224 



BATHYMETRICAL SURVEY OF 



of water is estimated at 90 million cubic feet, and the mean depth 

 at 18 feet. The breadth of the loch at the position of the deepest 

 sounding is 31 times the depth. The shore development is 2-45, and 

 the insulosity nil. 



Loch Coulin is very irregular in outline, and is cut up into three 

 basins, the north-western basin having a maximum depth of 32 feet, 

 and the central basin a maximum of 22 feet. The main basin is 

 confined to the broad south-eastern part of the loch, and the contour- 

 lines approach very close to the eastern shore, off which the slope is 

 steep. There are two isolated soundings less than 25 feet within this 

 area, and deep water is found at the entrance of the river Coulin. 



FIG. 40. LOCH COULIN, LOOKING NORTH. 



(Photograph by Mr. T. N. Johnston, M.B., C.M., F.R.S.E.) 



The area covered by less than 25 feet of water is over 80 acres, or 72 

 per cent, of the entire area of the loch. 



Temperature Observations. A series of temperatures was taken in 

 the deep part of the loch at 5 p.m. on July 24, 1902, with the following 

 results : 



Surface 

 5 feet 

 10 

 15 

 '20 

 30 

 40 , 



57'OFahr. 



57 -0 



57'l 



57 -0 



55 -5 



54'8 

 53 -0 



