250 



EIGHTEENTH CENTURY. 



PT. III. 



and, secondly, I must tell you that the rods, i and 2, are so 

 placed that when the engine-end of the lever-beam is raised, 

 as in the figure, the stopcocks a and c are open, and b and d 

 are shut ; and when that end of the beam falls, b and d will be 

 open, and a and c will be shut. 



Let us now begin with the machine as we see it in the 

 figure. In this position of the beam the cocks a and c are 

 open ; therefore, the steam below the piston will rush out at 



Fig. 43. 



A, B, Cold water tanks. ^ c. Outlet for cold water. D, e, Pumps for drawing off hot 

 water and sending it along s, s, back to the boiler, p. Tight-fitting piston. 

 a, d. Cocks for letting steam into the cylinder, b, c. Cocks for letting steam out 

 of the cylinder, e, e. Pipe which carries steam from boiler to cylinder, o, o. Pipe 

 which carries steam from cylinder to condenser, i, 2, Rods connecting the cocks 

 with the lever-beam. 



c into the condenser, there to be turned into drops of water, 

 while the steam from the boiler, entering at a^ will force the 



