25(3 



Appendices to Thirty-third Annual Report 



2. At the Waterton Dyke, which is next downstream from the 

 Stoneywood Dyke, and at which the Messrs. Pirie abstracted water by 

 means of their lower lade, the operations consist of — 



{a) the slapping of the dyke to the river bed for a space of 40 feet ; and 

 (6) the closing of the intake shiices to the Waterton Lade, except for 

 a pipe of 12-inch diameter, and a sluice gate to be used for 

 flushing purposes only in times of high flood in the river. 



3. At the Mugiemoss Dyke, which formerly presented perhaps the 

 most formidable obstacle amongst all the dykes in the river to the passage 

 of fish, the following works have been executed : — 



{a) The building up of the old fish pass and the construction of a new 

 pass in the upper dyke, 12 feet wide and 20 inches deep, measured down- 

 wards from the average level of the crest of the dyke. The new pass 

 descends from the crest of the dyke first at right angles to the line of 

 the portion of the dyke at which it commences, and curves round to the 

 right towards the centre of the river, giving entrance to the pool formed 

 by the subsidiary dyke mentioned below. 



The total length of this pass is over 70 feet. The bottom is con- 

 structed of random rubble pitching, cement grouted, and the difference 

 in level between the water surface above the dyke and in the pool below 

 is 3-66 feet. 



At the distance downstream of 124 feet or thereby, measured from the 

 centre of the sil) of the upper fish pass to the centre of the sill of the lower 

 fish pass, there has been constructed a subsidiary dyke at the above 

 mentioned difference of elevation below the upper dyke, roughly dividing 

 the fall from the water level above the upper dyke to the water level of the 

 saugh pool below the subsidiary dyke into two equal portions. The 

 subsidiary dyke runs straight across the river, and is provided with a fish 

 pass of the same dimensions in depth and breadth as the fish pass in the 

 upper dyke. 



As in the case of the Stoneywood Dyke, the millowners are under 

 obligation to keep the fish pass in the upper dyke running to its full 

 capacity at all times when sufficient water for the purpose is running in 

 the river. Thereafter, and subject to that condition, they may abstract 

 a specified quantity of water from the river, but no more, until water 

 is passing over the crest of the upper dyke to a depth of 7 inches, measured 

 from the average level of the crest of the dyke. Thereafter, as in the case 

 of Stoneywood, the millowners are entitled to take one equal half of any 

 excess of water flowing down the river. 



The Messrs. Davidson at Muggiemoss also abstract water for manu- 

 facturing purposes by a small upper lade, and the abstraction here has 

 also been settled by agreement. 



A tracing of the plan of the fixed orifice and the spill weir in the Stoney- 

 wood Lade is also given. 



Thurso. 



In visiting this district I was interested to find that a new departure 

 in salmon fishing was being experimented with by the tenant of the Ulbster 

 fishings. A 40-foot motor boat, the converted fishing boat M.E. 120, was 

 being employed with a sweep net about 300 yards in length. I was fortu- 

 nate to be able to observe operations in more than one locality, although 

 I never saw the completion of any shot. Hours were spent waiting for 

 the appearance of fish in numbers sufficient to warrant the shooting of so 

 large a net. The motor boat had with it an ordinary salmon coble, but 

 I did not see any portion of the net shot in Thurso Bay. Some miles 



