the southern part of the station, but is higher above the northern part, reaching above the platform. The walls along the platforms consist of a buff-colored brick wainscoting on the lowest part of the wall, and white glass tiles above. The platform walls are divided at intervals by blue tile pilasters, or vertical bands. The pilasters are topped by alternating blue-and-cream faience plaques of the number "116" and the Columbia University seal; both of these motifs are surrounded by faience wreaths. The seal shows a seated woman with a book of knowledge in her hand and three children standing near her feet. A blue-and-green cornice, made of faience, runs atop the wall and around the mosaic tablets. Mosaic wall tablets with the name "Columbia University" are installed along the platform walls. The mosaic tiles at all original IRT stations were manufactured by the American Encaustic Tile Company, which subcontracted the installations at each station. The decorative work was performed by tile contractor John H. Parry and faience contractor Grueby Faience Company. Entrances and exits The station has four entrance/exit stairs that serve both platforms. One pair ascends to the northwest corner of Broadway and 116th Street, while the other pair goes to the northeast corner of the same intersection. There is also an exit-only staircase near the southern end of the northbound platform that leads to the east side of Broadway at 115th Street, outside the Alfred Lerner Hall. There was a station house in the median of Broadway, just north of 116th Street, which was designed by Heins & LaFarge and dated to the station's opening in 1904. It was built as one of several station houses on the original IRT; similar station houses were built at Atlantic Avenue, Bowling Green, Mott Avenue, 72nd Street, and 103rd Street. The station house, which was identical to the one at 103rd Street, occupied an area of . The one-story station house contained exterior walls made of buff brick, with a foundation made of granite blocks. A limestone string course ran atop the exterior wall. At the corners of the station house were limestone quoins, which supported a copper-and-terracotta gable roof facing west and east. The ridge of the station house's roof was a skylight made of glass and metal. The doorways were centrally located on the north and south walls of the control house, topped by terracotta finials and a rounded