108 BATHYMETRICAL SURVEY OF 



Temperature Observations. Temperature observations taken in the 

 deepest part of the loch in the afternoon of June 19, 1903, gave the 

 following results : 



Surface 58'8 Fahr. 



10 feet 57'6 



20 55-3 



30 49-4 



45 48-7 



This series shows a range of temperature from surface to bottom of 

 about 10, there being a fall of about 6 between 20 and 30 feet. 



White Loch (see Plate XXX.). The White Loch lies immediately 

 to the east of Fingask Loch, into which it flows by an artificial mill-lade, 

 and the water has apparently been raised several feet by damming, in 

 order to supply the mill. At the east end of the loch, in the direction of 

 the Black Loch, a copious burn flows out of the bank into the White 

 Loch, but there is no evidence that it comes from the Black Loch, and 

 the local people think the burn has its source in a spring. The eastern 

 portion of the loch, called the Eie Loch, is separated from the larger 

 and deeper portion by a narrow constriction ; it is shallow, and almost 

 filled with weeds, with a central depression 15 feet in depth. Tradition 

 says this was once a separate loch, and that the connection was cut, the 

 depth in the constriction being 2 feet. The loch is surrounded by 

 gently sloping fields and wooded ground. It is about one-third of a 

 mile in length, with a maximum breadth of one-seventh of a mile, the 

 mean breadth being one-fourteenth of a mile, or 20 per cent, of the 

 length, and its waters cover an area of about 15 acres. Over 40 

 soundings were taken, the maximum depth observed being 32 feet. 

 The volume of water is estimated at 8,425,000 cubic feet, and the mean 

 depth at 13 feet, or 41 per cent, of the maximum depth. The length of 

 the loch is 56 times the maximum depth and 138 times the mean depth. 

 The western portion of the White Loch forms a simple basin, the 

 bottom sloping gently down on all sides to the deepest part, which is 

 approximately centrally placed. There is no evidence of any pronounced 

 irregularity of the lake-floor, nor of any steep slope. The area of the 

 lake-floor covered by less than 10 feet of water is about 8 acres, or 52 

 per cent, of the total area of the loch ; that covered by water between 

 10 and 25 feet in depth is over 4 acres, or 29 per cent. ; and that 

 covered by more than 25 feet of water is about 3 acres, or 19 per cent. 

 White Loch was surveyed on the same day as Fingask Loch (June 19, 

 1903), and its elevation above the sea was determined, by levelling from 

 bench-mark, as being 153 '7 feet. 



Temperature Observations. Temperatures taken in the deepest part 

 of the loch gave the following results : 



