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Appendices to Eighteenth Annual Report 



the gradient may agree with at least the minimum requirements of 

 Schedule G of the Salmon Fisheries (Scotland) Act, 1868, viz., one in five, 

 I would propose that the upper end of the pass be carried back from the 

 actual sill of the cauld, in an up-stream direction, till the proper gradient 

 throughout the pass has been attained. The pass, which would then be 

 about 22 feet long, would require to be provided with two stops or breaks. 

 I would suggest that the stops be only carried two-thirds of the way 

 across the pass, that they be placed on alternate sides, and that the higher 

 of the two be twelve feet from the top or exit of the pass, the other 

 eighteen feet from the top, and that the stops themselves be fourteen 

 inches in height. 



Gamock. In the Irvine district I inspected another passless weir on the 



Garnock water. 



The weir is the first obstruction met by fish ascending the river, being 

 situated below Kilwinning at the iron works of Messrs. William Baird 

 & Co. The river at this point has been constructed artificially for a 

 distance of about 200 yards, the course having formerly been to the west 

 of the present river. The weir is at the lower end of this artificial 

 channel, the channel being 80 feet across. It is constructed of concrete 

 faced with smooth cement. The down -stream face is deeply concave, so 

 that the water passing over the sill falls first in a vertical direction. 

 Below the weir an apron of stones exists, the distance from the crest of the 

 weir to the lowest or furthest down-stream part of the apron being 42 

 feet. The height of the weir at the upper end of the apron is 3 feet 3 

 inches. The height of the weir above the level of the pool below the 

 apron is 5 feet. 



The river Garnock joins the main river Irvine about 300 yards 

 above the mouth of the latter, but the Irvine is now ruined as a salmon 

 river, and fish entering from the sea prefer apparently to ascend the Gar- 

 nock, although the latter, in its lower reaches, is also polluted to an 

 almost fatal extent. I have not seen any river in Scotland polluted to a 

 more serious extent. 



In my opinion the weir of the Lanarkshire and Ayrshire Railway 

 Company, specially referred to in this report, is a most serious obstacle 

 to the ascent of salmon and sea trout, not primarily on account of the 

 height of the weir, but because the form in which it is constructed per- 

 mits neither of a leap, owing to the shallowness of the water on the sur- 

 face of the apron, nor of fish swimming up, owing to the concave face of 

 the weir and the entire absence of a fish-pass or even of a gap. 



The requirements of the weir, in order to provide for the ready ascent 

 of salmon and sea trout, seem to me to be (a) to provide for a greater 

 depth of water on the surface of the apron, (b) to furnish a gap in the sill 

 of the weir. 



(a) In order to provide for a depth of water suitable for a " take off" 

 to fish ascending the weir — and this I consider the more important of 

 the two requirements — I recommend that a shallow • pool be formed 

 on the surface of the apron, by the erection of a subsidiary dam dyke 

 at the extreme end of the apron, the structure to reach completely across 

 the river and to be 2 feet 6 inches in height. In accordance with the 

 requirements of Schedule G of the Salmon Fisheries (Scotland) Act, 1868 

 [31 & 32 Vict., cap. 123], this dam, the river being of a breadth less than 

 100 feet, shall be provided with a gap in the sill, and down-stream face, 

 4 feet wide and 6 inches deep. This subsidiary dyke should be constructed 

 of masonry or concrete, and the down-stream face should have an 

 inclination of one perpendicular to five horizontal. The end of the down- 

 stream face should coincide with the end of the present apron, the crest 



