Section, acts Jan. 25, 1929, ch. 102, title III, 45 Stat. 1119; Apr. 18, 1930, ch. 184, title III, 46 Stat. 198; Feb. 23, 1931, ch. 280, title III, 46 Stat. 1334; July 1, 1932, ch. 361, title III, 47 Stat. 502; Mar. 1, 1933, ch. 144, title III, 47 Stat. 1393; Apr. 7, 1934, ch. 104, title III, 48 Stat. 551; Mar. 22, 1935, ch. 39, Sec. 1, 49 Stat. 90; May 15, 1936, ch. 405, Sec. 1, 49 Stat. 1336; June 16, 1937, ch. 359, title III, Sec. 1, 50 Stat. 287; Apr. 27, 1938, ch. 180, title III, Sec. 1, 52 Stat. 273; June 29, 1939, ch. 248, title III, 53 Stat. 909, related to purchases of supplies and equipment on the open market, and is now covered by sections 6a and 6b of Title 41, Public Contracts