supply of alcohol and was known to have been drunk. On June 2, 1872, after an unsuccessful attempt to reach the North Pole, the expedition turned south to head back to the New York Navy Yard. Having been caught in an ice pack, 19 crew members were separated from the ship on an ice floe and floated 1,800 miles before being rescued. The remaining crew onboard the ship was forced to winter off Greenland in October 1872, with Polaris being broken down into two ships. Setting out on the ocean, the remaining expedition crew was rescued by a whaling ship on June 3, 1873. Upon the crew's return, Robeson immediately opened a naval investigation on June 5, 1873, inquiring into Hall's death and Buddington's lack of leadership and crew discipline. Captain Hall's journals and letters had been tampered with and destroyed; they may have contained information that was harmful to both Buddington and Bessels. The investigation under Robeson did not charge Bessels with Hall's murder, although there was circumstantial evidence Bessels did murder Hall. However, the entire Polaris expedition crew was exonerated. In 1968, Captain Hall's body was exhumed and modern scientific testing revealed he had been poisoned by arsenic before his sudden sickness and death. Bessels, who was in charge of Hall's medical care, is now believed to have most likely murdered Hall since Bessels had patriotic ties with his mother country Germany. Although Robeson's final report said Hall had died a "natural" death, certain information may have been suppressed, to prevent scandal. Captain Hall, before his death, named Robeson Channel in honor of Secretary Robeson. Submarine and torpedo testing (1869–1875) During Sec. Robeson's tenure, submarine, and torpedo technologies were tested by the U.S. Navy. , an experimental hand-cranked submarine owned by Oliver Halstead, had been semi-officially successfully tested in 1866 by Thomas W. Sweeny. However, the U.S. Navy did nothing with the ship until October 1869, when the ship was examined and recommended to Robeson by Cmdrs. C. Melancthon Smith, Augustus L. Case, and Edmund O. Matthews. Robeson appointed another committee to report on the boat's merit. After the second committee gave a favorable review, Robeson and Halstead signed a contract on October 29, 1869, to purchase the submarine for $50,000. Halstead, who contracted to test the submarine, was murdered, and the testing of Intelligent Whale was stalled for over a year. Because of lax security, in 1872,