And now, a short description of the way in which this decoration was painted. It is what is called “fresco,” an Italian word that means “fresh.” The name is used because the painting is done while the plaster of the wall is still fresh, that is to say, not “set” or dry. The following is the process. The wall was first covered, as in our houses to-day, with a coat of rough-cast plaster, which was allowed to dry thoroughly. In the meanwhile the artist had prepared full-sized drawings of his figures. As soon as he was ready, a thin coating of smooth-finish plaster was spread over such portion of the lunette as he could paint in a day. Upon this the drawing was placed and an assistant would go over all the lines with a blunt-pointed tool, pressing hard enough on the paper to leave a mark in the plaster underneath. There, when the paper was removed, appeared the figure, enclosed in grooved lines. Then the artist set to work and laid in the color, using paint that was mixed, not with oil, but with water to which some gluey substance was added. The plaster, you remember, was still damp, but since it contained plenty of cement, dried or “set” quickly, and as it dried, the paint dried with it, and became a part of the plaster. When it was done, the artist, if he wished, could add a few decisive strokes. The following day another portion of the lunette would be treated in the same manner and so on until the whole was painted. It is a method, you see, that left the artist no chance of fumbling over his work. He had to make up his mind beforehand exactly what he meant to do, and to do it quickly. Hence, with an artist so skilled as Raphael, the work has the extra charm that belongs to what has been done easily and fluently. You know how much pleasanter it is to listen to an easy, fluent speaker than to one who hesitates and corrects himself continually. So, too, in a work of art, the feeling that it has grown easily under the artist’s hand adds to our enjoyment of it. It seems to be a spontaneous expression of himself.