g2 BULLETIN 173, U. S. NATIONAL MUSEUM 



This was one of the earliest of the weighted flyball governors of 

 very light construction, designed to rotate at high speeds. It is more 

 sensitive to small changes in the engine speed and quicker to respond 

 to the changes than was the heavy-ball, unweighted governor. The 

 Porter governor was an important feature of the well-known Porter- 

 Allen engine that was successfully introduced about 18G7, and the 

 weighted principle is used in practically ail ball governors of the 

 present time. 



The governor is a very light one of the common form, with the 

 usual sliding element connected to the engine regulator. Attached to 

 the sliding element is a lever that carries a sliding weight so connected 

 that the effective weight of the counterpoise remains the same as the 

 sliding element moves through its range. 



KELLY AND LAMB STEAM ENGINE GOVERNOR, 1865 



U.S.N.M. no. 308667 ; original patent model ; transferred from the United States 

 Patent Office ; not illustrated. 



This model was submitted with the application for the patent issued 

 to Oliver A. Kelly and Estus Lamb, of Slatersville, R. I., January 

 31, 1865, no. 46111. 



The model represents a ball governor in which part of the regulat- 

 ing motion is obtained directly from the change in position of the 

 governor balls and partly from the motion of a nut along a screw 

 shaft. 



The motion of the nut is determined by the rotation of the screw 

 shaft, which, in turn, is derived from a ratchet wheel and two pawls. 

 The pawls are given a rocking motion by a crank on the governor 

 drive shaft. A cam slot controlled by the movement of the balls per- 

 mits one or the other pawl to engage the wheel as the balls move away 

 from their normal position and so determine the direction and 

 amount of the rotation of the screw shaft. 



PEAVEY FLUID ENGINE GOVERNOR, 1870 



U.S.N.M. no. 308678; original patent model; transferred from the United States 

 Patent Office; not illustrated. 



This model was submitted with the application for the patent issued 

 to Andrew J. Peavey of Boston, Mass., August 16, 1870, no. 106400. 



The model represents a stationary cylinder filled with oil within 

 which turns a paddle wheel driven by the engine at a speed de- 

 pendent upon the velocity of the engine. Also within the stationary 

 cylinder and surrounding the paddle wheel is a hollow cylinder, 

 which is hung loosely upon the shaft of the paddle wheel and is free 

 to revolve independently of it. This cylinder has a series of blades 

 or abutments projecting from the inner side of its rim, so that as the 

 paddle wheel causes the oil to revolve in the cylinder the moving oil 



