of the Fishery Board for Scotland. 



99 



' Macdonald Fishway Company,' has been formd at Washington to 

 work it, and it has been patented in Canada, Great Britain, and 

 Ireland. Several Fishways contructed on this principle are said to 

 be working successfully in New York, Georgia, Carolina, and other 

 States of the American Union ; and plans are at present being 

 prepared for enabling fish to ascend the great falls of the Potomac 

 Eiver, which are 72 feet in height. It is stated that the gradient 

 of the Macdonald Fishway may be as steep as 1 in 3 or 1 in 4, 

 and that the cost varies from 10 to 25 dollars per running 

 foot of Fishway ; that is to say, a dam or a waterfall, 8 feet in 

 vertical height, would require a Fishway not longer than from 24 

 to 32 feet. This is an immense improvement on any fish-passes 

 which have been constructed in this country — none having hitherto 

 proved successful with a steeper gradient than 1 in 8 or 1 in 9 ; 

 that is to say, a dam or waterfall, 8 feet high, has hitherto been 

 found to require a fishway from 64 to 72 feet in length. It will 

 thus be seen that the Macdonald system shortens the length of 

 the fishway by more than a half, and so effects a great saving of 

 expense. The management of the current of water in the 

 Macdonald Fishway is also novel and peculiar. The last great fish- 

 ladder constructed in Scotland is that at the Falls of Moriston, 

 erected to enable salmon to ascend from Loch Ness into the River 

 Moriston. The Falls are about 24 feet high. The ladder has a 

 gradient of 1 in 10, being 240 feet long, and has cost £1800. But, 

 according to the Macdonald system, the Fishway would have been 

 only 96 feet long, and would have cost from £192 to £480. If, 

 therefore, what is stated of the Macdonald system be correct, it is 

 obvious that it would be of great importance to have it applied, 

 not only to the natural and artificial obstructions in the Nith 

 District, but likewise to those in other Fishery Districts in Scotland, 

 where far greater stretches of good spawning-ground would be 

 opened up, by enabling salmon to ascend waterfalls which they are 

 at present unable to surmount. At this moment, there are up- 

 wards of 500 miles of rivers and lochs in Scotland, wholly or 

 partially closed against salmon by natural obstruction ; the chief of 

 these being the Falls of Tummel in the Tay District and the Falls 

 of Mounessie in the Lochy District, the former obstructing upwards 

 of 100 miles of water, and the latter 40 miles. The Macdonald 

 Fishway Company, who have been applied to by the Tay District 

 Board, state that a pass over the Falls of Tummel, which are 16 

 feet high, would require a Fishway 64 feet long, which could be 

 constructed at a cost of from £100 to £250, depending upon the 

 difficulties of the site, the strength of construction required, and the 

 cost of the substructure or foundations, which will vary between 

 very wide limits. Then there are Craigo dam, the ' Burn Loup,' and 

 the ' Loup of Edzell ' in the North Esk District ; the Falls of the 

 Conon, in the Conon District, which bar 20 miles of river and half-a- 

 dozen considerable lochs ; the Falls of the Kirkaig and the Falls of 

 the Polly in Sutherlandshire, the former of which shuts up several 

 miles of river and a chain of great lochs stretching from Sutherland 

 into the borders of Pioss-shire, and the latter of which prevents the 

 ascent of salmon into several miles of river and 11 lochs, one of 



