KEDGING. 



136 



to hold, she will, of course, move entirely along 

 with the tide, and the rudder will become useless ; 

 but if it be not quite lifted up, and merely allow- 

 ed to drag along the ground, it is evident that the 

 ship, thus clogged, will accompany the tide reluc- 

 tantly, and the stream will in part run past her. 

 Thus a relative motion between the vessel and the 

 water is produced, and, consequently, a steering 

 power is given to the rudder. 



In our case, the tide was running three miles 

 an hour ; and had the anchor been lifted wholly 

 off the ground, we must have been borne down 

 the river exactly at that rate ; but by allowing it 

 to drag along the ground, a friction was produced, 

 by which the ship was retarded one mile an hour ; 

 and she was therefore actually carried down at the 

 rate of only two miles, while the remaining one 

 mile of tide ran past, and allowed of her being 

 steered : so that, in point of fact, the ship became 

 as much under command of the rudder as if 

 she had been under sail, and going at the rate of 

 one mile an hour through the water. 



This power of steering enabled the pilot to 

 thread his way, stern foremost, amongst the shoals. 



