ON STEAM-SHIP PERFORMANCE. 215 



which the plan you have organized has developed ; in return for which we 

 shall be happy to render further service if desired. 



I have the honour to be, Sir, 

 Your obedient Servant, 



Samuel Archbold, 

 Engineer-in- Chief, U.S. Navy. 

 Vice-Admiral C. JR. Moorsom, 

 Chairman of the Committee on Steamship Performance, British Association. 



Description and dimensions of the Hull, Engines, and 

 Boilers of United States Sloop ' Wyoming.' 



Hull. ,, 



ft. in. 



Length over all 232 9 



Length on spar deck 209 9 



Length between perpendiculars 198 6 



Length of keel from back part of forward stern post 158 



Width of beam, moulded 32 2 



Width of beam, extreme 33 



Depth of hold 15 10 



Space allotted to machinery 50 8 



Draft of water (loaded) forward 13 3 



Draft of water (loaded) aft 13 4 



Area of immersed midship section sq. 391 



tons. 



Displacement 1475 



Tonnage 997 



Mean angle of entrance 17° 30' 



Mean angle of exit 15° 30' 



Engines. 

 Two in number, horizontal, with double piston rods, and direct-acting; 

 slide valves, and independent cut-off valves, and situated 76 feet 6 inches from 

 screw. One surface condenser common to both engines, containing 3000 

 square feet of tube-surface. 



ft. in. 



Cylinder, not jacketed, diameter 4 2 



Cylinder, stroke of piston 2 6 



The air-pump (one to each engine) is worked directly from the cross-head, 

 and consequently has the same stroke as the steam-piston. Its piston is a 

 barrel plunger, packed by a gland in the centre of the pump. The foot 

 valves of vulcanized rubber are situated beneath the plunger, and the deli- 

 veries above it. 



ft. in. 



Capacity of air-pump, one revolution cubic 3 3 



Area of foot valves, one end sq. 179 5 



Area of delivery valves, one end sq. 270 



There is also a cold water circulating pump to each engine of the same 

 dimensions as the air-pump. 



Boilers. 

 Three boilers, with vertical water space tubes over the furnaces. Shells of 



