The deep sea is a mysterious frontier, difficult to reach for exploration and seen by a very small number of scientists who brave the dangers of submerging themselves hundreds, even thousands of feet below the surface. Before inventor, engineer, and adventurer Otis Barton created the bathysphere in 1930, virtually nothing was known about this part of the earth. Even today, there is relatively little known of this other world deep in the ocean. 

A bathysphere is a hollow, steel sphere with very thick walls made to maintain a reliable pressurization at depths where diving unaided is not possible. The sphere is connected to a thick steel cable, at least one inch or more, and a solid rubber hose, which carries wires for electricity to provide light and communication lines, allowing the divers inside to stay in contact with those above water. The vessel would be lowered and raised from a ship. Unlike a submarine, it has no mechanism for self-propulsion.

In 1926, Barton (1899-1992) had been attending postgraduate studies in engineering at Columbia University when he read of naturalist and undersea explorer William Beebe’s plans to build his own deep-sea device. Barton, who had explored shallow depths of the waters off the coast of Massachusetts, had been working on his own design for such a vessel. When he saw Beebe’s blueprint, he thought he had some more feasible ideas. He also had a great deal of money, inherited from his grandfather.  

Nevertheless, Barton did not have enough money to fund an expedition all on his own. He finally decided to contact Beebe, who at first was disinterested in his ideas, but later, through an introduction by a mutual friend, took to his design for the vessel – not to mention his offer to build a model using his own funds.

It was 1928, and Barton and Beebe completed the first test model two years later. The device had three-inch thick windows made of fused quartz, the strongest transparent substance available. It also had a 400-pound lid that was fitted over a hole that served as the entry and was fitted with ten large bolts. The entire system, including cables, weighed nearly 10,000 pounds when submerged. 

The interior of the bathysphere was rather small and cramped, with only a light and telephone, oxygen tanks, and chemicals – soda lime to absorb carbon dioxide and calcium chloride to absorb moisture. There were also fans to circulate the air inside. The rounded vessel was approximately four feet, nine inches in diameter.  

The men tested the bathysphere in 1930, first unmanned, then with them both inside. They were aware of the stakes: if the bathysphere failed they would immediately be crushed to death by the pressure of the water above them. But the mission was a success. That first year they descended to a depth of 1,426 feet.

In 1932, the pair tested a larger bathysphere off the coast of Nonsuch Island, Bermuda, where they were successfully submerged 3,028 feet and set a world record that stood for 15 years, until Barton created a vessel called a Benthoscope in 1949, which allowed submersion to a depth of 4,500 feet. 

Both Barton and Beebe became very well known figures for their achievements and continued to explore the depths of the sea throughout their careers. Barton conducted dives of his own in the Bahamas while working on the fictional film "Titans of the Deep." He also wrote the book “The World Beneath the Sea," published in 1953. Today’s more advanced submersible research vessels use many of the same principles originally employed by Barton.