A copper dome was discovered on the ocean floor off Florida near a sunken Spanish treasure galleon. This artifact, found in 1980, may be the prototype for an early 17th-century submersible known as a "gullet" (or diving bell).
Researchers believe the diving bell was based on a 1606 design by Spanish inventor Jerónimo de Ayanza, which was later used to harvest pearls in Venezuela (left). Also shown is a diving bell created in 1616 by German inventor Franz Kessler (right)!
The principle of its operation is quite simple and is based on the principle of Archimedean support and the law of swimming. When the diving bell is lowered into the water, its interior is filled with air, which provides support and buoyancy. Archimedes' principle states that a floating body pushes out of water a volume of water equal to its own volume. This creates support and allows the bell to float on the surface of the water.
Researchers assumed that the round object was a huge cooking pot, and it has since been housed in the Mel Fisher Museum. But new research indicates that the object may actually be the top of an early diving bell, lost during the recovery of treasure from the ship several years after it sank.
According to Sean Kingsley and marine archaeologist Jim Sinclair, who was a member of the team that discovered the artifact, the object has a diameter of 147 cm—much larger than required for cooking—and does not show signs of burning or heating.
The Santa Margarita was a Spanish treasure galleon that sank during a hurricane in the Straits of Florida in 1622. Several early attempts were made to salvage treasure from the wreck, but its location was lost in subsequent centuries.
However, the mysterious object matches the descriptions of diving bells made around this time and was found alongside a large amount of iron ingots that researchers believe could have been used to anchor it to the seabed.
Jim Sinclair and Kingsley note that although there is no record of a diving bell being used to recover treasure from the wreck of the Santa Margarita, the Spanish were early pioneers in this field. They suggest that the device was based on a diving bell tested in 1606 by inventor Jerónimo de Ayants, whose design was later used to collect pearls in Venezuela.
Source: livescience.com
