No. 12248. Argued May 4, 1955. Decided October 27, 1955. Mr. David E. Feller, Washington, D.C., with whom Mr. Arthur J. Goldberg, Washington, D.C., was on the brief, for petitioners. Mr. Owsley Vose, Attorney, National Labor Relations Board, of the bar of the Supreme Court of Illinois, pro hac vice, by special leave of Court, with whom Mr. Marcel Mallet-Prevost, Asst. Gen. Counsel, National Labor Relations Board, was on the brief, for respondent. Mr. Robert G. Johnson, Washington, D.C., Atty., also