 Complete the following phrase:  Conversely, the walls inside Memorial Hall are made out of smooth concrete, with only a grid pattern resembling the headstones used for Canadian First World War soldiers etched into the walls. The exhibit is illuminated by a skylight that extends beyond from the buildings rooftop; while a glass-enclosed pool of water sits on the south side of Memorial Hall. The design of exhibit was intended to provide visitors with the feeling of weightlessness. The exhibit contains a single artifact, the original headstone for the soldier eventually reburied at the Canadian Tomb of the Unknown Soldier. The hall was designed so that sunlight that passes through the halls only window illuminates directly onto the headstone once a year, on 11 November at precisely 11 a.m., the time that the 