In the last half of the 19th Century the Torpedo Boat was built in large numbers. They were cheap and could be mass produced. With the advent of the Whitehead Torpedo these small boats could threaten battleships. In many navies, especially that of France, the torpedo boat was seen as the key to breaking the century of dominance of the Royal Navy. The large guns of the battleships were too slow in firing to hit the small, fast moving torpedo boats. The answer, at least initially, was the QF gun. QF stood for quick fire and the guns were designed for high rates of fire with sufficient explosive power to stop the flimsy torpedo boats of the time. The Royal Navy introduced the 3 Pdr (47mm), designated for its three pound shell weight, with the HMS Conqueror, laid down in 1879 and still found with the last British predreadnought, the Lord Nelson.
One of the primary producers of this piece of ordnance was Maxim Nordenfelt. Just as Maxim machine gun was used by almost every army, the Maxim Nordenfelt QF was used by almost every navy. David Piper ran across a Maxim Nordenfelt 3 Pdr QF in New Hampshire and sent in these photographs. This piece undoubtedly came from some unit in Teddy Roosevelt's Great White Fleet but which one? Starting with USS Maine BB-10, every predreadnought of the USN carried the 3 Pdr QF, except the last one to be laid down BB-25, the USS New Hampshire.