The gradual reduction in size of diving bells and the possibility of supplying them with pneumatic pumps or compressors from the surface led to the emergence of helmets that form part of diving suits. Scuba diving was becoming much easier.
In 1819, German engineer Augustus Siebe invented a helmet attached to a jacket and supplied by a pneumatic pump from the surface. His discovery of a non-return valve ensured that the air pumped into the helmet wouldn't flow back through the same conduit. Exhaled air escaped through the bottom of the jacket, making it crucial for the diver to remain vertical at all times (achieved by chest and back weights, with consequent flooding risks if leaning). From 1837 onwards, the Siebe-Gorman diving equipment company was established through a partnership with a prominent German industrialist of the time.
The equipment was perfected by using a complete suit to which the helmet - perfectly airtight - was adapted, featuring multiple front and side windows for better visibility. Additionally, heavy lead shoes were used to maintain verticality. Some men descended to 100-metre depths with this equipment. From this point onward, decompression sickness accidents became frequent among classic divers.
Using classic diving equipment and the underwater camera he himself invented, Frenchman Louis Boutan took the world's first underwater photographs in 1893. Seven years later, together with his brother Antoine Boutan, they designed a steel cylinder that supplied air to the classic copper helmet at 200 kg/cm² pressure.
