DIVING APPARATUS, contrivances by means of which divers are enabled to remain a considerable time under water. As the most skilled divers are unable to remain under water more than two or three minutes without artificial respiration, means have been devised by hermetically sealed helmets, diving bells, and diving dresses, so that they can stay for several hours at a time at considerable depths of water and at the same time carry on their work. The div ing bell was mentioned by the classic writers. Aristotle speaks of a diving bell or a reversed kettle or bell which was put over the head of the diver.
Sinclair in his work on gravitation (1669), mentions the diving-bell which was used in 1588, 1665, and 1687 to res cue the treasures of the Spanish Arma da. The diving bell then used was similar to those used at the present time, though of much more clumsy con struction. Dr. Smeaton was the first to use an air pump for the supply of air, about 1788. He constructed a cast iron diving-bell which sank by its own weight and afforded room for two men.
Diving-dress, water-proof dress, or armor, was described as early as 1664 The diving-dress used at the present time may be independent of any connec tion with persons above. The most
common one is a rubber cloth dress, with a copper helmet, having air-tight connections, and supplied by a reser voir, attached to the back and contain ing air, compressed to a number of atmospheres, which is supplied to the diver by means of a proper apparatus. Among the best known diving appara tus are those called by the name of Skaphander and those of Rouquairol Denayrouze•, in the United States, the Morse and the Schroder. By means of this apparatus the diver can remain from four to five hours under water with perfect freedom of motion. The diving apparatus most generally used in the United States is the rubber suit, copper helmet, with face plates of glass, and air pump. The diver is connected by rubber hose with the air pump which is constantly worked by an experienced man. Another man called the "tender" holds the air hose and a life line by which the diver signals his require ments. When the diver has to go into dark places, where the sunlight cannot reach, he is equipped with an incandes cent electric light.