THE FRESH- WATER LOCHS OF SCOTLAND 57 



These analyses seem to show that the upper layer contained more 

 organic matter (presumably vegetable matter) and a little more iron 

 than the lower layer. Microscopic analysis of the two layers indicates 

 that the mineral particles were rather more numerous and larger in the 

 top layer, while the clayey matter seemed to be more abundant in the 

 lower layer. 



Loch Garry (see Plate XV.). Loch Garry* lies to the east of Loch 

 Ericht, at a still higher elevation, and the scenery round about is very- 

 wild ; the height of the surface of the loch above sea-level is not given 

 on the Ordnance Survey map, but a height of 1326 feet is shown near 

 the outlet, so that the level of the loch is probably about 1320 feet above 

 the sea. In trend and in outline it somewhat resembles Loch Ericht, 

 narrowing towards the northern end. It is over 2J miles in length, 

 the maximum width being over a quarter of a mile ; the mean breadth 

 is slightly under a quarter of a mile (being 9 per cent, of the length). 

 Its waters cover an area of about 390 acres (three-fifths of a square 

 mile), and it drains an area thirty-seven times greater (or about 22 J 

 square miles). The total number of soundings taken in Loch Garry was 

 141, the maximum depth observed being 113 feet. The mass of water 

 contained in the loch is estimated at about 846,000,000 cubic feet, and 

 the mean depth at nearly 50 feet (being 44 per cent, of the maximum 

 depth). The length of the loch is 119 times the maximum depth, and 

 260 times the mean depth. 



Loch Garry forms a simple basin, except that the bottom sinks into 

 two depressions exceeding 100 feet in depth, separated by depths of 82 

 to 93 feet. The larger but shallower depression is situated in the 

 southern half of the loch, and is over a quarter of a mile in length, the 

 maximum depth therein observed being 105 feet. The smaller but 

 deeper depression is situated in the northern half of the loch, being only 

 about one-sixth of a mile in length, and containing the maximum depth 

 of the loch 113 feet. The 75-feet, 50-feet, and 25-feet depressions form 

 continuous areas, following approximately the outline of the loch. The 

 75-feet depression is nearly 1| miles in length, the 50-feet depression 

 nearly 2 miles in length, and the 25-feet depression 2 J miles in length. 



The area of the bottom between the shore and the 25-feet contour- 

 line is about 117 acres (or 30 per cent, of the total area of the loch); 

 that between the 25- and 50-feet contour-lines is about 83 acres (or 21 

 per cent.); that between 50 and 75 feet is almost the same; that 

 between 75 and 100 feet is about 87 acres (or 22 per cent.) ; and that 

 over 100 feet is about 19 acres (or 5 per cent.). 



Temperature Observations. The serial temperatures taken while 

 sounding out Lochs Ericht and Garry in June, 1900, are given in the 



* This loch must not be confounded with the larger Loch Garry in Inverness-shire. 



