Mahoning Coal Railroad. Nos. 768-771, in Supreme Court, Oct. term, 1931, Mahoning Coal Railroad Company and New York Central Railroad Company v. United States; Mahoning Coal Railroad Company v. [same; same] v. C. F. Routzahn, as collector of internal revenue for 18th district of Ohio; [same] v. United States, on petition for writs of certiorari to circuit court of appeals for 6th circuit; brief for respondents in opposition.