In 1714, an Englishman John Lesbrenai invented a strange submersible. It is shaped like a wooden barrel, in which oxygen is stored, and the top is an openable sealing cover, from which divers can get in and out of the barrel. Two "sleeves" are installed at the lower part of the barrel, from which people's hands can extend out of the barrel for underwater operations. Divers carried out diving activities in Plymouth and Madeira, and once dived to a depth of 18 meters and stayed for 3 minutes. In 1853, a French explorer focused on this and was the first to apply for the patent of "diving barrel".