on the river's western bank. Mayor John Purroy Mitchel was positioned to accept Rockefeller's offer. However, his successor John Francis Hylan ultimately did not accept the land, saying that the site had not been "improved". Moreover, the city had failed to propose a law that would have deeded the parkland to the Palisades Interstate Park Commission. In 1925, Hylan told one of Rockefeller's advisors that the city would consider another proposal to take the land and use it as a park. Following this, Rockefeller again offered the land to the city in 1926, though without success. In preparation for converting the land into a city park, Rockefeller hired the Olmsted Brothers firm, particularly Frederick Law Olmsted Jr., son of the designer of Central Park. Olmsted's design capitalized on the topography to reveal sweeping vistas of the Hudson River and the Palisades. Olmsted Jr. was guided by the four principles of park design that his father had established in creating Central Park: the beautiful, as seen in small open lawns; the picturesque, as shown in wooded slopes; the sublime, represented in the vistas of the Hudson River; and the gardenesque, exemplified by the park's Heather and Alpine Gardens. Olmsted Jr. had a preliminary report in 1927 and conducted a more exhaustive study in 1928-1930. In addition, James W. Dawson was hired to create a park-planting plan. Rockefeller also bought sculptor George Gray Barnard's collection of medieval art in 1925. He added several artworks to the collection, which became a branch of the Metropolitan Museum of Art (Met) in 1926. Rockefeller retained Barnard as an advisor for the collection, and they collectively decided to add a museum for the collection at Fort Tryon Park, which they chose for its elevation, views, and accessible but isolated location. The Billings mansion, which was originally supposed to house the collection, was destroyed in a March 1926 fire that burned down everything except the walls. In June 1930, Rockefeller offered of the park to the city for a third time, though he reserved for the future museum. Rockefeller also offered to improve the grounds for $2 million, though the city would be responsible for improving utilities in the park. In his letter offering the park to the city, Rockefeller proposed to name the park after Fort Tryon, but in September 1930, historian Reginald Pelham Bolton said that Rockefeller actually preferred to have the park be named