No. 4711. Heard April 8, 1953. Decided May 21, 1953. Thomas R. Haley, Seymour, Ind., Atty., N.L.R.B. (George J. Bott, Gen. Counsel, David P. Findling, Associate Gen. Counsel, A. Norman Somers, Asst. Gen. Counsel, and Frederick U. Reel, Atty., N.L. R.B., Washington, D.C., on the brief), for petitioner. W.D. Armour, Pittsburgh, Pa. (Nicholas Unkovic and Reed, Smith, Shaw McClay, Pittsburgh, Pa., on the brief), for Corning Glass Works, respondent. Joseph A. Robie, Donald W. Fisher and Mulholland, Robie