144 BATHYMETRICAL SURVEY OF 



10-feet basin is continuous, and about a mile in length, approaching com- 

 paratively close to the east end. The maximum depth of 23 feet was 

 observed immediately to the east of the central constriction, the depth in 

 the narrows being 14 feet, and in the large western expansion the greatest 

 depth is 19 feet. The volume of water is estimated at 69 million cubic 

 feet, and the mean depth at 10 feet. The area draining into the loch is 

 about 5J square miles. The survey was made on June 29, 1903, when the 

 elevation was 194-6 feet above the sea ; the Ordnance Survey map gives 

 196-0 feet, but the date when levelled is not indicated. A drift-mark was 

 observed 3 feet above the water, which might fall perhaps a foot lower, 

 giving a range in level of about 4 feet. The water was very dirty and 

 green in colour, and nearly uniform in temperature, the readings at the 

 surface and at 10 feet being 61-9 Fahr., at 15 feet 61-8, and at 20 feet 



Balgavies Loch (see Plate LI.) is situated less than half a mile to the 

 east of Kescobie Loch, and about 5 miles from Forfar. The length is half 

 a mile, and the width nearly uniform, 250 to 300 yards, the superficial 

 area being about 52 acres, of which about 60 per cent, is covered by less 

 than 10 feet of water. The deepest part lies near the east end, where the 

 maximum depth of 32 feet was recorded, but there is an isolated basin in 

 the south-western portion of the loch with a greatest depth of 18 feet. 

 The volume of water is estimated at 22 million cubic feet, and the mean 

 depth at 9J feet. Balgavies Loch drains directly an area of two-thirds of 

 a square mile, but since it receives the overflow from Kescobie Loch, the 

 total drainage area is about 6 square miles. The loch was surveyed on 

 June 29, 1903, when the elevation was 194*5 feet above the sea; the 

 Ordnance Survey map gives 195'1 feet, but the date when levelled is not 

 indicated. A drift-mark was observed 2 feet above the water, which 

 might fall a foot lower. Serial temperatures were taken in the deepest 

 part of the loch, with the following results : 



Surface .................. 62-5 Fahr. 



lOfeet .................. 62-4 



20 .................. 55-8 



30 .................. 52-5 



There was a range of 10 throughout the body of water, the upper 10 

 feet being practically uniform, while between 10 and 20 feet there was a 

 fall of 6-6, and between 20 and 30 feet a further fall of 3-3. 



