Under the directorship of Leon Arkus, the Sarah Mellon Scaife Gallery (125,000 square feet) was built as an addition to the existing Carnegie Institute. Designed by architect Edward Larrabee Barnes, it first opened in 1974 and more than doubled the museum's exhibition space, plus added a children's studio, theater, offices, café, and bookstore.[6] The New York Times art critic John Russell described the gallery as an "unflawed paradise."