Porter's Governor designed 1858 for stationary engines

Porter's Governor designed 1858 for stationary engines, size A for 4 h.p.

This is a form of high-speed steam engine governor, designed by Mr. C. T. Porter about 1858, and used very largely for stationary engines. The governor has a pair of arms pivoted at the top of a rotating spindle, and carrying small balls at their lower ends; two links connect the balls with a sliding sleeve, and this is loaded with a large central weight which tends to pull down the balls without increasing their centrifugal action. The sleeve is connected with the throttle valve by levers and rods. This, and other forms of governors running at high speeds, can be made as sensitive as desired, and are more powerful than the older forms, having large balls running at low speeds, examples of which can be found on the beam engines of James Watt