THE STEAM-ENGINE. 



557 



the cock more or less fully. The handle of this cock rises through the floor 

 of the engine, so that the engineer may regulate it at discretion. The pipe K 

 being conducted under the engine, as represented in fig. 67, terminates 

 in a vertical pipe, of greater diameter, containing two valves, both of which 

 open upward, and between these valves to this vertical pipe is attached 

 force-pump, by which the water is drawn from the horizontal pipe K into the 

 vertical pipe K', and from the latter is driven into a delivery-pipe by which i 

 is forced into the boiler. The details of the interior of this feed-pump are 

 represented on a larger scale in fig. 81. The extremity of the horizontal pipe 



Fig. 81. 



K' is represented in section at H, where it is joined on by a screw to the 

 bottom of the vertical pipe which is represented in fig. 67, at K, and which is 

 here represented in section. The vertical pipe, represented in fig. 67, con- 

 sists of several parts screwed together by nuts and bolts passing through 

 flanges. The lowest piece I is attached by a flange to the piece L : within 

 these is contained the valve Q resting in a seat made conical, so that the ball 

 which forms the valve shall rest in water-tight contact with it. The ball is 

 turned and ground to an accurate sphere, and whatever position it assumes 

 upon its seat its contact will be perfect. It is guided in its upward and down 

 ward motion by several vertical bars which confine it, and which are united at 

 the top, so as to limit the upward motion of the ball. A screw V is inserted 

 in the bottom of the piece I, by removing which access can be obtained to the 

 valve. The piece L is secured to the short pipe G by nuts and bolts passed 

 through a flange. The pipe G is cast upon the end of the feed-pump A. On 

 the foremost end of this feed-pump is constructed a stuffing-box C of the usual 

 form, having a gland D forced against packing by nuts and screws E. The 

 plunger B is turned so as to be truly cylindrical, and moves in water-tight 

 contact through the gland D. The plunger not being in contact with the inner 

 surface of the pump-barrel A, the latter need not be ground. The horizontal 

 rod by which the plunger B is driven is attached at its foremost extremity to 

 an arm which projects from the rod of the steam-piston, and consequently this 

 plunger is moved through a space equal to the stroke of the steam-piston. In 



