362 POPULAR LECTURES AND ADDRESSES. 



perhaps, 150 fathoms had run out in some 

 cases 175 fathoms suddenly the wheel would 

 almost stop revolving. In half a turn it was 

 obvious that there was this sudden difference 

 which showed that the sinker had reached the 

 bottom. The moment the difference was 

 perceived, the man standing by laid hold 

 of the rim of the wheel and stopped it. 

 Thus we achieved flying-soundings in depths 

 of 150 fathoms, with the ship going through 

 the water at the rate of 4^ knots, and 

 obtained information of the greatest possible 

 value with reference to the depth of the 

 water and the course to be followed by the 

 cable. I think this is of such great import- 

 ance that I never would like to go to lay a cable 

 without an apparatus for flying-soundings. The 

 warning that this practice gives of shallow 

 water, or of too great a depth of water, has 

 a value which the members of the Society of 

 Telegraph Engineers will readily appreciate. 

 It will also, no doubt, be found useful in 

 ordinary navigation. There is one interesting 



