FINDING THE WAY AT SEA. 717 



is the only form of material existence which can be realized in thought. 

 In what sense, and to what extent, this assertion is well founded, will 

 be my next subject of examination. 







FINDING THE WAY AT SEA. 



By K. A. PEOCTOE. 



THE wreck of the Atlantic, followed closely by that of the City of 

 Washington nearly on the same spot, has led many to inquire 

 into the circumstances on which depends a captain's knowledge of the 

 position of his ship. In each case, though not in the same way, the 

 ship was supposed to be far from land, when in reality quite close to 

 it. In each case, in fact, the ship had oversailed her reckoning. A 

 slight exaggeration of what travellers so much desire a rapid pas- 

 sage proved the destruction of the ship, and in one case occasioned 

 a fearful loss of life. And, although such events are fortunately infre- 

 quent in Atlantic voyages, yet the bare possibility that, besides or- 

 dinary sea-risks, a ship is exposed to danger from simply losing her 

 way, suggests unpleasant apprehensions as to the general reliability 

 of the methods in use for determining where a ship is, and her prog- 

 ress from day to day. 



I propose to give a brief sketch of the methods in use for finding 

 the way at sea, in order that the general principles on which safety 

 depends may be recognized by the general reader. 



It is known, of course, to every one, that a ship's course and rate 

 of sailing are carefully noted throughout her voyage. Every change 

 of her course is taken account of, as well as every change in her rate 

 of advance, whether under sail or steam, or both combined. If all 

 this could be quite accurately managed, the position of the ship at 

 any hour could be known, because it would be easy to mark down on 

 a chart the successive stages of her journey, from the moment when 

 she left port. But a variety of circumstances renders this impossible. 



To begin with : the exact course of a ship cannot be known, be- 

 cause there is only the ship's compass to determine her course by, and 

 a ship's compass is not an instrument affording perfectly exact indica- 

 tions. Let any one on a sea-voyage observe the compass for a short 

 time, being careful not to break the good old rule which forbids speech 

 to the " man at the wheel," and he will presently become aware of 

 the fact that the ship is not kept rigidly to one course, even for a short 

 time. The steersman keeps her as near as he can to a particular 

 course, but she is continually deviating, now a little on one side, now 

 a little on the other, of the intended direction ; and even the general 

 accuracy with which that course is followed is a matter of estimation, 



