44 POPULAR LECTURES AND ADDRESSES. 



exceedingly useful in some circumstances for 

 speeds below six or seven knots. 



31. The following description of the LOG AND 

 GLASSES in ordinary use is taken from Lieutenant 

 Raper's excellent book on navigation. 1 



" THE LOG. The log consists of the log-ship 

 and line. The log-ship is a thin wooden quadrant, 

 of about five inches radius ; the circular edge is 

 loaded with lead, to make it float upright, and 

 at each end is a hole. The inner end of the 

 log-line is fastened to a reel, the other is rove 

 through the log-ship and knotted ; and a piece 

 of about eight inches of the same line is spliced 

 into it at this distance from the log-ship, having 

 at the other end a peg of wood, or bone, which, 

 when the log is hove, is pressed firmly into the 

 unoccupied hole. 



"At 10 or 12 fathoms from the log-ship a bit 

 of bunting rag is placed to mark off a sufficiency 

 of line, called stray-line, to let the log go clear of 

 the ship before the time is counted. 



1 The Practice of Navigation and Nautical Astronomy, by Lieut. 

 Henry Raper, R.N. (tenth edition, 1870; original edition, 1840). 



