THE FRESH-WATER LOCHS OF SCOTLAND. 



35 



approximation to the total amount of rain falling annually on the 

 drainage areas of the lochs draining into the river Teith, although the 

 available records are far from sufficient for the purpose. Dr. Alexander 

 Buchan, F.R.S., has kindly supplied us with information regarding the 

 readings of the rain-gauges at observing stations within, and in the 

 vicinity of, the catchment-basins of these lochs. The positions of these 

 rainfall stations, and the mean annual rainfall, are shown on one of the 

 accompanying maps (see Plate III.), and further particulars will be 

 found in the following table : 



Grouping these stations and their mean annual rainfall into those 

 likely to represent the rainfall on the catchment-basin flowing out of 

 Loch Vennachar, and those representing the rainfall on the catchment- 

 basin flowing out of Loch Lubnaig, we arrive at an average rainfall of 

 76-25 inches for the Loch Lubnaig catchment, the mean height of the 

 rain-gauges being 538 feet above the level of the sea, and an average 

 rainfall of 75*37 inches for the Loch Vennachar catchment, the mean 

 height of the gauges being 528 feet. 



The entire catchment-basin flowing out of Loch Vennachar (i.e. the 

 combined drainage-areas of Lochs Katrine, Achray, Drunkie, and Ven- 

 nachar) is about 75-29 square miles, and the mean height calculated 

 from the bulk of laud above the level of the lochs is about 704-185 feet ; 

 the mean height of the surfaces of these fotir lochs above sea-level is 

 33 H feet, so that the mean height above the sea of the entire catchment 

 is about 1035-685 feet. The entire catchment-basin flowing out of Loch 

 Lubnaig (i.e. the combined drainage-areas of Lochs Voil, Doine, and 

 Lubnaig) is about 73*39 square miles, and the mean height above the 

 level of the lochs is about 935-129 feet ; the mean height of the surfaces 



