A week of heavy launching. I always enjoy the autumn publication season, and having a book of one's own amid the cornucopia adds an extra tang. As I've been asked to do Start the Week, I get to see the Velazquez exhibition at the National Gallery while the paintings are still being hung. The saints, the potentates and the princes of the church are magnificent. But it's the domestic scenes, the poetic within the prosaic, which captivate, especially An Old Woman Cooking Eggs and Kitchen Scene with Christ in the House of Martha and Mary. Larry Keith's chapter in the catalogue on Velazquez's technique is fascinating about his recreation of the fish in Kitchen Scene--you can almost smell …