No. 17503. Argued June 3, 1969. Decided July 18, 1969. Nan C. Bases, N.L.R.B., Washington, D.C., for petitioner (Arnold Ordman, Gen. Counsel, Dominick L. Manoli, Assoc. Gen. Counsel, Marcel Mallet-Prevost, Asst. Gen. Counsel, William F. Wachter, Atty., N.L.R.B., on the brief). Richard H. Markowitz, Wilderman, Markowitz Kirschner, Philadelphia, Pa., for intervenor. Godfrey P. Schmidt, New York City, for respondent. Before KALODNER, VAN DUSEN and STAHL, Circuit Judges. OPINION OF THE COURT VAN DUSEN