32 DAYS AND NIGHTS OF SALMON FISHING. 



account which Mr. Yarrell has mentioned, placing their 

 powers of leaping ten or twelve feet perpendicularly, 

 I hold to be beyond the mark. I have frequently 

 watched their endeavours to surmount falls, and I do 

 not think I ever saw a Salmon spring out of the water 

 above five feet perpendicularly. There is a cauld at 

 the mouth of the Leader-water, where it falls into the 

 Tweed, which Salmon never could spring over ; this 

 cauld I have lately had measured most carefully by a 

 mason, and its height varies from five feet and a half 

 to six feet from the level above to the level below it, 

 according as the Tweed, into which the Leader falls, is 

 more or less affected by the rains. Hundreds of Salmon 

 formerly attempted to spring over this low cauld, but 

 none could ever achieve the leap ; so that a Salmon in 

 the Leader-water was formerly a thing unheard of. 

 The proprietors of the upper water have made an 

 opening in this cauld of late years, giving the owner 

 of the mill some recompense, so that Salmon now 

 ascend freely. Large fish can spring much higher 

 than small ones; but their powers are limited or 

 augmented according to the depth of water they 

 spring from : in shallow water, they have little 

 power of ascension; in deep, they have the most 

 considerable. They rise rapidly from the very bot- 

 tom to the surface of the water by means of rowing 

 and sculling, as it were, with their fins and tail ; 

 and this powerful impetus bears them upwards in the 

 air, on the same principle that a few tugs of the oar 

 make a boat shoot onwards after one has ceased to row. 

 It is probably owing to a want of sufficient depth 



