[61] 



U. S. FISH COMMISSION STEAMER ALBATROSS. 



G3 



removed from the paper, and placed on the blade ; the wire stops are 

 cut, the free end of the wire led out, and three turns taken around 

 the measuring- reel in such a manner that the register will count ahead 

 during the transfer. The end is then taken to the service reel, and 

 clinched through the hole provided for this purpose. The two men 

 at the blade reel back the slack wire, the record keeper sets both 

 registers at zero, and takes his station for reading the one on the 

 measuring reel, the officer in charge watching that on the service reel. 

 The cranks are manned and the transfer begins, the reel being turned 

 at any desired speed. One of the men at the blade puts a slight ten- 

 sion on the wire by applying an old piece of canvas in his hand to the 

 iron rim at the base of the reel. 



The record keeper calls out " mark !" at every 50 fathoms registered 

 by the measuring reel, the officer in charge reads the register on the 

 service reel at the same iustant, and this being recorded the difference 

 between the two readings shows the error at that point. This process 

 being carried on until the reel is filled, furnishes data from which a cor- 

 rection table is made, by which soundings can be corrected readily by 

 inspection. 



A correction table once made for a certain reel is always available for 

 that reel, or auy others of the same dimensions, provided the amount 

 of wire on it is less than that for which the table was constructed. 



Correction table. — Reel No. 1. 



















5,000 





4,500 





4,000 



43 



81 



113 



140 

 162 

 178 

 189 

 196 





3,500 



53 



102 

 145 



183 

 215 

 242 

 264 

 280 

 291 

 298 





3,000 



49 

 92 



130 

 162 

 189 

 211 

 227 

 238 

 245 





2,500 





2,000 



38 

 70 

 97 

 119 

 135 

 146 

 153 





1,500 



32 

 59 

 81 



97 

 108 

 115 







1,000 



27 

 49 

 65 

 76 

 83 





500 



22 



38 

 49 

 56 







16 

 27 

 34 



11 



18 



7 



ILLUSTRATIVE EXAMPLES. 



Number of turns on the reel 4, 500 



Turns registered in sounding 2,500 



Turns remaining on reel 2, 000 



Corrections fathoms. - 189 



Turns do .... 2,500 



Depth 2,689 



The table given above illustrating our method of correcting sound- 

 ings gives the error for every 500 fathoms ; but that in actual use on 

 board gives it for every 50 fathoms and at any intermediate point it 

 can be ascertained by a simple interpolation. This table is the work of 

 Lieut. Seaton Schroeder, U. S. N. 



