Architect Chris Glass of Camden gives slide talk on Historic Maine Homes, 300 Years of Great Houses 7:30 p.m., preceded by 6:30 p.m. potluck supper, at the Old Town House on Town House Road, off Union Common. Free; to sup, bring dish to share and own flatware. Last names A to L bring salad or vegetable dish; M to Z bring meat, fish or egg dish. FMI: 785-5444.