Many of Yale's buildings were constructed in the Collegiate Gothic architecture style from 1917 to 1931, financed largely by Edward S. Harkness Stone sculpture built into the walls of the buildings portray contemporary college personalities such as a writer, an athlete, a tea-drinking socialite, and a student who has fallen asleep while reading. Similarly, the decorative friezes on the buildings depict contemporary scenes such as policemen chasing a robber and arresting a prostitute (on the wall of the Law School), or a student relaxing with a mug of beer and a cigarette. The architect, James Gamble Rogers, faux-aged these buildings by splashing the walls with acid, deliberately breaking their leaded glass windows and repairing them in the style of the Middle Ages, and creating niches for decorative statuary but leaving them empty to simulate loss or theft over the ages. In fact, the buildings merely simulate Middle Ages architecture, for though they appear to be constructed of solid stone blocks in the authentic manner, most actually have steel framing as was commonly used in 1930. One exception is Harkness Tower, 216 feet (66 m) tall, which was originally a free-standing stone structure. It was reinforced in 1964 to allow the installation of the Yale Memorial Carillon.