[7] CONSTRUCTION AND WORK OF FISH-HAWK. 9 



for six days' steamiug; she has a keel condenser which receives the dis- 

 chjirjje from the cylinder and escape valve. 



Both hull and machinery are constructed of the best material. Steam 

 is raised in a few minutes, and when under banked fires requires no at- 

 tention. She is an excellent sea-boat and has been of great service to 

 this ship. 



2(1. A ten -oared cutter 24 feet G inches in length. 



od, A gig 26 feet 5 inches in length. 



4th. A dingy 17 feet C inches in length. 



She has also several flat-bottomed boats 18 feet in length, used for 

 spawn taking. 



Atcnings and stanchions. — The promenade deck is covered with awn- 

 ings fore and aft, supported by turned wooden stanchions. 



ENGINES AND MACHINERY. 



General description. — Tliere are two propelling- screws, right and left 

 handed, one under ea<;h counter; each screw driven by one inverted 

 cylinder surface-condensing engine, 22-inch diameter of cylinder, and 

 27-inch stroke of piston. The two engines are fitted on one bed-x)late; 

 the surface condenser, common to both, is located between the engines 

 and forms a part of the framing for them. 



The center of the cylinder is about 49^ feet forward of the stern-post ; 

 the distance between the shafts being about 8 feet 8 inches. The engines 

 are inclined towards the center line of the vessel, the cylinders at the 

 upper end being about 36 inches from center to center athwartships.' 

 There is one overhead return-flue boiler 8^ feet diameter of waist and 21i 

 feet in length, with steam chimney G feet 2 inches diameter outside and 

 lOi feet high. 



The water of condensation is supplied by an independent steam pum}). 



The valve-chests are on the forward side of the cylinders, main valves 

 working by a link motion, the cut-off valve working on a separate face 

 within the main steam chest and operating by a link, one end of which 

 is connected to an eccentric and the other to a concentric disk on the 

 main shaft. 



The air-pumps are trunk-plunger pumps, driven by cranks on for- 

 ward end of main shafts ; the feed-])umps are driven from the same mo- 

 tion. The bilge-i)ump is independent. 



Cylinders are 22 inches diameterand 27 inches stroke of piston ; steam 

 openings 2 inches wide by 14 inches in length •, exhaust openings 3i inches 

 wide by 14 inches in length. All necessary lugs, flanges, nozzles, and 

 lower cylinder head are cast with the cylinder, and all flanges faced. 

 The lower ends are fitted with a sinall bonnet, with stuffing box and 

 gland, both bushed with composition ; also a composition " water valve" 

 seven-eighth inch diameter, which works either automatically or by 

 hand. Cylinders and steam chests are fitted with the necessary 2)ipes 

 and valves for applying the indicator, and are cased with black walnut 

 staves, secured by brass bauds and screws. 



