|David Chatterton (Editor). The Mind Alive Encyclopedia. Technology. Chartwell Books Inc., 1968, 1977.|
Named after a hummingbird, this weapon was patented in 1910 and first produced in 1914 by Franz Pfannl, an Austrian watchmaker. The technology to rifle such a small barrel was not available at the time, so accuracy was an issue. It also wasn't very powerful. So, I guess it was intended more for "family and friends." Production was discontinued in 1938.