ClipArt ETC
"In 1858, Hartman Bros. patented a turbine consisting of two revolving disks c and c' fixed to a shaft D. Between them was a segment of stationary reversing blades d d. Steam entered from a nozzle F and was exhausted at H; G is the casing." —Derr, 1911

Hartman's Compound Impulse Turbine

"In 1858, Hartman Bros. patented a turbine consisting of two revolving disks c and c' fixed to a shaft…

"A view of Wilson's invention is shown; a, b, and c, are vance which are attached to and rotate with the drum D, while d, e, and f are stationary guide vanes. Steam enters at the left, passes through the turbine longitudinally, and exhausts at the right." —Derr, 1911

Wilson's Compound Steam Turbine

"A view of Wilson's invention is shown; a, b, and c, are vance which are attached to and rotate with…