[23] U. S. FISH COMMISSION STEAMER ALBATROSS. 25 



THE POWER, ITS DISTRIBUTION AND THE SPEED OF THE SHIP. 



The nature of the service of the ship is such that uninterrupted 

 voyages of considerable length seldom occur, and as errors in experi 

 ments are principally in the beginning and ending, it follows that short 

 tests must be less reliable than long ones. For this reason I determined 

 to select one of our longest uninterrupted voyages, when the vessel's 

 bottom was clean and when she was near her average draught of water 

 for steaming. This opportunity occurred about seven months after the 

 ship had been put in commission, the voyage being from the New York 

 navy-yard to the Washington navy-yard. The coal used was anthra- 

 cite, containing more than the average percentage of ash and clinker. 

 The fires were not urged, there being no desire to make a quick voyage, 

 so that the performance must be considered as the average and not the 

 maximum. The wind was light but ahead ; the sea was smooth. 



Duration of voyage hours.. 42£ 



Total distance, in geographical miles of 6,086 feet 423 



Mean number of geographical miles per hour 10. 03 



Total number of revolutions of the starboard engine 200, 197 



Total number of revolutions of the port engine 200,411 



Mean number of revolutions per minute of the starboard engine 79. 05 



Mean number of revolutions per minute of the port engine 79. 06 



Slip of the starboard screw in per cent of its speed 14. 74 



Slip of the port screw in per cent of its speed 14. 75 



Mean steam-pressure in the boilers in pounds per square inch above the 



atmosphere 60. 05 



Mean pressure per square inch above zero in the starboard receiver 25. 53 



Mean pressure per square inch above zero in the port receiver 23. 78 



Mean vacuum in the condenser, in inches of mercury 24. 46 



Mean height of the barometer, in inches of mercury 30. 09 



Mean position of the throttle-valves, in eighths 7. 20 , 



Mean point of cutting off in the starboard high-pressure cylinder, in inches. 26. 333 



Mean point of cutting off in the starboard low-pressure cylinder, in inches. 14. 032 



Mean point of cutting off in the port high-pressure cylinder, in inches 19. 78 



Mean point of cutting off in the port low-pressure cylinder, in inches 17. 831 



Total number of pounds of coal (anthracite) 42,865 



Total number of pounds of ashes, clinkers, &c 8, 353 



Total number of pounds of combustible 34, 512 



Mean number of pounds of coal per hour 1, 016. 97 



Mean number of pounds of combustible per hour 818. 79 



Percentage of refuse in coal 19. 40 



Mean number of pounds of coal per hour per square foot of grate surface. . 10. 667 



Mean number of pounds of coal per hour per square foot of heating surface. 0. 4103 

 Mean number of pounds of combustible per hour per square foot of grate 



surface 8. 598 



Mean number of pounds of combustible per hour per square foot of heating 



surface 0.3303 



Mean number of strokes per minute of the circulating -pump 80 



Mean temperature of the external atmosphere 73. 73 



Mean temperature of the injection- water 65.73 



Mean temperature of the discharge-water 93. 78 



Mean temperature of feed-water 76. 39 



Mean temperature of the engine-room 119. 10 



