CERTIORARI TO THE CIRCUIT COURT OF APPEALS FOR THE SIXTH CIRCUIT. Nos. 420 and 421. Argued February 11, 1937. Decided April 12, 1937. The National Labor Relations Act, and orders made under it by the National Labor Relations Board, sustained upon the authority of National Labor Relations Board v. Jones Laughlin Steel Corp., ante, p. 1, as applied to a manufacturer of commercial "trailers," (vehicles designed for the transportation of merchandise), having its factory in Michigan, but which obtained