Through the 19th century, science and technology grew closer together, particularly through electrical and acoustic inventions and the corresponding mathematical theories. The late 19th and early 20th centuries witnessed a trend toward military mechanization, with the advent of repeating rifles with smokeless powder, long-range artillery, high explosives, machine guns, and mechanized transport along with telegraphic and later wireless battlefield communication. Still, independent inventors, scientists and engineers were largely responsible for these drastic changes in military technology (with the exception of the development of battleships, which could only have been created through organized large-scale effort).