28 



ON THE METHOD ADOPTED TO COMPOUND 



the remaining old cylinder and trunnion blocks, so that the 

 steam trunnion may be brought amidships, and to take tlie 

 exhaust steam from the high-pressure cylinder through the 

 pipe or passage between the air pumps, and oxhaust it through 

 the trunnion at the wing side of the reversed old cylinder, 

 carrying it thence by a pipe into the surface condenser, 

 which was already fitted at the fore end of the engines; this 

 will bring the slide valves on the wing side of this cylinder 

 also. The same quadrants and valve levers will come in 

 again, but will have to bo removed frotu the midship 

 columns to the wing columns in ea,ch case, and a n(!vv link 

 motion to bo fitted to each cylinder, witli the eocentrics on 

 the paddle shaft close to tho outside of the wing bearings, 

 where the original expansion cams were (itted. A now weigh 

 shaft to bo fitted across the after columns, to actuate these 

 links. The starting to be accomplished by a now steam start- 

 ing engine in place of the present hand starting wheels and 

 r;icks, with sta-rting valves to each cylinder; by ])utting tho 

 slide valves on the wing sides of oaeh. cylinder, tho feed 

 and bilge pumps will have to be shifted from the wing to 

 the mid.9hip corncT's of the side frames, and new feed pumps 

 would bo requii'cd. 



Two new steel cylindrical boilers would be rc(juii'cd, IG 

 foet diameter X 11 feet long, having in all six furnaces, 45 

 inches diameter x 7 feet long, giving 146 square feet of grate ; 

 572 3|-in tubes 7 foet long, and a tot.al heating surface of 

 4,500 square feet. 



Thus producing a componnd engine with cylinders 40 and 

 66 inches diametei' x 72 inches stroke, working at 80 lbs. 

 boiler pressure, and sacrificing tho least parts of tho old 

 machinery, — one cylinder, the entablatures, shafts, paddlo 

 wheels, condenser, side frames, air, circulating, and bilge 

 pumps, etc., being retained. 



