THE ISLA 71 



eventually a perpendicular weir of great height. An attempt was 

 made here many years ago to allow salmon to ascend by the erection of 

 an American fish-way of the Macdonald type. The floods, however, 

 soon choked up the side channels of the pass with gravel, so that 

 the steep descent of water was practically unchecked. I believe no 

 salmon ever negotiated the difficulty. 



The Isla is a long stream, its source being actually only a little 

 over six miles south-west of Lochnagar and one and a half miles 

 north-east of the point where the shires of Aberdeen, Forfar, and 

 Perth meet. The source is at an altitude of 3100 feet, in the Can- 

 lochan and the Cannes glens, two steep corries south of Carn-na- 

 Glasha. The length of the river is about forty-six miles. The scenery 

 of the upper part is remarkably fine. At the Eeekie Linn, 3J miles 

 west of Alyth, the river has cut a gorge fully 100 feet deep, and 

 descends by two falls of 60 feet and 20 feet, presenting during times 

 of flood a beautiful spectacle. Salmon do not reach as far as this, 

 however, being stopped by a double cascade in another deep and 

 narrow defile called the Slugs of Achrannie, about two miles below 

 the Eeekie Linn. Taking it all over the Isla is more famous for its 

 trout than for its salmon, but at the " back end " of the year a fair 

 number of fish are sometimes got in the lower reaches. At the 

 " Bonnie House of Airlie " the river, which to this point has been 

 running south, is deflected gradually to the west ; but there is not 

 any very marked separation between the Isla at this point and the 

 South Esk river which, in Glen Clova a short distance to the east, 

 has been running parallel to the Isla, but which is carried now to 

 the eastward, while the Isla begins its tortuous and sluggish course 

 through the alluvial plain between Meigle and the Tay. 



The Ericht is as long as the Isla above Meigle, and like the 

 upper division of that river, flows south from the hills on the 

 northern limits of Perthshire. Two streams, the Ardle and the 

 Blackwater, which is the lower Shee, join at Strone, 5 miles north 

 of Blairgowrie, to form the Ericht. The head streams of the Ardle 

 drain the southern and western slopes of Ben Vrackie, Ben Vuroch, 

 and Ben-y-Gloe. The Shee rises from high streams on either side 

 of Glas Thulachan, 3445 feet. The Spital of Glen Shee road from 

 Braemar to Blairgowrie follows the course of the river. 



The Isla has not, unfortunately, the making of a really good salmon 

 river. The physical conditions are against it ; yet if salmon had a 

 better lead into it, there is no reason why they should not enter 

 fairly early in the season. When one looks at the fine running water 



