Pneumatic motor success with pneumatic motors in the locomotive industry. In 1911 he designed a pneumatic locomotive and sold the patent to the H.K. Porter Company in Pittsburgh for use in coal mines. Because pneumatic motors do not use combustion they were a much safer option in the coal industry. Many companies claim to be developing Compressed air cars, but none are actually available for purchase or even independent testing. Impact wrenches, pulse tools, nutrunners, screwdrivers, drills, grinders, die grinders, sanders, dental drills and other pneumatic tools use a variety of air motors. These include vane type motors, turbines and piston motors.
The Work of Art in the Age of Mechanical Reproduction free", for lacking the "aura" of the original work of art. The Work of Art in the Age of Mechanical Reproduction The Work of Art in the Age of Mechanical Reproduction (1935, "Das Kunstwerk im Zeitalter seiner technischen Reproduzierbarkeit"), by Walter Benjamin, is an essay of cultural criticism which proposes that the "aura" of a work of art is devalued by mechanical reproduction. The subject and themes of the essay have much influenced the fields of art history and architectural theory, and of cultural studies and media theory. During the Nazi régime (1933–1945) in Germany, Benjamin wrote the essay to