This proposal for an athenaeum in Philadelphia, PA. combines a triptych of familiar forms - a box, a cone, and a barrel vault. These parts are combined in such a way so as to satisfy programmatic obligations while responding to both urban and interior situations emphasized by social encounters. At the urban scale, barrel vaults carve the building mass away, creating continuity of the social space of the city, the ground. Inside, aggregated cones function as thresholds, lightwells, and reading rooms.