10 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [8] 



Framing. — The main frame for carrying the cjiinders is the surface 

 condenser, which is strongly ribbed and bracketed for that purpose, 

 tlie outboard sides of the cylinders being supported, each by two 

 wrought-iron columns, 2J inches diameter, turned and finished. The 

 ends of these columns are fitted to flianges of lower end of cylinders 

 and to bed-plate, each end being fastened by two bolts 1^ inches diam- 

 eter. 



Steam chests are cast separate, fitted with faced joints and bolted to 

 cylinders, covers planed, finished and fastened with finished bolts and 

 case-hardened nuts. Set screws are fitted to break the joints. The cut- 

 oif valve operates in a separate chest, which is bolted to that of the main 

 valve. 



Pass-over valve. — To each cut-off chest is fitted a screw-valve for a 

 pass-over valve, 2^ inches diameter. The valve, seat, and stem are of 

 composition, and valve is worked by a hand-wheel in front of chest. 



Relief valve. — A composition relief valve of seven-eighths inch diam- 

 eter is attached to steam chests and to exhaust connection to condenser. 



Slide valves. — The valves are of cast iron, of a different texture from 

 that of the seats and scraped to a bearing surface. The main slide valves 

 are of the ordinary D form ; for steam openings 2 by 14 inches and 

 for exhaust openings 3^ by 14 inches, and are worked by a " Stephen- 

 son " link motion. The link is case-hardened and link block composi- 

 tion. The link is worked by hand, by means of a i)inion, quadrant 

 and " tumbling" shaft. 



Cut-off valves. — Cut-oft' valves are of cast iron, of the gridiron pat- 

 tern, with two openings 1^ by 13 inches. The valve is operated by a 

 link, one end of which is worked by an eccentric and the other end 

 lield in i)osition by a concentric disk on crank-shaft. Steam can be 

 cut off at points from three-fourths to one -fourth the stroke of piston. 

 Proper hand gear is fitted to alter the point of cut off and to hold the 

 link in i>osition. 



Cylinder-heads. — Upper cylinder-heads are ribbedfturned,andfinished. 

 Inside of heads are recessed for nuts of jiiston-rods and for heads of 

 follower-bolts. Wrought-iron eyebolts are fitted for lifting the heads 

 and set-screws for breaking the joints; also a "traveler" for removing 

 them. 



Bed-plate. — The bed-plate or frame is of cast iron, in one piece, and 

 extended forward to receive the pumps ; is hollow, of the box form of 

 section, 14^ inches in depth, and has all the necessary passage-ways for 

 water, bosses and nozzles or flanges for pumps, pillow blocks, &c., and 

 flanges or lugs for bolting in place. All surfaces for flanges, pumps, 

 hand-hold plates, and pipes are planed. 



Surface condenser. — The shell is of cast iron 1 inch thick, well ribbed, 

 strongly bracketed, and serves as a frame for the engines. The neces- 

 sary seating for cylinders and for cross head slides are cast on. All 

 joint surfaces are planed, and suitable bonnets are fitted for access to 



