With this progress, Rossi's group began a major experiment that could measure both primary energies and arrival directions of extensive air showers. Participating in this effort were: George Clark, William Kraushaar, John Linsley, James Earl, and Frank Scherb. Kraushaar came to MIT from Cornell in 1949, after earning his PhD under Kenneth Greisen. With the support of Professor Donald Menzel who was director of the Harvard College Observatory, Rossi's group deployed fifteen liquid scintillators, of area 1 square metre (11 sq ft) on the wooded grounds of the observatory's Agassiz station. The signals were brought on cables to a Quonset hut, where they were displayed on fifteen oscillographs and recorded photographically.