Editing Timeline of diving technology (section)

===Diving helmets improved and in common use===
* 1808: [[Brizé-Fradin]] designed a small bell-like helmet connected to a low-pressure backpack air container.<ref name="hds4537" />
* 1820: [[Paul Lemaire d'Augerville]] (a Parisian dentist) invented a diving apparatus with a copper backpack cylinder, a [[Diving rebreather#Counterlungs|counterlung]] to save air, and with an inflatable life jacket connected. It was used down to 15 or 20 meters for up to an hour in salvage work. He started a successful salvage company.<ref name="hds4537" />
* 1825: [[William H. James (inventor)|William H. James]] designed a self-contained diving suit with compressed air stored in an iron container worn around the waist.<ref name="History of scuba diving" />
* 1827: [[Beaudouin]] in France developed a diving helmet fed from an air cylinder pressurized to 80 to 100 bar. The [[French Navy]] was interested, but nothing came of this.<ref name="hds4537" />
* 1829: (1828?)
** [[Charles Anthony Deane]] and John Deane of [[Whitstable]] in [[Kent]] in England designed the first [[diving helmet]] supplied with airpumped from the surface, for use with a diving suit. It is said {{by whom|date=March 2017}}that the idea started from a crude emergency rig-up of a [[Firefighter|fireman]]'s water-pump (used as an air pump) and a knight-in-armour helmet used to try to rescue horses from a burning stable. Others say that it was based on earlier work in 1823 developing a "smoke helmet".<ref name="Lonsdale 2012" /> The suit was not attached to the helmet, so a diver could not bend over or invert without risk of flooding the helmet and drowning. Nevertheless, the diving system was used in salvage work, including the successful removal of cannon from the British warship HMS ''Royal George'' in 1834–35. This 108-gun fighting ship sank in 65 feet of water at Spithead anchorage in 1783.<ref name="Lonsdale 2012" /><ref name="History of scuba diving" />
** [[E.K.Gauzen]], a Russian naval technician of the [[Kronshtadt]] [[naval base]] in [[Saint Petersburg]], built a "diving machine". His invention was a metallic helmet strapped to a leather suit (an overall) with a pumped air supply. The bottom of the helmet was open, and the helmet strapped to the suit by a metal band. Gauzen's diving suit and its further modifications were used by the [[Russian Navy]] until 1880. The modified [[diving suit]] of the Russian Navy, based on Gauzen's invention, was known as "[[three-bolt equipment]]".<ref name="History of scuba diving" />
* 1837: Following up [[Leonardo da Vinci]]'s studies, and those of the astronomer [[Edmond Halley]], [[Augustus Siebe]] developed [[surface-supplied diving]] apparatus which became known as [[standard diving dress]].<ref name="spums_hx" /> By sealing the Deane brothers' helmet design to a waterproof suit, Augustus Siebe developed the Siebe "Closed" Dress combination diving helmet and suit, considered the foundation of modern diving dress. This was a significant evolution from previous models of "open" dress that did not allow a diver to invert. Siebe-Gorman went on to manufacture helmets continuously until 1975.<ref name="Lonsdale 2012" />
* 1840: The Royal Navy used Siebe closed dress for salvage and blasting work on the "Royal George", and subsequently the Royal Engineers standardised on this equipment.<ref name="Lonsdale 2012" />
* 1843: The Royal Navy established the first diving school.<ref name="Lonsdale 2012" />
* 1855: [[Joseph-Martin Cabirol]] patented a new model of standard diving dress, mainly issued from Siebe's designs. The suit was made out of rubberized canvas and the helmet, for the first time, included a hand-controlled tap that the diver used to evacuate his exhaled air. The exhaust valve included a non-return valve which prevented water from entering in the helmet. Until 1855 diving helmets were equipped with only three circular windows (for front, left and right sides). Cabirol's helmet introduced the later well known fourth window, situated in the upper front part of the helmet and allowing the diver to see above him. Cabirol's diving dress won the silver medal at the [[Exposition Universelle (1855)|1885 ''Exposition Universelle'']] in Paris. This original diving dress and helmet are now preserved at the ''[[Conservatoire National des Arts et Métiers]]'' in Paris.<ref name="Cabirol" />