The "Universal" Adjustable and Reversible Propeller Built by Paragon Engineers, Inc., Baltimore, Md
A 1922 catalogue photograph from NASA's Technical Reports Server showing a propeller assembly built by Paragon Engineers of Baltimore, Maryland, shot as a sepia print and rotated sideways on the page. The picture shows a large mechanical rig with a propeller hub, metal framing and a wheel at the upper right, offering a designer a documentary view of early aircraft-era machinery and its hardware.
