Copyright law of United States, act of Mar. 4, 1809, in force July 1, 1909, as amended by acts of Aug. 24, 1912. Mar. 2, 1913, Mar. 28, 1914, Dec. 18, 1919, July 3, 1926, May 23, 1928, and July 31, 1939; together with Rules for practice and procedure under sec. 25, by Supreme Court of United States.