“W. D. Terrell in garden with radio,” probably in the Washington, D.C., area, July 7, 1926, by National Photo Company, via Library of Congress Prints and Photographs Division.
Mr. Terrell was Chief of Inspection Service of Radio at the U.S. Department of Commerce during the 1920s.
Just as Ariel, in the fables of the Middle Ages, was a spirit guardian of the air, so in this day of wireless, the Radio Inspector, a modern Ariel, stands a silent watch over the ether. But though he may be silent and, indeed, an angel, he is far from a fable, as those who attempt to dispute his wavemeter soon find out.
— from “Guiding the Good Ship Radio,” an October 1925 interview with Terrell in Radio Broadcast magazine