181 



\.-\-\ raj mlly, but she has to remain in a certain position with her 

 to the \\ind perhaps for hours, and to go at a speed perhaps 

 of one mile an hour only with a side wind upon her. Unless she 

 is able to do this she is of no use for bringing up a cable from the 

 depths of the Atlantic except during exceptionally fine weather. 

 With i liis sliij) we have accomplished the most delicate operations 

 on the Atlantic when it was blowing almost a gale. The chief 

 why she is so under command is the twin screw arrange- 

 ment. By turning one screw full speed forward and the other 

 half speed backward, we hold the head of the ship up against the 

 wind, and go slowly along dragging, or holding her in position 

 when we want to splice. But the ordinary twin screw would 

 hardly have been sufficient ; we wanted greater force acting simply 

 in order to tend to turn the ship ; and then, as the paper states, it 

 occurred to me to put the two propeller shafts at a certain angle 

 to each other converging towards the stern. By this simple arrange- 

 ment we get a distance between the two propeller shafts, if they 

 were continued to the midship section, of some 40 or 45 feet, and 

 that is the real angle and the real leverage with which we turn 

 the ship, in turning the one screw forward and the other stern- 

 ward. On making the trial on the open sea, by throwing a barrel 

 over the stern, we found that we could turn the ship round and 

 round touching that same barrel again in eight minutes, so that 

 we have a power there of turning the ship quite irrespective of 

 her onward motion through the water. 



Mr. J. S<-oU Russell, F.R.S. : Could you turn her standing in 

 eight minutes ? 



Dr. Siemens : Yes. 



Tlic Chairman (Sir F. W. E. Nicholson) : What you mean is, 

 that you turn her without leaving the barrel ? 



Dr. Siemens : Yes ; her stern would come back to the barrel or 

 nearly so, thus showing the turning power that we have. The 

 only part of the ship which has given us some trouble is the 

 rudder, or rather the two rudders. The forging, although very 

 strong, has shown some signs of weakness, and one has been 

 replaced ; the other is about to be replaced by a stronger forging. 

 But this failure has given proof of the great manoeuvring power 

 which we possess in this ship. On the last occasion, when the 

 cable had been ruptured, the rudder was in a somewhat shaky 



