452 



STEPHENSON'S PATENT 



piston rod, and attached at the outer end to the plunger of the pump. One of the 

 pumps is shewn in section in fig. 29, to three times the scale of the engraving, or 2^ 

 inches to a foot. The barrel of the pump, A A, is made of cast-iron, If inches in 



FIG. 29. 

 Vi 



FIG. 30. 



FIG. 31. 



diameter inside, and three-eighths of an inch thick. B B, is the plunger, If inches in 

 diameter, and made of a wrought iron tube for the sake of lightness, plugged up at the 

 inner end, and having a short rod keyed into the other end, which is fixed into the 

 socket in the driving arm by a nut screwed on the end. The plunger B, passes 

 through a stuffing box, C, at the end of the pump barrel A, with a brass gland, D, 

 attached by screws, E E, to the flanch of the stuffing box. The plunger is turned 

 truly cylindrical, to move water-tight through the stuffing box, but the inside of the 

 barrel of the pump is not bored, as the plunger does not touch it. 



A plug, F, is screwed into the other end of the pump to afford a passage quite 

 through for the convenience of fixing. Two short pipes, G O, are cast upon the end 

 of the barrel A, to the lower one of which is bolted the tube L, having the piece 

 / fixed below it ; both are of brass, and the piece / has a short tube cast on its side, 

 with a screw made upon its outer end. H is the copper suction pipe, having a brass 



