EQUIPMENT. 



13 



again and not detached ; the speed of the reel was not quite so 

 rapid, as will be seen on making a comparison of the following 

 records, the one showing a sounding with a thirty-four pound 

 lead, the other with a cannon-ball detached on striking bottom. 



U. S. Coast Survey Steamer " Blake." Locality, tioenty miles N. W. of Sombrero Island. 

 Date, April 23, 1879. Sounding, No. '■lo. Line PP. Sinker used, shot; weight, 

 60 lbs. Steel wire used, 0.028" m diameter; weighs 14.5 lbs. to the nautical mile; 

 breaking strain, 240 lbs. 



Reading of Register 2,765 turns. 



Correction for stray line 6 



Correction for turns of wire 158 



Correct depth 2,929 fathoms. 



^ The time intervals are slower than one of the deepest soundings made with 

 the average, but this record is given as wire at the time it was taken. 



