opinion: February 28, 1957.
  No. 153.
  Olin Mathieson Chemical Corp. v. National Labor Relations Board.
  Argued February 28, 1957.
  Decided February 28, 1957.
  Wm. A. Stuart argued the cause for petitioner. With him on the brief was H. W. Stull. Solicitor General Rankin, Stephen Leonard and Dominick L. Manoli were on the brief for respondent.
  Per Curiam:
  The judgment is affirmed.