THE FORTH 41 



the year mentioned, therefore, the criticism as to the obstructive 

 action of the cruive has been removed, and as the flow through 

 the cruive-box is of easy gradient, fish experience no difficulty 

 in making the ascent. 



RIVER FORTH 



The Forth is formed by two head streams, the Duchray 

 Water and the Avondhu, which rise barely three miles from one 

 another and unite a mile west of " the clachan of Aberfoyle." 

 Each branch rises at a very high altitude, and each is remark- 

 able for the rapidity with which a quite low level is reached. 

 The denudation of this region has been extreme. Ben Lomond 

 is 3,192 feet, and the source of the Duchray is about the 3,000 

 feet level on the north side of the mountain, and only about a 

 mile and three-quarters from the shores of Loch Lomond. The 

 course of this stream is so broken by falls that it is not possible 

 for salmon to ascend. The length of its channel is only 13| 

 miles, and the junction is only 80 feet above sea-level. The 

 Avondhu, i.e. the black water, rises at an altitude of about 

 1,900 feet, and after 9 miles of rapid descent passes into 

 Loch Chon, a mile and three-quarters long and 290 feet above 

 sea-level. Continuing its descent, it next enters Loch Ard, 

 two miles and a quarter long and 103 feet above the sea, from 

 which Aberfoyle is not far distant. 



The great, low, transverse valley which stretches across 

 Scotland between Forth and Clyde has its ill-defined divide 

 running also in a transverse direction for a considerable distance 

 south of the Forth. It is a flat alluvial region in which a river 

 can make but little headway, and hence the Forth in working 

 to the eastward describes the most extraordinary succession of 

 windings. It has 18 miles to go to Stirling and only 80 feet 

 of a fall. The result is that with its many " links " or 

 " crooks " it actually travels 39 miles. There is much same- 

 ness in the course, each part looking very much like the other, 

 yet this expanse of flat country and varied woodland, with 

 the mountainous region of the Trossachs in the distance, has a 

 charm of its own, and, when well lit, conveys a splendid sense 

 of space and freedom ; a landscape that looks best with great 

 white clouds in a high sky. It is through this flat expanse 



