What is associated with: around 1862 this doctor invented a machine gun that could fire about 350 rounds per minute?

What is associated with: around 1850 helmholtz clocked impulses moving along these body parts at about 90 feet per seco… What is associated with: around 1850 it used a fleet of over 700 ships by 1930 this us industry was practically defunct? What is associated with: around 1850 you could find eugene delacroix painting the ceiling of this french museums salon… What is associated with: around 1862 this american locksmith introduced a dial operated combination lock for bank vault… What is associated with: around 1870 christopher sholes 2 friends invented the 1st practical one of these including a q… What is associated with: around 1870 he bought some farmland in massachusetts developed his famous potato there? What is associated with: around 1870 the flag seen here was adopted by this country? What is associated with: around 1875 this woman beats her future husband marksman frank butler in a shooting match?