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Rh thanks to the progress of military meteorological science during the war and to several months' patient experimenting with various devices, it was found possible to utilise specially adapted balloons. The Air Inventions Committee, the Munitions Inventions Department, the Inspectorate of H.M. Stores, Woolwich, Army Intelligence officers experienced in the use of silk balloons for other military purposes, and the manufacturers, all assisted the War Office in arriving at a result which proved to be effective and as nearly as possible "fool-proof." Designs and apparatus were tested in the workshop and laboratory, at experimental stations near London, and on Salisbury Plain. They were taken out to France and tried under the actual conditions of war, and gradually each difficulty was overcome and each detail reduced to its simplest form.

In its standard form in which it was being manufactured at the rate of nearly 2,000 a week the propaganda balloon was made of paper, cut in 10 longitudinal panels, with a neck of oiled silk about 12 inches long. The circumference was about 20 feet and the height, when inflated, over eight feet. The absolute capacity was approximately 100 cubic feet, but the balloons were liberated