duff hygrometer for measuring forest fire hazards.
Contributors: Forest Products Laboratory (U.S.)
Series: Technical note -- no. 238.; Technical note (Forest Products Laboratory (U.S.)) -- no. 238.
Publisher: Forest Products Laboratory, U.S. Forest Service
Published: 1931
Place of publication: Madison, Wis
Language: eng
Subjects: Hygrometers.; Forest litter -- Moisture.
Notes: Caption title.

"July, 1931."

Also issued online.