[61] 



U. S. FISH COMMISSION STEAMER ALBATROSS. 



6; 



removed from tlie paper, aud placed ou 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, aud 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 instant, 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 any others of the same dimensions, provided the amount 

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



Correction table. — Beel No. 1. 



ILLUSTRATIVE EXAMPLES. 



Number of turns ou 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 simi)le interpolation. This table is the work of 

 Lieut, Seaton 3chroeder, U. S. K. 



