Training aircraft gunners has always been a task requiring some creativity, as it requires a lot more than just a paper target for an infantryman to blast away at. In the very early years of aerial combat in WWI, a wide variety of ideas were considered, and one of the better ones was building a gun-shaped camera. In this way, a trainee could engage in a very realistic and yet safe dogfight, and the photographic evidence would allow him and his instructor to assess his performance. One particularly neat early gun camera was the Hythe MkIII:
A lot of careful thought went into the Hythe, far beyond simply a camera in a gun-shaped shell. For starters, it was made in 1915 to very closely match the handling, balance, and weight of a Lewis Gun (one of the most common aerial guns at the time with British and US forces). It could be fixed to the top wing of a biplane or on a flexible ring mount just like a real gun, and was maneuvered and aimed exactly like a real Lewis. The shutter was tripped by the trigger, just like a gun, and film was advanced by using a replica of the Lewis’ charging handle. In addition, a real Lewis magazine mounted atop the device, and could be changed just like a Lewis (we’ll elaborate on that in a moment).
As far as camera hardware, the film canister and exposure area was located in the square box at the rear of the cooling jacket. It used 120mm film, and could hold 12 or 16 frames worth (sources vary on this point). A shutter and lens were located near the muzzle end of the device:
The Hythe must have been designed with input from aircraft instructors, because its operation uses the procedures most important in dogfighting of the era. Ammunition was more limited on a Lewis than with a belt-fed weapon, and the camera only held a handful of pictures. So the student’s goal would be to make a clean hit on an enemy aircraft with his first shots, not attempt to “walk it in”, which would waste a great deal of ammo. The initial trigger pull on the Hythe snapped a photo, so it was only the initial aim that was recorded for evaluation. To take a subsequent photo, the gunner would have to rack the “gun’s” charging handle, an operation that any good gunner should learn to do instinctively. In addition, the Hythe had a device inside that would punch a small hole in the edge of the film, and that device was operated by removing and replacing the Lewis magazine from the top of the “gun”. Proper practice would require changing magazines between strings of fire (another operation the gunner should become able to do blindfolded and upside down), and the Hythe would leave definite evidence of whether the trainee actually did so.
Of course, using a gun camera for marksmanship practice is only useful if the camera can actually show precisely where the gunner was aiming – and the Hythe took this into consideration as well. In front of the film was located a glass plate with a reticle, which would be superimposed on each photograph. For initial setup, the film canister could be replaced by a mirror, and the reticle plate adjusted to precisely match the sights atop the “gun”. This allowed the Hythe to actually give useful feedback to a gunner.
All in all, it’s one of the cooler not-really-a-gun items we’ve come across in some time. The Hythe was actually in official British use all the way up to 1934, when it was finally replaced by more modern gear (and the Lewis guns were on their way out as aircraft armament). I’ll leave you with a few more photos, including a couple showing the Hythe in period use: