MECHANICS A XI) USEFCL ARTS. 49 



flange on its top, carrying a standard on which is secured the end of a lever* 

 working on a pin. In the small cylinder there is a packed piston, having its rod 

 connected to the lever mentioned, a short distance from its jointed end. This 

 lever is extended horizontally forward, and its other end secured to a spring- 

 balance. There is a small chamber in which there is-a plunger valve inserted in 

 a vertical tube passing down to the bottom of the boiler and open to the water. 

 The rod of the valve is also connected with the lever mentioned. This valve 

 covers the mouth of a bent tube, which passes down into the fire box. The 

 spring balance is set at the pressure to be carried 60 or 80 Ibs. and the valve 

 then covers the tube leading into the furnace. Whenever the pressure in the 

 boiler on the small piston exceeds that at which the spring holds it down, the 

 piston will rise, and also the valve which covers the mouth of the tube leading 

 to the furnace. The superincumbent pressure of the steam then forces the 

 water in the boiler through the tube into the furnace, and extinguishes the fire. 



Improvement in the Construction of the Governors of Steam Engines. In the 

 ordinary steam engines, no provision is made for the control of the engine in 

 case the governor becomes suddenly inoperative. If, by reason of its driving 

 belt or gear giving way, or by other accidental causes, the governor is stopped, 

 it leaves the throttle-valve wide open, and the steam full on the engine. An 

 increase in the speed at once takes place, which often results in doing much 

 injury to the machinery. An invention by John Tremper, of Philadelphia, Pa., 

 has for its object the detachment of the governor entirely from the valve the 

 instant it becomes inoperative, and at the same time to close the valve by 

 means of a spring or weight applied for that purpose, and thus stop the 

 engine. Another object is to regulate the movement of the valve w.hile the 

 governor is in operation. 



Improved Engine Connection for Transmitting Motion to Shafts. An invention 

 for effecting the above purpose, by Thomas Doyle, of Xew York, consists 

 in the arrangement of two beam engines in line with each other that is to 

 say, with their beams in the same plane and with the cylinder ends of the 

 engines contiguous to each other, and connecting their piston rods or beams 

 by an intermediate beam. By this means the two shafts which are parallel 

 with, and at some distance from each other, are caused to rotate at a uniform 

 speed. The mam object of this invention is its application to drive two pairs 

 of paddle wheels to propel a vessel, but it may also be used .for driving two 

 parallel shafts for other purposes. "With the above method of connecting the 

 engines, the cranks of the two shafts are always kept in opposite positions, 

 and when one piston is descending the other is always ascending. This 

 mode of connecting the engines appears to form a simple and effective arrange- 

 ment for driving two shafts, to which it causes the power to be transmitted 

 equally, if .the resistance be equal, or always in proportion to the relative 

 amount of resistance. - 



Packing Pistons for Steam Engines. An improvement, patented by J. T". 

 Pettis, of Hillsdale, Michigan, is intended to enable the engineer to tighten 

 the packing of the piston, without going to the trouble of removing the 

 cylinder head, and various other appurtenances. This is done by making 

 the piston rod hollow, and passing a solid rod down its centre to the 



