Photos displaying on either side of this one in the Prints & Photographs Online Catalog may yield clues—view the neighboring photos: www.loc.gov/pictures/related/?&pk=hec2013012531&s...
Harris & Ewing,, photographer.
[Paragon adjustable and reversible aircraft propeller created by Spencer Heath and tested on October 11, 1922, Bolling Field, Washington, D.C.]
[1922 October 11]
1 negative : glass ; 4 x 5 in. or smaller
Title and date information from Flickr Commons Project, 2015; and Aerial Age Weekly, Dec. 1922.
Gift; Harris & Ewing, Inc. 1955.
No known restrictions on publication.
Library of Congress, Prints and Photographs Division, Washington, D.C. 20540 USA, hdl.loc.gov/loc.pnp/pp.print
Harris & Ewing Collection (Library of Congress)
General information about the Harris & Ewing Collection is available at hdl.loc.gov/loc.pnp/pp.hec
Higher resolution image is available (Persistent URL): hdl.loc.gov/loc.pnp/hec.42506
Owner: The Library of Congress
Source: Flickr Commons