ON DEEP-SEA SOUNDING. 369 



at seven or eight knots, 1,500 fathoms of piano- 

 forte wire, with ring, short hemp line, and 30 Ibs. 

 sinker at the end, is quite manageable. 



In reply to Mr. Gray, I may state that we 

 brought up specimens of the material of the 

 bottom by means of a tube fitted simply with a 

 common door-hinge valve. The tube came up full 

 of mud where the material was soft. There are a 

 great many different plans of doing this, but we 

 found no difficulty in getting specimens of the 

 bottom with this tube and simple valve. 



APPENDIX A. 



ON FLYING SOUNDINGS. 



APPROXIMATE soundings of great use, both in 

 cable laying and in ordinary navigation, may be 

 obtained in depths of 200 fathoms, or less, with re- 

 markable ease, without reducing the speed of the 

 ship below five or six knots, even when the wire is 

 being paid out. For this purpose let the weight fall 

 direct from the wire wheel over the taffrail, with a 

 brake-resistance of from five to ten pounds. The 

 moment of its reaching the bottom is indicated by 



VOL. ill. U i>, 



