiently to serve for a while longer, the new cathedral was begun by the nave, not the usual procedure. The nave rose in one supreme effort; from start to finish its plan never deviated. It has been taken as the typical masterpiece. "The façade of Paris, the tower of Chartres, the sculpture of Rheims, the nave of Amiens" is a popular summing up. [Illustration: _The Transept of Amiens Cathedral (1220-1280)_]