Image ID:  FHS192
Image Date:  [no date]
Image Title:  Carving Airplane Propellers From Rough Blocks.
Image Caption:  [Caption 1:] Craftsmen at the Forest Products Laboratory at Madison, Wisconsin, study wooden propeller design during World War I.

[Caption 2:] The efficiency of airplane propellers depends upon the permanency and uniformity of blade angles, tracking, and balance. The investigative propeller work conducted by the Forest Products Laboratory included mahogany, maple, birch and white oak and gum.
Photographer:  [unknown]
Use Restrictions:  Permission from the Forest History Society required for any use of this image.
Repository Contact Information:  Forest History Society, Inc.; 701 William Vickers Ave., Durham, NC 27701; Tel.: (919) 682-9319; Fax: (919) 682-2349.