8 



Appendices to Fifteenth Annual Report 



whole length of the dam at either side of the ladder, and on a high 

 enough level to prevent there being any pool in the river, or sufficient 

 depth of water farther up than the entrance to the said pass or 

 ladder, by which the fish might be induced to remain there 

 obstructed in their ascent, and not be led to the ladder. 



Note. — The Commissioners would recommend the following 

 details to be adopted in the construction of salmon ladders, 

 in addition to those given in the foregoing bye-law, but do 

 not insist on them, provided some other perfectly efficient 

 arrangement be substituted, — viz., the side walls to be not 

 less than twenty-two inches in height ; the breaks to be not 

 less than eighteen inches in height, w r ith openings of ten 

 inches in breadth at the alternate ends of each break, and 

 ^ve feet apart in cases where the gradient of the ladder is 

 one in five and of a greater distance, but the same propor- 

 tions being maintained where the gradient is easier than one 

 in five. 



7. No dam shall be so altered as to create a greater obstruction to 

 the free passage of fish than at present exists. 



Whitehall, 19th July 1865. 



(This bye-law to take effect from the 28th July 1865.) 



It will be observed that the object aimed at, in sections 1 and 2, is to 

 provide that all water not required for milling purposes shall be made to 

 flow down the fish-pass and over the mill dam, instead of being allowed 

 to run to waste. There is no more important provision in the whole 

 bye-law, as the larger the volume of water flowing from a fish-pass, the 

 more will fish be tempted to ascend it. There is, however, none which 

 is more systematically contravened. 



The regulations with regard to hecks in sections 3, 4, and 5 were made 

 with a view of preventing salmon being killed in mill lades. In many 

 cases, however, the hecks have become damaged in such a way as to 

 serve an exactly opposite purpose than that for which they were intended, 

 for while they do not prevent salmon entering mill lades they form an 

 effectual barrier to their exit. 



In section 6 the Commissioners seem to recognise that the chief 

 requisite in making a fish-pass that salmon not only can, but will ascend, 

 is to provide an attractive entrance in a proper position. It will be 

 observed that they lay down that the entrance shall be placed where 

 there is most running water, and that it shall not project beyond the 

 foot of the obstruction. These provisions are, however, frequently 

 infringed. It is not uncommon to see the entrance to the pass placed at 

 some distance below the foot of the fall, where the fish are not the least 

 likely to find it. 



With regard to section 7, it is commonly complained when a mill 

 dam or cruive dyke is repaired, that it has been altered in such a 

 manner as to create a greater obstruction to the free passage of fish 

 than formerly. Owing, however, to the want of accurate information as 



Wm. J. Ffennell, 

 Feed. Eden, 

 James Leslie, 



Fisheries Department, Home Office, 

 29th day of April 1865. 



Approved, 

 G. Grey. 



