Nikola Tesla U.S. Patent 1,061,206 - Turbine Patent Wrapper Page 20

884 Erased per 13 Erased pew a . per a 9084 center of the same, under the combined influence of radial and tangential forces, in a curved path of least relative velocity, and propelling the rotor by the viscous and adhesive action thereon of the fluid, as set forth. 13. The method of transforming heat into mechanical energy which consists in directing steam or gas under pressure through a divergent nozzle upon the peripheral portion of a rotor, causing the expanded fluid to flow, under the combined influence of radial and tangential forces in natural spirals with continuously diminishing velocity towards the axis of the rotor, and propelling the same by the adhesive and viscous action thereon of the fluid, as set forth. 14. The method of converting the heat energy of steam or gas under pressure which consists in directing the fluid upon the peripheral portion of a rotable system, causing it to flow towards the axis of the same, under the combined influence of radial and tangential forces, in natural spirals with continuously diminishing velocity approximating that of the adjacent parts of the system, and propelling the same by the adhesive and viscous action thereon of the fluid, as set forth. 1. 8.75 A machine adapted to be propelled by a fluid consisting in the combination with a casing having inlet and outlet ports at the peripheral and central portions, respectively, having plane spriced surfaces betwveen of a rotor with passages through which the fluid may flow in natural spirals and by adhesive and viscous action impart its energy of movement to the rotor, as described. 2.76. A machine adapted to be propelled by a fluid, comprising a rotor composed of a plurality of plane spaced disks. -16