216 REPORT — 1860. 



iron, tubes of brass, placed two on one side of the ship (of which one con- 

 sists of a single furnace and is used as an auxiliary or " donkey," and to sup- 

 ply the deficiency of fresh water caused by leakage, &c.) and one on the 

 other side, facing each other, with a fire-room fore and aft between them. 



ft. in. 



Length of boiler 24 9 



Breadth, including fire-room 29 



Depth, exclusive of steam drum 10 2 



Depth, inclusive of steam drum 10 ft. diameter 14 2 



Fire-room, length 21< 9 



Fire-room, width 8 6 



Heating surface in all boilers sq. 7890 



Tubes, in length 2 1\ 



Tubes, internal diameter 2 



Tubes, in number 4-230 



Furnaces. 



ft. in. 



Breadth, except " donkey," which is 2 ft. 6 in 3 



Length ". 5 10 



Area of all grates sq. 242 



Smoke-pipe, one telescopic, height when up (above grate) ... 52 



Diameter 6 10 



Area sq. 36 7 



Least area between tubes in all boilers sq. 35 65 



tons. 



Weight of boilers 74*75 



Weight of water in boilers 41*37 



ft, in. 



Cubic contents of water space 1484 



Cubic contents of steam space 1318 



Contents of combustion chamber, each furnace 6183 



Distance of fire-bars from top of furnace 2 



Distance of fire-bars from ash-pit 1 4 



Propeller, one true screw of brass. 



ft. in. 



Number of blades 4 



Diameter of screw 12 13 



Diameter of boss 1 9| 



Pitch 19 



Length 2 6 



Projected area at right angles of axis sq. 41*36 



Total weight of machinery, spars, &c, with Avater in boilers tons 227 



Carries 235 tons Anthracite coal. 



The coal used was Blackheuth Anthracite of the hardest variety. Its 

 analysis, as given by Professor Johnson, is — carbon, 92*12 ; water, hydrogen, 

 and volatile matter, 4*83 ; ashes, &c, 3*05. Specific gravity 1*477. 



