Henry W. Ashmusen of the Ashmusen Manufacturing Co. of Providence, Rhode Island developed three HOAE beginning in 1908. It has been reported (Ae39) that Ashmusen engines powered a Wright Biplane owned by George Beatty and a Bleriot XI owned by Stanley Y. Beach. The specific engines used were not noted. George Beatty, himself, was very interested in aircraft engine development. He designed and built engines in the US and UK (Ae39, aerofiles.com). Another Ashmusen reference is the 1920 book by E. Charles Vivian (ECV) in which a chapter covers horizontally-opposed aircraft engines. The Ashmusen O-595 is described as a notable US engine among several HOAE from various countries. Vivian's book is available on the Internet and can be found here.
O-150 - - {3.625 / 3.625 / 149.6} / {92.1 / 92.1 / 2452}
4cyl; Ashmusen; 25hp@N/A rpm; 1912; Wt = 124#; TC = none.
J1912.
Applications: None found.
N/A - - {N/A / N/A / N/A} / {N/A / N/A / N/A}
8cyl; Ashmusen; 60hp@N/A rpm; 1908; Wt = 235#; TC = none.
Single-ignition engine.
Ae39.
Applications: None found.
O-595 - - {3.75 / 4.5 / 596.4} / {95.3 / 114.3 / 9773}
12cyl; Ashmusen; 105hp@1800rpm; 1917-1919; Wt = 345#; TC = none.
Geared to 0.5 with propeller driven from camshaft; single ignition.
aerofiles.com (photo in Powerplants entry); Ae39; ECV; J1919; NASM has information on this engine in their holdings of G.M. Bellanca's archives.
Applications: None found.