VII. REGULATORS. 467 



b. Mercury vacuum gauge for condensing steam engines. 



c. Thermometer for measuring high temperatures. 



d. Bourdon's patent steam-pressure gauges, for high and low 

 pressure boilers. 



c. Bourdon's patent vacuum gauges. 



/'. Schaffer's patent steam-pressure gauges for high and low 

 pressure boilers. Two of these gauges are in section showing 

 interior arrangement. 



ff. Schaffer's patent vacuum gauges, for condensing steam 

 engines, &c. 



h. Schaffer's patent hydraulic-pressure gauges, with maximum 

 indicators. 



i. Blast furnace gauge, mercury ; indicating 6 Ibs. pressure. 



k. 7-figure counter, in section, for counting steam engine revo- 

 lutions and speeds of machinery. South Kensington Museum. 



32 7a. Patent Water Gauge for steam boilers, independent 

 of level or distance. John Nicholas. 



This instrument is for indicating in an office or ship's cabin the quantity of 

 water in the boiler or other vessel to which it is attached. The boiler may 

 be any distance from the office, and upon any relative level. The small tank 

 represents a portion of a boiler to which the stand pipe is attached ; in the 

 centre of the stand pipe is a brass tube, open at the top into the steam space, 

 and communicating at the bottom with the right-hand union. The left-hand 

 union opens directly into the water space. The right-hand union is connected 

 by a lead pipe with the top part of the gauge glass, the other by a similar 

 tube with the bottom of the glass, forming a continuous tube, one end of which 

 is open to the steam and the other to the water space. This system is now 

 entirely filled Avith water, which will always have the same level inside the 

 brass tube as in the boiler, and any movement in the boiler will cause a 

 corresponding motion in the brass tube, such movement being continuous 

 throughout the system. A small quantity of oil is placed in the gauge to 

 show readily this movement, and the line of contact in the glass tube repre- 

 sents the position the of water in the boiler. 



197 7a. Indicator of Pressure, marking in points, thus 

 avoiding the difficulty of propulsion. 



Marcel Deprez, 16, Rue Cassine, Paris. 



1977b. Model of Indicator, for steam-engine. 



Marcel Deprez, 16, Rue Cassine, Paris. 



1977c. Dianemometre, or rule, showing the graphic solution 

 of indicator diagrams. Marcel Deprez, 16, Rue Cassine, Paris. 



VII. REGULATORS. 



1997. Spherical Governor for Steam Engines. Patented 

 by John Bourne. H.M. Commissioners of Patents. 



1998. Governor for Steam Engine. Gros, Paris. 



Gg 2 



