of the Fishery Board for Scotland. 



401 



water from the lade, when the sluice at the wheel and the byewash sluice 

 hereinafter mentioned are both kept shut. Provided always, that the said 

 bye-law shall not apply to millers or manufacturers when taking measures 

 necessary for the protection of their premises during heavy floods, or when 

 rivers are cumbered with ice, or while necessary repairs arc being executed 

 on any emergency, provided that nothing be omitted or done unnecessarily to 

 defeat the objects of this bye-law. Furthermore, in all cases when the intako 

 sluice is more than 300 yards from the water-wheel, it shall not be impera- 

 tive to shut the intake sluice, or to keep the byewash sluice shut, during 

 ordinary meal hours, or during any stoppage of the wheel not exceeding an 

 hour at a time. 



3. At the intake of every lade there shall be placed and constantly kept a 

 heck or grating for each opening, or one embracing the whole openings, the 

 bars to be not more than 3 inches apart, if horizontal ; and not more than 2 

 inches, if vertical. 



4. A similar heck or grating shall be placed and constantly kept across the 

 lade or troughs immediately above the entrance to each mill wheel. 



5. A similar heck or grating shall be placed and constantly kept across the 

 lower end of each tail lade at its entrance into the main river. 



Note. — To prevent any obstruction to the flow of the water by the hecks 

 or gratings in the lades, it is recommended that the lade should be 

 increased in width where the hecks are placed, and that the heck, 

 instead of being in a straight line across, should be curved or pointed 

 up or down stream, and thereby increased in length, so that the 

 aggregate of the openings between the bars shall exceed the sectional 

 area (or waterway) of the lade, and thus compensate for the space 

 occupied by the bars. 



6. There shall be a byewash sluice placed as near as practicable above 

 each water-wheel in the embankment of the lade, of not less than 3 feet in 

 width, with its sill as low as the bottom of the lade, and the said sluice shall 

 be raised to a height sufficient to allow the smolts to descend for at least five, 

 but not exceeding eight hours each week, from the 15th March to the 1st 

 July, not more than six days intervening between each time of opening. 

 There shall be a salmon pass or ladder on the down-stream face of every 

 dam, weir, or cauld capable of affording a free passage for the ascending fish 

 at all times when there is water enough in the river to supply the ladder. 

 The width shall not be less than 4 feet in the clear in rivers of less than 100 

 feet in breadth at the site of the dam, nor less than 5 feet in breadth in rivers 

 of less than 200 feet and more than 100 feet in breadth as aforesaid, nor less 

 than 6 feet in breadth in rivers of more than 200 feet in breadth as aforesaid. 

 The upper sill shall be not less than 6 inches below the lowest part of the 

 crest of the dam for the whole width of the ladder. The inclination shall in 

 no case be steeper than 5 horizontal to 1 perpendicular, but wherever prac- 

 ticable, shall be 7 or 8 horizontal to 1 perpendicular, and in all cases shall be 

 provided with breaks or stops placed at suitable intervals, so as to lessen the 

 velocity of the current sufficiently to allow the fish to ascend without 

 difficulty. 



The foot of the ladder shall be placed where there is most running water, 

 and with the best lead for the fish to approach it ; and if the ladder should 

 project beyond the toe of the dam, there shall be an apron of stone formed to 

 the dam, extending as far down the river as the entrance to the pass or 

 ladder, and extending throughout the 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. 



