[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 Kew 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 performaucie must be considered as the average and not the 

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



Duration of voyage liours . . 42^ 



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



Mean number of geograpbical miles per bouv 10.03 



Total number of revolutions of tbe starboard engine 200, 197 



Total number of revolutions of tbe port engine 200,411 



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



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



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



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



Mean steam-pressure in tbe boilers in pounds per square incli above the 



atmospbere 60. 05 



Mean i)ressure per square incb above zero in tbe starboard receiver 25. 53 



Mean pressure per square incb above zero in tbe port receiver 23. 78 



Mean vacuum in the condenser, in incbes of mercury 24.46 



Mean beigbt of tbe barometer, in incbes of mercury 30. 09 



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



Mean point of cutting off in tbe 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 oft' in tbe port low-pressure cylinder, in incbes W. 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 uumber 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 pouuds of combustible per bour per square foot of grate 



surface 8.598 



Mean uumber of pour.ds 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 discbarge-water 93. 78 



Mean temperature of feed- water 76. 39 



Mean temperature of tbe engine-room 119. 10 



