STATIONARY ENGINES,

195

leather seats enjoys the greatest favour in Cornwall . The pole case,that is, the case into which the plunger enters, is placed on one legof what is termed the H-piece. The H-piece is provided with a

Fig. 125.—Pit Work, showing Pumps, Rods, Cisterns, &c.

door or cover, through which the suction valve may be examined.The seating of the valve is made conical on the outside, and issomewhat smaller than the conical neck formed to receive it in the