!n 1860, a mine engineer Benoit Rouqyayrol, developed a device for resque workers in mines filled with contaminated air. The device was called the Aerophere. It consisted of a canister with compressed air and a hose and mouthpiece to breath. A noseclip prevented contaminated air from entering the nose. 

In 1865, with the help of Navy officer Auguste Denayrouze, the device was made suitable for diving. 

The diver carried a canister with compressed air on the back. A  demand regulator working with a membrane was attached to it. The design featured some parts developed by Siebe. With a compressor air was brought to the container and from there to the mouth. The regulator was capable of leveling the air pressure in the lungs to the pressure of the surrounding water. A noseclip prevented water from coming in the nose. In this case you see a reproduction Aerophere.

 

Many divers complained about the system. Especially because it was cold and dangerous without protective dress and helmet. In the same year, 1865, Denayrouze developed a copper and brass half helmet. It was attached to a protective dress and to the Aerophere. The helmet was referred to as "le Groin" or "the pig's snout" because it looked like a pig's face.
The diver could disconnect the air hose and walk around for some minutes. The system was never popular. Maybe because of the large foot weights that had to be carried. It is a shame that people lost interest in the device. Nevertheless, it is the worlds first diving regulator and it took until 1943 for Jaques Yves Cousteau to rediscover it!

Original Aeropheres can be seen at the Diving Museum in Espalion, France. This one is behind glass.



Here is a complete setup at the museum. Again, it's an original Aerophere.

Around 1870, Auguste Denayrouse developed a three bolt diving helmet. This was a very revolutionary design. 
Companies like Cabirol and Siebe used twelf bolt designs. 
The three bolt had the advantage that it was absolutely watertight but the disadvantage
 that is was very hard to get through the rubber collar.
The helmet was used in combination with the Aerophere or regular surface air supply.
Many French and other companies from countries like  England, Germany and Russia would later copy this design. 
You are looking at the mother of all three bolt diving helmets (behind glass) in the diving museum in Espalion. DENAYROUZE is stamped into the breastplate.