[45] WORK OF STEAMER ALBATROSS. 649 



They are to be placed in the main hold fore and alt, one forward of 

 the other, with the fire-room athwart-ships between them. 



A steam chimney is placed over the fire-room — between the boilers — 

 and is supported on wrought-iron built-up girders, supported by the 

 boilers, essentially as recommended in my quarterly report dated 31st 

 of March, 1884. 



The external diameter of the boilers is 12 feet, and the length on line 

 of axis is 10 feet 3 inches. Each boiler has three furnaces, 36 inches 

 internal diameter, and exposes a length of grate of C feet G inches, 

 making an aggregate of 117 square feet of grate surface. 



The tubes are to be wrought-iron lap-welded, 3 inches external diam- 

 eter, 7 feet 9 inches long, No. 10 wire gauge in thickness; there are in 

 all 394 tubes, including 48 stay-tubes, which are No. 8 W. G. thick. 



The shells of the boilers are to be f of an inch thick; the longitudinal 

 seams are double strapped; the circumferential *seams are to have sin- 

 gle straps; all the seams are butted. 



The heads are to be ^ inch thick, butted and strapped. The heads 

 are braced by If -inch rods, spaced 12 inches centers, and the other flat 

 surfaces are stayed by 1^-inch screw-stays, spaced 7£-inch ceuters. 



The steam-chimney is 7 feet 4 inches in diameter (the same as the old 

 one) and is 10 feet high. 



The flue is 4 feet 4 inches in diameter, is in four sections, stiffened by 

 the Adamson rings, and is | inch thick. 



The boilers are to sit in and be secured to wrought-iron saddles, which 

 are to be riveted to the floor frames. The holding-down bolts are \\ 

 inches in diameter, and six in number for each boiler. 



The old stop-valves, checks, blows, salinometers, gauges, etc., are to 

 be utilized as far as possible. 



A new 8i-inch stop-valve, a section of 8^-inch copper steam pipe, a 

 3-inch safety-valve, one new escape-pipe, two safety feed-valves, and 

 two sections of feed and blow pipe are to be made new. 



The covering of the boilers will consist of half an inch of kaolin, 

 half an inch of hair felt, and half an inch of wood pulp. 



The center of the smoke-pipe will come about 5 feet 3 inches forward 

 of the present one. We will put four ventilators (instead of two) into 

 the fire-room, and, by bringing them close to the smoke-pipe, we will 

 leave more "floor room" on deck than at present, and will bring the 

 ventilator hoods clear of the main-stays, that we may run them up 

 about 8 feet into the air. As there will be a boiler on both sides of the 

 fire-room, we will need all the air we can get into the fire-room. 



The iron in the old coal-bunkers is to be utilized in the new ones. 

 We will get the new boilers and bunkers between the same bulk heads 

 that inclose the old ones, but the new arrangement affords a space of 12 

 inches in the clear (at the smallest place) around the boilers, and an 

 increase of more than 30 tons of coal in the bunkers. 



