In 1847 alumnus Benjamin Franklin Greene became the new senior professor. Earlier he had done a thorough study of European technical schools to see how Rensselaer could be improved. In 1850 he reorganized the school into a three-year polytechnic institute with six technical schools. In 1861 the name was changed to Rensselaer Polytechnic Institute. A severe conflagration of 10 May 1862, known as "The Great Fire", destroyed more than 507 buildings in Troy and gutted in the heart of the city. The "Infant School" building that housed the Institute at the time was destroyed in this fire. Columbia University proposed that Rensselaer leave Troy altogether and merge with its New York City campus. Ultimately, the proposal was rejected and the campus left the crowded downtown for the hillside. Classes were temporarily held at the Vail House and in the Troy University building until 1864, when the Institute moved to a building on Broadway on 8th Street, now the site of the Approach.