Pomeroy's career began during the silent era, when he worked as a special effects engineer for Famous Players-Lasky and its successor studio Paramount Pictures. For 1923's "The Ten Commandments," Pomeroy designed the parting of the Red Sea sequence and an effect in which the commandments appeared in letters of flame. He worked on "Peter Pan, Old Ironsides," and "The Rough Riders," all for Famous Players or Paramount. His work on the groundbreaking aviation film "Wings," released in 1927, earned him the Academy Award for Engineering Effects at the first-ever Academy Awards ceremony.