Mr. Norcross, who was an old college friend of Uncle Bob's, greeted them cordially and when Miss Cartright remarked on the airiness of his workshop he answered: "Yes, I have plenty of air up here; of course I enjoy it, too. But air, after all, is not the important factor which I consider. My stock in trade is light. Without it I could do nothing. Through the medium of strong sunlight I must test my work, for stained glass is beautiful chiefly as the light plays through it. It is not a tapestry nor a picture--it is primarily a window. Its colors must be rich in the light but not glaring; and its design must be so thoughtfully executed that the telling figures will stand forth when there is a strong sunset, for instance, behind them." "Of course, then, you must take care that the colors you use do not prove too powerful and overshadow your central figures," said Miss Cartright. "Ah, you paint?" "Yes, but not as I want to," was the wistful answer. "I do portraits. So I can readily see that your problem is a unique, and far more difficult one than mine. I have only a changeless color scheme to consider, while your colors shift with every cloud that passes across the sky." Mr. Norcross nodded with pleasure at her instant appreciation of his difficulties. "Have you ever seen stained glass in the making?" he asked. She shook her head. "Neither have any of the rest of us, Norcross," put in Mr. Cabot. "That is what we came for. I have been toting these two youthful friends of mine all over the world and together we have investigated almost every known form of glass, from the Naples Vase down to an American lamp chimney." Mr. Norcross smiled. "So you see," Uncle Bob went on, "I wanted them to witness this phase of glass-making." "They certainly shall. How did you chance to be so interested in the making of glass?" inquired the artist, turning to Giusippe. "I am a Venetian, senor. For over six generations my people have been at Murano." "Oh, then, what wonder! And that accounts for your own personal color scheme." The artist let his eyes dwell upon the Italian's face intently: then glanced at Miss Cartright. "I did a portrait of Giusippe," she responded quietly, "when I was in Venice a few years ago. He did not look so much like an American then." "Modern clothing certainly does take the picturesqueness out of some of us," answered Mr. Cabot. In the meantime Giusippe had wandered off to the distant side of the studio and now stood before a large glass panel calling excitedly: "Is this the window you are making, senor? How beautiful! The violet light behind the woman's head, and that yellow glow on her hair--it is wonderful! And her white drapery against the background of green!" Mr. Norcross came to his side, flushing with gratification. "The mellow tones playing on her hair were hard to get. I spent a lot of time working at them. It isn't easy to get the results one wants when making stained glass."