Fisher was a prolific writer, producing journalism as well as technical books and articles, and addressing various social issues surrounding the First World War, the prosperous 1920s and the depressed 1930s. He made several practical inventions, the most notable of which was an "index visible filing system" which he patented in 1913 and sold to Kardex Rand (later Remington Rand) in 1925. This, and his subsequent stock investments, made him a wealthy man until his personal finances were badly hit by the Crash of 1929.