XV11 



Thus, at the head of Loch Tay, there are large lakes, viz., Lo3b 

 Tay, Loch Tummel, Loch Rannoch, &e. Thess act as compensa- 

 tion reservoirs, and, by pouring out their superfluous water, afford 

 to the fish a larger or smaller stream constantly flowing all the year 

 round. 



Again, when Mr. Napier, head-water bailiff of the Forth district, 

 was under examination it forcibly struck me that the city of 

 Glasgow was supplied from Loch Katrine, and that the water from 

 this lake was considered the purest in the world. I also recollected 

 that beside Loch Katrine there were Loch Achray and Loch Ven- 

 nachar, intervening between the head waters of Loch Katrine and 

 the Teith. At the bottom of Loch Vennachar there is a compen- 

 sation or overflow weir. Thus, then, from the above-mentioned 

 three lakes, and also from two others, Loch Voil and Loch Lubriaig, 

 there is a constant stream of water — the compensation water for 

 the mills being settled by Act of Parliament — flowing down the 

 river at all times of the year. 



These fine lakes in fact act as big reservoirs, and keep the head 

 of the river always up to a certain point, so that there is always a 

 certain amount of water moving downwards, thus tending much to 

 keep up the general health of the fish. The question, therefore, 

 of making compensation reservoirs at the head of salmon rivers 

 deserves more attention than it has hitherto received. 



The above-mentioned idea of the influence of lakes on salmon 

 disease I am bound to say does not hold good in all cases. The 

 Cumberland Derwent, for instance, has lakes in its upper waters ; 

 the Doon runs out of a large lake, Loch Doon ; the Dee (Kirk- 

 cudbright) runs out of Loch Dee, and its tributary the Ken through 

 Loch Ken ; and on the Cree there is Loch Trool. All these 

 rivers have suffered from disease. 



3. Fkost and Sxow. 



The next cause to which the salmon disease has been attri- 

 buted is frost and snow. 



Relative to this point the following evidence was given us : — 

 At Melrose we were informed by Mr. Donaldson, the super- 

 intendent of water police, that the Tweed and tributaries were 

 frozen close over from the 13th to the 30th of December, 1878. 

 There were a few fish up before then, and they were driven down 

 to the pools by the frost while in the middle of spawning. 



" A frost came on the 30th of December, and lasted a week, but 

 all through January the river was frozen over again. The fish 

 got on the ridds in February, two months behind time. The fisL 

 became unhealthy." 



" The River Tweed w r as ice-bound in January and February, 

 1879, and the water was very low." 



At Kelso the Duke of Roxburghe stated : " The fish were kept 

 off their beds for many weeks last winter. The spawning was 

 consequently very late." 



" The reason why they were unable to spawn was, that the river 



in the spawning districts was for a long time a solid mass of ice." 



P. 712. b 



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