These articles caught the attention of Otis Barton, an engineer who had long admired Beebe and who had his own ambition to become a deep-sea explorer. Barton was convinced that Beebe's design for a diving vessel would never be capable of withstanding the extreme pressure of the deep ocean, and with the help of a friend who arranged a meeting with Beebe, proposed an alternative design to him. Barton's design called for a spherical vessel, which was the strongest possible shape for resisting high pressure. Barton had the good fortune that years earlier, Theodore Roosevelt had proposed a similar idea to Beebe, and Beebe approved of Barton's design. Beebe and Barton made a deal: Barton would pay for the sphere and all of the other equipment to go with it. In return, Beebe would pay for other expenses such as chartering a ship to raise and lower the sphere, and as the owner of the sphere, Barton would accompany Beebe on his expeditions in it. Beebe named their vessel the Bathysphere, from the Greek prefix "bathy-" meaning "deep" combined with "sphere".