SALMON 13 



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 bottom 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 in the pool below the 

 Leader-water cauld, that prevented the fish from 

 clearing it ; because I know an instance where 

 Salmon have cleared a cauld of six feet belonging 

 to Lord Sudely, who lately caused it to be measured 

 for my satisfaction, though they were but few out 

 of the numerous fish that attempted it that were 

 able to do so. I conceive, however, that very large 

 fish could leap much higher. 



Although I think the powers of Salmon to leap 

 perpendicularly have been much overrated, yet I 

 know that they will ascend steep cataracts in a 

 wonderful manner. Mr. Smith of Deanston, in the 

 Carse of Stirling, has invented a sort of stair, by 



