100 BATHYMETKICAL SURVEY OF 



White Loch (see Plate XXXVIII.). The White Loch (or Loch of Inch) 

 is the upper and shorter loch, but is broader than the Black Loch. It is of 

 oblong form, nearly a mile long, and a little less than half a mile in greatest 

 breadth. There are two basins of over 20 feet in depth the northern 

 and deeper has the maximum of 38 feet near the east shore the southern 

 with the greatest depth of 24 feet close to the south-east shore. Between 

 these basins, in the centre of the loch opposite Inch island, the depth is 

 15 feet. The mean depth is 14 feet, the area about 149 acres, or a quarter 

 of a square mile, and the volume 92 millions of cubic feet. The drainage 

 area is about a square mile. No streams enter, and the outflow is by the 

 canal connecting the two lochs. The loch was surveyed on August 19, 

 1903, when the elevation was found to be the same as the Black Loch, 

 53'95 feet above the sea; the elevation as determined by the Ordnance 

 Survey on July 26, 1893, was 53'0 feet. 



The temperatures were 



Surface 62-3 Fahr. 



10 feet 62-0 ,, 



20 60-7 



35 60-2 



Black Loch (see Plate XXXVIII.). The Black Loch (or Loch Crindil) 

 is considerably over a mile long, by one-third of a mile in greatest breadth. 

 In form it is narrowly triangular, broadest towards the south. The loch is 

 divided into two basins of over 25 feet in depth by a bank, on which the 

 depth is only 18 feet, opposite the mouth of the Sheuchan burn. The 

 larger basin is the southern one, where the maximum depth of 50 feet 

 occurs between the Heron isle and the east shore. The northern basin has 

 a depth of 34 feet. A very small elliptical area at the north is nearly cut 

 off from the main loch. In this is a depth of 27 feet. The mean depth is 

 over 23 feet, the area 146 acres, or nearly a quarter of a square mile, and 

 the volume of water 149 millions of cubic feet. The drainage area, 

 including the White Loch, measures nearly 6 square miles. The feeders 

 are the canal from the White Loch, and the Sheuchan burn. The Messan 

 burn flows out to the north-west. The loch was surveyed on the same 

 day as the White Loch, and was found to be at the same level, 53'95 

 feet above the sea ; the elevation as determined by the Ordnance Survey 

 on July 7, 1893, was 52'7 feet, the water having recently been raised 

 one foot. 



The temperatures were 



Surface 62-5 Fahr. 



10 feet 61-0 



20 60-3 



30 60-0 



40 60-0 



50 , 60-0 



