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Technology System of Mechanics, of the Science of Motion Alexander Hogg c.1788
Barker's Mill, Perpetual Motion, Pendulum, Human arm muscles, Percussion
Antique Copper engraving engraved by J. Page, printed on hand made hemp and flax laid paper.
Published "According to an Act of Parliament" by Alexander Hogg, at the Kings Arms No 16 Paternoster Row, London circa 1788
Condition= Excellent with no discolouring, Platemark complete. soft fold bottom left corner
Barker's Mill: Also known as Segner's Reaction Turbine, Parent's Mill, the Scotch Turbine, the Hydraulic Tourniquet or Barker's Mill. It was probably first invented in 1760 by Andreas Segner using Hero's steam reaction turbine as a model. Water from above pours into the funnel at the top of the central rotor, pivoting freely about its axis. Projecting from the bottom of the rotor are two pipes, each closed at the end, but with a rearward-facing hole. Water spouts out of these holes, making the rotor spin.
( http://physics.kenyon.edu/EarlyApparatus/Fluids/Barkers_Mill/Barkers_Mill.html )
Platemark = 23.5cm x 37.5cm (9.4 x 15 inches)