"Louis I. Kahn: The Making of a Room," a small exhibition at the Arthur Ross Gallery of the University of Pennsylvania, is a reminder that the famous architect still has much to teach us. This show, which concentrates on his drawings of interiors, begins with a sketch of an imaginary room, made for a 1971 Philadelphia Museum of Art exhibition. Timeless is a hackneyed word, but how else to describe this little domed chamber: a fireplace, a window, two people talking. "In a small room one does not say what one would in a large room," Kahn writes. A characteristically gnomic utterance, but the humanist message of the drawing is crystal clear. This has something to do with the rough way in which it is made; in an age when architects are consumed—some might say overwhelmed—by whiz-bang digital wizardry, this scratchy charcoal sketch is a throwback to an earlier era.