THE FRESH- WATER LOCHS OF SCOTLAND. 217 



induced the Lake Survey to sound it. The trouble taken was well 

 repaid by the curious nature of the bottom revealed by the soundings.* 



Eilean Subhainn is 292J acres in area, its shore-line being very 

 irregular. The surface of the ground is uneven, though nowhere except 

 in the south-east corner is it very elevated ; here, however, a small hill 

 rises to a height of 84 feet above the level of Loch Maree. The greater 

 part of the island is not more than 30 to 40 feet above Loch Maree, 

 this rise for the most part taking place in the first 30 yards, and in 

 some places there are vertical cliffs from 20 to 30 feet in height. In 

 these cliffs it is seen that the island is composed of Torridon Sandstone ; 

 the rock does not appear elsewhere except around the little loch, the 

 island being covered with peat, with a considerable number of fir trees 

 round the shore and in the south-east corner. 



The loch lies in a small hollow in the centre of the island, being 

 situated about a quarter of a mile from the south-east shore, and one- 

 third of a mile from the west shore of the island, and about 150 yards 

 from the Lily Loch. Its level was determined on July 24, 1902, to 

 be 57*4 feet above sea-level, and 27'9 feet above the surface of Loch 

 Maree. 



The loch trends in an east and west direction, and its length is a 

 little over 250 yards ; its maximum breadth is about 100 yards, and the 

 mean breadth about 70 yards. Its waters cover an area of nearly 5 

 acres, and its drainage area is ten times greater, or 51 acres; the shore 

 development is 1-62 and the insulosity 0-02. The maximum depth is 

 64 feet, and hence the bottom of the loch is 30 feet below the level 

 of Loch Maree, and 6J feet below sea-level. The volume of water 

 contained in the loch is estimated at 6 millions of cubic feet, and the 

 mean depth at 46^ feet. 



The loch is fairly regular in outline, and has three small islands in 

 it. The deepest part is a mere hole near the western end ; on the ridge 

 running across from the island near the north shore to the island with 

 the tree there is only 5 feet of water, but there is a considerable depth 

 of mud. In the eastern part of the loch depths of 12 feet were met 

 with. Eighty -five per cent, of the total area of the loch is less than 

 50 feet in depth. This loch is the only one situated on an island in 

 another loch which has been visited by the Lake Survey. It was 

 surveyed on July 24, 1902. 



Temperature Observations. Many surface temperatures were taken 

 in Loch Maree between July 16 and 24, 1902, the greatest range 

 observed being from 53-3 off Letterewe at 11 a.m. on the 21st, to 57-0 

 at Talladale at 7 p.m. on the 22nd. The surface temperature in the 

 south-east end of the loch was almost always higher than that in the 



* The method of sounding out this loch is interesting: it was found impossible to 

 transport a boat to the loch, and Mr. Garrett took soundings by hand while swimming. 



