RULES FOR CALCULATING THE STEAM ENGINE. 219 



Third operation. 21'7l 



375 



10855 

 15197 

 6513 



8-14125 

 Parallel bar 4 



Radius bar 12-14 feet. 



II. When the radius bar and piston rod are attached to the links at different distances 

 from the beam. 



RULE. Multiply the radius of the beam by the distance of the radius bar, and divide the 

 product by the distance of the piston rod or cross head, for the prepared length of the beam. 



Also, multiply the length of the stroke by the distance of the radius bar, and divide the 

 product by the distance of the piston rod, for the prepared length of stroke. 



And to the length of the parallel bar add the prepared length of the beam, and subtract 

 its true length, for the prepared length of the parallel bar. 



The values thus deduced will then be the lengths of the beam, stroke, and parallel bar, 

 prepared for the calculation of the length of the radius, according to Rule I. (236.) 



Example. Let the radius of the beam be 64 inches, the parallel bar 50 inches, the stroke 

 42 inches, the radius bar connected 68 inches from the beam, and the piston rod con- 

 nected 84 inches from the beam. 



Beam 64 Stroke 42 



68 68 



512 336 



384 252 



84) 4352 (51-81, 84) 2856 (34, prepared stroke. 

 420 prepared beam 252 



152 336 



84 336 



680 * 



672 



80 51-81 



Parallel bar 50-00 



101-81 

 Beam 64-00 



37*81 prepared parallel bar. 

 2 



75-62 



