Leyden ball Leyden ball A Leyden ball is a fictional bullet used in the nineteenth century Jules Verne science fiction novel, "Twenty Thousand Leagues Under the Sea". It contains a capacitance charge of electrical energy, which discharges instantaneously upon the bullet's impact. A similar, but more complex non-lethal electronic weapon, meant to disable people, has been developed for police use in the modern day. In his 1870 science fiction classic "Twenty Thousand Leagues Under the Sea", Jules Verne wrote about a hunting expedition using a very unusual form of bullet: the balls sent by this gun are not ordinary balls, but little
Twenty Thousand Leagues Under the Sea of underwater breathing apparatus designed by Benoit Rouquayrol and Auguste Denayrouze in 1865. They designed a diving set with a backpack spherical air tank that supplied air through the first known demand regulator. The diver still walked on the seabed and did not swim. This set was called an "aérophore" (Greek for "air-carrier"). Air pressure tanks made with the technology of the time could only hold 30 atmospheres, and the diver had to be surface supplied; the tank was for bailout. The durations of 6 to 8 hours on a tankful without external supply recorded for the Rouquayrol set in