IMPORTANT EVENTS IN OCEAN ENGINEERING HISTORY
Department of Commerce National Oceanic and Atmospheric Administration Diving for Science and Technology
The second principal historical mode of diving is bell diving. One of the earliest reports of the use of a device that enabled a diver to enter the water with some degree of protection and a supply of air involved the diving bell Colimpha used in Alexander the Great's descent in approximately 330 B.C., depicted by an Indian artist in a 1575 miniature (Figure 1-2). An account of this dive appeared in the 13th century French manuscript, The True History of Alexander. In his Problernata, Aristotle described diving systems in use in his time: "they contrive a means of respiration for divers, by means of a container sent down to them; naturally the container is not filled with water, but air, which constantly assists the submerged man." Dive apparatus 300 BC (photo 2/2002 museum: Man in the Sea, Panama City, FL).
In the 1000 years following this period, very few developments occurred in diving. It was not until 1535 that Guglielmo de Lorena developed a device that can be considered a true diving bell. Davis (1962) tells of a diver who worked for about an hour in a lake near Rome using de Lorena's diving apparatus, which rested on his shoulders and had much of its weight supported by slings. De Lorena's "bell" thus provided a finite but reliable air supply.
In 1691, the British astronomer Sir Edmund Halley (who was then Secretary of the Royal Society) built and patented a forerunner of the modern diving bell, which he later described in a report to the Society. As Sir Edmund described it, the bell was made of wood coated with lead, was approximately 60 cubic feet (1.7 cubic meters) in volume, and had glass at the top to allow light to enter; there was also a valve to 1-1 vent the air and a barrel to provide replenished air (Figure 1-3). In his history of diving, Davis (1962) suggests that Halley undoubtedly knew of a development reported by the French physicist Denis Papin, who in 1689 had proposed a plan (apparently the first) to provide air from the surface to a diving bell under pressure. Papin proposed to use force pumps or bellows to provide air and to maintain a constant pressure within the bell. Davis speculates that Halley's choice of the barrel rather than forced air method of replenishment may have reflected Halley's concern that Papin (who was also a Fellow of the Royal Society) would accuse him of stealing his concept. Halley's method was used for over a century until Smeaton introduced a successful forcing pump in 1788. In 1799, Smeaton dived with his "diving chests," which used a forcing pump to replenish the air supply (Larson 1959).
Diving bells continue to be used today as part of modern diving systems, providing a method of transporting divers to their work sites while under pressure and, once at the site, of supplying breathing gas while the diver works. Both modern-day open (or "wet") and closed bells are clearly the successors of these ancient systems.