Winthrop Beach, Mass., beach erosion control study. Letter from the Secretary of the Army transmitting a letter from the Chief of Engineers, United States Army, dated October 10, 1947, submitting a report, together with accompanying papers and illustrations, on a cooperative study for beach erosion control of Winthrop Beach, Mass., made under the provisions of section 2 of the River and Harbor Act approved on July 3, 1930, as amended and supplemented.