396 SEC. 12. APPLIED MECHANICS. 



V. REGULATORS. 



1997. Spherical Governor for Steam Engines. Patented 

 by John Bourne. 



Lent from the Patent Office Museum by the Commissioners 

 of Patents. 



1998. Governor for Steam Engine. Gros, Paris. 



1998a. Gyrometric Governor for Steam Engines. 



Messrs. Siemens Brothers. 



It consists of an open cup of parabolic shape, fixed upon a vertical spindle, 

 and caused to revolve within the closed chamber containing the liquid, the 

 bottom of the cup being open and always immersed below the surface of the 

 liquid. When the cup is made to revolve rapidly, the liquid contained in it 

 rises round the sides of the cup and sinks in the centre, the surface of the 

 liquid assuming the inverted parabolic form ; and on reaching the edge of the 

 cup it overflows into the surrounding chamber, while at the same time a 

 fresh supply of liquid is drawn into the cup through the opening in the 

 bottom ; and the power absorbed in putting the overflowing liquid into 

 motion offers a continuous resistance to the rotation of the cup. On a level 

 with the edge of the cup, a series of fixed vanes are placed round the cir- 

 cumference of the external chamber, and a corresponding set of blades are 

 also fixed round the outside of the cup just below the rim, so that the sheet 

 of liquid overflowing from the edge of the revolving cup is thrown against the 

 vanes, and by these is thrown back against the blades on the cup, whereby 

 the overflowing liquid is made to offer an additional resistance to the rotation 

 of the cup. 



The internal radial arms uniting the shell of the cup to the centre boss 

 serve to communicate the rotary motion to the liquid inside the cup, while 

 the bottom of the external chamber is provided with a number of radial ribs, 

 for the purpose of checking rotary motion in the liquid outside the cup. 



So long as the cup is driven at a constant speed, the overflow is constant, 

 and produces an absolutely constant resistance ; and, hence, if the cup be 

 driven by a constant driving power, independent of the engine, its speed is 

 as uniform as that of a chronometer, within a very small margin of variation, 

 which is definitely fixed ; and it continues revolving at an unchanging speed, 

 totally independent of the engine, and consequently affords the means of 

 forming a governor for controlling the speed of the engine to a constantly 

 uniform rate. 



1999. Model of Holt's Injection Water Regulator. 



This is an automatic valve for regulating the supply of injection 

 -water admitted into steam-engine condensers, according to the 

 requirements of the vacuum. It is useful in engines having a 

 verv variable load, and where water is taken from town's water- 

 works for condensation. Henry S. Holt, C.E., Leeds. 



1999a. Series of Models of Governors, &c. for Steam 



Engines, invented by Thomas Silver, of Philadelphia. 



a. Differential marine governor. 



b. Method of adjusting pneumatic governors when in motion. 



c. Marine governor. 



