In 1862, which doctor invented a hand-cranked, multi-barrel machine gun?

Around 1850, Hermann von Helmholtz measured how fast impulses travel along which body parts? In the mid-1800s, which U.S. industry sent out hundreds of ships, many from New Bedford, Massachusetts? Around 1850, Eugène Delacroix painted the central ceiling of the Galerie d'Apollon in which French museum? Around 1862, which American locksmith introduced a dial-operated combination lock for bank vaults? Around 1870, Christopher Sholes and partners developed the first practical version of which machine, with a QWERTY keyb… In the early 1870s, which plant breeder developed his famous potato on farmland in Massachusetts? Which sharpshooter beat her future husband, marksman Frank Butler, in a shooting match? Around 1890, which Scottish author bought an estate in Samoa that he called Vailima, or "five streams"?