APPENDIX No. 7. Vol. iv., p. 146.
Description of Machinery and Boilers of the American coasting Steamers “Bristol” and “Providence.”
Beam Engine.—Cylinder, 110 in. diameter, with a stroke of 12 ft. Balance, puppet valves, with adjustable drop cut off. Surface condenser, with 8500 square ft. of tube surface. Bucket and plunger circulating pump connected with beam.
Paddle-Wheels.—Of iron, 39 ft. 6 in. diameter, with a face of 12 ft. Wheel-shaft, 21 in. diameter.
Boilers.—Three in number, extending fore and aft the vessel in the hold. Fire-room, athwart ship. Boilers of the flue and tubular type; with double tier of furnaces, one above the other, on the plan for which the constructing engineer has a patent. Shell of boilers, back of furnaces, circular. Extreme length, 35 ft. Diameter of round shell, 12 ft. 5 in. Width of furnace front, 12 ft. 7 in. Number of furnaces in each boiler, four. Interior of boilers, flues below, and 5-in. tubes above.
| Total amount of fire-surface | 13,800 square ft. |
| Grate-surface | 510 square ft. |
| Pressure of steam carried, 25 lbs. to square inch. | |
| Effective horse-power, 3000. | |
| Speed, 18 to 20 miles per hour. | |
| Engines and boilers designed by Erastus W. Smith of New York. |
The engines of the Bristol and Providence are believed to be the largest single marine engines afloat in any part of the world.
APPENDIX No. 8. Vol. iv., p. 219.
(Transatlantic Steam.)
Comparative Statement of average Sailings of Collins and Cunard Lines for the second half of the Year 1851.