"Date of publication: April 1947." "Dates of survey: 17 October-25 November 1945." This report was written primarily for the use of the United States Strategic Bombing Survey in preparation of further reports of a more comprehensive nature. Reproduced by a photolithographic offset process from the first edition of the report. To expedite, standardize and clarify the printing of this and other reports, minor changes have been made on the cover, title page, and some drawings.