Join the army air service. Be an American eagle!

Bull received his artistic training at the Philadelphia Art School. He was an expert on animal and bird anatomy, as well as on taxidermy, which earned him a position as Chief Taxidermist at the National Museum in Washington, D.C.

Image of American eagle fighting a large black German eagle, juxtaposed with a fleet of U.S. fighter planes. Caption below title reads, "Consult your local draft board. Read the illustrated booklet at any recruiting office, or write to the Chief Signal Officer of the Army, Washington, D.C. Apply to Air Service Trade Test Board, 755 Boylston St., Boston, Mass."