Public domain
Washington, D.C. The U.S. Weather Bureau station at the National Airport. Inflating a pilot balloon with hellium gas. The balloon is used for determining winds aloft
From the collection of Library of Congress. Free to download, adapt and use — no permission needed.
Credit lineWashington, D.C. The U.S. Weather Bureau station at the National Airport. Inflating a pilot balloon with hellium gas. The balloon is used for determining winds aloft. 1943-01-01. Driscoll, Fred. Farm Security Administration/Office of War Information Collection, Library of Congress. Public domain.