transcending his authority under a valid statute. *525 Francis G. Caffey, U.S. Atty., of New York City (William C. Fins. Vincent H. Rothwell, and Cornelius J. Smyth, all of New York City, of counsel), for appellants. Root, Clark, Buckner & Howland, of New York City (Elihu Root and William D. Guthrie, both of