POWERS OF SWIMMING AND LEAPING. 33 



in the pool below the Leader-water cauld, that pre- 

 vented 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 there 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 per- 

 pendicularly 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 means of which Salmon are 

 enabled to ascend streams in full waters in spite of 

 natural or artificial obstructions. One side of the river 

 under a weir or cauld is separated from the main stream, 

 and intersected by transverse pieces of wood or stone, 

 each of which reaches about two thirds of the width of 

 the gap. There are two ranges of these steps, one on 

 each side, and the steps on one side face the centre of 

 the interval between the steps on the other; so that the 

 fish ascend from side to side in a zigzag direction, and 

 can rest in their ascent, should they find it necessary. 

 This is a very ingenious contrivance, and it has been 

 constructed on the Teith, near Doune, with complete 

 success. But I conclude it can only come into operation 

 in such floods as raise the water to a higher level than is 

 required for the mill-dam ; and therefore if rude steps 

 of rolling stones were constructed at a portion of the 

 back of the cauld, the end would be answered in a better 

 manner, since the ascent miarht be made more gradual. 



