A Howell torpedo was found by US Navy dolphins around Coronado Island, San Diego in June of 2013, while on a mine finding exercise. Two interesting things about that news item, for one, dolphins turn out to be a lot better at finding mines than our current technology... and the other, they found a Howell torpedo, one of only 3 known in existence.
The Howell torpedo was an early competitor to the Whitehead torpedo, but was significantly better in some ways, but had it's own limitations. For propulsion, the Howell used a flywheel, which was spun up on board the ship before firing. One of the benefits of the flywheel was one of the drawbacks of the Whitehead at the time, the flywheel acted as a sort of gyro, keeping the torpedo on course. The effect on the torpedo from wave action only caused the torpedo to roll, not alter it's course, and that was compensated for by it's rudders. Whitehead had significant problems keeping his torpedo on course, which he eventually solved by buying the rights to gyroscope gear, and suing Howell out of existence. The Whitehead used compressed air for propulsion and was silent compared to the noisy flywheel of the Howell. However the Whitehead left a wake, that the Howell didn't.
In the end, only 50 Howell torpedos were built. The US Navy dropped the Howell in favor of the Whitehead, as did most modern navies at the end of the 19th Century. The Howell was no pushover at the time, it could run straight, had a range of 400 yards (twice the Whitehead) and carry a 100 pound warhead. It the torpedo was fired in anger and missed it's target, a water soluble patch would dissolve over the primer, rendering the torpedo inert. But the best part was the body of hard rolled brass, a sight appreciated by the likes of Jules Verne.
Animation by vbbsmyt
Magazine cutoffs were a staple of some 19th/20th Century military rifles. They were to be used in single shot mode, with the magazine in reserve, till some wise officer ordered them released, and then to be used as repeaters.
This modification apparently is not for rifles alone, as Webley automatic pistols have this feature as well, no doubt mandated by some government agency. The system works with the magazine, which has an extra locking hole, where the magazine is not inserted all the way and locked in the second hole, keeping the bullets held in reserve and out of battery. The slide doesn't use the magazine to lock open after firing, and the shooter has but to drop another round in that big .455 hole and continue shooting. If repeating operation is desired, the catch is pushed and the magazine shoved home.
The feature does seem odd in a pistol, but it is simple and it works. The commercial pistols seem to have this cutoff also. The original idea of a magazine cutoff was an officer controlling the behavior of his troop of men. In the British Army, there were few men who weren't officers and carried pistols. Very confusing. At the time cutoffs were in vogue, the idea had some merit, as the British Army was usually a long way from home, really outnumbered, and every cartridge had to be carted the whole way on someone's back.
My friend Roy Shadbolt kindly sent these pictures of his .455 Webley pistol showing the magazine cutoff details.