No. 21569. January 25, 1968. Robert M. Lieber, Washington, D.C. (argued), Arnold Ordman, Gen. Counsel, Marcel Mallet-Prevost, Asst. Gen. Counsel, Dominick L. Manoli, Associate Gen. Counsel, Allison W. Brown, Jr., N.L.R.B., Washington, D.C., Roy O. Hoffman, Director, N.L.R.B., San Francisco, Cal., for petitioner. Charles P. Scully, Donald C. Carroll, San Francisco, Cal., W. Thomas Arruda, Oakland, Cal., Levy, DeRoy, Geffner Van Bourg, San Francisco, Cal., for respondents. Before HAMLIN, DUNIWAY and