LENY WATER 49 



but improved facilities for the distribution of spawning fish brought 

 about. 



An increase to the Leny water would increase to some extent the 

 drawing power of the river as compared with the stream from Loch 

 Vennacher, and might, therefore, be regarded as to some extent a 

 condition adverse to the latter, but the ascent and the rising proper- 

 ties of the fish in the whole of the Teith would be improved. 



In this connection it might be necessary to deal to some extent 

 with the Falls of Leny. These falls have two channels separated by 

 a rocky island. The channel at the right bank is quite precipitous, 

 but the channel by the left bank, although rocky and broken, is not 

 impassable to fish. In cold winters, or perhaps more accurately 

 after cold autumns, fish will not ascend the fall with any freedom. 

 To reduce the gradient of the left channel and to blast or remove 

 two or three of the worst rocks would result in fish ascending at an 

 earlier date and at more frequent periods ; but before any alterations 

 were decided upon it would be well to study carefully the effects of 

 increased water flow. 



There is no doubt that in favourable winters a very considerable 

 number of fish pass through the Leny into the loch. It is probable 

 that with easier ascent and an increased stock of fish brought about 

 by the various means adopted in other parts of the district, and let 

 us hope by the reduction of both netting and pollution in the lower 

 Forth, Loch Lubnaig would come to be a spring fishing loch of some 

 repute, instead of a rather second-rate loch as at present. The 

 success attained by impounding water in the upper Helmsdale is an 

 example of what can be done by the operation suggested, and refer- 

 ence to this will be found in the chapter dealing with that river 

 (p. 226). 



The catchment basin of Lochs Doine, Voil, and Lubnaig is cal- 

 culated as 73*39 square miles by the officers of the Bathymetrical 

 Survey, reference to whose reports has already been made, and in deal- 

 ing with the rainfall and water of the area it is stated, 1 " The usual 

 practice among engineers is to add 2J per cent, of rainfall for each 

 100 feet of height above rain-gauges. . . . Applying this rule to 

 Loch Lubnaig catchment basin, where we have an observed rainfall 

 of 76'25 inches at an average height of 538 feet, we must add 20 per 

 cent, for the additional 809 feet of mean height, making an average 

 annual rainfall over the entire catchment basin of 91'5 inches." In 

 the same valuable paper, from information supplied by the late Dr. 



1 Scottish Geographical Magazine, xvi., No. 4, p. 221. 

 D 



