As the work on the church progressed three friends of David's journeyed from Salisbury to see him. They had come from Lombardy a long time ago, when they were Piero, Andrea and Gianbattista. At Avignon they were known as Pierre, Jean-Baptiste and Andre, and in Spain they were rechristened Pedro, Juan and Andres. Now they were called Peter, Andrew and John,--and sometimes the Apostles. Peter understood vaulting; Andrew could carve a stone image of anything he saw, and John had great skill in the laying of pavements. They talked of cathedrals and palaces with a familiarity that took one's breath away. The building of a cathedral seemed to be full of a kind of fairy lore. The plan was that of a crucifix, the chancel being the head, the transept the arms and the nave representing body and legs. The two western towers stood for Adam and Eve. There was a magic in numbers; three, seven and nine were better than six, eleven or thirteen. Certain flowers were marked for use in sacred sculpture as they were for other purposes. Euphrasy or eyebright with its little bright eye was a medicine for sore eyes. The four-petaled flowers,--the cross-bearers,--were never poisonous, and many of them, as mustard and cabbage, were valuable for food or medicine. But when Roger took this lore to Mother Izan for her opinion she remarked that if that was doctors' learning it was no wonder they killed more folk than they cured. In fact the three Lombard builders, while each man was a master of his own especial art, had done most of their work in cities, and when it came to matters of the fields and woods they were not to be trusted. But when David found Roger a little inclined to vaunt his superior woodcraft he set him a riddle to answer: “The baldmouse and the chauve-souri, The baukie-bird and bat, The barbastel and flittermouse,-- How many birds be that?” And the masons were all grinning at him before Roger found out that these were half a dozen names for the bat, from as many different places. The vaulting of the roof of the church was now under consideration. For so small a building the “barrel vault,” a row of round arches, was often used; but David's voice was for the pointed arch throughout. “The soarin' curve lifts the eye,” he said, “like the mountains yonder.” He drew with a bit of charcoal a line so beautiful that it was like music. It was not merely the meeting of two arcs of a circle, but the meeting of two mysteriously curved perfect lines. Sir Walter Giffard saw at a glance that here was the arch he had dreamed of.