This company built French Le-Rhone engines under license (US&S).

From Appendix A2/6: The main text states that this brand manufactured rotary engines under French license. Specifically, the Le Rhone Model C of World War I.

The Model C was an air-cooled 9-cylinder engine, giving 80 HP at 1200 rpm, and a total displacement of almost 11 liters.

In the photo of this engine, owned by the Smithsonian Museum in Washington, we see it with a 4-blade propeller.

“Union-Le Rhone 9C” (somewhat mutilated)