224 



THE LAST CRUISE OF THE CARNEGIE 



that it took from two to three hours to make a sounding, and used 

 a considerable amount of our supply of gasoline, it will be ap- 

 parent how greatly this simple change helped us. 



Bottom-snapper with Countersunk Lead Weight 



By countersinking the lead weight on the bottom-snapper the center of gravity was 

 lowered to insure striking the bottom head on. 



Another advance in methods was the modification of a Sigsbee 

 reversing-frame to contain two thermometers instead of one. 

 This frame was attached to the sounding-wire near the bottom- 

 snapper, and the original single thermometer gave us only the 

 temperature of the bottom-water. This information itself is of 

 great interest to oceanographers. However, we needed a check 



