Nos. 12754, 12812. Argued September 10, 1956. Decided November 23, 1956. Writ of Certiorari Granted April 1, 1957. See 77 S.Ct. 682. Mr. Arthur J. Goldberg, Washington, D.C., with whom Mr. David E. Feller, Washington, D.C., was on the brief, for petitioner in No. 12754 and intervenor in No. 12812. Mr. Arnold Ordman, Attorney, National Labor Relations Board, of the bar of the Supreme Judicial Court of Massachusetts, pro hac vice, by special leave of Court, with whom Mr. Marcel Mallet-Prevost, Associate