French submarine Plongeur in the context of Siméon Bourgeois

Twenty Thousand Leagues Under the Seas (French: Vingt Mille Lieues sous Les Mers) is a science fiction adventure novel by the French writer Jules Verne. It is considered a classic within its genres and world literature. It was originally serialised from March 1869 to June 1870 in Pierre-Jules Hetzel's French fortnightly periodical, the Magasin d'éducation et de récréation. A deluxe octavo edition, published by Hetzel in November 1871, included 111 illustrations by Alphonse de Neuville and Édouard Riou.

It was widely acclaimed on its release, and remains so; it is regarded as one of the premier adventure novels and one of Verne's greatest works, along with Around the World in Eighty Days, Journey to the Center of the Earth and Michael Strogoff. Its depiction of Captain Nemo's submarine, Nautilus, is regarded as ahead of its time, as it accurately describes many features of modern submarines, which in the 1860s were comparatively primitive vessels. Verne was inspired by a model of the French submarine Plongeur, which he saw at the Exposition Universelle in 1867.

A pneumatic motor (air motor), or compressed-air engine, is a type of motor which does mechanical work by expanding compressed air. Pneumatic motors generally convert the compressed-air energy to mechanical work through either linear or rotary motion. Linear motion can come from either a diaphragm or piston actuator, while rotary motion is supplied by either a vane type air motor, piston air motor, air turbine or gear type motor.

Pneumatic motors have existed in many forms over the past two centuries, ranging in size from hand-held motors to engines of up to several hundred horsepower. Some types rely on pistons and cylinders; others on slotted rotors with vanes (vane motors) and others use turbines. Many compressed-air engines improve their performance by heating the incoming air or the engine itself. Pneumatic motors have found widespread success in the hand-held tool industry, but are also used stationary in a wide range of industrial applications. Continual attempts are being made to expand their use to the transportation industry. However, pneumatic motors must overcome inefficiencies before being seen as a viable option in the transportation industry.

The Musée national de la Marine in Rochefort is one of the main naval museums of France.

Rochefort Naval museum is part of the Musée national de la Marine, which is organised around its main location in Paris, and it antennas in Rochefort, Toulon, Brest and Port-Louis.